Thoughts on 2010 hurricane season so far

by Steve Goddard

The Atlantic Hurricane Basin remains dead quiet, and is now falling below the 1944-2005 average.

http://www.weatherstreet.com/hurricane/2010/Hurricane-Atlantic-2010.htm

I have not spent a lot of time studying hurricanes, but I have read that the “purpose” of hurricanes is to move heat quickly from the tropics to higher latitudes. Heat flow is always driven by differences in temperature. If two places were at the same temperature, there would be no heat flow.

Suppose that temperatures at higher latitudes (60N) were very warm – as they have been. What motivation would there be for hurricanes to form? The video and stil below shows UNISYS SST anomalies, with all anomalies between -1.0°C and +1.0°C removed.

Note that the Atlantic hurricane basin has very few places which are warmer than 1.0°C above normal. This agrees with Bob Tisdale’s graph.

By contrast, SST anomalies in the North Atlantic are far above normal. The difference in temperature between the tropical and north Atlantic is far below normal. Supposedly, it is that difference which gives hurricanes their raison d’être .

Things can change quickly. 1950 was the second most active hurricane season on record, and the first hurricane didn’t form until August 12.

Does it make sense that the heat engine which drives hurricane formation is basically shut down? What do you think?

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117 thoughts on “Thoughts on 2010 hurricane season so far

  1. ..and yet the MSM and other alarmists continue to spout the “more devastating hurricanes” nonsense.

  2. I don’t think it is just driven by heat alone,
    thermal gradient is like water pressure,
    if you don’t turn on the tap, there is no flow,
    if “they” knew what drives the flows,
    they could forecast on the nose.
    I am still processing data,
    looking for the errata.

  3. You never know. This could be the “calm before the storm” or the monkey could be right.

  4. One wonders if any of the warmists is preparing to apologize to Dr. William Gray any time soon…..

  5. The lack of anomalies suggests the situation is normal. What is “normal?”
    “Normal” is not zero hurricanes. And, of course, it only takes one to get everyone wonderfully excited.
    My understanding is that it isn’t the contrast between the arctic and tropics that matters so much as the contrast between the mid-latitudes and tropics. “Normal” has the tropic seas at their warmest right now, and contrasting nicely with the cooler ocean up in the mid-latitudes.
    Then, right about now, we sadly notice the sunsets are earlier, and the nights are getting longer. This is quite “normal,” but it means the sweltering land-masses start to cool, and rather than continents contributing to uplifting air, (which in some ways clashes with the uplifting air over the tropical seas,) the continents start to fuel areas of decending air, (which in some ways compliment the uplifting air over tropical seas.)
    Land cools more swiftly than the sea. Therefore it is “normal” for continental air to decend in mid-latitudes, enhancing the tropical uplift to the south and south-east. And then, lo and behold, we see a sudden uptick in the number of hurricanes, starting in mid-August.
    It’s all quite normal, unless, of course, one of these suckers comes whirling north and clobbers your neck of the woods.

  6. At least when Ehrlich wrote The Population Bomb he was canny enough to put his predictions in the future; the warmists are saying that hurricanes should be up now, and the Atlantic’s not playing nice (and long may it be so!) Go figure…

  7. The experts are all in general agreement. I pay attention to their prognostications. Even the amateurs mostly all agree, however there is a background sense that something is amiss. The idea of stripping out the difference in temperature is a very novel idea. I have never seen that before in many seasons of tracking hurricanes. It is a breath of fresh air and flies in the face of conventional wisdom that one picks up from the “would be pros” that hang around places like Weather Underground. Ever since early in the season Dr. Masters has been advocating the belief that SSTs were at extreme levels so therefore this would be a spectacular year for canes. This has been more recently reinforced by the pros and “would be pros” by citing the behaviour of the MJO and its forecast. Yet the weakness in activity remains evident and documented in Dr. Maue’s infamous chart.
    There will probably be some hurricane activity eventually this year but the level appears to be much less that forecasts. Many of these pros have come to rely on the GCMs which are continuously run to generate future tracks of potential hurricanes. This happens daily. These are well documented in the bowels of Weather Underground blog and repeated over and over again. The GCMs continue to call for activity especially when they get out to around 240 hours in the future but very few can take these forecasts seriously. NHC doesn’t seem to, they tend to express their future conviction in terms of 48 hour forward looking at best.
    My personal work has been focused on the CV wave generator and its general limitations. The speed at which the Trades carries wave events across Africa and then across the tropical Atlantic is quite limited to the basic 10 to 15 KTs which the trades blow at. The success rate of these wave in developing is another varible that has been identified in the 10% to 15% range. Given these constraints the remaining hurricane season will only produce a very much lowered level of named storms in spite of the drum beats of the pros. The African CV portion of the season is the bulk of hurricane activity in the Atlantic. As it goes, so does the season. Hence the dilemma. Due to the overall variability, those of us who really are concerned know to sit, watch and wait while be extra vigilent.
    The heat transfer aspect of hurricanes although understood in concept has needed a little extra work. Thanks for your efforts, I’m am sure some of the pros are listening and taking notes.

  8. Joe Bastardi predicted back in April that this season would be active and he mentioned the ‘physical drivers’ involved. A weak El Niño and warmer ocean temperatures in the ‘Atlantic tropical breeding grounds’.
    Weak trade winds ‘which reduce the amount of dry air injected into the tropics from Africa,’ plus high humidity ‘which provide additional upward motion in the air and fuel tropical storm development.’
    He obviously didn’t anticipate Nina developing so quickly, but how this influences the final mix is entirely up in the air.

  9. If the the ocean temperatures at the tropics and high middle latitudes are not anomalous this year, that means the temperature differences between the tropics and the high middle latitudes must be at the average. According to hypothesis, the hurricanes are driven by the absolute temperature difference between the tropics and the high middle latitudes — which is at normal values because there are no anomalous ocean temperatures — so there should be a normal number of hurricanes. Thus this hypothesis does not explain the lack of hurricanes so far. If you actually watch what has been going on on the satellite photos at the national hurricane center’s website, you would see that so far all the start-up tropical storms are having their “tops” blown off them by strong high level winds — they call it “shear” — and they are also traveling “too fast” over the ocean to intensify. You’d probably be better off hypothesizing that the lack of hurricanes is connected to the odd jet-stream pattern that is causing the Russian heat wave. If this hypothesis is true, you would expect hurricanes to start forming more or less when the heat wave breaks because the jet-stream has returned to normal.

  10. richard telford says:
    August 15, 2010 at 2:17 am
    another post with Goddard revelling in his ignorance.

    Welcome to the science of climatology.
    When in Rome do as the Romans do.

  11. I am a meteorologist, and I am noticing that a lot of upper level wind shear is tearing apart the storms. This is clearly not driven by AGW, but is interesting to note. The so called “record breaking SSTs” that Dr. Jeff Masters of Wunderground was hyping about, claiming that it was due to AGW,
    http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1480
    and even has an appalling poll to the right hand side. Apparently, the so called “record breaking SSTs” are falling, and OOPC confirms this, as the La Nina gets stronger.
    http://ioc-goos-oopc.org/state_of_the_ocean/sur/pac/nino3.4.php
    http://ioc-goos-oopc.org/state_of_the_ocean/sur/atl/tna.php
    By the last link, it shows that Atlantic SSTs are now .5-1 Degree Celcius above normal, and falling. How pathetic. The so called claims for the hyperactve hurricane season of 2010 are falling apart, day by day. This is looking more and more like 2006, over and over again.

  12. To those who would like to learn about hurricanes I would recommend reading “Tropical Weather and Hurricanes”. Fundamentals of Physical Geography – Dr. Michael Pidwirny, University of British Columbia Okanagan, http://www.physicalgeography.net/fundamentals/7u.html
    Also, “Hurricane Basics” (NOAA National Hurricane Center), http://www.nhc.noaa.gov/HAW2/english/basics.shtml
    These are links from the Hurricanes section of my page “Meteorology for South Florida and the Caribbean”, http://www.oarval.org/meteorologFL.htm
    Historically, the Atlantic Hurricane Season peaks between mid-August and end-October. The middle of the season is near September 10.
    These natural heat engines cool the tropics into the Hadley cells, as needed.
    I think Dr. William Gray and Dr. Phil Klotzbach, from Colorado State University know a lot about hurricanes and I feature their forecast work prominently. But pay attention to Ryan N. Maue’s “2010 Global Tropical Cyclone Activity Update”, http://www.coaps.fsu.edu/~maue/tropical/

  13. Steven, you said: Does it make sense that the heat engine which drives hurricane formation is basically shut down? What do you think?
    Note it is a heat engine not a temperature engine. Although you use the terms as synonyms in your article this is incorrect. A volume of dry air has much lower heat content -enthalpy- than the same volume of humid air; up to ~80 times less. It is this that gives the wet adiabatic lapse rate that leads to the instability, and thus to the convective weather that eventually forms storms and then hurricanes.
    Perhaps the air in the mid-latitudes is just slightly drier than normal as the jet stream has moved more equatorwards in the last few years and that is enough to reduce the instability so that strong storms are not viable once they move out of the tropics?
    It would be very useful if people stopped confusing temperature and heat content and instead were more disciplined about the terms.
    All the temperature graphs are very interesting but they are really meaningless in terms of the Earth’s energy budget as there is the implicit but incorrect assumption that temperature equals heat content. Perhaps someone should create a ‘heat content’ anomaly map using humidity and temperature to obtain the heat content?
    I have not seen a ‘heat’ mapping or a ‘heat graph’ in any of the articles on global warming, yet it is heat energy that should be being measured.

  14. Hurricanes “form” when the tropical waves (depression trough generating pulses that travel from east to west) provide energy to humid (unstable) air. This occurs year-round but the seasonal affect of the sun sends the area of maximum heat energy from the equator into the area of north latitude 10 to 20 degrees. In this area (ITCZ or inter tropical convergence zone) the rising unstable air not only forms thunderclouds and rain, it is subjected to the coriolis force provided by the earth’s rotation.
    It is that rotation that creates the cyclonic (rotating) pattern that starts the hurricane “engine”. If the upper levels (in the atmosphere) have the correct advection patterns to remove the rising air, a circuit is set up and a warm-core develops within the storm system. This system feeds on the heat energy in the moist warm air and can grow in wind strength and size. Its winds also push the sea water and create a surge that creates flooding when the system approaches land.
    At present, all signs point to ideal conditions for tropical cyclone formation. The heart of the “season” is August 15 to October 15 and unless there is a major change to the current conditions, we can expect a lot of activity in a very short period.
    All of the atmospheric and oceanic parameters are pointing to a heaping helping of hurricanes. Better batten down the hatches, boys.

  15. Sadly even if only one Hurricane appears very late on you can be sure that all the Warmists and Media will trot out the tired old “Global Warming” proof ad nauseam.
    What is it with these sad sack ‘believers’ ? Act on Facts not faiths, folks!

  16. I question the use of anomalies in this case. IF hurricanes are related to temperature differences it would be the differences in actual temperatures not anomalies. If the higher latitude northern Atlantic SST has a +1.5 to 2.5 anomaly it is still many degrees cooler than actual temperatures of the the lower latitude northern Atlantic and the temperature difference still exists.

  17. Funny thing is that a lot of us that are long-term residents/natives of Florida collectively shrugged off the hurricane season warning because it just didn’t “feel” right.

  18. I read the following years ago and assume that the story is true (in most details, anyway!).
    Al Capp was famous for his strong views on various aspects of American life (and perhaps other subjects as well). Included were hippies and their like, and they reciprocated by making him a favorite target of heckling when he gave public talks. At one talk, a long-haired individual stood up and swore at great length at Capp, who stood silent, listening. When the heckler finally stopped, Capp said “Now that the individual has identified himself, what does he have to say?” The crowd applauded and Capp gained their support.
    Similarly with outbursts here of the type “another post with Goddard revelling in his ignorance”. Such posters are cordially invited to state why and to what they object so strenuously.
    IanM

  19. This isn’t an AGW/anti-AGW argument. Many of the hurricane forecasters are skeptics.
    I am just throwing out an alternative explanation for what we are (not) seeing so far.
    It is also important to note that there are different ways of looking at a problem. I am suggesting a macro-physical view, in contrast to the micro-physical approach which people are used to hearing about.

  20. “By contrast, SST anomalies in the North Atlantic are far above normal. The difference in temperature between the tropical and north Atlantic is far below normal. Supposedly, it is that difference which gives hurricanes their raison d’être .”
    In the spirit of skepticism, I find this reasoning questionable.
    Yes, the thermal gradient between tropical and polar regions is a driving force behind globally observed wind and weather patterns. But it doesn’t necessarily hold true that a specific warm area in the North Atlantic would have a direct impact on the rate of cyclone formation in the Tropical Atlantic. I can’t see any obvious mechanism of causality. Could someone explain it?

  21. Ian W says:
    August 15, 2010 at 5:34 am
    I have not seen a ‘heat’ mapping or a ‘heat graph’ in any of the articles on global warming, yet it is heat energy that should be being measured.
    Hi Ian.
    On the http://hurricanetrack.com premium site, there are TCHP (Tropical cyclone heat potential) maps that are used as a background for the tracks of each named storm. Shows the full heat content of the Atlantic basin and the Caribbean and GoM are ready to “go”.

  22. I have not spent a lot of time studying hurricanes, but I have read that the “purpose” of hurricanes is to move heat quickly from the tropics to higher latitudes. Heat flow is always driven by differences in temperature. If two places were at the same temperature, there would be no heat flow.

    The scale of that motion is much larger than the scale of a forming hurricane. Suppose a large temperature difference led to stronger winds in the Hadley Cell (and also the Ferrel Cell north of the tropics). I’d expect that to create more vertical wind shear (a velocity change in the wind wrt to altitude) and that would squash TS development.
    While tropical storms do move a huge amount of heat north, I think it’s more side effect than driver.
    Extratropical “baroclinic” storms, on the other hand, do depend on horizontal temeperature differences over distances and include cold and warm fronts that exchange heat basically north and south. Those I’d expect to increase in intensity with greater temperature differences, and that’s at odds with claims that the Arctic will warm more than mid-latitudes. Whole different subject.
    I’m pretty much mystified as to what’s going on in the Atlantic now. I’m going to avoid speculation, there will be plenty of analysis from people with better insight than me.
    BTW, most people have likely missed it, but I’ve been in a bit of a discussion about TS genesis over at http://wattsupwiththat.com/2010/08/10/klotzbach-on-atlantic-hurricane-season-analysis/#comment-456892 – I see the discussion is continuing, I haven’t read the new posts there yet.
    That link includes some pointers to “Divene Winds” by Kerry Emanuel, another good book on hurricanes, though Emanuel is more theorist (and AGW supporter) than observer, and when it comes to tropical storms, nature toys even more with theorists than observers.

  23. “The U.S. landfall of major hurricanes Dennis, Katrina, Rita and Wilma in 2005 and the four Southeast landfalling hurricanes of 2004 – Charley, Frances, Ivan and Jeanne, raised questions about the possible role that global warming played in those two unusually destructive seasons. In addition, three category 2 hurricanes (Dolly, Gustav and Ike) pummeled the Gulf Coast in 2008 causing considerable devastation. Some researchers have tried to link the rising CO2 levels with SST [Sea Surface Temperatures] increases during the late 20th century and say that this has brought on higher levels of hurricane intensity.”
    “These speculations that hurricane intensity has increased have been given much media attention; however, we believe that they are not valid, given current observational data.”
    This is from “Extended Range Forecast of Atlantic Seasonal Hurricane Activity and U.S. Landfall Strike Probability for 2010” (Dr. William Gray, Dr. Phil Klotzbach, Colorado State University, part 10, June 2 ’10, .pdf), http://hurricane.atmos.colostate.edu/Forecasts/2010/june2010/jun2010.pdf

  24. Several years ago, I read an article (I think on Brett Anderson’s Accuweather blog) speculating that polar amplification would lead to reduced hurricanes. This is where I got the idea from.

  25. It could be that filtering out average SST’s is a proxy for weather system pressure gradient differences between fronts. Wonder what those would show looking back at active years. The Jet stream is nearly non-existent and very messed up right now with no organized flow or connected loops, so large frontal systems are not being pushed in succession or jammed up to each other. Could that be the reason? No significant battles between systems because the Jet Stream, in its confused state of mind, is taking a nap?
    http://squall.sfsu.edu/gif/jetstream_norhem_00.gif

  26. Joe Bastardi posted at Accuwx earlier this week (pro site) on this same topic. His take was it has to do more with the warmth over North Am then the warm over the North Atlantic. Pre-season, he was forecasting above average tropical activity for the Atlantic basin. He is expecting activity to increase significantly as North Am cools. He is also expecting it to continue later into the year than usual

  27. stevengoddard says: {August 15, 2010 at 6:26 am}
    “Tom in Florida
    The point is that the difference in temperature is lower than normal.”
    Yes, I understand you say that but perhaps you should show the actual temperatures and see what the real difference is. The below link shows both actual mean temps and the anomalies for the Atlantic.
    http://www.cpc.ncep.noaa.gov/products/hurricane/atlsst.html

  28. richard telford ,
    I read these posts to get information and better understand what may actually be what.
    Apparently you have a take on this subject that is more learned than Goddard’s, would you put forward your argument so I can learn?

  29. The two charts suggest that, so far, 2010 is average with regard to storms. The problem is that the average is 1. Had there been two we would now be 100% above average, and if three, we would be right up there with the busy 2005 season. Thus, until about mid-September – what is there to talk about?
    The really odd thing about these charts (other than not knowing who prepared them) is that the 2010 forecast shown in red on the right side does not include the 1944-2005 average. What has happened to the concept of “regressing toward the mean”? – not part of climate science, I guess!
    The exchange-of-heat idea expressed in this posting is – in principle – a correct one. However, it is too simple. Think of the atmosphere as music. One needs all the notes to have a proper experience. If you take all of some one note out of the music it will not sound correctly. All the rest of the music is still there – it just doesn’t work.
    The point is that there is still warmth in the tropical ocean (a large area) and not so much in the northern latitudes (a smaller area). At the moment a part is missing. When and if that part enters the system, then the hurricane season will ramp up. We do not, at the moment, know what the missing part is. That’s what the planned GRIP study might find out:
    http://wattsupwiththat.com/2010/08/11/nasa-to-get-a-grip-on-hurricane-formation/#more-23281
    And as the charts shown suggest — they have chosen to get the effort underway in time for an expected ramp-up. That is, they are playing the average. Someone, maybe the funding agency, understands this concept.

  30. The “heat engine” is always working. In fact, it works better in the moist subtropical zones when upper-air wind shear is blowing, and the heat from Tstorms & showers is diffused quickly into the upper atmosphere. Only when the shear decreases to the point where it cannot diffuse & move away the heat effectively, does the next aspect come into effect — tropical storms.

  31. There is little historical support for the high number of hurricanes [8-14] being predicted for the La Nina year 2010. The previous pattern of the high number of hurricanes during more recent La Nina years 1995-2007 seems to have ended.
    The average since 1904 for La Nina years is about 6.3 hurricanes [highest 11, lowest 3]
    60 % of the LA Nina years have had 6 hurricanes or less.
    During the previous global cool period [say 1964-1975] there was an average of only about 5 hurricanes during La Nina years
    My best estimate is about 4-5 hurricanes [ max of 6] this year as we are again at the start of a 10-30 year cooling period.[so we all claim?]

  32. Tom in Florida, your link shows me that temps are cooling since July. So to me, where the temps were once pretty good for a riproaring season, it seems less so now.

  33. “Dave Springer says:
    August 15, 2010 at 5:16 am
    richard telford says:
    August 15, 2010 at 2:17 am
    another post with Goddard revelling in his ignorance.
    Welcome to the science of climatology.
    When in Rome do as the Romans do.”
    Or perhaps, when in Romm, do as the Rommans do!

  34. Tropical fish here…. Although heat is an important component and heat distribution could well have a strong impact, based on my long observational experience while living all my life in the tropics, there has not been a single predictive factor that can be identified as “the smoking gun” of hurricane formation and hence the difficulty in long-range prediction using a single factor.
    Personally, my belief (yes only a belief) is that transient synoptic and mesoscale patterns have the most influence. And sure, one could make that case that these could in the end be related to temperature, although I suspect it is the other way around.
    I might be all wrong about this but I believe hurricane formation needs an East-West corridor in the ocean with widely spaced pressure gradients North and South, while at the same time this corridor must be bordered at the point of formation by two relatively distant counterrotating upper level systems, one North, one South, and with winds just strong and balanced enough and no more, to have the right effect on the corridor so that the environment for large thunderstorms becomes conducive for spin development.
    This can even happen over land, as I’ve seen giant thunderstorms come off the coast of Africa already spinning, and those usually turn into hurricanes pretty quickly once over water.
    So far this year it has not happened, not that it couldn’t happen at any time, and hence the long term unpredictability of these phenomena. I watch for those conditions to develop daily on the global vapor satellite movie here:
    http://www.nrlmry.navy.mil/sat-bin/display10.cgi?SIZE=full&PHOT=yes&AREA=global/stitched&PROD=vapor&TYPE=ssmi&NAV=global&DISPLAY=Latest&ARCHIVE=Latest&CGI=global.cgi&CURRENT=20100815.1200.multisat.wv.stitched.Global.x.jpg&MOSAIC_SCALE=15
    Just a pet theory of course :). But, if by NOAA’s admission, synoptic and mesoscale pattern prediction beyond 10-days is a coin toss, and should these turn out to be important in hurricane formation, how could we then predict hurricane formation more that 10-days in advance?

  35. In our part of Florida, it has not been a typical summer. It’s been much drier than normal (we’re short about 18 inches of rain) with very few of the typical summer thunderstorms, although a few have started lately. We’d normally be pumping the canals every few weeks, and this year they are dry. One would think that’s unrelated to what is going on off the west coast of Africa where our hurricanes originate, but maybe not?
    Yes, the annual hurricane forecast is a regular joke here in Florida. Hurricane track prediction is another area rife with comedy. About the only year they got the tracks right was 2005 (2006?), if memory serves, and that year it seems like they nailed every one.
    This has all the hallmarks of something that is not well understood. We’d all have a bit more respect for these folks if they’d simply admit it.
    Gerry

  36. Ian W: You wrote, “Perhaps the air in the mid-latitudes is just slightly drier than normal as the jet stream has moved more equatorwards in the last few years…”
    I have been searching for a dataset that illustrates this. Do you know of one?

  37. Would some of those ‘failed’ hurricanes this year, have even been classified as hurricanes in the 1950s, before the advent of satellite monitoring?
    .

  38. >>thermal gradient is like water pressure,
    >>if you don’t turn on the tap, there is no flow,
    In a nutshell….
    Hurricanes are simply low pressure systems that get tightly wound up because of a lack of Coriolis force in the tropical regions (because the Earth is ‘fatter’ there).
    Low pressure systems form when jetstreams move vast quantities of upper air out of a region.
    Jetstreams form when columns of warm and cold air come into close proximity
    However, the jetstreams have been all over the place this year (from a European perspective). They were more southerly than usual this winter (hence the cold winter), and they were still southerly this summer (hence Russia bakes).
    I have never studied the jetstreams in regard to Atlantic hurricane formation, but I can bet that the latitude of the upper jetstreams is important.
    .

  39. The current NHC discussion notes mention “A large area of dry air and Saharan dust is E of the wave axis to west Africa.”
    Saharan dust is important – it blocks sunlight at mid-level altitudes and that both heats the air (reducing convective potential) and reduces sea surface heating (reducing energy input to surface air and reducing convective potential).
    Mid level dry air is important because it evaporates rain (reducing convection potential).
    Things to watch, along with the cooler SSTs feeding in from the north.

  40. Ocean’s Color Affects Hurricane Paths
    http://www.sciencedaily.com/releases/2010/08/100813121916.htm
    “In the study, to be published in an upcoming issue of Geophysical Research Letters, a journal of the American Geophysical Union, Gnanadesikan’s team describes how a drop in chlorophyll concentration, and the corresponding reduction in ocean color, could cause a decrease in the formation of hurricanes in the color-depleted zone. Although the study looks at the effects of a simulated drop in the phytoplankton population (and therefore in the ocean’s green tint), recently-published research argued that global phytoplankton populations have been steadily declining over the last century.”
    Scratching my head.

  41. As an addendum to this “strange” season, TD5 is backing off the continent and heading back over the GoM….
    If it continues southward for the next day, it may well become the tropical storm (or even weak hurricane) that was originally expected.

  42. Pamela Gray says: {August 15, 2010 at 8:10 am}
    “Tom in Florida, your link shows me that temps are cooling since July. So to me, where the temps were once pretty good for a rip roaring season, it seems less so now.”
    I would agree regarding the eastern Atlantic. However, any temps over 80F (27C) can spawn tropical systems, which is probably why they place a green dividing line at that temp . After they come into being the near environment takes over regarding further development. It would be nice to find a similar chart of previous years to compare.

  43. Most of the storms this season, did nothing but drive up insurance costs.
    Even our local media in SWFL has grown tired hyping the non-existent storms.
    Normally this time of year the Gulf would be bright orange-red, on the NOAA SST chart. But our pool, which is right on the Gulf waters, was barely usable all summer. It’s way too cold.

  44. The energy for a hurricane comes from the temperature difference between the water and the air above. The temperature at some other latitude does not directly cause a hurricane and I think the word “purpose” is an anthropomorphism. A hurricane is just a heat engine that converts some of the thermal energy from the temperature difference into kinetic energy.
    There is a principle of physics here that explains a lot. There is no conservation of entropy the way there’s conservation of energy. If you have two bodies, one hot and one cold, you can extract physical energy with a heat engine. But you can also just “waste” that temperature difference by letting the heat flow from the hot body to the cold one. Energy is conserved and you get slight warmer bodies in the end than if you had extracted some physical energy. But the “potential” for extracting physical energy is simply lost.
    Thus, things like wind shear can disrupt hurricanes and simply prevent their formation (or lessen them). When this happens, there is no energy “buildup” that needs to be dissipated eventually (unlike, say, earthquakes). This makes long term hurricane forecasting hard as hell. Temperature differences (air-to-water) in the Atlantic, Caribbean, and the Gulf of Mexico matter. Wind shear matters. The weather patterns in Africa matter.
    Gray’s model, which is just an empirical fit, is the best available. It is of limited value and Gray reports its accuracy honestly. We can see a week or two ahead by looking at the Atlantic but September is a total wild-card. Premature crowing about a light season is highly risky.

  45. richard telford says:
    August 15, 2010 at 2:17 am
    another post with Goddard revelling in his ignorance.

    Let me counter that:
    Another post with telford revelling in his ignorance.
    Hmm. I can see where this kind of rhetoric may lack the possibility of resolution. It also lacks actual information. It does, however, bear a remarkable resemblance to those badly spelled and randomly capitalised comments posted by poorly-educated adolescents attacking posts critical of World of Warcraft or the latest Twilight saga.
    When I first started questioning the whole global warming doctrine a few years ago, it was sparked not so much by any knowledge I may have had of the vast and complex subject of climate (effectively nil), but by the language being used, which had all the characteristics of a cult, religion, or conspiracy theory — things with which I am, unfortunately, fairly well acquainted. “Facts” were provided in a condescending manner; counter-arguments brushed aside with impatience and, all too often, a gratuitous personal attack.
    In short, my scepticism started because the proponents of global warming simply pissed me off.
    This may not seem a particularly scientific methodology, but in reality it’s actually not a bad rule of thumb. While I’m not a scientist (nor have I ever played one on TV), I’ve read a lot of scientific literature, starting at a very young age. As an unsophisticated kid it wasn’t easy to discern good science from bad, but I’ve always had an ear for language, and fairly quickly began to notice that the flat-earthers, hollow-earthers and others promoting what I would later discover to be pseudo-science, all tended to talk the same. It was like they all had the same speech patterns. The same “accent,” if you will.
    And to my ear, the proponents of global warming fairly screeched with this accent.
    I’m well aware that scientists can launch horrendous and personal attacks against each other, and we all know that Newton was hardly dispassionate when it came to defending his calculus; but when presenting their theories to the world, real scientists seldom treat their readers with either condescension or animosity. And virtually all of them know that whatever the state of science is at the time, it is never “settled.”
    The “settled” science is left to the crackpots trying to warn us against attacks from aliens living within the core of the Earth.
    The constancy of the speed of light has been tested in hundreds of ways over the years and could be considered one of the most “settled” elements of modern physics. Yet when John Moffat suggested that light might be slowing down, his idea was examined on its own merits, not dismissed out of hand with adolescent insults concerning his intelligence. And when Martin Fleischmann and Stanley Pons claimed to have succeeded in creating “cold fusion,” the scientific community, although expressing doubt, still took the time to try replicating the experiments.
    As for global warming, I’ve now absorbed enough of the science to know that any claim of the science being “settled” is not just laughable, but bordering on criminal. I’ve watched the Climategate coverup, and seen the AGW crowd’s predictions batting close to zero. In other words, I am no longer a sceptic because of the language being used.
    But thanks to you, and many, many, many AGW proponents like you, I am constantly reminded of my roots in this whole debate and what first prompted me to look at it more closely.
    To return the favour, and for your reading enjoyment, may I recommend The Hollow Earth by a Dr. Raymond Bernard (appropriately enough, a pseudonym), printed in 1964. It may actually help you to improve your rhetoric and, therefore, your ability to make enemies and influence people — to become sceptics.

  46. You folks are making insightful comments. Just two of the ones I find interesting are:
    beng says: at 7:46 am
    “The “heat engine” is always working. In fact, it works better in the moist subtropical zones when upper-air wind shear is blowing,…”
    Ric Werme says: at 9:09 am
    “Mid level dry air is important because it evaporates rain (reducing convection potential).”
    To this last I say “virga.”
    http://en.mimi.hu/meteorology/virga.html
    Or see photo under “Dry as a Bone”, here:
    http://the-oort-cloud.blogspot.com/2008_05_01_archive.html

  47. Ralph says:
    August 15, 2010 at 9:06 am
    > Hurricanes are simply low pressure systems that get tightly wound up because of a lack of Coriolis force in the tropical regions (because the Earth is ‘fatter’ there).
    Hurricanes don’t form on the equator in part because there is no Coriolis effect. “Fattness” isn’t the key, surface angle relative the Earth’s rotational axis is.
    > Low pressure systems form when jetstreams move vast quantities of upper air out of a region.
    Well, sort of, but the extratropical low you’re talking about has a cold core and frontal systems. Tropical storms have a warm core (due to an eye and subsidence in the eye) and no fronts. They are also generally more compact. When an old hurricane makes its transition to and extratropical low the wind field widens.
    The two types of lows are very different beasts.

  48. I’m curious to read Hansen’s tome “Storms of my Grandchildren,” which is considered to the be the lost book of the New Testament by some Real Climate commentators:
    http://www.stormsofmygrandchildren.com/
    He supposedly goes into detail about why the hurricanes, floods etc. will kill us all. I held my nose and read Gore’s “Earth in the Balance,” so I can probably laugh my way through Hansen’s book! However, I don’t plan to pay full retail!!

  49. “richard telford says:
    August 15, 2010 at 2:17 am”
    “another post with Goddard revelling in his ignorance.”
    Goddard clearly posted this thread as a thought experiment. Did you drop by to participate with your ideas, or just to drop off a grenade. Now the latter would just be “ignorant”.

  50. Frederick Michael
    The temperature in Phoenix 105F. The temperature at 35,000 feet above Phoenix is -65F. Why isn’t there a hurricane in Phoenix? There is plenty of humidity this time of year.

  51. Steve, seems we may have gone through or are going through a major climatic shift. If the sun has anything to do with the climate we seem we are now on a downward tier unlike ~1955-2004 when we were definitely up on activity. It will take about five to six more years to be certain. Since this has not happened for decades, no, really centuries, most meteorologists and GCMs get used to certain patterns matching certain responses that may no longer hold true. I looked back for another downward solar movement from one tier downward to another and didn’t find one looking back as far back as 1700. There is one other upward movement in the early 1700s and one about 1955, other that those anyone’s guess is just as good as mine as you look further back from 1700, scanty records.
    That might be why some patterns don’t seem to work the way they have usually acted in the last three centuries, speaking of PDO, ENSO, NAO, currents, hurricane predictions, etc. I guess one loose way to look at it is the earth climate system might actually be now resisting cooling, if proper physics allows such a human trait, as embedded thermal warmth built in the oceans now reverses. What would the proper physics properties be in action to do this resistance? Small thermal conductivity in the oceans (~0.58 W/m2/m/K) and earth’s deep rock and soil along with tiny negative temperature differentials.
    I look at this way, in the year 1700 the earth put it in gear and in 2004 or so put it back in reverse as it was in the 1600s, or at least neutral and now we are just coasting. 🙂

  52. This subject is a bit out my league, however the jet regularly or irregularly perhaps, messes with us in southern Alberta. This year is no exception. We have been running about two to three weeks late, relative to normal summer conditions. Any gardener in Calgary will attest to that. Perhaps the whole inter-influenced system is also running late as well.

  53. There are four ingredients needed to make a large storm, available heat energy, moisture to change phase states to generate the low pressure zone, ion potentials to drive the “precipitation” (not just condensation), and a global lunar tidal effect to drive the wind patterns that tighten up as the Coriolis effects strengthens as the storm moves off of the equator.
    We have been having three of these ingredients showing up in the three named disturbances so far. However the global “pole to equator ion charge gradient” is currently stagnating, all of the seasonal drivers of these shifts in charge gradients will occur later in the year than is the”Normal” (although nonrandom pattern of distribution.)
    The solar cycle has been slow, but is starting to pick up as we approach the heliocentric conjunctions of three of the four outer planets that drive the global ion potentials that create and drive these large storms. I have posted a detailed forecast of the dates to expect these storms to be produced several time over the past year.
    Due to the geomagnetic effects of the increased coupling, of the solar fields extended out from flares and coronal holes, as the Earth passes through the focused area that lines up heliocentrically with the outer planets:
    Neptune on the 20th of August, the Earth will have an increased homopolar generator charge potential inducted into it, then relaxed over the next two weeks (till end of August 2010) that will induce the typical discharge pattern that generates the large flows of ions that allow the global tropical storms to attain sizable effects above cat 1 – cat 2 levels, because of increased wind and precipitation production, powered by the enhanced action of the opposing ion charges swept into the cyclonic flow structure.
    September 21st through 24th 2010 will see the bigger set of conjunctions that will do a much better job of driving the intensity of resultant global tropical and extra-tropical storms, that form on the discharge side of the ion flux patterns, after these dates. No the season is not over yet.
    The lunar declinational tides that peak at the culmination of the declinational sweep occur at Maximum South on 19th August then heads North with tropical moisture in tow until the effects has run its course by the 2nd to 4th of September 2010, is the window of opportunity for the first weaker outbreak of global TS.
    The lunar declination is Maximum South again on the 15th of September 2010, ahead of the peak of charging of the Uranus / Jupiter heliocentric conjunction of the 24th of September 2010, and it should be in phase with the movement of tropical moisture laden warm air crossing the equator following the moon, as it moves North across the equator on the 23rd of September.
    The same day of the peak charging effects of the homopolar generator as the Earth responds to the increased inductive effects carried on the solar wind to affect the coupling through to the outer planets from the sun out of a large coronal hole created on the sun just for the purpose of providing the magnetic field energy needed. This powers up the cycle of positive ion charging along the ITCZ, by pushing more moisture into the lower atmosphere, to then add drive to the ion discharging phase, driving the resultant outbreak of global wide intense tropical storms, that will occur post conjunction.
    By the time the Moon reaches maximum North declination on the 29th of September 2010, the global ACE values will be close to peak for the year. Inertial momentum of the global systems should carry on the enhanced zonal flow through the next two weeks.
    With the continual decreasing electromagnetic coupling as the Earth moves past these outer planets the severe weather activity levels, will drop with continued attempted recovery enhancements at the lunar declinational culminations, until by the time of the synod conjunction of Venus and Earth on the 29th of October 2010, we will see a last hurrah, then a slow shift into the storms of a deep cold NH winter.

  54. Ian W said:
    “It would be very useful if people stopped confusing temperature and heat content and instead were more disciplined about the terms. ”
    I would say that it might be better to get rid of the term “heat content” and just stick
    with heat as the thermal, as opposed to work, energy which is transferred from a higher temperature system to a lower temperature system. Once heat transfer has occurred, the system then has internal energy which cannot be separated into any kind of work energy and heat content. But humans seem to want to pretend that the thermal energy is still separate from the work energy in some separate internal ensemble.
    There would not be so much discussion about heat transfer in the atmosphere if heat were considered as the net thermal energy transfer from the warmer body to the cooler body. There is always a time delay for input thermal energy to pass into and through a body thus causing an change in equilibrium temperatures by delaying the transfer of the heat energy to a cooler body.

  55. Richard Holle says: {August 15, 2010 at 2:04 pm}
    “to drive the wind patterns that tighten up as the Coriolis effects strengthens as the storm moves off of the equator.”
    “don’t understand what you mean by “as the storm moves off the equator”.
    Tropical systems that intensify to hurricanes do not form on or near the equator.
    They are in the 12-15 degrees area.

  56. stevengoddard says:
    August 15, 2010 at 11:44 am
    Frederick Michael
    The temperature in Phoenix 105F. The temperature at 35,000 feet above Phoenix is -65F. Why isn’t there a hurricane in Phoenix? There is plenty of humidity this time of year.

    I’ve heard of oceanfront property in Arizona but I haven’t gone there to see it. When I mentioned the temperature difference between the water and the air above it, I should have been more specific. It needs to be a body of water as big as the hurricane. Anything less can’t sustain the hurricane.

  57. Tom in Florida says:
    August 15, 2010 at 2:42 pm
    Richard Holle says: {August 15, 2010 at 2:04 pm}
    “to drive the wind patterns that tighten up as the Coriolis effects strengthens as the storm moves off of the equator.”
    “don’t understand what you mean by “as the storm moves off the equator”.
    Tropical systems that intensify to hurricanes do not form on or near the equator.
    They are in the 12-15 degrees area.
    Reply;
    Much editing of a spontaneous, (non cut and paste response) was needed, evidently not enough was done…..Would you prefer I said that; As the tropical air mass that becomes the tropical storm, moves off of the ITCZ and further away from the equator, the Coriolis effect kicks in and strengthens, to assist the formation of the cyclonic circulation along with the associated ionic drives?
    I was trying to post a comment without writing a whole book. Thanks for the peer / peer review.

  58. I would like to echo Andres Valencia’s admonition, “But pay attention to Ryan N. Maue’s “2010 Global Tropical Cyclone Activity Update”, http://www.coaps.fsu.edu/~maue/tropical/.
    Many of you are no doubt familiar with Livingston and Penn’s theory that visible sunspots may be on the verge of disappearing because of decreasing magnetic field strengths. Evidently, the field strengths associated with sunspots have inexorably been decreasing over time, and the belief is once they drop below a certain strength, sunspots will not be visible. It looks like we may be seeing something like that wrt hurricanes.
    Maue’s website documents the “accumulated cyclonic energy” (ACE) that tropical storms, both Atlantic and Pacific, have produced by month (and year). ACE factors in storm strength and duration instead of just numbers of storms. It has been dropping for the last several years, and is now at the lowest level in over thirty years.
    If you look at the three named storms this year, two of them are among the weakest in the record books. I’m not sure if Colin would have even been recorded prior to the satellite era. It looks like either something is either taking or preventing storms from developing much energy. Very curious.

  59. stevengoddard says: {August 15, 2010 at 4:11 pm}
    “I’ve been in Phoenix in August when the dew point was over 70 degrees. It can get incredibly humid there during the monsoon season”
    A dew point of 70 degrees with an actual temperature of 100 degrees equates to about 35% relative humidity. Not really all that humid.

  60. Richard Holle says: {August 15, 2010 at 4:00 pm}
    Sorry Richard, wasn’t trying to be nit picky. It’s just that there are many who do not follow hurricanes and mentioning them with “equator” can create incorrect images.

  61. Don´t worry about names NOAA has opened a newer and more flexible birth´s register.
    And, be careful not to stir your cup of coffee/tea too much or opening your shower, NOAA will name it right away.

  62. Just a couple of weeks ago on July 29, Phoenix had a dew point temp of 75.2. Their highest was 79 back in 1957. I don’t care if the temperature was only 90, a dew point in the 70s is ugly. This is rather irrelevant to this post however, but, it looks as if TD #5 may become the fourth named storm once it gets back out over the Gulf again tomorrow.

  63. Would anyone care to comment on the low pressure just off the coast of Alabama which is now judged at 50% of becoming a TD or greater?
    They say it’s a remnant of TD5 which died off the evening of Aug 11 around 150 miles due south of Pensacola and which NOAA, as of 8PM EDT, says is located over the central panhandle. and moving south.
    1. It seems to me it’s further west than that, but no matter.
    2. It’s appears to be both strengthening and getting more organized, very quickly.
    3. This TD5, IMO, inexpert though it is, originated/came out of the eastern US as a part of the rather long running clockwise flow that doubles back further south, most of the portions of which sweep SW and have been blowing the Gulf and Caribbean clean of any Cape Verde origin stuff.
    4. The thing is that that long running pattern I mentioned in 3, above had been very oblong longitudinally running from west of Texas to, oh, just short of Bermuda, and this has tightened into a lot more of a circular pattern.
    Anyway, any thoughts?

  64. As others have mentioned it looks like upper level shear has a large effect on whether the thunderstorm activity can organize into a tropical storm or hurricane.
    On another note, why to we not see equivalent activity in the South Atlantic?

  65. Dusty says:
    August 15, 2010 at 5:24 pm
    Reply;
    Bonnie, td3, and now td4 have all been squall lines at best, hundreds of mile East of the real center of atmospheric circulation, in what would like to be the outer rain bands of a real hurricane.
    Both td3 and td4 had their area of origination as a result of the continental outflows coming off of the Eastern seaboard, then after clearing most of Florida, they attempted to name them. I don’t see where they get off on calling these little disturbances as “Tropical storms”
    With td5 the building effects seen are due to the secondary tidal effects as the moon goes toward maximum South declination on the 19th August 2010, at which time it will collapse completely, like the others. All three of these attempted named areas of precipitation show up in the forecast maps on my site. (see name link above)

  66. BarryW says:
    August 15, 2010 at 6:31 pm
    On another note, why to we not see equivalent activity in the South Atlantic?

    Interesting question! It might be that the ocean surface is warmer in the North Atlantic.
    http://en.wikipedia.org/wiki/Thermohaline_circulation
    Notice how the surface circulation is south-to-north in the Atlantic. So, in the South Atlantic, the surface current has just been around the Cape of Good Hope but in the North Atlantic, the surface current has just been across the equator.
    This is just a guess but it makes sense.

  67. Tom in Florida…
    It looks as if the legend on that map belongs on a relative humidity map. Saturation has nothing to do with dew point. However, you are right to a degree. It does depend a lot on what you are used to. In Phoenix, average summertime dew points are in the 40s and 50s. Also, I know several people who live in Florida full time and they all describe summer there as “stifling” when temps are in the 90s and dew points in the 70s.

  68. I wish I had kept notes, but a couple of times already this season, depressions that the NHC gave probabilities of 40%+ of developing into a TS not only failed to strengthen, but fizzled out into remnant lows while still over water (“while still over water” is the interesting thing). I started following the NHC off and on several years prior to Katrina, and much more closely thereafter. I just don’t remember that happening before.
    I’ve also notice that the discussions now contain little or no description of what the various models are projecting – just a single, summarized prediction that attempts to merge the differing model projections. Makes the discussions, er, dry.
    There’s has been, and still is, a large area of Saharan dust over the tropical Atlantic. Reading between the lines on the NHC indicates this dry air just snuffs out storm development. I know zilch about normal conditions (wind, rain, etc) of Africa. Does anyone know if this is a typical condition for this time of year?

  69. jtom says:
    August 15, 2010 at 7:57 pm
    Reply;
    If you want a more open detailed discussion of the total process here is a link to a board where hundreds of pro mets and amateurs from across the country participate in the gory details with their own learned opinions included.
    http://www.storm2k.org/wx/
    you might need to sign up to post questions…I have been lurking there for most of a year….

  70. What’s the connection between the pleasantness of dew points and hurricane formation?

  71. Frederick Michael says:
    August 15, 2010 at 8:51 pm
    “What’s the connection between the pleasantness of dew points and hurricane formation?”
    Reply;
    long term contributors to WUWT babysitting me to make sure “my pseudo-science here to fore unproven conjectures” don’t tarnish the site’s pure science reputation. I thank them for their concerns, and applaud their efforts, I am old enough to stand or fall on my own.
    Advances in science come from the fringes, not from the center of the mainstream, but so do the classic flops, and scams, and are due watching carefully.
    I have stated the complete detailed forecast for the rest of 2010 hurricane season, in the face of “nobody else can do it, so it can’t be done” gatekeepers who have been shutting out “Lunar”, “planetary”, and “Moon” studies from NSF or any other form of grant funding since they started the peer review process, and pushed for models instead of cycles study in the mid 1950’s, 30 years before they thought about AGW.
    So here I am playing Russian roulette with hurricanes, and they don’t want anybody else here to get shot.

  72. stevengoddard says:{August 15, 2010 at 8:20 pm}
    “Tom In Florida
    The highest dew points on your map are 70 degrees. I lived in Houston for a long time, and 70 degree dew points are not pleasant.”
    These are not my maps, they are from links on the right side of this blog.
    Dew points last night in my area were 76 degrees. I would also think that Houston is a different environment than Phoenix.
    Now as I understand it, the main issue with dew point is the difference between it and the actual temperature. The greater the difference the less relative humidity. That affects the evaporation of perspiration/moisture on the skin which is, as we all know, how the body cools itself. So in a situation where the dew point is 70 degrees with a temperature of 100 degrees evaporation can still take place and the body can still cool itself. It is still very hot and may feel unpleasant if you are not used to it. When the dew point is 76 degrees and the temperature is 88 degrees (as it was early last night) the relative humidity is very high and little evaporation takes place leaving the body sopping wet with very little ability to cool itself. That can be very unpleasant, even if you are used to it.

  73. My (ignorant) two cents worth.
    I do not think the recent past can be relied upon for this years forecast. I think we are seeing a major shift in weather patterns in the northern hemisphere. For example the change in the jet stream last winter giving us very cold weather in the EU, Mongolia, China and the eastern USA and “warmer” weather elsewhere. This summer we saw the same thing with the stalled jet stream in Russia, and very cool weather on the west coast of the USA.
    NASA reported A Puzzling Collapse of Earth’s Upper Atmosphere on July 15, 2010 due to the very low solar activity the last few years. That is in contrast to what was happening in the solar cycles before cycle 24.
    Solar activity reaches new high – Dec 2, 2003
    ” Geophysicists in Finland and Germany have calculated that the Sun is more magnetically active now than it has been for over a 1000 years. Ilya Usoskin and colleagues at the University of Oulu and the Max-Planck Institute for Aeronomy say that their technique – which relies on a radioactive dating technique – is the first direct quantitative reconstruction of solar activity based on physical, rather than statistical, models (I G Usoskin et al. 2003 Phys. Rev. Lett. 91 211101)
    … the Finnish team was able to extend data on solar activity back to 850 AD. The researchers found that there has been a sharp increase in the number of sunspots since the beginning of the 20th century. They calculated that the average number was about 30 per year between 850 and 1900, and then increased to 60 between 1900 and 1944, and is now at its highest ever value of 76.
    “We need to understand this unprecedented level of activity,” Usoskin told PhysicsWeb.”

    There is also the changes in albedo from cloud cover as measured by the Earthshine Project
    http://www.hindawi.com/journals/aa/2010/963650.html
    “…..The earthshine observations reveal a large decadal variability in the Earth’s reflectance, which is yet not fully understood, but which is in line with other satellite and ground-based global radiation data….”
    Climate Scientists really do not actually know what is going to happen this year because many are blind to the recent changes. I think that since the sun has not been pumping as much energy into the oceans for the last few years the hurricane season will be at or below normal.

  74. The greater the difference the less relative humidity. That affects the evaporation of perspiration/moisture on the skin which is, as we all know, how the body cools itself.
    ———–
    It’s my sense that perspiration is not the way that we cool until around 75 degrees ambient, absent physical exertion. Below that, dilation of surface blood vessels for radiative cooling seems to be the mechanism.
    Most people find sweatiness disagreeable and often conclude that the humidity must be high if their skin is wet.

  75. Although I follw most that is put forth on WUWT, this one cranks up my “illogical hypothesis/theory” alarm. I have no background in this, so much of what I am saying may be complete rubbish. But the bits I know don’t seem to tie in with his arguments here.
    When a hurricane or tropical storm forms north of Suriname or a bit east or west of that, I find it hard to believe that the heat accumulation there consults with the northern Atlantic as to whether or not to form. It would seem to be all about convection and Coriolis effect, massaged by the prevailing winds. When it all gets into some kind of “in phase” condition, it is “organized” enough to start rotating as a unit – not necessarily enough to maintain itself, but possibly.
    What any of this has to do with temperature differential escapes me.
    Steve:

    I have read that the “purpose” of hurricanes is to move heat quickly from the tropics to higher latitudes. Heat flow is always driven by differences in temperature. If two places were at the same temperature, there would be no heat flow.

    I would argue all three of these sentences, if for no other reason than to see where Steve is coming from.
    1. What source does Steve have for the idea that hurricanes move heat quickly away from the tropics? Most of their time is spent IN the tropics, albeit on a slightly poleward path, and then they peter out on reaching the mid-latitudes.
    2. The latter two sentences and his map argue that such temperature flow is horizontal (between two “places” [his term]), while my understanding of hurricanes is that it is RISING air that creates hurricanes. I submit that creating a hurricane and moving a hurricane are two essentially separate mechanisms.
    At the same time, simply rising hot, moist air would not create any rotation necessarily. One would think that the prevailing wind patterns north of S America play a part in the formation of hurricanes, giving them a kick start on rotation – or not. Winds plowing straight into the center of a mass of rising moist air would tend to rip it to shreds, while wind currents that supplemented the Coriolis effect would tend to increase the rotation.
    ALL of the mechanisms I can logically identify with the formation of hurricanes are local.
    3. In addition, it is TOTALLY known that many N Atlantic hurricanes end up traveling INTO the Gulf of Mexico, which is a VERY warm body of water. This would seem to belie Steve’s assertion that weather systems go from warm to cold and that this is the driving force for hurricanes.
    4. In this context looking at temperature ANOMALIES does not make sense. Anomalies are not temperature. HEAT FLOW is from warmer to colder. NOT from how much variation there is from “average”. AIR FLOW is from more dense to less dense. Hence convection. Hence wind currents. Anomaly differences between Point A and Point B geographically have nothing to do with CREATING hurricanes – it is only pressure differences (and the Coriolis effect), plus the Hadley Cell flows.
    I may not have made a lot of sense on all of these points, and I don’t tie them together well, but I just don’t think Steve is correct on this. What is going with convection on off the S American coast has NOTHING to do with what temp anomalies in the far north. In addition, MOVEMENT of hurricanes isn’t even tied to temperature gradients (much less anomalies) – otherwise few hurricanes would ever enter the Gulf of Mexico.
    See this almost current SST http://www.osdpd.noaa.gov/data/sst/contour/usatlant.fc.gif . I am tryin to insert the image here: If it fails to post, please go see the map at the above link…
    Which direction would a hurricane go, if it was driven by temperature differential (much less temp anomalies)? Obviously the ones that didn’t dive into the Caribbean would head NORTH, according to Steve’s premise.
    I can’t see any validity to this argument. Hurricanes do not form in one place because of conditions in one of the possible locations that the air mass might travel to in 10 or 15 day’s time. And temp ANOMALIES don’t move systems – air pressures do. The only temperature effect involved has to do with convective RISING, not movement.
    If I am wrong, beat on me, guys.

  76. @jtom says August 15, 2010 at 7:57 pm:
    There’s has been, and still is, a large area of Saharan dust over the tropical Atlantic. Reading between the lines on the NHC indicates this dry air just snuffs out storm development.

    jtom – wouldn’t this Sarahan dust also be an aerosol that tends to cool?
    I would logically agree with your point, also. Airborne particulates – don’t they act as nucleating objects for water vapor condensation, which would then increase rainfall locally, removing heat from the developing system?
    In support of this (and hoping this doesn’t get me laughed off the site!), Wikipedia summarizes hurricane formation factors thusly:

    The formation of tropical cyclones is the topic of extensive ongoing research and is still not fully understood.[37] While six factors appear to be generally necessary, tropical cyclones may occasionally form without meeting all of the following conditions. In most situations, water temperatures of at least 26.5 °C (79.7 °F) are needed down to a depth of at least 50 m (160 ft);[38] waters of this temperature cause the overlying atmosphere to be unstable enough to sustain convection and thunderstorms.[39] Another factor is rapid cooling with height, which allows the release of the heat of condensation that powers a tropical cyclone.[38] High humidity is needed, especially in the lower-to-mid troposphere; when there is a great deal of moisture in the atmosphere, conditions are more favorable for disturbances to develop.[38] Low amounts of wind shear are needed, as high shear is disruptive to the storm’s circulation.[38] Tropical cyclones generally need to form more than 555 km (345 mi) or 5 degrees of latitude away from the equator, allowing the Coriolis effect to deflect winds blowing towards the low pressure center and creating a circulation.[38] Lastly, a formative tropical cyclone needs a pre-existing system of disturbed weather, although without a circulation no cyclonic development will take place.[38] Low-latitude and low-level westerly wind bursts associated with the Madden-Julian oscillation can create favorable conditions for tropical cyclogenesis by initiating tropical disturbances.[40]

    That seems to generally agree with my points above. NONE of the factors has anything to do with anything that is happening in northern latitudes, whether anomalies or actual temps.
    (I seriously wish this site had a PREVIEW function…)

  77. Feet2theFire
    Have you ever looked at SSTs before/after a hurricane moves through?
    Temperatures drop several degrees, because of energy transferred from the water to the atmosphere. Higher latitudes are colder than the tropics, so the heat necessarily moves towards the higher latitudes (basic thermodynamics.)

  78. Feet2theFire says:{August 16, 2010 at 7:54 am}
    ” 3. In addition, it is TOTALLY known that many N Atlantic hurricanes end up traveling INTO the Gulf of Mexico, which is a VERY warm body of water”
    That is due to the Bermuda high which normally develops each summer near, you guessed it, Bermuda. It is one of the main steering currents for hurricanes. Absent a strong cold front out coming out of the U.S., hurricanes will travel clockwise around the Bermuda high and end up in the Gulf of Mexico. Nothing to do with going from colder to warmer or warmer to colder.

  79. What Hurricane season is that you are referring to ? I must not have paid my dues or something; because I have not been getting any Huricanes yet !

  80. As an addendum to this “strange” season, TD5 is backing off the continent and heading back over the GoM….
    If it continues southward for the next day, it may well become the tropical storm (or even weak hurricane) that was originally expected.

    We have been quacking like ducks for 3 days straight now, here in P-cola, and am not looking forward to more of the same. Ivan came back at us eventually, too…I guess we’re well nigh irresistible.

  81. Perhaps someone should create a ‘heat content’ anomaly map using humidity and temperature to obtain the heat content?

    It would be relatively straight-forward to create one. Besides the “dry bulb” temperature, all you need is some measure of humidity, such as wet bulb, dew point, or relative humidity. Find the two on a psychrometric chart, and you have the enthalpy.
    http://en.wikipedia.org/wiki/Psychrometrics

  82. stevengoddard says:
    August 16, 2010 at 8:58 am
    Have you ever looked at SSTs before/after a hurricane moves through?
    Temperatures drop several degrees, because of energy transferred from the water to the atmosphere. Higher latitudes are colder than the tropics, so the heat necessarily moves towards the higher latitudes (basic thermodynamics.)

    Actually the heat transfer may be even larger because of the water vapor transmitted, which releases huge amounts of heat when it condenses into rain.
    However, some (or all) of the SST reduction after a hurricane passes through may come from the turbulence mixing the surface water with the colder deeper water. Any tropical weather pattern will take heat with it.

  83. “”” Frederick Michael says:
    August 16, 2010 at 3:10 pm
    stevengoddard says:
    August 16, 2010 at 8:58 am
    Have you ever looked at SSTs before/after a hurricane moves through?
    Temperatures drop several degrees, because of energy transferred from the water to the atmosphere. Higher latitudes are colder than the tropics, so the heat necessarily moves towards the higher latitudes (basic thermodynamics.) ”
    Actually the heat transfer may be even larger because of the water vapor transmitted, which releases huge amounts of heat when it condenses into rain. However, some (or all) of the SST reduction after a hurricane passes through may come from the turbulence mixing the surface water with the colder deeper water. “””
    “”” some (or all) “””
    Are you sure that you proof read your post ?
    Why do you suppose that the SSTs “drop several degrees” as Steve stated; if it isn’t in giving up the latent heat of evaporation required to transport that huge amount of water into the vapor phase ?
    And just how would you plan to vaporize that much surface water if (all) of the SST reduction comes from mixing.
    Roy Spencer once quoted the rate of energy transport to the atmosphere in something like a Cat-3 Hurricane; and the number makes Total Global Thermo-Nuclear War sound very attractive, in comparison.
    Who says that there is tubulent mixing of surface waters with deep ocean waters during a hurricane; if that was occurring the destruction of shallower water life would be amazing. and it would take one hell of a ruckus to get all that cold water to the surface in almost nothing flat.
    All those oil rigs ride out Hurricanes that pass through there, so I doubt that there is much mixing of waters for more than a few tens of metres; much of which is not too different from the surface temperature.

  84. Suppositions and opinions with out real data reference, is why I quit reading Scientific American, and other rags, and went to the research library to read research papers back in the 80’s.

  85. Have any of you been out at sea in a small boat in a gale?
    As the wind rises the whitecaps grow larger, along with the waves, until the top of every wave is breaking and cascading forward (down wind) into the trough ahead. This constant churning of the water creates a foam which blows in the wind like suds. As the wind rises the entire surface of the sea is either churning whitecaps or cascading breakers or suds. (I think the suds are called “spindrift.”) The sea is less and less blue or green, and more and more white. There is also salt spray all over the place, snatched from the tops of waves and whistled down wind.
    I experienced this when I was an idiotic teenager. (I’d decided only wimps stuck to the intercoastal waterway, and sailed from Newport straight to Cape May, in October.) At the height of the storm I was a bit less than scientific and objective, and a bit more prone to blubbering and pleading than I’ll ever publicly admit, yet the peak gusts were never up to hurricane force. I can’t even imagine what the sea surface must be like inside a force five hurricane.
    Now, with twenty-twenty hindsight, I can be scientific and objective, and I think few people have any idea of the mixing that occurs at the sea’s surface, when winds rise above thirty knots. In a force five hurricane the spindrift suds must get sucked right up to the top of the troposphere. All sorts of organic oceanic matter winds up mixing with ozone in the lower stratosphere. All the organic stuff that ends with “ine,” such as bromine and chlorine and fluorine and iodine, reacts with ozone and, among other things, utterly screws up climate models.
    Not only is heat whipped off the sea’s surface and hurtled upwards, but huge amounts of latent heat is released as the water vapor turns to liquid water, and again as that liquid water turns to ice crystals at the very top of a hurricane.
    Then where are we, with all that heat? We are nearly three times as high as Mount Everest, at an altitude where there is next to no air between the heat and outer space. Because there is little CO2 left above, there is no way any “greenhouse effect” can keep a huge amount of heat from radiating out into the icy depths of inky space.
    It would be neat to focus a satellite on the top of a hurricane, and measure the amount of heat the top releases. I imagine the amount would be staggering. And this is even before the hurricane acts as a “heat transport,” moving tropical heat towards the poles.

  86. All this discussion about how hurricanes form and why they go where they do is interesting and thought provoking. However, growing up in South Florida, taught me that the time to discuss the number of hurricanes in the current season is Oct. 15, not Aug.15. Let’s do it again in a couple months. After all that’s when we’ll have the data.

  87. This hurricane season seems to be turning into an object lesson in science by press release. How else to explain the way the TV weather forecasters seem to be reading from the same script as they report, in breathless excitement, on how the remnants of tropical depression five seem to be on the brink of reforming into a tropical depression before making landfall?
    We’ve gone from major hurricanes to minor hurricanes to tropical storms to now we’re to get excited about the state of tropical depressions (or their remnants)? Let’s see how the next six weeks unfold before getting all excited about possible tropical depressions or prematurely naming them before they turn into tropical storms.

  88. A circulation dome south of the equator in the mid South Atlantic is now in place – might not last but it is there now. The dome in the North Atlantic is ill defined. A “spinner” came off the east coast of Africa in the last 24-hours around Cape Verde’s latitude, which quickly started to dissipate because of the dry air north and east of it.
    Another interesting thing to note is that for the first time this season, Indian Ocean moisture has now reached the west coast of Africa.
    You can see all of this here:
    http://www.nrlmry.navy.mil/sat-bin/display10.cgi?SIZE=full&PHOT=yes&AREA=global/stitched&PROD=vapor&TYPE=ssmi&NAV=global&DISPLAY=Latest&ARCHIVE=Latest&CGI=global.cgi&CURRENT=20100817.0900.multisat.wv.stitched.Global.x.jpg&MOSAIC_SCALE=15
    Animate using the last 10 or so images available.

  89. Feet2theFire says:
    August 16, 2010 at 8:09 am
    ………………………………………..
    Dust in the air is indicative of very dry air, which violates one of the parameters for hurricane development given in your Wiki article, “High humidity is needed, especially in the lower-to-mid troposphere; when there is a great deal of moisture in the atmosphere, conditions are more favorable for disturbances to develop.”
    There is nothing for the dust to nucleate.
    ………………….
    tree hugging sister says:
    August 16, 2010 at 11:43 am
    As an addendum to this “strange” season, TD5 is backing off the continent and heading back over the GoM….
    If it continues southward for the next day, it may well become the tropical storm (or even weak hurricane) that was originally expected.
    We have been quacking like ducks for 3 days straight now, here in P-cola, and am not looking forward to more of the same. Ivan came back at us eventually, too…I guess we’re well nigh irresistible
    ……………………………………
    Well, it did go south over the Gulf, was given a 60% chance of becoming at least a TS, and has now fizzled out. Another miss. The next eight weeks will tell the tale.

  90. @ Tom in Florida says August 16, 2010 at 10:07 am:

    Feet2theFire says:{August 16, 2010 at 7:54 am}
    ” 3. In addition, it is TOTALLY known that many N Atlantic hurricanes end up traveling INTO the Gulf of Mexico, which is a VERY warm body of water”

    That is due to the Bermuda high which normally develops each summer near, you guessed it, Bermuda. It is one of the main steering currents for hurricanes. Absent a strong cold front out coming out of the U.S., hurricanes will travel clockwise around the Bermuda high and end up in the Gulf of Mexico. Nothing to do with going from colder to warmer or warmer to colder.

    That is my point exactly.
    Steve Goddard says

    I have read that the “purpose” of hurricanes is to move heat quickly from the tropics to higher latitudes. Heat flow is always driven by differences in temperature. If two places were at the same temperature, there would be no heat flow.

    Heat convects UPWARD, not because heat in an atmospher goes from hot to cold, but because it is less dense and rises.
    Heat does not travel horizontally along the surface because of heat or cold. I travels because of PRESSURE differential and air currents. The heat goes with the air masses. But so does cold. Actually it is COLD air masses that move toward WARM air, which is less dense.
    In both horizontal and vertical movements, it is PRESSURE that drives the air and the heat/cold gets carried with it.
    I agree with Tom that it has “[n]othing to do with going from colder to warmer or warmer to colder.” I believe I was trying to say that. I must have stated it incorrectly. Steve Goddard is the one who is claiming it has something to do with moving heat. I think that Steve’s statements quoted in this comment are wrong.

  91. “In both horizontal and vertical movements, it is PRESSURE that drives the air and the heat/cold gets carried with it.”
    Oh, and Coriolis effect.

  92. @ George E. Smith says August 16, 2010 at 5:02 pm:

    Who says that there is tubulent mixing of surface waters with deep ocean waters during a hurricane; if that was occurring the destruction of shallower water life would be amazing. and it would take one hell of a ruckus to get all that cold water to the surface in almost nothing flat.

    George, you might be interested in this. About 25 years ago I saw a science article which I cannot source at all right now. I did clip it and file it, but have since lost it.
    In the article it discussed how much erosion occurred on the ocean bottom (I believe it was off the east coast of Florida) during a heavy storm. The scientists involved were completely surprised at the amount of erosion, which they said amounted to many, many years of normal erosion. I do not recall the depths involved, but I had the impression it was in the shallow ocean around the Bahamas – perhaps 100 feet or more. I have the general recollection that the storm was not a hurricane.
    The main thrust of the article was both the amount of erosion and the surprise of the scientists. That is why I clipped it out and kept it. And why I still remember the basic facts, even if I don’t recall the numbers or names, or when this was. Mid-to late-80s come to mind. They were definitely talking about turbulence and what it did to the ocean bottom.
    While you have nothing to go on here other than my poor recollection, I hope it may indicate that the mixing DOES go down to some sizable depth. I don’t know what the range of the thermocline is in hurricane areas, but 100 feet or so sounds like it might be near the thermocline. And if the erosion/mixing goes below the thermocline, then I would think that there is some colder water brought up to the surface. Perhaps not. It seems like a more complicated condition than just simply saying, “No, there is no mixing at all,” one worth studying if understanding of hurricanes and their effects.

  93. Well, I am not a hurricane expert, but is a hurricane not just a rather large messy heat engine? Which takes energy from the ocean and dumps it out at high altitudes, where it is radiated into space? And have we not had a couple of very quiet years? I really expect a very active, very strong hurricane this year or next, depending on the jet stream shear effect. Nothing to do with global warming, just common sense. If the air conditioner has been off a while, it has to run pretty hard to catch up once it turns back on………..

  94. “”” Feet2theFire says:
    August 17, 2010 at 11:18 am
    @ George E. Smith says August 16, 2010 at 5:02 pm:
    Who says that there is tubulent mixing of surface waters with deep ocean waters during a hurricane; if that was occurring the destruction of shallower water life would be amazing. and it would take one hell of a ruckus to get all that cold water to the surface in almost nothing flat.
    George, you might be interested in this. About 25 years ago I saw a science article which I cannot source at all right now. I did clip it and file it, but have since lost it. “””
    Well feet-2 I appreciate you recollection; and don’t doubt the truth of what you read. But I would submit, that there is a considerable difference between bottom erosion, and water turnover. Certainly if you have a tidal water flow (over the bottom) which you certainly would in the Bahamas; and then on top of that you add a dynamic loading change by adding a storm driven wave motion on top, the cyclic pressure changes on the bottom will not be inconsequential when added to a continuous current so the scooping of bottom sands etc is going to follow a pulsing pattern which yes will totally change the bottom configuration; but never bring any of that bottom water to the surface.
    You only have to go snorkelling in the surf line in shallow water, and little wave motion to see the scalloping that occurs due to wave action on the top of moving water ( the bottom is typically scoured outwards by water running out from the waves breaking on the beach (even small waves) and the surface wave action is what scallops the bottom sand into waves that you can follow out to quite large depths. I spent a good part of my youth in summer time swimming all day at beaches where I could dive down and see the sand waves on the bottom. There wasn’t any bottom water coming up to the top out there.

  95. Make me eat my words later .
    I predict the weakest Huricane season in history .
    Reasoning : storms develope based on large differences of temperature .
    The global warming is expending the heat area more towards the poles hence leaving behind ( at the tropics ) a calmer weather , free of the punches of cold fronts decending from the pole . Hence less intense storms , NO huricanes , ZERO !
    Let’s waite and see , I have the knife and fork ready to eat this .
    Please comment , thank you .
    PS : take a look at the phenomenal High pressure ridge stretching from Hawai to the Great Lakes , there stationed for the last three month , a Wall stopping /deflecting any cold air dropping from the pole … To see it , dark area – low humidity – go to :
    http://weather.unisys.com/satellite/sat_wv_hem_loop-12.html
    ( home site at : http://weather.unisys.com/satellite/sat_wv_west.html
    Doru
    Canada

  96. I don’t have any confidence in anyones ability to predict severe weather. The best that can be done is to track a storm after it forms. Even this is an imprecise science usually based on on 20-30% degree of probability. You might as well read the Farmers Almunac. Keep blowing smoke everyone. I can’t wait to 2013 when the solar flares are mixed into the equation. Fun reading

  97. Whenever they say “very active hurricane season” you can be sure to expect nothing, when they say it will be a “very weak season” batten down the hatches…just like weather casters predicting our weather with an oracle bone & a chickens foot!

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