NOAA issued its updated Atlantic hurricane season outlook today saying the season is shaping up to be above normal with the possibility that it could be very active. The season has already produced four named storms, with the peak of the season – mid-August through October – yet to come.
“Our confidence for an above-normal season is still high because the predicted atmospheric and oceanic conditions that are favorable for storm development have materialized,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center, a division of the National Weather Service. “Also, two of the four named storms to-date formed in the deep tropical Atlantic, which historically is an indicator of an active season.”
The conditions in place now are similar to those that have produced many active Atlantic hurricane seasons since 1995, and include above-average Atlantic sea surface temperatures and a stronger rainy season in West Africa, which produces wind patterns that help turn storm systems there into tropical storms and hurricanes.
The updated outlook calls for a 70 percent chance of an above-normal season. Across the Atlantic Basin for the entire season – June 1 to November 30 – NOAA’s updated seasonal outlook (which includes the activity to date of tropical storms Andrea, Barry, Chantal, and Dorian) projects a 70 percent chance for each of the following ranges:
- 13 to 19 named storms (top winds of 39 mph or higher), including:
- 6 to 9 hurricanes (top winds of 74 mph or higher), of which
- 3 to 5 could be major hurricanes (Category 3, 4 or 5; winds of at least 111 mph)
These ranges are above the 30-year seasonal averages of 12 named storms, six hurricanes and three major hurricanes.
The updated outlook is similar to the pre-season outlook issued in May, but with a reduced expectation for extreme levels of activity. Motivating this change is a decreased likelihood that La Niña will develop and bring its reduced wind shear that further strengthens the hurricane season. Other factors are the lack of hurricanes through July, more variability in the wind patterns across the tropical Atlantic Ocean and slightly lower hurricane season model predictions. In May, the outlook called for 13-20 named storms, 7-11 hurricanes and 3-6 major hurricanes.
“The peak of the hurricane season is almost upon us and it’s important to remain prepared for hurricanes through November,” said Joe Nimmich, FEMA Associate Administrator for Response and Recovery. “Make sure to review your family emergency plan, check that your emergency kit is stocked and consider insurance options. Learn more about how you can prepare for hurricanes at www.ready.gov/hurricanes.”
On the Web:
Updated 2013 Atlantic Hurricane Season Outlook:
http://www.cpc.ncep.noaa.gov/products/outlooks/hurricane.shtml
NOAA’s mission is to understand and predict changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Twitter, Facebook and our other social media channels. Visit our news release archive.
“The headline could also have been “NOAA revises downward its estimate of hurricane activity”. (The May estimate was 7-11 hurricanes, now 6-9.) But that would have been off message.”
Meh. I too was caught up short by the slight downgrade half way into the article, but in fairness to main bullet point is above average activity. Hurricane frequency prediction in any given year is fairly well established science. I’ve been concerned since spring as a follower of Joe Bastardi and Joe D. We’re are so due here in the northeast. If we do get hit with one up here, the howling winds of propaganda will be at least as strong as the hurricane’s.
Is the fact that both ‘deep tropical Atlantic’ tropical storms fell apart and dissipated before they reached Cuba significant?
From looking at the way the cloud formations are behaving over the mid Atlantic via the fulldisk satellite image. Then l have real doubts about their claims that this season will have high hurricane activity. To me at the moment it looks like the weather activity will be in the form of plenty of small scale storms turning up rather then big hurricanes.
To hit the upper end of their prediction we need a TS each week from now until the end of hurricane season.
I wonder what the past decade of hurricane activity would have been recorded as if it were to occur in the pre-satellite era with so few cyclones making landfall. How many cyclones that never hit land went unrecorded?
However if we look at the season to date figures, the Atlantic tropical season is still well BELOW average with respect to ACE using ’81-’10 climatology. The NOAA, K/G and Bastardi’s weren’t forecasting a slow start. So I would take this reforecast with a huge chunck of salt.
Any idea what Bastardi and D’Aleo are predicting? They seem to have a better grasp on this subject than the NOAA.
The Weather Channel is “hyping” new Pacific Storms. Oh, wait, they don’t exist as actual low pressure areas, but they are computer model results. They stated that the USA models predicted at least 3 new storms [hurricanes maybe]. It gets better, the Europe computer models predicted no low pressure areas.
I have watched these people become disheartened when storms don’t become stronger. Are they crazy? Do they really want viewers that bad that is depresses them if damaging hurricanes don’t form?!?!
Dr. Lurtz: Yes TWC really does get disheartened when storms don’t become stronger. Cantori and crew don’t get to stand in front of a camera in a stiff breeze pontificating to an adoring audience, viewership doesn’t rise (and advertizing revenue along with it), and they can’t use the weakening storm to blather on about global warming. Watch their shows – it’s global warming all the time (sometimes very subtle) and/or disaster porn. They FEED on disaster.
“Motivating this change is a decreased likelihood that La Niña will develop and bring its reduced wind shear that further strengthens the hurricane season.”
So, if we are expecting an above average North Atlantic Hurricane season, and El Nino’s work against tropical storm development, would a ” decreased likelihood of La Nina” lead to fewer Hurricanes? The above quote is a train-wreck of grammatical confusion.
@Rob
The PDO went negative in 2007, not in 1998/99.
Various commenters have linked storm activity to global cooling. The Klotzbach & Gray 2008 chart showing this link is here: http://members.iinet.net.au/~jonas1@westnet.com.au/hurricanes.jpg
(I’ve lost the original link but kept the content. The full paper is here: http://members.iinet.net.au/~jonas1@westnet.com.au/HurricanesKlotzbachAndGray20080805.pdf)
Wide ocean surface expanses of 26.5 C are required and 2′-5′ of subsurface temperatures at or below the threshold play the biggest part in storm concentration.
Role of SST in Hurricane Genesis
Sea Surface Temperature. Hurricanes can only form in extensive ocean areas with a surface temperature greater than 26.5 deg C. This is because the warm ocean water provides sensible heat and water vapor that fuels the intense convection of a hurricane, and assists the conversion of a cold-core tropical depression to a warm-core cyclone.
One of the remarkable relationships of tropical cyclone climatology is the existence of a threshold sea-surface temperature below which tropical cyclones do not form. The most favorable regions according to the sea temperature criterion include the northwest Atlantic (including the Gulf of Mexico) and the northwest Pacific. The cooler temperatures of the southwest Atlantic and northeast Atlantic apparently explain why no tropical cyclones form there. Although it is easy to understand a positive correlation of sea-surface temperature with tropical cyclone formation, it is not at all obvious why there should be such a sharp cutoff in formation at 26.5 deg C. Because of the exponential variation of saturation vapor pressure with temperature, there is a rapid increase of saturation specific humidity and equivalent potential temperature with temperature at a constant relative humidity. It is not surprising, therefore, that oceans with temperatures of 30 deg C should produce more tropical cyclones than with 28 deg C. But why should no storms form with sea temperatures below 26.5 deg C? Certainly convective instability and thunderstorms occur over water with much lower surface temperatures. At this point the answer is not known
Hurricanes (or tropical cyclones) are generated in the warm ocean regions shown below. Strictly speaking, the name hurricane is applied only to hurricanes that start in the Atlantic Ocean and that part of the Pacific Ocean east of the International Dateline. Hurricanes that occur in the Pacific Ocean west of the Dateline and the Indian Ocean are called typhoons. Typhoons of the Bay of Bengal and Arabian Sea are locally called cyclones. Lesser known names for hurricanes are “WillyWilly” in Australia, “Baguio” in the Philippines and “Cordonazo” in Mexico. South America is not affected by hurricanes since none form in the South Atlantic Ocean
I join those above who noted the misuse of “normal” for “average.” Normal means according to a norm, or what something is supposed to be. Normal human body temperature is 98.6 F, and substantial departures from that norm are cause for concern and may induce grievous bodily harm. That norm was established through long medical experimentation and is well established. Other such norms exist. Dramatist George Bernard Shaw was induced to visit an oculist even though he had no vision troubles. After a thorough examination, the doctor assured Shaw that his eyesight was normal, but pointed out that that condition was very rare.
For weather there are no norms. No one knows what the temperature or humidity or cloud cover is supposed to be, and there seems to be no method of arriving at figures for such “norms.” Was the temperature, pressure, etc. in the Garden of Eden normal? If so, what was it? No one knows, or can know. If we seek to arrive at what our climate is supposed to be (a norm), when in history was it actually normal? Who makes that decision? How are figures arrived at? There are–and can be–no norms for any of the factors of climate, because it is a chaotic system of an unimaginable number of variables.
Now for average: Why did someone decide that a thirty-year period is the proper one to establish an average figure for climate variables? Why not the entire climate/weather history? I see the thirty-year period as totally arbitrary, chosen from thin air. Even if we accept it, we have no need to accept “adjustments” (read: changes) to past figures in order to enhance the more recent ones for political gain. If any adjustments are made, they should be for verified degrees of UHI or similar factors; but even there, they must be taken with care. We could rely on two sets of figures: a “recent average” going back thirty years, and a “historical average” going back to the beginning of the historical record.
These predictions are about as vaulable as the Pre-season College football rankings. The truly amazing thing is that people actually take both predictions seriously. They are never right.
Maybe we should create a fatasy hurricane league.
Yawning in Florida
Skrallz says:
Is “above-normal” synonymous with “above-average”? Or do they have different meanings in this context? If not, it seems it’s more logical to stick with “above-average”, as “normal” is not clearly defined. Also “above-normal” would seem to fall into the latest “extreme weather” narrative that the media and CAGW industry has been pushing lately.
Exactly.
The only thing I’d add to that is that peopp\le should NEVER talk about “above or below average” unless they give some indication of the typical distribution of the data, so as to put the observation in a proper context.
Assuming a symmetrically distributed dataset, half of observations are above average, half are below, and it is entirely possible that the average value has never been recorded in the entire history of the dataset. Whether “normal” or “average”, neither means a damn thing without the full context.
“Lesser known names for hurricanes are “WillyWilly” in Australia …”
———————————
Nope. A willy-willy is a small revolving dust-storm. We call hurricanes cyclones here.
And, well spotted to those above who called out the inappropriate use of the word “normal” in this context. I wonder what their definition of a “normal” intensity hurricane is? Is it the mean, or the median? Or could it be that there ain’t no such animal?
Several important ingredients are needed for a tropical disturbance to become a tropical cyclone and later strengthen into a tropical storm or hurricane:
1.A tropical disturbance with thunderstorms.
2.A distance of at least 500 kilometers (300 miles) from the equator.
3.Ocean temperatures of 26.5°C (80°F) or warmer to a depth of at least 50 meters (164 feet) below the surface.
4.Lots of moisture in the lower and middle part of the atmosphere.
5.Low wind shear.
This is what makes a tropical storm, temperature plays a part but so does relative position. Wind shear prevents anything from spinning up in a great many places where the temp would otherwise allow a tropical storm. Tropical disturbances also only form in certain locations with the right mix of circumstances.
So to get to the point, NOAA always seems to predict a above normal season, except the one time they got burned by predicting a normal one and having it go haywire on them, ever since then they have erred on the above side. Not only do they hedge their bets with a wide range of possible numbers and types of storms, they also only give it a 70% chance….which means a 30% chance of a normal season. Finally when the number of storms doesn’t pan out they bail to the average energy index, do some post op on the storms and everything comes out all right /sarc.
So take what they post with a grain of salt….
To much wind shear.. Polar jet intrusion is to massive.. I think NASA has it wrong…
Robert W Turner says:
August 8, 2013 at 10:44 am
Possible, but that is a lot of dry air out there. In a normal hurricane season, there’s a bunch of talk in June at the start of the season, then nothing much happens until mid August, then things pick up quickly and fade away in September and October.
Technically, we don’t know, but I think we know about many of the bigger storms. they produce long period ocean swells that travel for thousands of miles and are noted by ship and harbor personnel.
Christopher Landsea headed an effort to review a lot of old ship logs and other records to make a better data for forecasters looking for analog years and to have a better historical record.
As we approach the bottom of the a-c wave
http://blogs.24.com/henryp/2012/10/02/best-sine-wave-fit-for-the-drop-in-global-maximum-temperatures/
you will find “weather” (rains, storms) at > [30] latitude, becomes less
In fact I expect that in about 5-7 years there will be droughts coming up
similar to 1932-1939 at >[40]
I can see how the climate will change, apparently the computer cannot…
and it isn’t our fault…
http://blogs.24.com/henryp/2013/04/29/the-climate-is-changing/
I understand your confusion. The reduced chances of La Nina conditions have led them to LOWER their forecast for the season:
13-19 named storms versus 13-20 previously
6-9 hurricanes versus 7-11 previously
3-5 major hurricanes versus 3-6 previously
However, the first part of the article makes no mention of there being a reduction in the forecast. I can understand their rationale for doing so – if they’re expecting activity to be above normal, they want to ensure that is the take-home message that those living in hurricane-prone areas receive. It does make for a mixed message generally, though.
Come again? Where are all these hurricanes that have formed because they didn’t hit the US in their development? Pacific storms don’t hit the CONUS. Atlantic storms that reach the US generally aren’t going to be strengthening by the time they reach that latitude, but weakening. The exception is storms crossing Florida into the Gulf of Mexico, but they don’t lose much strength over the moist peninsula. The alternative is crossing Cuba, which really DOES weaken them.
Keith says:
August 9, 2013 at 1:47 am
The impression I’ve gotten is El Niño brings windshear, but that there isn’t much difference between neutral and La Niña.
Klotzbach & Gray combine in one paragraph:
This rather sounds like a list of independent attributes instead of close interrelationships. I think these are some of the predictors they use, and they look for independent attributes for that.
Most weather forecasts I see on TV don’t emphasize the adjustments, especially if it’s only a few degrees. It’s generally more important to have the latest forecast than to know the trend in forecasts.
K&G have more space to get into all the details, plus their previous forecasts are as available as the most recent so they have motivation to discuss the changes. In fact, just under the title, they note:
http://pjmedia.com/weathernerd/2013/07/31/dustnado-saharan-sneeze-to-snuff-storms-albeit-temporarily/ And don’t forget the dust storm that will block tropical storm formation for a short while.
Where is Dr. Hansimian when we need him?
Kindest Regards
Just looking at observables and not the theory that tries to explain it, eastern pacific hurricanes have been high (despite the prediction they’d be low). The theory is this is driven by ENSO, but just looking at the observables that a high eastern pacific hurricane season usually implies a low Atlantic hurricane season seems at odds with the prediction. I’d be more inclined to believe correlated observables over a theory that attempts to correlate the observables.