Guest post by Ric Werme
The CSU Klotzbach/Gray Aug 18-31 hurricane forecast is out. Based on the NOAA historical tropical storm and hurricane frequency below, they are betting on an uptick in activity.
They’re still looking for active weather:
We expect that the next two weeks will be characterized by heightened amounts (130 percent or more) of activity relative to climatology.
More:
The above-average forecast is due to a combination of factors. The primary factor is that most of the global models are very enthusiastic about TC development over the next few days. Most of the models indicate that the wave currently moving off of the west coast of Africa will develop into a classic Cape Verde-type hurricane in the next few days. These systems typically propagate across the tropical Atlantic and generate large amounts of ACE in the process. Most of the models indicate that the system should be entering an environment favorable for storm intensification, and therefore, the likelihood of this system having a long lifespan across the basin looks good. Models also indicate that TC development in the western Caribbean as well as additional development in the tropical Atlantic also is possible over the next week or so. We do not expect the MJO to play much of a role in modulating storm activity, and since we overall have very favorable climate conditions for an active season, we believe that the next two weeks should be active.
So, things are primed and ready to fire, it’s just that the trigger isn’t here yet, but it’s coming. (Barring unforseen events. There’s always that out….)
They also look at the past two-week forecast:
The two-week forecast of tropical cyclone activity from August 4 – August 17 did not verify well. Activity at above-average levels was predicted, while observed activity was at below-average levels. The primary reasons why we believe activity was reduced during the two-week period were due to dry mid levels in the atmosphere and increased vertical stability This dryness was not expected. Also, several upper-level cold lows intruded into the tropics during the period, imparting upper-level westerly shear and hindering storm formation. However, it is not unusual for the first half of August to be almost tropical cyclone-free.
The only ACE generated during the period was by the remnants of Tropical Storm Colin that regenerated on August 5 but was then torn apart by shearing from an upper-level low on August 8. Our forecast was for an above-average ACE value of 10 or more units (>130% of climatology), while a below-average ACE of 2 units (22%) occurred. The Madden-Julian Oscillation was of a fairly weak magnitude throughout the period and likely did not play much of a role in modulating TC activity.
So, a good collection of suppressors – dry mid-level air and upper level shear
blowing the cloud tops off. While K&G have said the short time frame makes it
difficult come up with meaningful comparisons, predicting > 130% and getting
only 22% must be tough to see.
I find this comment as to why the previous ecxpectations were frustrated quite interesting:
“The primary reasons why we believe activity was reduced during the two-week period were due to dry mid levels in the atmosphere and increased vertical stability This dryness was not expected. Also, several upper-level cold lows intruded into the tropics during the period, imparting upper-level westerly shear and hindering storm formation.”
That would be consistent with my points about the current equatorward position of all the air circulation systems and especially the mid latitude jets. This is a good opportunity to see whether that scenario suppresses tropical storm activity.
I don’t see any sign of a poleward shift yet especially since the polar highs are predicted to strengthen over the coming days. Thus my current bet would be on continuing lower than average tropical storm activity.
I’ll take the bet against Atlantic named-storm
development over the next two weeks at even odds.
If nothing much shows by next Tuesday, I’ll go with
2 to 1 odds against.
Watch the zonal flow at:
http://www.ssec.wisc.edu/data/comp/cmoll/cmoll.html
Klotzbach and Gray make forecasts based on actual data. They sure beat the pants off the likes of Mann. Mother Nature can be very fickle, let’s see what she has up her sleeve before we laugh too hard at the Dynamic Duo.
So far the only prediction that has been correct is Richard Holle’s. Earlier this year he stated that there would be little development of any tropical disturbances through the 20th of August. He is correct. (Read his detailed predictions on this thread). It remains to be seen if he is going to continue to be correct. But either way, and while many may disagree with his theories, at least he has the guts to be specific on things including the reasons for his predictions.
The OLD WAY — that made the 2005 prediction, before Politicized NOAA Head ordered Super Seasons predicted EVERY year…
1. Warm Water drives ‘canes, so: a La Nina (cold Pacific-Equator) makes small storms heading up the East Coast.
2. Nuetral .. is above average slightly because:
3. El Nino (hot) – – starts near Peru & thus is right “under” the Caribbean. So it disturbs the storm-tracks — without a long buildup, the ‘canes are weak.
4. Unless it’s an El Nino MODOKI … these start in the West Pacific & that is a couple WIDTHS of the ATLANTIC away.
>>> Thus 2007: extra heat, no disturbance.
5. Unless it is TOO strong — you get Saharan DUST “STORMS” which dull other Storms. Just look at the NOAA Global Aerosol Map — they extend all the way from Africa PAST CUBA. Now THAT is hurricane supression !!!
http://www.osdpd.noaa.gov/ml/air/aer_month.html
PS http://www.osdpd.noaa.gov/ml — leads to a LOT of products, including Sea Ice under “Oceans”
>> PSS: Please note a rapid change can Mix Nino & Nina because the winds change fast, while Pacific Water is still creeping along at a tenth their speed … as: last Winter, when the El Nino warm Moist air charged into the La Nina East Coast Cold Pattern: Result: = Record East Coast SNOW.
“The primary factor is that most of the global models are very enthusiastic about TC development over the next few days. ”
Doesn’t this choice of language strike one as a bit odd? Generally I’ve noticed there seems to be a perverse excitement amoungst the warmists for the actualization of their “doom and gloom” scenarios. They take delight and eagerly anticipate disasters. But why? Wouldn’t a “normal” person who predicts disasters hope that they are wrong?
Try changing a few words and see how the sentence looks. For example: “The primary factor is that most of the political models are very enthusiastic about nuclear holocaust developing over the next few days. ” or “The primary factor is that most of the social models are very enthusiastic about a mass murder over the next few days. “
Sorry, I meant 2005, not 2007 (the Katrina/Rita/Wilma year).
Still got Sea Ice on my brain — but there is a connection: Huge Smoke clouds from Russian Peat fires are slowing Arctic winds & cutting “Ice Export”.
As we say in the climate debate:
The three most important things are, results, results, results.
Today’s global water vapor loop shows the dome in the South Atlantic still in place, albeit moving a bit west with some moisture entrenching from the North East.
The dome in the North Atlantic is still ill defined on its southern portion but it does show enough spin to possibly affect a giant thunderstorm now coming off the coast of Africa – that one is not a “spinner” yet, but it does show some clockwise outflows. Although not much of it is there, dry air off the South coast of Western Sahara could again win that battle – we will know in 12-hours.
Another big storm behind it at the same latitude has now started to dissipate and has taken more of a “wave” look.
The track of these storms has now moved north of 10D N. This could indeed be the start of the Cape Verde Season.
Moisture from the Indian Ocean is still entrenching into the East coast of Africa, albeit less than yesterday.
All of this can be seen here – animate the last ten frames or so at the largest scale for best detail:
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=20100818.0900.multisat.wv.stitched.Global.x.jpg&MOSAIC_SCALE=15
In the pure fiction department, here’s a 300 hour forecast showing a longlived hurricane going extratropical as it heads for me in New England.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_ten_300m.gif
I haven’t checked it out, but apparently “Yes, that’s a hurricane… develops in the eastern Atlantic over the next couple of days. All models have it developing… but where it tracks (assuming they’re right on development) is anyone’s guess at this point.”
Again, this is from the pure fiction department. It’s as likely that if we do get a hurricane then it will be from a different storm. The rest of the map is fiction too!
Out of curiosity, what does Piers say about the next couple of weeks? I don’t know much about this, but what is going to change to create all this activity?
SSTs continue to plummet in that region
http://weather.unisys.com/surface/sst_anom.html
The problem with the Cape Verde season is that the engine is limited. In the next 104 days, there will be about one wave every three days. Give or take. This is history speaking. The chance of any particular wave developing into a named storm is less that 1 in 5. Using this as a guide line, we will see about 5 or 6 CV storms in the time remaining.
Forgot to mention in my last post that both the GFS and NOGAPS models have that area turning into a storm by 18Z and then into a major hurricane:
http://moe.met.fsu.edu/cgi-bin/gfstc2.cgi?time=2010081806&field=Sea+Level+Pressure&hour=Animation
http://moe.met.fsu.edu/cgi-bin/ngptc2.cgi?time=2010081800&field=Sea+Level+Pressure&hour=Animation
Bets anyone?
There are two categories of models; those that have been properly validated and those that have not. The output of validated models is almost as good as hard data. The output of non-validated models has very limited utility. The best use is in the development of new experiments. However, as predictive tools they are reasonably useless.
One wonders whether, after the next two weeks, the models used by Klotzbach and Gray have not accurately predicted what happened, that these two gentlemen will admit that their models have not been validated, and are, therefore, just about the same as guessing.
So, like a desperate gambler on a losing streak, they just doubled-down for the next forecast?
This should be interesting.
After one big hurricane tracks through the region, SSTs will be close to normal along that path. Making it even more difficult for more to form.
@geo From the Gamblers song:
“I can see you are out of aces.”
“Don’t count your hurricanes before their hatched!”
Grandma knew better….
“If the predictions don’t fit, why don’t they quit?”
Uuuhhhmmmm – No other funding sources?
Clearly, there are not nearly enough phytoplankton producing dimethylsulfoniopropionate. I guess the little buggers better hop to it, then!
http://wattsupwiththat.com/2010/08/15/plankton-cause-hurricanes-urgent-action-required/
Oh, good! A farce!
I am predicting hurricane activity at 70% of normal.
This is based on my inverse Klotzbach and Gray model (c). Here is my secret formula:
predicted activity = 100 – (Klotzbach_Gray_prediction – 100).
It has been working great the last 3 years! Everyone knows this is hard problem, and it will take time for results to improve. As long as nobody is grandstanding on the efficacy of the model results, then this is a useful academic exercise and I applaud them for being very open with negative results and discussions of what went wrong.
This is what science really is. Compare this behavior with Henson’s climate predictions, he is so inwardly focused that bad results are correct, it gets in the way of progress.
Steven,
Check out the SST loop…
http://weather.unisys.com/archive/sst/sst_anom_loop.gif
I wonder where in the world K&G get the data to feed into that model to get any sort of increase in their “ACE value”… The Cape Verde is cooling off faster than my coffee.
Charles Wilson says:
August 18, 2010 at 5:19 am
I have noted that. The prognosticators seem to want to duplicate the 2005 season every year. I have yet to see a prediction of “normal to low” hurricanes since 2005 caught them by surprise.
It seems to me that a key factor that is being ignored by hurricane forecasters is the solar cycle phase of the season being forecasted. The year after a solar minimum has significantly less hurricanes [average of only 3.6 hurricanes] the last one, 2009 had 3 hurricanes; the second year after a solar minimum [like 2010] is always slightly higher with an average of only 5.7 hurricanes. The 8-14 hurricanes being projected by many of the forecasters are very unlikely to materialize as the solar support is just not there yet regardless of what may happen the next two weeks. The global temperatures are up because of the El Nino not due to the solar activity. After the July 2008 solar minimum, the SIDC International Sunspot number is only 23, much slower in ramp up than cycle #23 and others. Hence the 2010 forecasts are going to be high again in my opinion as the solar support is just not there for such high hurricane season forecast.