Dear Friends
Lots of reports were published on the "overestimation" of the 2006 hurricane season in the North Atlantic. Just one example:
Researchers: Late El Nino, Dry Atlantic Confounded '06 Forecasts
FORT COLLINS, CO (AP) -- A late El Nino and increased dryness in the Atlantic are credited with a slightly below-average hurricane season this year.
That contradicts predictions from Colorado State University hurricane forecasters, who predicted a well-above-average season in their forecasts last December, in April and in early June.
But lead author Philip Klotzbach says a variety of factors interact with each other to cause year-to-year and month-to-month hurricane variability.
He also says it's impossible to understand how all the processes interact with each other to 100 percent certainty.
The 2006 hurricane season had nine named storms, five hurricanes and two major hurricanes -- but no Category Four or Five hurricanes.
Well, as early as April - two months before the second Colorado University and NOAA's forecast - several coupled models were already indicating an El Niño event developing in the middle of the year. Why the forecasts were so bullish on an active season if an El Niño should develop during the season ? Well, the season had a busy start, but then it turned to be very calm right when El Niño developed and strenghtened. Well, the interesting thing I am seeing is the scenario to 2007. I read some report on the media that continuity of El Niño in the first half of 2007 could bring another relatively calm season, according to experts. Probably this is based on NOAA's CFS model indication. But others models are starting to show neutrality and even the possibility of a cold event in the Pacific rigght during the season of 2007.
The australian POAMA model, for example, is indicating near neutral conditions in the summer of 2007 (July). But some individual members of the latest 30 runs of the model indicated a trend to a cool Pacific in the Niño 3 region.
http://www.bom.gov.au/climate/coupled_model/poama.shtml
NASA's climate model points to a rapid reversal toward a cool Pacific aorund July 2007.
http://nsipp.gsfc.nasa.gov/exptlpreds/l ... e=forecast
The same is shown at the Cliper model:
http://www.cpc.ncep.noaa.gov/products/a ... figf12.gif
But the CFS forecast from NOAA is not showing any reversal so far in the Pacific. The trend, according to the CFS coupled model, is a warm Pacific persisting during the hurricane season of 2007:
http://www.cpc.ncep.noaa.gov/products/a ... SSTSea.gif
As Philip Klotzbach told the Associated Press, lots os factors interact with each other to determine hurricane variability. Well, this a matter for discussion, we believe that the second half of the 2007 season may get much more active If this phase reversal trend in the Pacific gets confirmed during the first half of 2007. If it takes place around July or August we still believe activity would be enhanced, but any change after that should bring minor or no influence in the hurricane season.
Our chief-meteorologist just posted his forecast in his weather blog** at our homepage here in Brazil (content in Portuguese) and the forecast is 14 named storms, 8 hurricanes, four major.
Best Wishes
Alexandre
MetSul Meteorologia Weather Center
Brazil
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**
http://www.metsul.com/blog/?cod_blog=1