The first early forecast for the 2015 hurricane season has been released by the Colorado State University Tropical Meteorology Project, predicting another quiet year:
We anticipate that the 2015 Atlantic basin hurricane season will be one of the least active seasons since the middle of the 20th century.
It appears quite likely that an El Niño of at least moderate strength will develop this summer and fall.
The tropical and subtropical Atlantic are also quite cool at present.
We anticipate a below-average probability for major hurricanes making landfall along the United States coastline and in the Caribbean.
– Drs Philip J. Klotzbach and William M. Gray, Colorado State University, April 9, 2015
|Atlantic Hurricane Season||April 2015 forecast||Average|
|Named storms (>35mph winds)|| 7||12|
|Hurricanes (>72mph winds)||3||6.5|
|Major hurricanes (>111mph winds)||1||2|
|US landfall likelihood||28%||52%|
|Gulf Coast landfall probability||15%||30%|
|Major Hurricane in Caribbean probability||22%||42%|
|Manatee County hurricane landfall probability *||0.3%||0.7%|
|Manatee County tropical storm probability*||8.1%||17.1%|
|Manatee County >75mph wind gusts probability*||2.3%||5.0%|
Early season forecasts are based on historical statistics and computer models that predict outcomes using climatological conditions present in January to March. The CSU model has been accurate in predicting above or below average seasons 23 out of 33 times, or 70%.
Measurements used include sea surface temperature, sea level pressure, and zonal wind strengths. Eastern tropical Pacific conditions in August to October, such as weak trades, low SST and SLP, are associated with La Nina formation, which is conducive to high activity in the tropical Atlantic. High SST, SLP and strong trades prevent warm air propagating from Western Pacific to the tropical Atlantic area and is referred to as El Nino, which correlates to a quieter Caribbean summer.
Similar conditions to 2015 in prior years since 1950 characterized by at least moderate El Niño formation and cool SST in the eastern Atlantic were used to create a forecast that is for the upcoming hurricane season to be well-below average activity.
The questions remain of the strength and duration of El Nino conditions and the eastern Atlantic low Sea Surface Temperatures anomaly.
Updates to the CSU forecast with be released June 1, July 1, and August 3.