Colorado State University forecasters predicted on Apr 6 that the 6-month hurricane season beginning Jun 1 will be above average. Accuweather.com mainly concurs. The researchers predict 16 named storms in the Atlantic. Nine of those storms are expected to turn into hurricanes, five of them major. The forecasts note three "higher concern areas" -- coastal Texas and Louisiana, the Florida Peninsula, and the Carolinas. An average season sees 11 named storms, including six hurricanes.
The forecasters based their predictions on the combination of warm surface temperatures in the tropical Atlantic and neutral surface temperatures in the Pacific.
In Apr 2010, the Colorado State team saw a 69 per cent chance of a big one making landfall along the US coast, but none did. A Discovery Channel report on the season points out that it is unwise to take the early forecasts to the bank. Many of the important features of atmospheric and ocean circulation that encourage or dampen hurricane formation and steer storms along one path or another are just not there yet, the netword explained. Among the great unknowns is the El Niño-La Niña cycle in the equatorial Pacific Ocean. Warm El Niño conditions create powerful high-level winds over the Atlantic Ocean that rip the tops off many budding tropical storms. La Niña conditions have the opposite effect, encouraging tropical storm formation. On this side of the Spring Barrier, whether the current La Niña conditions prevail into the new hurricane season this summer is pretty much anybody's guess.
The National Ocean and Atmospheric Administration's Climate Prediction Center waits until the middle of May -- May 19 this year -- to issue its first hurricane season outlook. (WRITTEN Apr 2011)
EXTENDED RANGE FORECAST OF ATLANTIC SEASONAL HURRICANE ACTIVITY AND LANDFALL STRIKE PROBABILITY FOR 2011 (Colorado State University 6 Apr 2011)
2011 Atlantic Hurricane Season will be Active, Have more US Landfalls (Accuweather 30 Mar 2011)
Early Hurricane Forecasts: What Are They Worth? (Discovery Channel 7 Apr 2011)