The forecasting team at Colorado State University (CSU) led by Phil Klotzback and Bill Gray say in their first forecast for the 2011 hurricane season that they expect it to be an above-average Atlantic basin tropical storm season along with having an above-average probability of a major hurricane landing on the U.S. coastline and in the Caribbean. "The U.S. was extremely lucky in 2010 in that none of the 12 Atlantic basin hurricanes that formed crossed the U.S. coastline," said Philip Klotzbach, a team spokesperson. The CSU December forecast calls for 17 named storms, 9 hurricanes and 5 major hurricanes (Category 3-4-5, with sustained winds of 111mph or greater). There should be 85 named storm days, 40 hurricane days and 10 major hurricane days. The 2011 forecast begins to look very similar to the 2010 season's actual results, especially in terms of the number of days for each forecasted category of storm. The CSU hurricane forecast team predicts a 73 percent chance that at least one major hurricane hit the U.S. coastline in 2011. Importantly, the CSU team expects that the probability of a major hurricane making landfall on the entire U.S. coastline is 73% compared to the average for the last century of only 52%. The average for a storm making landfall along the U.S. East Coast including the Peninsula of Florida is estimated at 49% compared to the historical rate of 31%. The higher probability of a strong hurricane barreling through the Gulf of Mexico and hitting the Gulf Coast with attendant damage to the offshore oil and gas industry will keep energy companies focused on preparing for next year's hurricane season.

What made the 2004-2005 and 2008 seasons so destructive was not the high frequency of major hurricanes but the high percentage of hurricanes that were steered over the US coastline. The US hurricane landfall events of these years were primarily a result of the favorable upper-air steering currents present during these years. "Given the current upper ocean heat content anomalies in the tropical Pacific, we believe that El Nino conditions are unlikely. This could mean a more active hurricane season." Because we are predicting an above-average hurricane season in 2011, the probability of U.S. and Caribbean major hurricane landfall is estimated to be above the long-period average. "On average, about one in four Atlantic basin hurricanes makes U.S. landfall, and therefore, we would expect to see more land falling hurricanes in 2011".

Atlantic hurricanes go through multi-decadal cycles. Cycles in Atlantic major hurricanes have been observationally traced back to the mid-19th century. This active cycle is expected to continue for another decade or two at which time we should enter a quieter Atlantic major hurricane period like we experienced. The team will issue seasonal updates of its 2011 Atlantic basin hurricane activity forecast on April 6, June 1 and Aug. 3.

Source: Colorado State Univ., PPHB