ATLANTIC BASIN SEASONAL HURRICANE FORECAST FOR 2007

PROBABILITIES FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE LANDFALL ON EACH OF THE FOLLOWING COASTAL AREAS

1)       Entire U.S. coastline - 64% (average for last century is 52%)

2)      U.S. East Coast Including Peninsula Florida - 40% (average for last century is 31%)

3)      Gulf Coast from the Florida Panhandle westward to Brownsville - 40% (average for last century is 30%)

4)      Above-average major hurricane landfall risk in the Caribbean

ABSTRACT

Information obtained through November 2006 indicates that the 2007 Atlantic hurricane season will be more active than the average 1950-2000 season.  We estimate that 2007 will have about 7 hurricanes (average is 5.9), 14 named storms (average is 9.6), 70 named storm days (average is 49.1), 35 hurricane days (average is 24.5), 3 intense (Category 3-4-5) hurricanes (average is 2.3) and 8 intense hurricane days (average is 5.0).  The probability of U.S. major hurricane landfall is estimated to be about 125 percent of the long-period average.  We expect Atlantic basin Net Tropical Cyclone (NTC) activity in 2007 to be about 140 percent of the long-term average.  This forecast is based on a recently-developed 6-11 month extended range statistical forecast procedure which utilizes 52 years of past data and began being utilized operationally in 2002.  Predictors in this scheme include five selective measures of September-November North Atlantic and Pacific sufrace pressure and 500 mb height fields and a measure of the stratospheric quasi-biennial oscillation (QBO).  A second new etended-range early December experimental statistical prediction scheme is also consulted.  Analog predictors have also been utilized.  The influences of El Niño conditions are implicit in these predictor fields, and therefore we do not utilize a specific ENSO forecast as a predictor.  We expect current El Niño conditions to dissipate by the active part of the 2007 Atlantic basin hurricane season.