April 9, 2008 -- Information obtained through March 2008 indicates that the 2008 Atlantic hurricane season will be much more active than the average 1950-2000 season.

We estimate that 2008 will have about 8 hurricanes (average is 5.9), 15 named storms (average is 9.6), 80 named storm days (average is 49.1), 40 hurricane days (average is 24.5), 4 intense (Category 3-4-5) hurricanes (average is 2.3) and 9 intense hurricane days (average is 5.0). The probability of U.S. major hurricane landfall is estimated to be about 135 percent of the long-period average. We expect Atlantic basin Net Tropical Cyclone (NTC) activity in 2008 to be approximately 160 percent of the long-term average. We have increased our seasonal forecast from early December.

This forecast is based on a new extended-range early April statistical prediction scheme that utilizes 58 years of past data. Analog predictors are also 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 La Niña conditions to continue to weaken by the start of the 2008 Atlantic basin hurricane season.

This forecast also contains an analysis of all of our extended-range forecasts that have been issued for the last 13 years (1995-2007). These real-time operational early April forecasts have not shown forecast skill over climatology during this 13-year period.

This has occurred despite the fact that the skill over the hindcast period (varying from 40- 55 years) showed appreciable skill (approximately 40-50% of the variance explained).

This last 13-year failure of our 1 April scheme has led us to perform new research which has led to the development of this new, more skillful, 1 April hindcast scheme.

The current early April forecast consists of a new set of two predictors along with an adjustment based on our early December forecast. This new forecast approach has shown appreciable hindcast skill (r 2 = 0.64) over the last 58 years (1950-2007). It is surprising that the global atmosphere-ocean system has such a strong extended-range predictive signal. This scheme also shows appreciable hindcast skill over the more recent 13-year period from 1995-2007 (r2 = 0.57) for which our previous early April schemes have not been able to show real-time forecast skill over climatology.

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