Long-range forecasts made last spring for the 2010 Atlantic hurricane season almost unanimously predicted lots of storms. Though they generally underforecast how many we would actually observe, they were right it would be an active season.
Our summary of these forecasts, posted in May, essentially outlined the prevailing wisdom that this year would be really, really active – much more so than recent historical averages were showing. The table above shows pre-season predictions from some well-known prognosticators, along with the 2010 numbers so far.
The 2010 statistics not only eclipsed the forecasts in each of these categories, they made history in passing them by (and the season technically has about two more weeks). In remarkable fashion, the ocean-atmosphere interplay throughout the tropics in 2010 allowed for a hyper-production of cyclones rarely matched in modern times. Only 2 seasons since 1944 recorded more named storms: 1995 (19) and 2005 (28).
Two significant reasons why this year’s numbers were so high are rooted in the oceanic conditions in both the Atlantic and Pacific Basins.
Sea surface temperatures (SSTs) in the Atlantic were warmer than average throughout the tropics, and the phase of ENSO (El Nino-Southern Oscillation) in the Pacific slipped into the La Nina category prior to the start of summer. Both factors are consistent with an increase in Atlantic hurricane frequency. Warm SSTs can provide more energy for storms to develop and maintain themselves, while the La Nina condition present in the Pacific is often associated with a seasonal reduction in destructive wind shear over the Atlantic.
The source article Hurricane season in 2010 making history - Capital Weather Gang .