NOAA’s Climate Prediction Center updated its El Nino discussion today and states “El Nino conditions are present across the equatorial Pacific Ocean.” This is perhaps worth noting because Atlantic hurricane activity can be reduced during El Nino periods by tending to increase the levels of vertical wind shear over the main development region.
The above graphic (courtesy of NOAA) clearly shows that sea surface temperatures remain +0.5 to +1.5C above-average across much of the equatorial Pacific Ocean.
It is also worth noting that NOAA’s CPC adds “Current observations and dynamical model forecasts indicate El Nino conditions will continue to intensify and are expected to last through Northern Hemisphere winter 2009-10.” The models disagree on the eventual strength of El Nino, but nearly all of the dynamical models predict a moderate-to-strong episode.
NOAA seasonal forecasters as well as Klotzbach/Gray are currently forecasting a near normal Atlantic hurricane season. Many people scoffed on June 18th when the United Kingdom Met Office indicated below normal activity with only six tropical storms predicted as the most likely number to occur in the North Atlantic this season. It will be interesting to see if the numbers from Klotzbach/Gray and NOAA are decreased in their updates scheduled for next week.
Just don’t forget that it is not only about the numbers. It only takes that one hurricane over a particular location to make for a bad year. We still need to be prepared – no matter what the seasonal forecasts call for.