ENSO Discussion:  The Climate Prediction Center has issued an El Nino Watch in their latest ENSO Diagnostic Discussion.  The latest daily SST analysis for 7 June indicates that conditions in the tropical Pacific have continued to warm and the values for NINO 3.0 and 3.4 for the week centered on June 3 was +0.4 and +0.3 respectively indicating conditions overall on the warm side of neutral . The outlook is for a steady warming of tropical Pacific SST's (map of Nino areas) through summer with moderate El Nino conditions possible by the beginning of the dry season this Fall.  At this long range there is of course much uncertainty in the SST forecasts which can have great impact the Florida dry season.

The latest ensemble runs of the CPC CFS model for Nino 3.4 and Nino 3.0 show rapid warming with El Nino conditions developing by early summer and perhaps reaching moderate to borderline strong conditions during the upcoming dry season. The latest seasonal run of the CFS indicates the possibility of a moderate to strong El Nino during the upcoming dry season. Most SST models agree with the general warming trend this summer, but the model spread is high regarding the strength of El Nino. Taken at face value the CFS ensemble mean would result in a very strong response for Florida with greatly increased storminess and rainfall for the upcoming dry season on par with 2002-03 and 2006-07.. Due to the uncertainty -this long range outlook for the 2009-10 dry season is based on the expectation of SST's in the range of +1 to +1.5 during the dry season which results in an above normal response to El Nino. We will watch the progression of the El Nino during the summer and hold out the possibility of raising the forecast to well above normal Florida response in storminess and rainfall as we get closer to the beginning of the dry season.

Our research over the years has clearly shown that when ENSO is neutral or weak other teleconnections (NAO, AO, PNA, and MJO) can play a major role in Florida Dry Season weather. They can act to enhance or suppress the impact of an ENSO, or cause extreme variability within the dry season on their own. Refer to our research report for background.

This discussion will be updated by July 30th.

For a more in depth discussion on ENSO and it's effects on Florida see our "EL NIÑO-Southern Oscillation And Florida Educational Material." For a formal definition of El Niño and La Niña see CPC's FAQ on "What is El Niño and La Niña."