Each month, the European Center for Medium Range Weather Forecasting (ECMWF) runs a climate model to predict temperature and rainfall trends throughout the world. This model also is used to predict sea surface temperature, and this helps meteorologists predict the upcoming hurricane season.

The May update to the ECMWF climate model was released to the public today. It shows a more favorable Atlantic for the peak season period of August/September/October, with near-normal rainfall in the both the Atlantic Main Development Region (MDR) and Caribbean Sea. This is different from previous runs, as the model previously predicted an unusually dry tropical Atlantic.  This trend has been consistent with the CFSv2, CanSIPS and NMME models, which all previously predicted below-average precipitation in the Atlantic MDR and Caribbean Sea but have recently transitioned to predicting near or slightly above average precipitation in this area.

Interestingly, the model continues to show a moderate to strong central Pacific “Modoki” El Niño, although somewhat weaker than shown on previous runs. It shows above-average temperatures in the tropical Atlantic, which is usually a positive factor for Atlantic tropical cylones.  The “Modoki” El Niño is a rare type of El Niño with warmer anomalies in the central Pacific and near-average to even below-average sea surface temperatures in the far eastern Pacific. The above ECMWF map shows the warmest anomalies centered west of 120 degrees West – a classic signature of a “Modoki” El Niño. The “Modoki” El Niño does not typically suppress the Atlantic for development as much as the traditional Eastern Pacific Niño because the Atlantic vertical wind shear is usually not as high with this setup. “Modoki” El Niños have resulted in particularly active or destructive seasons – the most notable example of this setup was 2004, which was a very active year for the United States with several hurricane landfalls. We will have to keep watching the evolution of model trends as we get closer to the season, but it looks more likely every day that we will have a more active Atlantic hurricane season than the experts believed several weeks ago.