A weekly review of the North Atlantic SSTA pattern as tropical cyclone season approaches is underway. Currently, the North Atlantic basin averages +0.55C which is somewhat warmer than normal. Most of the anomalous warmth is in the Gulf of Mexico, the subtropics and middle latitudes. The tropics are generally near normal except for sudden and recent warming of the far eastern tropical North Atlantic.

During northern hemisphere spring La Nina events have a tendency to weaken. The weakening is caused by eastward transition of the Madden Julian oscillation, an area of heavy tropical convection from very warm waters in the West Pacific tropics eastward and erasing the La Nina-biased cool waters of the tropical East Pacific. A MAJOR effort on the part of the MJO takes place the next 2 weeks.

We’ve seen a plethora of category-5 major tropical cyclones in recent years including Surigae to the east of the Philippines yesterday. In each case, the tropical cyclone intensified rapidly due to passage over warm water plumes.

Severe flooding continues to occur across rain-soaked Louisiana. River flooding will expand across most of Louisiana and southern Mississippi today. Another day of excessive rainfall and severe weather already underway will intensify drifting eastward across Louisiana into southern Mississippi and coastal Alabama today.