Loop Current Could Mean Trouble for Hurricane Season

Dr. Jeff Masters in Yale Climate Connections:

Potential trouble is brewing in the Gulf of Mexico for the coming Atlantic hurricane season: waters with a high amount of heat energy. Sea surface temperatures (SSTs) in mid-May were 27-28 degrees Celsius (81-82° F) across most of the Gulf, 0.5 to 1.5 degrees Celsius (0.9-2.7°F) above the 1981-2010 average. That’s a lot of heat energy for potential hurricanes to feast on. 

What’s more, the Gulf waters have the potential to be at near record-warm levels during the peak part of hurricane season, if the southeastern U.S. gets a sustained heat wave that brings light winds and hot conditions to the Gulf for an extended period. (The first half of May was record-warm for Galveston, Texas, which contributed to the unusually warm ocean temperatures off the Texas coast.)

But sea surface temperatures don’t tell the whole story. When a hurricane traverses a shallow area of warm ocean waters, its powerful winds will churn up cold waters from the depths, cooling the surface and putting the brakes on any rapid intensification the hurricane may have had. But when unusually warm ocean waters extend to great depth, 100 meters or more below the surface, the hurricane’s churning winds simply stir up more warm water, allowing dangerous rapid intensification to occur if wind shear is low. Thus, total Ocean Heat Content (OHC) is a key metric used to determine the potential for hurricane rapid intensification. And unfortunately, given the present ocean current configuration, there will be high ocean heat content in the Gulf of Mexico this hurricane season.