Gulf Of Mexico SST/SSTA Regime Ahead Of A Tropical Cyclone

Discussion: The preliminary forecast track for Tropical Disturbance 99L (next storm name is “Ida”) is into the southeast Gulf of Mexico tomorrow night, across the central Gulf of Mexico during the weekend and turning north into the Louisiana coast late Sunday night/early Monday morning. The forecast track is PRELIMINARY and confidence will increase once the storm has fully developed and especially once into the Gulf. Glancing at the SST across the Gulf of Mexico reveals normally warm 29C/85F in the southeast Gulf although north of the Yucatan Peninsula is cooler than normal. In the central Gulf SST warms slightly to a near normal 85.5F. However, the west-central/east-central Gulf of Mexico are warmer than normal (86F-86.5F) and somewhat warmer than normal in the northwest Gulf (87F). Assuming limited upper shear, a tropical cyclone should have no difficulty reaching hurricane intensity across 29C/85F water. When a hurricane moves across 30C/86F water the risk of a major hurricane increases dramatically.