Unexpected: Cooling of Both the Tropical East Pacific/North Atlantic
07/06/2019, 5:16 pm EDTLa Nina-like South America SSTA
07/08/2019, 4:24 am EDTTropical cyclone to emerge over northern Gulf of Mexico later this week
WARM Gulf of Mexico SSTA; System could be an over-achiever
Discussion: A tropical disturbance is forecast to form in the northeast Gulf of Mexico later Wednesday and drift southwestward and then west while intensifying to a tropical storm eventually making landfall (as a tropical storm) Saturday on the central Louisiana coastline (Fig. 1). The preliminary forecast track is based on the highly reliable ECMWF model.
Of concern is the warmer than normal Gulf of Mexico in the area where this system is forecast to develop, strengthen and track. SST of nearly 88F is noted along the potential track. This system could intensify rapidly if upper shear is light.
The NOAA/WPC rainfall forecast for late Wednesday to late Friday indicated 3-6 in. for the east-central Gulf of Mexico (Fig. 2) and another 3-6 in. for the northern Gulf of Mexico for late Friday and the weekend (Fig. 3). The forecast is very preliminary but all north/northeast Gulf of Mexico coastal interests should be on the alert for a significant tropical event late this week into next weekend.
Fig. 1: The Gulf of Mexico sea surface temperature anomalies (SSTA) and annotated actual surface temperatures plus a preliminary projection of where a tropical cyclone may emerge later this week based on the ECMWF model.
Fig. 2: NOAA/WPC day 4/5 rainfall forecast.
Fig. 3: NOAA/WPC day 6/7 rainfall forecast.