Mexican Bay of Campeche disturbance may become a tropical depression

A small but well-defined disturbance (96L) has moved off of Mexico's Yucatan Peninsula, into the southernmost Gulf of Mexico (the Bay of Campeche). The low is moving west-northwest at 10-15 mph. Visible satellite loops show a small but concentrated area of heavy thunderstorms associated with the low. A surface circulation is not evident in satellite loops, or in this morning's QuikSCAT pass. Wind shear is low, in the 5-10 knot range.


Figure 1. Current satellite image of the Bay of Campeche disturbance, 96L. Image credit: NOAA.

The system won't be over water long, but is sufficiently well-organized that is may be able to organize into a tropical depression or tropical storm. Landfall should occur on the Mexican coast in the southwestern Bay of Campeche, near Veracruz, tonight or Tuesday morning. However, the latest 06Z (2 am EDT) run of the HWRF model takes 96L northwestward, keeping it over water until Tuesday afternoon. This model run intensifies 96L into a 60 mph tropical storm before making landfall near Poza Rica late Tuesday afternoon. The topography of the southernmost Bay of Campeche often acts to spin up tropical systems, and I give this storm a 60% chance of becoming a tropical depression, and a 30% chance of becoming a tropical storm. NHC is currently giving 96L a medium (20-50% chance) of developing into a tropical depression. Heavy rains of 3-6 inches can be expected in a small area near where 96L comes ashore.

Elsewhere in the tropics
A small closed circulation has developed in the middle Atlantic Ocean, near 13N 30W, about 400 miles west-southwest of the Cape Verdes Islands, as seen on this morning's QuikSCAT pass. This disturbance is under about 30 knots of wind shear, which is too high for development to occur. Wind shear is expected to stay near 25-30 knots over the disturbance the next three days, which should keep it from developing. NHC is giving this disturbance a low (<20% chance) of developing.

There may be a better chance for development for a tropical wave that moved off the coast of Africa today. The GFS and UKMET models predict that this wave will spin up into a tropical depression by Thursday this week.

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Jeff Masters