Gulf of Mexico disturbance 95L worth watching

A cold front that pushed off the Southeastern U.S. and Gulf Coast has stalled out over the waters immediately offshore. An area of low pressure, Invest 95L, has developed in the Gulf of Mexico, about 100 miles southeast of the Deepwater Horizon oil disaster. Satellite loops show that this low does have a broad surface circulation, but heavy thunderstorm activity is being limited by 15 - 20 knots of wind shear. Water Vapor satellite loops show that 95L is embedded in a large region of dry air associated with an upper-level cold-cored low pressure system, and this dry air will hinder 95L's development. The cold, dry air associated with this upper-level low is giving 95L a subtropical appearance, with the main heavy thunderstorm activity (to the south) located well away from the center of circulation. NHC is giving 95L a 20% chance of becoming a tropical or subtropical depression by 2pm Monday. Wind shear is forecast to be in the 20 - 30 knot range Sunday through Monday, so any development of 95L should be slow. The disturbance is moving west at about 10 - 15 mph, and a general westward motion towards Texas should continue through Monday. None of the reliable computer models develop 95L into a depression. The Hurricane Hunters are on call to investigate 95L on Sunday, if necessary.

Elsewhere in the tropics, we should keep an eye on the region to the east of South Carolina for possible development, as well as the western Caribbean. None of the reliable models is showing a tropical storm developing in the Atlantic over the coming week, though.


Figure 1. Afternoon satellite image of Invest 95L.

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I am on vacation for the coming week, and Dr. Rob Carver will be handling most or all of the blogging duties July 5 - July 12. One of us will be posting on July 4 if there is a major development to report.

Jeff Masters