WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

No change to Ingrid; possible Gulf of Mexico storm this week

By: Dr. Jeff Masters, 2:04 PM GMT on September 16, 2007

Tropical Depression Ingrid has shown little change over the past day. The depression is slowly tracking west-northwest in the teeth of strong upper-level westerly winds, which are creating about 25 knots of wind shear over the storm. Satellite loops of Ingrid show that the storm has managed to keep a repectable amount of heavy thunderstorm activity near its center, but these thunderstorms are disorganized. This morning's QuikSCAT pass showed a well-formed circulation, but top winds of only 25 mph.

The wind shear is expected to remain around 20-30 knots Sunday and Monday, then decline to 10 knots on Tuesday and Wednesday. It is questionable whether Ingrid can survive the high sustained levels of shear expected for the next two days. It is unclear whether Ingrid (or its remains) will recurve out to sea or be forced westward towards the U.S. in the 6-10 day time frame, but residents of Bermuda and the U.S. East Coast should continue to watch this system--it could reform if it is destroyed by wind shear.

Gulf of Mexico storm possible this week
The four reliable computer models for forecasting genesis of tropical cyclones have been very busy the past few runs cooking up some nasty storms in the Western Caribbean and Gulf of Mexico for the coming week. Neither the timing nor the location of these hypothetical storms has been consistent. However, the models are insistent enough that something might happen, that I believe there is about a 40% chance we'll see a tropical storm in the Gulf of Mexico by week's end. A few possibilities, from this morning's model runs:

NOGAPS: A tropical storm forms in the Western Caribbean Tuesday, and moves north, hitting South Florida Friday.

UKMET, ECMWF, and GFS: A tropical storm forms in the central Gulf of Mexico Thursday and moves west, hitting Texas on Saturday.

The seed for formation of a tropical storm in the Western Caribbean would be one of the tropical waves from Africa that are parading across the Atlantic. A Gulf of Mexico storm could get spawned from a tropical wave, or from an old frontal zone stretching from the Carolinas southwards along the U.S. East Coast then across northern Florida.

Tropical wave in the mid-Atlantic
A tropical wave near 9N, 39W, midway between the Lesser Antilles Islands and the coast of Africa, is moving west at 10-15 mph. This wave has shown an increase in heavy thunderstorm activity over the past day, and some slow development is possible over the next 2-3 days. Wind shear has increased some over the wave, to 10-20 knots, and is expected to remain below 20 knots over the next 2-3 days.

I'll have an update Monday morning by 10am EDT.
Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.