Tropical Storm Imelda Forms, Forecast To Produce Life-threatening flash flooding in the Houston and Galveston areas.

1:45 PM AST Update: Tropical Depression Eleven has been upgraded to Tropical Storm Imelda.

At 1:00 PM Tuesday AST, the National Hurricane Center has begun to issue advisories on Tropical Depression Eleven, 90 kilometers southwest of Galveston, Texas.

The center of Tropical Depression Eleven was located near latitude 28.7 North, longitude 95.4 West. The depression is moving toward the north near 11 KM/H, and this general motion is expected to continue through early Wednesday. A north-northwestward motion is expected Wednesday night and Thursday. On the forecast track, the center of the depression will move inland over the Upper Texas coast later today, and move farther inland tonight and Wednesday.

Maximum sustained winds are near 55 KM/H with higher gusts. Some slight strengthening is possible before the center moves onshore. The estimated minimum central pressure is 1009 millibars

Forecast Cone for Tropical Depression Eleven as of 1:00 PM Tuesday 17th September 2019. Credit: National Hurricane Center
Forecast Cone for Tropical Depression Eleven as of 1:00 PM Tuesday 17th September 2019. Credit: National Hurricane Center

Watches & Warnings

Watches and Warnings for Tropical Depression Eleven as of 1:00 PM Tuesday 17th September 2019. Credit: National Hurricane Center
Watches and Warnings for Tropical Depression Eleven as of 1:00 PM Tuesday 17th September 2019. Credit: National Hurricane Center

A Tropical Storm Warning is in effect for Sargent to Port Bolivar, Texas

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next few hours.

For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office.

Hazards Affecting Land

Rainfall: The depression is expected to produce total rainfall accumulation of 5 to 10 inches with isolated maximum of 15 inches across the upper coastal region of Texas into far southwest Louisiana through Thursday. This rainfall may produce life-threatening flash floods.

Wind: Tropical storm conditions are expected somewhere within the warning area this afternoon and evening.


This tropical depression is of no threat to the Windward Islands, including Trinidad and Tobago.

Tropical Depression Eleven Discussion

 Tropical Depression Eleven approaching the Texas Coast. Credit: Weathernerds
Tropical Depression Eleven approaching the Texas Coast. Credit: Weathernerds

Satellite, radar, and surface data show that the area of low pressure near the Upper Texas coast has become better defined this morning. The associated deep convection has also become better organized, and winds from the Houston Doppler Radar support an initial intensity of 30 kt. Based on these data, advisories are being initiated on a tropical depression. The system has very little time left over water in which to strengthen, but given the recent increase in organization, the system is forecast to become a tropical storm before it moves inland. As a result, a Tropical Storm Warning has been issued for a portion of the Upper Texas coast. Regardless of the intensity of the system, the primary threat associated is flooding rainfall that is expected over portions of eastern Texas and southwestern Louisiana over the next day or two.

The initial motion estimate is 005/6 kt. The cyclone should move inland very soon, and a general northward motion around the western side of a mid-level ridge centered over the Tennessee Valley should continue through tonight. The system is forecast to turn north-northwestward on Wednesday and that general motion is forecast to continue until dissipation occurs. The NHC track forecast follows the solution of the majority of the dynamical models.

Key Messages:

  1. This system is likely to produce life-threatening flash flooding along portions of the Upper Texas Coast, including the Houston and Galveston areas.

Discussion by National Hurricane Center’s Forecaster Brown.

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