9:30 p.m. CST, Tuesday, February 3, 2011
This is my Thursday evening update on the winter storm expected to impact Southeast Texas overnight tonight and Friday morning.
...A Winter Storm Warning is in effect for all of Southeast Texas including the Houston/Galveston area until Noon CST Friday. A Winter Storm Warning means that a a significant winter storm or hazardous winter weather is occurring, imminent, or likely, and is a threat to life and property...
...A wintry mix of snow, sleet and freezing rain will produce significant snow and/or ice accumulations across Southeast Texas tonight and during the morning hours Friday with the storm winding down early Friday afternoon. In addition, the possibility now exists for a few isolated, high based thunderstorms that could enhance accumulations of snow or ice at some locations...
...Numerous traffic accidents have been reported in South Texas due to icy highways and secondary roads and many of these are now closed...
There has been a noticeable lull in the precipitation over Southeast Texas this evening and this is probably causing a lot of people to second guess the forecast. However, it shouldn't be more than a few hours before we start seeing a mixed bag of wintry precipitation move in from the south and west as a potent upper air disturbance approaches our area from the west. Snow is starting to develop over portions of West Texas extending eastward into the Texas Hill Country and the city of San Antonio. This is the first sign that the winter storm is starting to get cranked up. This area of snow will likely expand further in the next few hours and continue tracking eastward toward Central and Southeast Texas.
Meanwhile, well to our south, widespread freezing drizzle, light freezing rain, sleet and some snow is creating havoc in South Texas with may highways and secondary roads severely iced over generally south of a line from Laredo to Victoria. Numerous traffic accidents have been reported and at least one fatality and numerous serious injuries have occurred.
As of 9:30 p.m., the following major accidents and/or road and highway closures have been reported to the National Weather Service Offices in Corpus Christi and Brownsville by the Texas Department of Transportation, the Texas Department of Public Safety and local law enforcement agencies:
1. US Highway 59 in Goliad, TX...multiple vehicle accident...bridge iced over.
2. Interstate 35 in Laredo, TX...closed from downtown to mile marker 13...iced over with numerous accidents.
3. Widespread power outages due to ice in Brownsville, Harlingen and Santa Rosa.
5. Half of Raymondville, TX without power. Ambulance services suspended due to iced over roads,
6. Major fatality rollover accident on Highway 186 between Port Mansfield and Raymondville. One fatality confirmed along with several serious injuries and multiple persons ejected from the vehicle.
7. At least 17 motor vehicle accidents in Donna and Weslaco.
8. At least 5 motor vehicle accidents in Zapata County with bridges iced over.
9. Expressway 77 in Willacy County and Raymondville is iced over and closed. At least 20 accidents have been reported this evening.
10. Bridges beginning to ice over in Port Lavaca and Victoria.
We may get some intermittent light mixed wintry precipitation here in Southeast Texas between now and midnight but the main event will occur after midnight in the pre-dawn hours Friday morning.
My expected precipitation types, snow and ice accumulations are as follows:
Galveston Island, Texas City, League City, Anahuac, High Island, Freeport, Angleton:
Precipitation types: Wintry mix of sleet and freezing rain with some snow.
Snow accumulations: average of 1/2 to 1 inch...with a few isolated 2 inch totals.
Ice accumulations: average of 1/10 of an inch with a few 1/4 inch totals.
Greatest potential of ice accumulation:
Gulf Freeway (IH-45) - Galveston Causeway;
State Highway 146 - Dickinson Bayou Bridge, Kemah/Seabrook Bridge.
Houston, Katy, Sugar Land, Humble, Alvin, Wharton, Victoria, Columbus:
Precipitation types: Primarily snow and sleet with some freezing rain.
Snow accumulations: average of 1 to 3 inches...with a few isolated 4 inch totals.
Ice accumulations: generally less than 1/10 of an inch.
Greatest potential of ice accumulation:
State Highway 146 - Kemah/Seabrook Bridge and Fred Hartman Bridge;
Beltway 8 - Ship Channel (Jones) Toll Bridge;
Loop 610 - Ship Channel Bridge at the Port of Houston.
Columbus, Navasota, The Woodlands, Conroe, Huntsville, Cleveland, Livingston, Coldspring:
Precipitation types: Primarily snow with some sleet.
Snow accumulations: average of 2 to 4 inches...with a few isolated 5 to 6 inch totals.
Ice accumulations: less than 1/10 of an inch.
Note: The above amounts assume precipitation falling from a stratiform cloud layer. Any embedded elevated convective development (thunderstorms) will have the potential to produce locally enhanced ice and snow accumulations.
Driving conditions will quickly deteriorate during the pre-dawn hours once the main precipitation event materializes. Surface temperatures are currently near or just above freezing in the Houston/Galveston area. However, once freezing or frozen precipitation starts falling, evaporative cooling will quickly drop the air temperature to at or below freezing resulting in rapid ice and/or snow accumulation particularly on elevated surfaces such as bridges and overpasses. Approach these areas with an abundance of extreme caution and assume they are iced over even if you can't see the ice.
If you don't have to be out on the road for a very compelling reason, please stay home. If you must drive, remember to take a survival kit that includes a cell phone, blankets, drinking water and flashlights. If you're involved in an accident, remember that police, fire and EMS will probably be responding to hundreds of others at the same time so you may be waiting awhile for assistance. Be patient and move your vehicle off the roadway if you can.
I will send out another update early Friday morning.