…Arctic cold front will barrel through Southeast Texas late this weekend ushering in much colder weather and rain changing to…or mixed with…freezing rain and sleet by early next week resulting in possible ice accumulations… 

Computer forecast models indicate that an Arctic cold front will race through the Lone Star State this coming weekend and be through Southeast Texas and off the Upper Texas Coast by late Sunday evening.  Although the exact timing is difficult to pinpoint several days out…it appears the Arctic cold front will move through the Bryan/College Station…Huntsville and Lufkin area by Noon Sunday…into the Houston Metropolitan Area by 3:00 PM and off Galveston Island by 6:00 PM.  If there is any adjustment necessary to these times, it will probably be that the cold front will arrive several hours later than what is indicated here. 

The usual signs that an Arctic cold front has passed will be quite evident with an abrupt wind shift to the North or Northwest followed by a rapid drop in temperatures over a several hour period.  Temperatures ahead of the cold front will climb into the 60’s and 70’s during the day Sunday.  However, these readings will rapidly fall into the 40’s within a 3-hour period following frontal passage.  Scattered showers and thunderstorms will be possible during the morning hours Sunday…with increasing chances as the cold front gets closer Sunday afternoon with showers and thunderstorms likely by Sunday evening.  There is the possibility of a few severe thunderstorms containing large hail and/or damaging winds Sunday afternoon and evening as the cold and warm air masses collide over the area but this threat will begin to decrease by late evening and the overnight hours. 

Low temperatures Monday morning (MLK Day) will drop into the 30’s over inland areas and 40’s along the coast.

High temperatures during the day Monday will rise very little and remain in the 30’s and 40’s areawide.  In addition, a good chance of rain throughout the day along with very windy conditions will make the day feel very raw and colder than it actually is with wind chill temperatures in the 20’s and 30’s. 

Sunday night and Monday…expect North winds of 20 to 30 mph and gusty over inland areas and 25 to 35 mph with frequent gusts of 40 to 45 mph along the coast…especially Galveston Island and Bolivar Peninsula.  Over offshore waters of the Gulf of Mexico, a few wind gusts may exceed 45 knots (52 mph) along with seas of 10 to 15 feet.

Tide levels will fall to 1 to 2 feet below normal by Monday night especially in northern Galveston Bay…Trinity Bay and areas along Clear Lake…Clear Creek…Dickinson Bayou…and the Houston Ship Channel.  This may cause some normally navigable areas by shallow draft vessels to temporarily become too shallow to navigate safely.

Small Craft Advisories will likely be issued and Gale Warnings may become necessary by Sunday afternoon. 

Monday night…Tuesday and Tuesday night…things will get even more interesting.  As temperatures fall into the low to mid 30’s Monday night and Tuesday morning…the rain will begin to change to or become mixed with freezing rain and/or sleet (ice pellets).  Freezing rain is rain that falls as liquid but then freezes into a glaze of ice on exposed objects on and near the ground…particularly power lines…trees…elevated roadways and bridges.  This will cause extremely hazardous driving conditions that may result in numerous traffic accidents and road closures.

TRAVEL MONDAY NIGHT AND TUESDAY SHOULD BE AVOIDED UNLESS ABSOLUTELY NECESSARY AS MANY ROADS AND BRIDGES WILL BECOME INCREASINGLY HAZARDOUS IN SOUTHEAST TEXAS.  

At this time, it appears that areas along and north of Interstate 10 (including Houston) will have the best chance of seeing ice accumulations.  However, depending on how low temperatures drop over the coastal counties, it is also possible that some ice will occur over these areas, as well.  If it appears that significant ice accumulations of ¼ inch or greater will occur, the National Weather Service may issue a Winter Storm Watch or Winter Storm Warning for all…or portions…of the area.  Should this materialize, there will be a threat of power failures caused by the weight of accumulating ice on power lines and trees falling into power lines.  Therefore, plan on having extra blankets on hand or a safety-approved alternate power source such as an electric generator for plugging in a portable heater.  Remember, NEVER RUN A GENERATOR INDOORS OR IN AN ENCLOSED AREA as it will give off deadly carbon monoxide fumes that are colorless and odorless.  It would also be a good idea to have a backup supply of food and water on hand in case power failures become widespread over the area delaying power being restored by utility companies.  

There will be little chance of seeing any snow in Southeast Texas as the thermal profile of the atmosphere will result in very cold air near the surface but much warmer air (above freezing) a few thousand feet above the ground. This is a classic “temperature inversion” scenario that often occurs in winter over Southeast Texas favoring freezing rain and sleet rather than snow.  Much further north, there will be a chance of accumulating snow from New Mexico eastward through the Texas Panhandle and North Texas and into Oklahoma where the layer of cold air will extend further upward into the atmosphere.  

Low temperatures Tuesday morning will range from the mid 20’s in the Bryan/College Station…Conroe/Huntsville…and Lufkin/Livingston areas…near 30º in the Houston Metropolitan area and inland portions of the coastal counties and low to mid 30’s along the immediate coast including Galveston Island.  The chance of rain…freezing rain and/or sleet will continue during the day Tuesday.  Depending on how much ice accumulates, high temperatures will remain at or below freezing (32º) over ice covered areas to the mid and upper 30s over areas with little or no ice. 

Although temperatures will not drop to extremely cold readings (as would normally occur if skies were clear), the threat of accumulating ice will pose a significant hazard to driving conditions as well as the threat of power failures.

All persons in Southeast Texas should monitor future weather forecasts and listen for watches, warnings or advisories that may become necessary early next week.  Future e-mail updates will be sent by the Jamaica Beach Weather Observatory as conditions warrant.  

Jim O’Donnel
Jamaica Beach Weather Observatory