Thursday Arctic Blast Update - LCRA Thursday Arctic Blast Update - LCRA


The latest forecast solutions have not changed significantly since Wednesday. This is shaping up to be a memorable arctic outbreak that will rival some of the historic cold air outbreaks in Texas history. The coldest period is expected to occur from late Sunday through Tuesday morning. Forecasts continue to show good agreement on widespread wintery precipitation occurring Sunday night into Monday. But I want to highlight weather development for today as widespread freezing rain is now occurring across the Hill Country and parts of Central Texas.

This Afternoon and Tonight

Arctic air now covers the Hill Country and all of Central Texas. As of late morning, temperatures were below freezing generally from just north of San Antonio to La Grange, to College Station. Meanwhile, a widespread area of rain showers and isolated thunderstorms is spreading east across the Hill Country and Central Texas regions thanks to a trough of low pressure coming east out of northern Mexico. With temperatures at or below freezing, the rain has begun to freeze, creating a glaze on surfaces. As a result, the National Weather Service has posted a Winter Storm Warning for the Hill Country, along with Travis and Williamson Counties until midnight. The rain and isolated thunderstorms are forecast to persist across the entire region this afternoon and evening. The rain is forecast to taper off from west to east late evening and toward midnight. Ice accumulations up to a quarter inch are forecast for areas in the winter storm warning. A Winter Weather Advisory has been posted for Bastrop, Hays and Lee Counties, where  are glaze of ice is expected and accumulations to a tenth inch will be possible. A cold rain is predicted for the coastal plains region this afternoon through daybreak Friday. Total rain amounts through Friday morning are forecast to average between 0.5 and 1 inch across the Hill Country and between 1 and 1.25 inches for locations along and east of Interstate 35.

The temperature is forecast to remain nearly steady and below freezing across the Hill Country and most of Central Texas this afternoon through tonight and into Friday morning. Therefore, ice forming this afternoon will likely remain frozen overnight into Friday morning, causing hazard driving conditions—especially on elevated roadways and flyovers. For the middle Texas coast, this afternoon’s temperature will hover around 40 degrees, but fall to the mid-30s overnight.

Friday

Cloudy and cold weather is forecast across the region Friday as the upper trough responsible for Thursday’s rain slowly exits to the east. However, a few light showers will still be possible towards the coast.  A modest of warm up of a only a couple of degrees is expected. Parts of the Hill Country will likely remain below freezing. High temperatures are forecast to be around 30-34 degrees across the Hill Country, the mid-30s across Central Texas and the low 40s across the coastal plains.  Lows Saturday morning will include the mid and upper 20s across the Hill Country, the upper 20s to low 30s across Central Texas and the upper 30s near the coast.

SATURDAY

There will be a very slight chance for a mixture of rain, sleet and snow flurries to develop Saturday morning into Saturday afternoon when the next upstream trough of low pressure pushes east out of the Desert Southwest. Few impacts are expected as most temperatures should be just above freezing. Otherwise, expect cloudy and cold conditions Saturday and Saturday night. High temperatures are forecast to be in the mid-30s across the Hill Country, the mid and upper 30s across Central Texas and the low 40s for coastal areas. Lows Sunday morning will feature the low 20s across the Hill Country, the mid and upper 20s across Central Texas the low 30s coastal area.

SUNDAY THROUGH TUESDAY

Weather conditions will remain cloudy and quite cold Sunday.  High temperatures will range from the low and mid-30s across the Hill Country to the mid- and upper 30s across Central Texas, to the low and mid -40s near the coast.

A blast of bitterly cold arctic air is predicted to sink south across the area late Sunday into Sunday night, bringing our region some of the coldest air seen in more than 30 years!

  • Lows Monday morning are forecast to be around 8-10 degrees across the Hill Country, around 10-15 degrees across Central Texas and the low 20s across the coastal plains.
  • High temperatures Monday will include the low 20s across the Hill Country, the mid-20s across Central Texas and around 28-30 degrees towards the coast.

Forecasts solutions are now showing some consistency now in calling for a strong trough of pressure to rotate southeast across Texas late Sunday into Monday. This system is forecast to produce a widespread area of wintery precipitation across the entire region beginning late Sunday afternoon/Sunday evening, continuing through Monday afternoon. It’s still too early to have a good handle on accumulations, but forecasts suggest several inches of snow will be possible across the Hill Country and Central Texas regions and even an inch or two for the middle Texas coast.

The precipitation is forecast to end Monday afternoon, with the sky clearing for Monday night.  This will set us up for some brutally cold temperatures.

  • Lows Tuesday morning are predicted to be between 5 and 10 degrees across the Hill Country, be around 8 to 14 degrees across Central Texas and around 13-17 degrees across the coastal plains.

Mostly sunny but cold weather is predicted for Tuesday, with high temperatures in the mid and upper 30s.

Looking out further, slightly milder temperatures are forecast Wednesday through Friday.  There are some indications more snow will be possible next Wednesday.

PREPARATIONS

This is not going to be a “normal” freeze coming up and maximum preparations and precautions will be required for this outbreak.

  • Protect all and any exposed pipes, shut off and drain sprinkler systems. Open cabinet doors and closet doors to get as much heat against outside facing wall pipes as possible starting Sunday night. In some cases the best course of action may be to shut off water to a structure and drain pipes overnight when water usage is low to avoid pipes freezing and bursting.
  • Heavily cover and protect any tropical vegetation, citrus, or vulnerable plants. Given the intensity and depth of the freezing conditions this will likely be a killing freeze for much of the tropical landscape of this region.
  • Pets and livestock should have proper shelter, feed, and water. Normal water supplies will likely freeze over including stock ponds and lakes.
  • Persons should plan to limit outdoor exposure Monday and Tuesday as wind chills will be dangerously cold for our region. Prolonged exposure could result in frostbite and hypothermia.

Bob