A very significant outbreak of arctic air is expected Thursday through next Tuesday. This outbreak will likely bring our region the coldest temperatures we’ve seen in more than 10 years. Forecast solution indicate the coldest of the arctic air will arrive sometime late Saturday or Saturday night, with very cold readings persisting into Tuesday. Wintery precipitation is looking more and more likely for late Sunday and Monday.

This Afternoon through Friday:

Colder air settled in across the region overnight as Tuesday’s cold front reached the middle Texas coast. Late morning temperatures ranged from the upper 20s and lower 30s across the Brownwood/Coleman area to around 40 degrees in the Austin area to the mid and upper 50s near the coast. Much of the area has been seeing a light mist through the morning hours. This mist is expected to transition to scattered light rain showers this afternoon. Today’s temperature is forecast to remain nearly steady.

Rain showers and even a few isolated thunderstorms are forecast to increase across the area overnight and continue through Thursday as a trough of low pressure slowly pushes east out of Mexico. Parts of the Hill Country, generally north of a Llano to Junction line, could see the rain become freezing rain or sleet late tonight into Thursday morning as temperatures fall to around 30-32 degrees. No significant sleet accumulations are forecast, but the freezing rain may cause travel concerns across bridges and overpasses. Across the rest of the region, readings are predicted to remain above freezing, keeping all of the precipitation liquid. Lows Thursday morning will be in the mid-30s across Central Texas and in the upper 40s to low 50s across the coastal plains.

Thursday’s weather will feature a good chance for rain showers and isolated thunderstorms throughout the day, with the rain tapering off in the evening.  The rain should diminish across the coastal plains shortly after midnight. Total rain amounts are forecast to range from roughly 0.5-0.75 inches across the Hill Country, to around 1 inch across Central Texas, to around 1-1.25 inches across the coastal plains. High temperatures Thursday will include the mid and upper 30s across the Hill Country, the upper 30s to low 40s across Central Texas and the mid-50s across the coastal plains. Lows Friday morning will include the upper 20s to low 30s across the Hill Country, the low and mid-30s across Central Texas and the lower 40s towards the coast.

Friday is shaping up to be mostly cloudy and cold.  High temperatures will include the upper 30s across the Hill Country, the upper 30s to low 40s across Central Texas and the upper 40s to low 50s near the coast. Lows Saturday morning are forecast to be near 25-28 degrees across the Hill Country, around 30 degrees across Central Texas and be around 38-40 degrees near the coast.

Saturday through Tuesday

Saturday will start off with a very slight chance for sleet or snow across the Hill Country and Central Texas regions as a weak wave of low pressure tracks east out of West Texas.  With limited moisture in place, no significant sleet or snow amounts are predicted. Otherwise, cloudy and cold conditions are forecast. Colder air is forecast to spread south across the area Saturday afternoon into Saturday night.

  • High temperatures Saturday will include the mid and upper 30s across the Hill Country, the lower 40s across Central Texas and mid to upper 40s near the coast.
  • Low temperatures Sunday morning will include the upper teens to 20 degrees across the Hill Country, the low and mid-20s across Central Texas and the lower 30s across the coastal plains.

On Sunday, an even colder surge of arctic air is forecast to spread south across the region, and this bitterly cold air mass is predicted to remain across the area through Tuesday. Sunday’s sky looks to remain mostly cloudy.

  • High temperatures Sunday are forecast to be near 28-30 degrees across the Hill Country, be around 30-32 degrees across Central Texas and near 38-40 degrees near the coast.
  • Lows Monday morning are forecast to be near 15-20 degrees across the Hill Country, near 20-22 degrees across Central Texas and in the upper 20s across the coastal plains.

Forecasts call for an increasing chance for snow across the Hill Country Sunday evening as another wave of low pressure tracks east out of Mexico. This system will cause a mixture of sleet and snow to develop across Central Texas and the coastal plains regions Sunday evening. Periods of snow and sleet are forecast to continue across the Hill Country, Central Texas and coastal plains regions Monday. All of the precipitation is forecast to end from west to east Monday afternoon. Much uncertainty remains around exactly how much snow will fall during this time period, but accumulations to or greater than an inch will certainly be possible. The coldest temperatures of this outbreak are predicted to occur Monday night into Tuesday morning as the sky clears. Sunny and a little milder weather is forecast for Tuesday into Wednesday.

  • High temperatures Monday are forecast to be in the upper 20s across the Hill Country, in the low 30s across Central Texas and in the middle 30s across the coastal plains.
  • Low temperatures Tuesday morning are forecast to be near 8-10 degrees across the Hill Country, be between 10 and 15 degrees across Central Texas and in the low 20s across the coastal plains.
  • High temperatures Tuesday will be in the low 40s.

Everyone should be making preparations now for an extended period of very cold weather. These preparations should include the 4 P’s: plants, pets and livestock, pipes and people.

I’ll pass along another update on Thursday.

Bob