Monitoring A Possible Outbreak of Arctic for Late Next Week - LCRA Monitoring A Possible Outbreak of Arctic for Late Next Week - LCRA


Here’s an update on weather conditions for the rest of this week and an outlook into next week. There are strong signals we will see much colder temperatures spreading into our area just before Christmas.

This Afternoon through Friday:

A weak wave of low pressure moving across our area early this morning produced some light showers and scattered thunderstorms. Rain amounts were less than a quarter inch. All of this activity has since pushed to the east and southeast of our region. Clouds are clearing, and a mostly sunny sky is expected this afternoon. High temperatures will range from the low 60s west, the upper 60s near the coast.

The sky is forecast to be clear Wednesday night through Thursday night. This will allow temperatures to become cold on both nights. In fact, a light freeze is forecast for the Hill Country both nights. Lows Thursday and Friday mornings are predicted to be in the low 30s across the Hill Country, the mid and upper 30s across Central Texas, and the low 40s across the coastal plains. Thursday’s temperature should warm to the mid-60s.

Friday’s weather will feature a mostly sunny sky and cooler temperatures due to passage of a cold front Thursday night. Expect a high temperature in the mid-50s. Lows Saturday morning will range from the low 30s across the Hill Country, to the mid-40s near the coast.

This Weekend into Monday

Part of Central Texas and the middle Texas coast could see a few light rain showers Saturday morning when a weak wave of low pressure slides east across North Texas. The probability for rain will only be 20 percent. Otherwise, expect a partly cloudy sky Saturday and Saturday night. Saturday’s temperature is forecast to reach the low 50s. Lows Sunday morning will range from the low 30s across the Hill Country, to the low 40s near the coast.

Clouds are predicted to increase across the region Sunday ahead of a trough of low pressure ejecting east out of the southern Rockies. There will be a 20 percent chance for light rain showers by late Sunday afternoon. This will be followed by a 40-50 percent chance for additional rain showers Sunday night through Monday evening. Rain amounts over the period are forecast to be heaviest across the coastal plains region where totals of 1.5-2 inches are forecast. Across Central Texas, totals of 0.5-1.5 inches are forecast. Hill Country totals are forecast to average around a quarter inch, or less.

High temperatures Sunday are forecast to be in the low 50s. Lows Monday morning will generally be in the low and mid-40s. High temperatures Monday are forecast to be in the low and mid-50s.

Next Tuesday and Wednesday

Another cold front is forecast to move across the area Monday night that will reinforce the cool temperatures already in place. Tuesday and Wednesday’s weather is forecast to be partly cloudy and cool. High temperatures are predicted to be in the low 50s Tuesday, and in the low 60s Wednesday. Lows Wednesday and Thursday mornings are expected to be in the 40s.

Arctic Outbreak/Trending Much Colder Late Next Week

There has been quite a bit of talk over the past couple of days about a potential arctic outbreak taking place late next week. Here is the latest information on the potential for arctic air as of midday Wednesday. Forecasts call for a an unusually strong ridge of high pressure to build north across Alaska late this week and this weekend that will help dislodge a mass of extremely cold Siberian air (currently -55 to -75F) over the Arctic Ocean and down across western Canada. The arctic air is forecast to reach Montana and the Dakotas by next Tuesday, then drop south across the Plains states Wednesday into Thursday.

Being we are just over a week away from this arctic outbreak, the forecast models are struggling on how to handle the shallow, but extremely cold air mass. One model in particular has been showing the air pressing directly south into Texas late next week, bringing our region near historic cold temperatures. Meanwhile, other model solutions are showing the coldest of the air moving more to the southeast than to the south, leaving Central and South Texas quite cold, but sparing us from the historic cold.

Based on the latest set of model runs, I do expect the arctic air to make its way south through Texas next Thursday into Thursday night, with the very cold air sticking around through Christmas. But I am currently leaning more toward “less extreme ” solution, with the bulk of the extremely cold air staying off to our north and northeast. Keep in mind, the historically cold solution is still be a possibility, but most of the data I am seeing is pointing toward less extreme temperatures for the Hill Country and Central Texas.

In any event, everyone should be planning for very cold temperatures beginning next Thursday that will continue through the Monday after Christmas. Expect a hard freeze—even across the coastal region.

Roughly speaking, I expect low temperatures through this period to be in the teens across the Hill Country, in the low to mid-20s across Central Texas, and mid to upper 20s across the coastal region. Daily high temperatures look to be in the low 40s. Somewhat milder temperatures look to return in the week after Christmas.

In regards to precipitation through this cold period, forecasts are currently calling for the pattern to remain on the dry side. As of now, a white Christmas is not predicted.

The forecast for the magnitude of cold weather late next week is still quite fluid. I urge everyone to closely monitor forecasts over the next several days and to begin thinking about cold weather protective actions for late next week.

Bob