Big changes in the weather pattern are forecast to take place across Texas next week when a large trough of low pressure drops south across the Rockies and stalls over the Desert Southwest.  This system has the potential to bring our region our region the best chance for rain it has seen in over a month.  At the same time, a batch of cold, Canadian air is forecast to spread into Texas out of Canada.  Some of the coldest air so far this season is expected to sink south into the state.  This is the big picture.  Unfortunately, the exact details of this pattern change are still fairly uncertain.  Forecast solutions are struggling with the timing of the big cold front and the determination of just how far south the cold front will travel into Texas.  The models are also struggling with just how long the trough will remain over the Southwestern U.S.—a key factor as to how long the wet pattern will last.

Blending together several of Wednesday’s forecast model solutions, the leading edge of the colder air is forecast to reach the northern Hill Country Monday morning, with the front continuing south and pushing off the middle Texas coast Monday evening.  A large dome of Canadian high pressure sinking south behind the cold front will bring additional cool air for the remainder of the week.

The trough of low pressure sinking into the Desert Southwest is predicted to cause the development of overrunning clouds and light rain beginning Monday afternoon, with periods of rain continuing Tuesday through Thursday.  Rainfall forecasts call for total rain to average somewhere between a quarter and a half inch.  But depending on how this situation evolves, I wouldn’t be surprised to see some isolated heavier totals as well.

In regards to how cold it might get, here is the latest blended model forecast:

  • High temperatures Monday will range from the 60s across the Hill Country to the 70s across Central Texas to the 80s near the coast.
  • Low temperatures Tuesday morning will range from mid-40s Hill Country to the mid and upper 50s near the coast.
  • High temperatures Tuesday will generally be in the 50s, with low 60s expected towards the coast.
  • Low temperatures Wednesday morning will range from the upper 30s to low 40s across the Hill Country to the low and mid-50s towards the coast.
  • High temperatures Wednesday will again be mostly in the 50s, with mid-60s towards the coast.
  • Low temperatures Thursday morning will generally be in the 50s.
  • High temperatures Thursday will generally be in the 60s to around 70 degrees.

The cloudy and damp pattern is forecast to diminish next Friday as the Southwestern trough lifts off to the northeast.  However, cool temperatures look to continue into the following weekend.

Stay tuned for more updates as the changing pattern evolves. Temperatures could trend cooler or possibly warmer than currently forecast.  The rain may trend heavier as well.