Updated 915am CT – Thursday / 19 March 2015
.. Another Strong Upper Level Low Pressure Storm Systems on the Way ..
.. Second Weather System Passes Late Tomorrow into Saturday ..
.. Two to Four Inches or More of Rainfall Possible Friday through Saturday ..
On this Thursday morning…. a weak stationary front is just north of our area and extends from central Louisiana west northwestward through central and north central Texas then into west Texas and central New Mexico. As a result of this surface weather pattern, our local surface winds are south southeasterly.
In the upper levels of the atmosphere.. a strong upper level low pressure disturbance is located over southwestern Arizona and the northern part of the Baja Peninsula. As a result, our upper air winds at about 18,500 feet are west southwesterly at 35 to 45 mph.
The strong upper level disturbance.. to our distant west.. will be approaching the area by later this afternoon into tonight with abundant atmospheric moisture in place across the area. The approaching upper level storm will combine with the weakening stationary front just to our north to result in renewed rain and thunderstorm chances beginning by daybreak tomorrow.
Once the rain begins it will continue across the area through tomorrow night through Saturday before slowly decreasing Saturday night. Given some atmospheric instability, there will be some embedded thunderstorms as the system passes. Forecast precipitation amounts.. in both the manual NWS guidance as well as the atmospheric model output.. have increased with upwards of 2 to 4 inches of rain possible tomorrow through Saturday and Saturday night. NWS Austin-San Antonio meteorologists are suggesting that some isolated spots may see as much as 6 to 8 inches of rain. They have already issued a Flash Flood Watch (it doesn’t go into effect until 4pm tomorrow). Local interests throughout south central Texas.. especially with numerous events going on around the area.. are strongly encouraged to monitor the latest information regarding this potential heavy rain/flood event for tomorrow into the upcoming weekend.
As the upper level low pressure area moves more overhead tomorrow, the front to the north will turn back into a cold front and surge southeastward across the area resulting in cooler temperatures beginning tomorrow into the weekend.
After rain chances decrease Saturday night into early Sunday, clouds will break a bit Sunday into Monday.
Another relatively strong cold front will move southeastward through the area by daybreak next Wednesday.
Regarding my forecast, my local forecast confidence: My forecast confidence is medium to high through the week and into the weekend. The main questions will be the precipitation timing and amounts as well as flash flood potential.
Have a good Thursday….
Meteorologist Troy Kimmel