Updated 845am CT – Wednesday / 23 April 2014
…. Slim Thunderstorm Chances Over Next 18 Hours and Again over the Weekend ….
…. A Cold Front into Texas Again Late Sunday into Monday ….
On this Wednesday morning…. a weakening stationary front extends westward from the Mississippi and Louisiana coasts into south Texas near Del Rio. High pressure /1020mb/.. north of the front.. is situated over the Great Lakes. As a result of this surface weather pattern, our local surface winds are south southeasterly.
In the upper levels of the atmosphere… a trough, or line, of upper air low pressure is over the northeastern USA while another stronger upper air trough is over the western third of the country. As a result of this upper air wind pattern, the upper level winds over south central Texas and the Austin metro area about 18,000 feet above the ground are south southwesterly 15 to 25 mph.
Now that the high pressure area.. following the weak cold front early on Tuesday.. has moved to the east of the area, we’ve seen a return to a south southeasterly surface wind across our area.
A partly cloudy sky will continue over the next few days. A weak upper air disturbance could trigger one or two thunderstorms tonight into the early morning hours tomorrow but probabilities of rain, at any given location, are very slim and will mainly be west of the Austin area.
Another upper level low pressure disturbance.. off the Pacific Ocean and across the southwestern USA and northwestern Mexico.. will approach the area by the weekend with a strong cold front approaches our area by late Sunday into early Monday. Even as cooler air moves in, at this point, rain chances again look limited and mainly late Saturday into Sunday in advance of the front.
Regarding my forecast, my local forecast confidence: My forecast confidence is high to very high for tomorrow through Friday (some questions about the isolated thunderstorms tonight into early tomorrow). My confidence falls back to medium to high confidence for Saturday through Sunday night into very early Monday as the next upper level low pressure storm system and surface cold fronts approaches the area. Forecast confidence rises back to very high in the wake of the series of cold fronts early next week.
Have a good Wednesday…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel