Updated 845am CT – Friday / 25 April 2014
….Thunderstorm Chances over the Weekend ….
…. A Strong Cold Front Moving Across Texas Early Next Week ….
On this Friday morning…. surface high pressure /1015mb/ is centered over eastern Oklahoma and western Arkansas. A developing surface low pressure area /1000mb/.. with an associated cold front.. is over California and Nevada. A weakening stationary front extends from central Louisiana into south central Texas.. southeast of the Austin area.. to the Rio Grande south of Del Rio. 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 extends southward from the Great Lakes through the Ohio Valley region. Another strong upper air disturbance is moving ashore onto the Washington and Oregon coast with a trough.. or line.. of low pressure extending southward along the west coast of the USA. As a return 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 westerly 30 to 40 mph.
The weak front.. to our south.. will wash out by later today into tonight and result in a quick return to a south southeasterly surface wind. Other than morning low clouds.. partly cloudy skies will prevail into and through the weekend.
The strong upper level low pressure disturbance.. along the west coast.. will approach the area over the weekend with a stronger cold front approaches our area by Monday. Rain and thunderstorm chances will reappear in the forecast beginning tomorrow and continuing Saturday night through Sunday in advance of the front. Severe weather appears quite likely in areas north and northeast of our local area.. it will be a good idea to keep up with latest daily severe thunderstorm outlook through the weekend from the NWS/Storm Prediction Center at http://www.spc.noaa.gov/.
The front itself is now forecast to be slower than I first thought.. it will not move through the Austin area until later Monday into Tuesday with drier (and unseasonably warm) air arriving first and then cooler air a bit later.
Once the front passes.. clearing skies.. much cooler and drier area will be in store for the middle and latter part of next week as high pressure from southern Canada and the Rockies builds southward into the southern plains states.
Regarding my forecast, my local forecast confidence: My forecast confidence is high to very high today through Saturday.. then back to medium confidence for Saturday night through Sunday and Monday as the next upper level low pressure storm system and surface cold front approaches the area. Forecast confidence rises back to very high in the wake of the series of cold fronts for early next week.
Have a good Friday…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel