Updated 845am CDT Friday / 25 October 2013
…. A Cold Front Weakening Overhead ….
…. A Passing Upper Air Storm System and Rain Chances for our Weekend ….
On this Friday morning…. a weakening cold front extends westward from northern Florida to just offshore the middle Gulf Coast then across south central Texas and northwestward into the southern Rockies as a stationary front. A large eastward moving high pressure area is centered.. behind the front.. over Missouri. As a result of this surface weather pattern, surface winds are light and variable across our area.
In the upper levels of the atmosphere… a eastward moving trough.. or line.. of upper level low pressure is along the eastern USA seaboard. An upper air low pressure disturbance is over northern Arizona with an associated trough.. or line.. of low pressure extending southward into northwestern Mexico. As a result, the upper level winds over south central Texas and the Austin metro area about 18,000 feet above the ground are westerly at 15 to 25 mph.
On this Friday, a stable weather pattern continues across south central Texas. A weak cold front has moved south southwestward over the area in the early morning hours this morning. However, it is weakening rapidly as it senses the eastward moving upper level low pressure storm system over northern Arizona. As the front washes out and moves back northward as a warm front later today, low level moisture will increase rapidly tonight into Saturday. As the upper air system moves across Texas over the weekend and produces atmospheric instability and atmospheric lift, we’ll see rain chances return to the forecast for our area as the system moves by to our north.
Rain chances will decrease as the upper air storm system moves off to the northeast and the weather pattern stabilizes by midday and afternoon Sunday into early next week with rain chances dropping from the forecast and more sunshine for the area.
There continues to a weakening in the forecast guidance for the low pressure storm system that had been forecast for the central and southern plains states for the middle and latter part of next week. The latest guidance is now calling for a relatively weak cold frontal passage next Friday.
Regarding my forecast, my local forecast confidence: Very high forecast confidence through today and tonight.. then high confidence for the weekend into the early part of next week as it regards the progress and timing of upper air low pressure and fronts over the southern plains and any associated rain chances. My forecast confidence falls to very low for next middle into latter part of next week as it regards the intensity and timing of the cold front as well as associated rain chances.
Have a good Friday…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel