Updated 845am CST Tuesday / 11 November 2013
…. A Strong Cold Front Moves Through As Colder Air Moves South ….
…. The NWS has Issued Freeze Warnings for Many Areas ….
…. A More Unsettled Period with Rain Chances Late Week into Weekend ….
On this Tuesday morning…. a southward moving cold front extends from western North Carolina and eastern Tennessee across Mississippi into south central Texas and then west northwestward across far west Texas and New Mexico. Surface high pressure.. ushering in the coldest air of the season over the Mississippi Valley and the great plains.. is centered behind the front over eastern Nebraska and western Iowa. As a result of this surface weather pattern, surface winds are becoming gusty northerly over our area.
In the upper levels of the atmosphere… a deepening trough.. or line.. of upper air low pressure extends south southwestward across the eastern 2/3rds of the USA. Another strong upper level low is off the northwest coast of the USA. As a result of the overall upper level wind flow, the upper level winds over south central Texas and the Austin metro area about 18,000 feet above the ground are west northwesterly 20 to 30 mph.
As the deep upper air trough continues over the eastern half of the country and our upper level winds have become stronger west northwesterly, the cold front is moving southward across the area. Clouds will be picking up as the colder air continues to move south into the area with the clouds decreasing my later today into tonight.
Much cooler temperatures.. in fact, the coldest of the fall season so far.. will continue to move into the area. With winds lightening up by later tonight, it is very likely that early morning temperatures tomorrow and Thursday morning, assuming a clear sky, will fall to near the freezing mark especially in outlying and low lying areas. In any case,
NWS offices around our area have issued freeze warnings for tonight. A freeze warning has been issued.. effective 12 midnight tonight through 9am tomorrow.. for the Austin metro area including Travis, Williamson, Hays, Milam, Burnet and Blanco counties. The freezing temperatures in the metro area will likely be away from the downtown area in outlying and low lying areas.
As this strong surface high moves eastward by the end of the week and as another low pressure storm system gathers over the western USA, we’ll see a fairly rapid return to warmer temperatures and clouds by as early as late Thursday into Friday. Rain chances even show up by as early as late Friday through our upcoming weekend.
Another cold front.. again, rather strong in nature.. will move through the area next Monday with a slim chance of rain. Cooler temperatures and clearing skies will follow for Monday night into Tuesday.
Regarding my forecast, my local forecast confidence: High to very forecast confidence through Thursday into Friday (some question about exactly how chilly it gets at night and when the clouds pick up Thursday into Friday) with a moderate to high confidence forecast for the weekend into early next week (regarding rain chances and the exact timing of the next cold front).
Have a good Tuesday…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel