Updated 915am CT – Friday / 13 February 2015
…. A Warming Trend Through the Weekend ….
…. Rain Chances Return by Sunday into Monday ….
…. Colder Air Returns Us to Winter Next Week ….
On this Friday morning…. surface high pressure is located over Illinois and western Tennessee. As a result of this surface weather pattern, our local surface winds are becoming southerly.
In the upper levels of the atmosphere.. a deep upper level trough.. or line.. of low pressure covers the eastern half of the USA with a ridge.. or line of high pressure.. along the west coast. As a result, our upper air winds at about 18,500 feet are west northwesterly at 20 to 30 mph.
The chilly surface high pressure area, that has settled southward over our area in the wake of Wednesday night’s front, is moving eastward and we’re seeing a return southerly surface wind flow. As a result, we’ll see a pretty stout warming trend today through our weekend.
Clouds will increase a bit over Texas by Sunday into Monday as the atmosphere becomes increasingly moist and a bit more unstable. Another cold front will try to “backdoor” itself (moving in from the northeast) on Sunday. The best chance of rain and even isolated thunderstorms appears to be in the Sunday night.. Monday and Monday night time period with the approach and passage of a strong upper level low pressure disturbance.
Timed with the movement overhead of the upper air low pressure disturbance, very cold arctic air will surge southward out of western and central Canada and into the central USA and into Texas. Although atmospheric model guidance has tended to pull back a little in its forecast on the intensity of the cold air, this front will still likely usher in some of the coldest air of the new year with overnight low temperatures across our area likely to be freezing. The much colder temperatures will likely linger through much of the remainder of next week.
Skies will initially clear as the coldest air arrives but there continues to be signs in the longer range guidance that clouds and the chance of overrunning clouds and precipitation may return by later next week.
Regarding my forecast, my local forecast confidence: My forecast confidence is high to very high through Sunday.. then my confidence decreases to a medium to high by Sunday night through Thursday with the forecast cold frontal passage, exact extent of cold air as well as associated clouds and rain chances.
Have a good Friday….
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel