Updated  130pm Wednesday / 15 February 2012

…. Clearing Skies as Cooler and Drier Air Mass Moves into the Area ….
…. Another Storm System and Cold Front Brings Rain Chances Friday Night ….
…. Clearing Again On Sunday But Clouds Pick Up Again by Early Next Week ….

On this Wednesday… a surface high pressure area is over the Appalachians and eastern seaboard while a low pressure area is over southern Kansas with a cold front extending southward into Texas. As a result of this surface pressure pattern, a southerly wind is becoming northwesterly across our area as the front passes.

In the upper levels of the atmosphere… a broad trough.. or line.. of upper air low pressure is over the western third of the USA. Embedded within that flow, there are strong upper air disturbances over northwest Texas (it’s moving east northeastward) and another over eastern California and western Nevada (it’s diving southeastward). As a result of this pressure pattern, the upper air winds over our area of Texas are, in general, southwesterly across Texas and our local area.

As the cold front passes the area today, the skies will quickly clear from west to east with a drier and more stable air mass taking hold for tonight into Thursday.

Another upper air disturbance combined with a quick turn around to a south southeasterly surface wind flow and increased atmospheric moisture will result in increased clouds by tomorrow night into Friday with a return to rain chances again Friday night and into early Saturday. The disturbance will trigger the development of a surface low over south Texas which will move eastward into the Gulf of Mexico.

As that surface low moves eastward across the northern Gulf (and away from us), rain chances will drop and a more stable atmosphere will return by late Saturday through Sunday. As a result, sunshine will increase as we wrap up the weekend.

Clouds will increase again as yet another weather system.. in a progressive (quick moving) series of disturbances.. affects Texas by the first part of next week. I’ve removed rain chances from this part of the forecast.

My forecast confidence through this week is high to very high (timing in progressive/fast moving weather patterns, like we’re in, can be problematic, though). My confidence for the forecast for next weekend into next week is medium (with exact rain chances and time of clearing on Saturday as well as Monday and Tuesday’s clouds and any rain chances being the main questions) .

For Austin and south central Texas… tonight will see a mostly clear sky. Lows in the 40s with a northwesterly wind. For tomorrow, mostly sunny. Highs in the 60s with a northerly wind.

Have a good Wednesday night and Thursday…
Meteorologist Troy Kimmel