Updated  130pm Monday / 23 January 2012

…. Stormy Weather Starting Tomorrow Will Last into Wednesday Night ….
…. Beneficial Rainfall of 1 to 2 Inches Likely with Isolated Heavier Amounts ….
…. A Drier and More Stable Pattern Late Week into the Weekend ….

On this Monday… a weakening frontal system extends southwestward  extends from southeastern Louisiana into the Gulf of Mexico well offshore of the Texas coast then into northern Mexico south of Brownsville. Surface high pressure is over central Texas. As a result of this surface pressure pattern, northeasterly surface wind is blowing across our area.

In the upper levels of the atmosphere… the upper level wind flow has once again flattened again over Texas with a mostly zonal (west-to-east) upper level wind flow over the area as a northeastward moving upper air low pressure trough extends southward into the Mississippi Valley. Another deepening upper air trough.. or line.. of low pressure is moving east southeastward through California. As a result of this pressure pattern, the upper air winds over our area of Texas are light to moderate westerly.

In the wake of last night’s cold front, surface high pressure has built into our area. The overall pattern, however, is still very progressive and the surface high will move east of the area by later today into tonight with a quick return to a south southeasterly wind and low level moisture. This will be “helped along” by the deepening upper air trough over California as it moves into the southwestern USA. Enough low level moisture will return by later tonight into early Tuesday for lower clouds, some patchy fog and even a chance of rain.

As the upper air low pressure area approaches from the west and the front off the Texas coast  returns quickly northward as a warm front, rain.. rain showers and thunderstorms will become more numerous tomorrow through tomorrow night and continuing into Wednesday and even Wednesday night. This system is quite dynamic and very beneficial rainfall is likely.. upwards of 1 to 2 inches.. along with the possibility of some hail from the stronger thunderstorms.

Once the upper air storm passes overhead and to the east of our area, by early Wednesday, we’ll see rain chances decrease even though clouds and slim rain chances may linger a bit into Wednesday night. Cooler air will move southward into the area in the wake of the front.

In the progressive weather pattern.. another cold front will quickly pass through the area Friday night into early Saturday morning. Limited moisture return and limited instability ahead of this second cold front will mean no mention of rain as the system passes.

Surface high pressure will build southeastward from the Rockies for Saturday but will move east of the area by Sunday with a south southeasterly surface wind returning.

My forecast confidence through Wednesday and Thursday is high to very high. My forecast confidence for Thursday into Sunday is high.

For Austin and south central Texas… tonight will see thickening clouds as we become  cloudy with isolated patches of rain/drizzle after midnight. Lows around 50 with easterly wind. For tomorrow, a cloudy sky with an increasing chance of rain showers and thunderstorms by late in the day. Highs will be in the 60s to near 70 with southeasterly wind 8 to 15 mph.

Have a good Monday night and Tuesday…
Meteorologist Troy Kimmel