Updated  130pm Tuesday / 24 January 2012

…. Stormy Weather Over the Next 24 to 36 Hour Period ….
…. 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 Tuesday… a warm frontal system extends southwestward  extends from the mouth of the Mississippi River in southeastern Louisiana west southwestward into the Gulf of Mexico and then onshore into south Texas. Low pressure is deepening.. in response to an approaching strong upper level storm system.. over west Texas.  As a result of this surface pressure pattern, a easterly/southeasterly surface wind is blowing across our area.

In the upper levels of the atmosphere… a deepening upper air trough.. or line.. of low pressure is moving eastward through southern Arizona.. southwestern New Mexico and northern Mexico. As a result of this pressure pattern, the upper air winds over our area of Texas are moderate to strong southwesterly.

We’ve seeing a quick return to a southeasterly wind and low level moisture. This will be “helped along” by the deepening upper air trough west of El Paso as it moves eastward. As the low pressure area approaches from the west and the front off the Texas coast  and over south Texas returns quickly northward as a warm front and as atmospheric instability and lift increases, rain.. rain showers and thunderstorms will become more numerous today into tonight and tomorrow. This system is quite dynamic and very beneficial rainfall is likely.. upwards of 1 to 2 inches in general with isolated totals to 3 inches along with the possibility of larger hail from the stronger thunderstorms especially later tonight into early tomorrow with severe thunderstorms possible.

Once the upper air storm passes overhead and to the moves east of our area and then a cold front moves through, by midday tomorrow, we’ll see rain chances decrease even though clouds and slim rain chances may linger a bit into tomorrow night. Cooler air will move southward into the area in the wake of the front with drier weather and the return to sunshine Thursday and Friday.

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 and clouds increasing a bit.

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

For Austin and south central Texas… tonight will see rain.. rain showers and thunderstorms with periods of heavy rain possible along with some hail in the stronger thunderstorms. Lows in the 50s with southeasterly wind. For tomorrow, a cloudy sky with rain shower chances decreasing. Highs in the 60s with southeasterly wind turning northwesterly.

Have a good Tuesday night and Wednesday…
Meteorologist Troy Kimmel