Updated 130pm CDT Monday / 13 August 2012

…. An Isolated Evening Thunderstorm Possible This Evening ….
…. A Mostly Dry and Stable Summer Weather Pattern Continues ….
…. Rain Chances Up Slightly by Friday into the Weekend ….

On this Monday… a weak stationary front extends from a surface low pressure area over northeastern Arkansas southwestward across the Ark-La-Tex region and north Texas into far southwest Texas. Ahead of the weak front, weak surface high pressure continues over the southeastern USA and the Gulf of Mexico. Another surface high is north of the front over Nebraska. As a result of this surface pattern, a south southwesterly surface wind is prevailing across our area.

In the upper levels of the atmosphere, the upper high pressure ridge, acting like a lid on the atmosphere, is located over Arizona and New Mexico into west Texas. A trough.. or line.. of upper level low pressure extends southward from the Great Lakes states southward over the eastern half of the USA.  As a result of the upper air wind flow, the upper level winds are light northerly over our area.

Although a tropical air mass continues across the area, the large stable upper level high pressure area to our northwest continues its influence on our area weather by keeping a “lid” on the atmosphere. With the intense daytime heating, the advancing and weakening cold front and several rain cooled boundaries still in place just to our north from overnight thunderstorms, we will see isolated showers and thunderstorms through midnight tonight. Strong gusty winds will accompany any thunderstorms that do develop.

A dry and stable weather pattern will prevail tomorrow into mid and late week when another cold front will drop southeastward into Texas with more moisture and instability in place. As a result, I’ll increase the cloud cover a bit along with a slightly better chance of rain showers and thunderstorms Friday into the weekend.

For Austin and south central Texas… tonight will see isolated rain showers and thunderstorms until midnight otherwise expect to see a partly cloudy sky with lows in the 70s. Southerly wind. For tomorrow, a mostly sunny sky will continue with highs around 99 with a southerly wind.

Have a good Monday night and Tuesday…
Meteorologist Troy Kimmel