Updated  930am CDT Thursday / 29 March 2012

…. Major Changes Necessary in Forecast with Rain Chances Dropped ….
…. Clouds Linger Through Tonight into Early Friday Before Sunshine Returns ….
…. A Cold Front Due Early Monday with a Slim Chance of Showers / Thunderstorms ….

On this Thursday… a broad area of surface low pressure is over the western parts of the south central states with a trough.. or line.. of surface low pressure extending southward from a low pressure area over the northern Texas and Oklahoma panhandles into southwest Texas. A cold front extends southward from western South Dakota into western Colorado and northeastern Arizona. Surface high pressure is located from Florida and the eastern Gulf of Mexico eastward over the western Atlantic Ocean. As a result, a southerly surface wind is blowing across our area of Texas.

In the upper levels of the atmosphere, a rather zonal (west-to-east) upper air flow exists across the United States. Within the flow aloft, an upper air disturbance is over east Texas. As a result of the upper air wind flow, upper level winds are west southwesterly across our area of Texas.

With the south southeasterly surface wind across our area, abundant moisture continues across the area.

Much has changed, however, as far as the lifting mechanisms available for rain chances are concerned. The upper air disturbance, that moved into the area yesterday and resulted in our unexpected rain chances, has settled east of our area and has taken the best atmospheric lift to the east of the area. In addition, the other upper air disturbances to the west that were expected to result in continued rain chances through tomorrow, appear to be no longer a factor. As a result, we’ll hold onto clouds through tonight and early Friday before upper high pressure builds in for the weekend. This will allow for more sunshine and much warmer than average afternoon highs.

A southeastward moving cold front is forecast into the area by early Monday. The front will pass through the area with only widely scattered rain showers and thunderstorms and clearing and cooler temperatures Monday night into mid week.

My forecast confidence over the next seven days is high to very high.

For Austin and south central Texas… tonight will see a cloudy sky. Lows in the 60s. Southerly wind will prevail. For  tomorrow, a mostly cloudy sky early will give way to partial clearing. Highs in the 80s with southerly winds.

Have a good Thursday night and Friday…
Meteorologist Troy Kimmel