Updated 930am CDT Wednesday / 5 September 2012

… A Dry Forecast Continues …
… Cold Front Due Early Saturday with a Slim Chance of Rain …
… A Little Cooler Saturday Night into Sunday and Monday …

On this Wednesday… surface high pressure is over the Gulf of Mexico and Florida with another surface high over the four corners area. A trough. or line.. of low pressure extends southward from a surface low over southwestern Kansas into west Texas and southeast New Mexico. As a result of this surface pattern, a southerly surface wind is prevailing across our area.

In the upper levels of the atmosphere, a upper high pressure ridge, acting like a lid on the atmosphere, is situated from Texas westward into the southwestern USA. An area of upper air low pressure is over the southeastern USA and the adjacent northeastern Gulf of Mexico. As a result of the upper air wind flow, the upper level winds are light and variable over our area.

A dry and stable summertime weather pattern continues across our area.

The upper air pattern is still slated to change across the USA by late week into the weekend as a trough.. or line.. of upper air low pressure over the eastern half of the country and our winds aloft over our area turn northwesterly and increase. This will support a surface cold front to sweep southeastward through our area of Texas early Saturday morning. The situation.. due to time of day and the expected atmospheric moisture profile.. will be less favorable for precipitation than I thought yesterday. Accordingly, isolated to widely scattered rain showers and thunderstorms will develop just ahead of.. along and just behind the front. It appears that rainfall of 1/4 inch or less will occur with these thunderstorms locally.

Skies will clear with lower humidity and slightly cooler temperatures for Saturday night through Sunday and Monday as the surface high pressure behind the front builds into the area from the north northwest.

For Austin and south central Texas… tonight will see a mostly clear sky with lows in the 70s with a southerly wind 8 to 15 mph. For tomorrow, some morning low clouds will give way to a mostly sunny with highs around 101 with a southerly wind 8 to 15 mph.

Have a good Wednesday night and Thursday…
Meteorologist Troy Kimmel

Contact me:
tkimmel@mail.utexas.edu
http://www.facebook.com/troykimmel