Updated 845am CST Wednesday / 6 March 2013
A Dry and Stable Air Mass Continues Across Texas …
Increasing Clouds with a Chance of Rain by Late Week into the Weekend …
Our Next Cold Front Due in the Early Morning Hours on Sunday …
On this Wednesday… a surface high pressure area extends southward through the plains states into Texas. A cold front extends from a surface low pressure area over the Carolinas into north Florida and the Gulf of Mexico. A trough.. or line.. of low pressure.. is over far west Texas and eastern New Mexico. Given this surface pressure pattern, surface winds are northeasterly but becoming more easterly as the high moves east of the area.
In the upper levels of the atmosphere, a strong upper level low pressure is over the eastern seaboard of the USA with another one moving ashore onto the west coast of the USA. Between the two areas of low pressure.. a ridge of upper air high pressure extends northward from Mexico into Texas. As a result of this upper air wind flow, our upper level winds are light to moderate west northwesterly with winds over Austin at about 18,500 feet being west northwesterly around 20 to 30 mph.
The surface high.. that is currently overhead.. will settle eastward into the lower Mississippi Valley by tonight into tomorrow with a return south southeasterly wind.
By Friday into the weekend, clouds and humidity will be on the increase as low pressure deepens to our west. Some light rain will develop as early as late Friday night with a better chance of rain showers and thunderstorms by Saturday night into Sunday as the atmosphere becomes more unstable and a cold front approaches the area.
The cold front will move through the area Sunday morning with the best chance of rain showers and thunderstorms in the 6am to 10am time frame. Current NWS rainfall guidance suggests that we could see between 1/4 and 1/2 inch of rain in the Saturday into Sunday time frame.
Slightly cooler air will prevail in the wake of the front Sunday night into the first couple of days of next week with some lingering clouds.
Have a good Wednesday night and Thursday…
Meteorologist Troy Kimmel