Updated  930am Tuesday / 6 March 2012

…. Clouds Thickening as Upper Level Low Pressure Approaches from the West ….
…. Rain Showers and Thunderstorms Due for the Middle and Latter Part of Week ….
…. 1 to 3 Inches of Rain Possible Mid/Late Week Before Late Weekend Clearing ….

On this Tuesday… surface high pressure is situated over the eastern USA with a deepening trough.. or line.. of surface low pressure over far west Texas and eastern New Mexico. As a result of this surface pressure pattern, a southerly surface wind is blowing across our area.

In the upper levels of the atmosphere, a trough.. or line.. of upper air low pressure is digging southeastward along the west coast of the USA.  As a result of this pressure pattern, the upper air winds are moderate westerly across Texas.

Skies are becoming mostly cloudy with clouds expected to continue thickening overnight tonight. Enough low level moisture will return for some patchy rain showers beginning tomorrow with the approach of the upper level low pressure area from the west. As the upper level low continues to approaches us from the west and an associated cold front also approaches the area by the end of the week, atmospheric lift and instability will be increasing. As a result, rain shower and thunderstorm chances will be increasing from mid into late week. While the threat of severe weather for us looks limited (and more to the areas to our north), current forecast guidance suggests one to three inches of rain could fall locally before the cold front moves through the area by early in the weekend and precipitation chances begin to taper off.

A drier and more stable weather pattern will develop by Sunday with partial clearing expected to continue into the new week.

My forecast confidence through the week and through next weekend is medium with rain timing/chances and the exact timing of the late week cold front contributing to the forecast uncertainty.

For Austin and south central Texas… tonight will see a mostly cloudy sky. Low 60s. For  tomorrow, a cloudy sky with a few sprinkles. Highs in the 70s. Southerly winds will continue over the next 24 hours.

Have a good Tuesday night and Wednesday…
Meteorologist Troy Kimmel