Updated  130pm Monday / 5 March 2012

…. Clouds on the Increase over the Next Few Days ….
…. Rain Showers and Thunderstorms Due for the Middle and Latter Part of Week ….
…. 1 to 3 Inches of Rain Possible Mid and Late Week Before Weekend Clearing ….

On this Monday… surface high pressure is situated over the northern Gulf of Mexico and over the four corners region. A cold front extends from a surface low over the southern Appalachians into central and northern Mississippi and southern Arkansas into central Oklahoma and southwestern Kansas. 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 located over the eastern 1/3rd of the USA. A strong upper air disturbance is moving eastward into the southwestern USA and northwestern Mexico from the Pacific Ocean.  As a result of this pressure pattern, the upper air winds are moderate west northwesterly across Texas.

A clear sky across Texas will be giving way to increasing clouds over the next couple of days as southerly surface winds bring abundant surface moisture northward through the state.

Skies will become mostly cloudy tonight into Tuesday with enough low level moisture for some patchy rain beginning Wednesday with the approach of the upper level low pressure area from the southwestern USA and northern Mexico. As the upper level low only slowly 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. Current forecast guidance suggests one to three inches of rain could fall locally before the cold front moves through the area late Friday and precipitation chances begin to taper off.

A drier and more stable weather pattern will develop next weekend with partial clearing expected.

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 the sky turn partly cloudy. Low 40s to near 50. For  tomorrow, Mostly cloudy. Highs in the 70s. Southerly winds will continue over the next 24 hours.

Have a good Monday night and Tuesday…
Meteorologist Troy Kimmel