Updated 130pm CDT Monday / 27 August 2012
… Watching Isaac But Little Effect Expected Locally on Current Forecast Track …
… A Few Showers and Thunderstorms Through Tomorrow …
… Otherwise, A Mostly Dry Seven Day Forecast …
On this Monday… surface high pressure is over the eastern USA and over the four corners region. As a result of this surface pattern, a light east southeasterly 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 northwest of the local area over the southeastern Rockies and southwestern plains. As a result of the upper air wind flow, the upper level winds are light northeasterly over our area.
Tropical cyclone Isaac continues a little over 800 miles east southeast of Austin. The current National Hurricane Center track forecast suggests a landfall in southeastern Louisiana sometime late tomorrow afternoon into tomorrow night into early Wednesday.
On this track, I expect little effect locally other than a more northerly wind later tonight into Tuesday and into mid week.
Unrelated to Isaac, a weak disturbance overhead will combine with available moisture.. atmospheric instability along with daytime heating to create scattered rain showers and thunderstorms into early tonight and again tomorrow when I expect widely scattered rain showers and thunderstorms over our area.
Beyond tomorrow, a mostly dry and stable weather pattern is expected to continue across the area; I do not expect any frontal passages/air mass changes. Upper level high pressure, acting like a “lid” on the atmosphere, will build back overhead and will result in sinking air in the atmosphere, so no rain chances for the upcoming long Labor Day weekend.
Temperatures should continue to be near or even slightly above seasonal averages.
For Austin and south central Texas… tonight will see a partly cloudy sky with a few rain showers and thunderstorms before midnight with lows in the 70s with a light wind. For tomorrow, it’ll be partly cloudy with a few rain showers and thunderstorms with highs in the 90s with a northeasterly wind.
Have a good Monday night and Tuesday…
Meteorologist Troy Kimmel