Updated 130pm CDT Friday / 29 June 2012

…. Afternoon Highs Down a Few Degrees as Upper Level High Pressure Weakens ….
…. Slightly Better Rain Chances for the Weekend with a More Unstable Air Mass ….
…. Upper Level High Pressure Ridge Rebuilds Again for Next Week ….

On this Friday… a surface high pressure area is located over the southeastern USA  and to the west over the four corners region. A trough.. or line.. of surface low pressure extends southward from eastern Colorado and western Kansas into eastern New Mexico and west Texas. As a result of this pressure pattern, a south southeasterly surface wind is prevailing across our area.

In the upper levels of the atmosphere, the area of upper air high pressure is located from the Tennessee Valley westward to over Colorado and New Mexico with a weakening of the upper ridge across our local area. As a result of the upper air wind flow, the upper level winds are light and easterly over our area.

Upper level high pressure is still situated overhead although the strongest part of the “heat dome” has continued to shift north of our local area. As the upper level high overhead continues to weaken through the weekend, we’ll see a few more clouds and a slight drop in the average afternoon high temperatures. In addition, beginning today, we’ll see enough instability develop in combination with daytime heating and available moisture to help widely scattered to scattered rain showers and thunderstorms to build.

By Monday and continuing through next week, the upper level high will rebuild and strengthen overhead so I’ll decrease clouds a bit.. drop any mention of rain and bring up daytime high temperatures again.

For Austin and south central Texas… tonight will see an isolated evening thunderstorm otherwise it’ll be partly cloudy with lows in the 70s. South southeasterly wind. For tomorrow, partly cloudy with widely scattered afternoon rain showers and thunderstorms with highs in the 90s. South southeasterly wind.

Have a good Friday night and Saturday…
Meteorologist Troy Kimmel

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