Updated 915am CT – Friday / 31 July 2015
.. Cold Front Washing Out Overhead ..
.. Rain and Thunderstorm Chances Continue Today Through Saturday ..
.. Heat Ridge Builds Back In Over the Weekend into Next Week ..
On this Friday…. a weakening cold front extends westward from southern Louisiana then west northwestward overhead of our south central Texas area. A trough.. or line.. of surface low pressure extends south southwestward from the Texas panhandle into far southwest Texas. Surface high pressure.. north of the front.. is over Missouri.. Kansas and Colorado. As a result of this surface weather pattern, our local surface winds are light southerly or light and variable in areas north of the weakening front.
In the upper levels of the atmosphere.. an upper level high pressure area.. acting like a “lid” on the atmosphere.. continues to shift westward and is centered from New Mexico across the four corners region into Utah. An upper level low pressure trough is deepening and extends southwestward from Hudson Bay across the Great Lakes and into the Tennessee Valley region. As a result, our upper air winds at about 18,500 feet, have become more north northeasterly.
Our atmosphere has become more unstable over the last 12 hours as the upper level high pressure area shifts more westward as the trough from Canada to over the Great Lakes and Tennessee Valley continues to deepen. Even so, we’ll likely see afternoon high temperatures around 99 to 100 degrees along the IH35 corridor today.
However, with the cold front moving over the area and atmosphere a bit more unstable with better moisture and instability moving into the area from the east, I expect widely scattered to scattered rain showers and thunderstorms today into tonight and tomorrow. With ongoing outdoor summer activities, everyone should remember the danger of cloud-to-ground lightning and strong gusty winds that will accompany any thunderstorm.. keep your eye on the sky!! With the increased cloud cover, daytime high temperatures will be down a degree or so as well.
Beyond the weekend into early next week, upper level high pressure appears to rebuild with a vengeance over the area with rain chances dropping from the forecast and afternoon high temperatures climbing back to or above the century mark.
Have a good Friday….
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel