Updated 800am CT – Friday / 05 September 2014

…. Slim Rain Chances Over Next Few Days with Little Change in Local Weather Pattern ….

On this Friday morning…. high pressure is centered over the southern Appalachians with a cold front moving southeastward from Missouri through central Kansas.. northwest Oklahoma into the Texas panhandle and then into New Mexico. As a result of this surface weather pattern, our local surface winds are east southeasterly.

In the upper levels of the atmosphere… an upper air low pressure disturbance moving through the westerly wind flow over northwestern third of the country. Upper level high pressure.. acting like a lid on the atmosphere.. covers the southern USA from Georgia westward across Texas and into New Mexico. As a result of this pattern, the upper level winds over south central Texas and the Austin metro area, about 18,000 feet above the ground, are southerly 10 to 18 mph.

As a result of the weakening of the upper level high above us.. afternoon heat will combine with available low level moisture and limited atmospheric instability to give us widely scattered afternoon and early evening rain showers and thunderstorms over the area this afternoon and continuing into the weekend.

The cold front moving into northwest Texas will move southeastward through tomorrow finally pulling up stationary just to our north by tomorrow night into Sunday. Any precipitation along this front should remain to the north of the area but it is something we need to watch for late tomorrow afternoon into tomorrow night. The front will wash out as a stationary front overhead or just north of the area by Sunday into Sunday night.

By early into mid parts of next week, we’ll see the atmosphere become a little more stable once again with very minimal rain chances with temperatures remaining above seasonal averages.

By late Thursday into Friday of next week, preliminary computer guidance would suggest the first stronger cold front of the upcoming fall season will arrive with a chance of rain showers and thunderstorms. Temperatures will cool a bit and humidity will drop as well by late next Friday into Saturday as high pressure behind the front settles southward into Texas in the wake of the front which should move off the Texas coast.

Regarding my forecast, my local forecast confidence: My forecast confidence is high through the weekend (reference any precipitation timing and amounts)… then high to very high Monday through Thursday (concerned with very minimal afternoon rain chances). With the arrival of the front by late next week, my forecast confidence is medium (exact frontal timing and rain chances and amounts being the issues that concern me).

Have a good Friday….
Meteorologist Troy Kimmel

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