Updated 845am CDT Friday / 13 September 2013
…. Very Slim Thunderstorm Chances Linger Through Next Two Days ….
…. An Otherwise Typical Late Summer Weather Pattern Continues ….
…. Continuing to Watch the Tropical Cyclone over the Southwestern Gulf ….
On this Friday morning…. surface high pressure continues over the eastern Gulf of Mexico. A southward moving weak cold front extends westward from central Alabama and Mississippi into north central Texas. As a result of this surface weather pattern, surface winds are southeasterly over our area.
In the upper levels of the atmosphere… an upper level high pressure area has continued to settle southwestward from the northwestern Gulf of Mexico into the southern plains states. Being on the south side of the upper air high and with the upper level low to our southwest, winds over south central Texas and the Austin metro area about 18,000 feet above the ground are relatively light.
Atmospheric moisture will continue today as well as tomorrow to combine with daytime heating and atmospheric instability as well as the upper level low to our southeast to produce very isolated rain shower and thunderstorm development. Frequent cloud to ground lightning and gusty winds may accompany the thunderstorms that do develop.
By Sunday into next week, a slightly more unstable air mass will move northwestward into Texas from the Gulf of Mexico and I will keep a slim rain chance on Sunday increasing it slightly into next week. These local rain chances for beyond Sunday are strongly tied to the development and future movement of the tropical cyclone over the southwestern Gulf of Mexico. According to meteorologists at the NWS/National Hurricane Center, there is a fairly high chance that the tropical cyclone will develop into a tropical storm (next name on the list, Ingrid) over the southwestern Gulf of Mexico today into tonight. Computer guidance.. as of this Friday morning.. continues to strongly indicate that the system will be steered more westward toward Mexico than northwestward toward Texas and, as a result, I am going to keep my rain chances slim for Sunday into early next week. It should be noted, however, that we should continue to watch this system and watch where the remnants, after landfall along the east coast of Mexico, go since it possibly turn more northward toward central and west Texas and could bring us better rain chances by the middle and latter part of next week.
Regarding my forecast, my local forecast confidence: High to very high forecast confidence through Sunday and Monday.. then a decrease in confidence to low to medium Tuesday through Friday of next week with the weakened remnants of the gulf system possibly moving out of Mexico into west and central Texas during that time period (and perhaps increasing our chances of rain).
Have a good Friday…
Meteorologist Troy Kimmel