Updated 845am CT – Thursday / 3 July 2014
…. Precipitation Chances Overt the Next Day or So ….
…. Summertime Heat Continues ….
On this Thursday morning…. a weakening stationary front extends westward from a low pressure area over southern Mississippi to southeast Texas just north of Houston to just north of the Austin area into another low pressure area southeast of Midland. Surface high pressure area is over the western and central Gulf of Mexico. As a result of this surface weather pattern, our local surface winds are south southwesterly.
In the upper levels of the atmosphere… an area of upper level high pressure continues to be centered over the southwestern and south central USA with an upper level low pressure trough (line) extending southward from Hudson Bay into the Tennessee Valley region. 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 northwesterly at 8 to 18 mph.
Even though it has weakened a little, the upper level high pressure area continues overhead and to our west. As a result, a mostly stable air mass prevails across our area. However, as noted yesterday, a few unexpected rain showers and thunderstorms did develop across the area with maximum daytime heating.
Today into tomorrow, forecast guidance continues to suggest that the upper level high pressure area will continue to weaken a little with the deepening of the upper level trough over the eastern half of the country. As a more pronounced low level flow picks up from the Gulf of Mexico, it will allow for increased moisture and atmospheric instability combining with the weakening front just to our north as well as daytime heating to result in widely scattered rain showers and thunderstorms. Current projected rainfall amounts suggest that areas that see precipitation (with a relatively slim rainfall probability at any given location) will only see trace to 1/4 inch rainfall amounts.
Current guidance suggests that any rain chances will drop from the forecast by Saturday into Sunday as well as early next week.
Overall, I expect our temperatures to be close to or just above seasonal averages over the next seven days.
Regarding my forecast, my local forecast confidence: My forecast confidence is high high today through tomorrow (afternoon rain and thunderstorm chances with coverage, timing as well as rainfall amounts, being the issues). My forecast confidence rises back to high to very high for Saturday and into Sunday as well as through next week.
Have a good Thursday and a great Fourth of July holday weekend…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel