Updated 845am CDT Wednesday / 14 August 2013
…. A Weak Cold Front Moves Southward into Texas ….
…. A Chance of Rain and Thunderstorms Through Late Week ….
…. Stable Dry Weather Pattern for the Weekend into Early Next Week ….
On this Wednesday morning…. a southward moving cold front extends southwestward from Alabama into northwest Louisiana and north central Texas /around Waco/ then westward to south of Midland and northwestward into New Mexico. High pressure is over the Gulf of Mexico and over southern Colorado with another surface high north of the front over the western Great Lakes and upper Mississippi Valley. A trough.. or line.. of low pressure extends from the front over west Texas and runs southwestward into Mexico. As a result, surface winds are south southwesterly across our local area.
In the upper levels of the atmosphere… a upper level high pressure area.. acting like a “lid” on the atmosphere.. has shifted to the west of our area as a upper level low pressure trough.. or “line” of low pressure.. deepens over the eastern half of the USA. As a result of this upper air pattern, winds over south central Texas and the Austin metro area about 18,000 feet above the ground have become more northwesterly but still are generally light.
The summer weather pattern continues this morning even though the center of the upper level high has shifted westward of our area. Clouds continue to be few and far between temperatures continuing well above seasonal average. This is changing, though, as a weakening cold front moves southward into the area from north Texas.
By this afternoon, the cold front will settle southward into our area from north Texas. The front will produce atmospheric lift with a moist and somewhat more unstable air mass in place; as a result, I still expect scattered rain shower and thunderstorm activity as the front washes out overhead of or just south of our local area. The front will wash out and return northward as a weak warm front by Saturday. Anytime during this period, we’ll see those slim rain chances linger. Strong gusty straight line thunderstorm winds
may accompany any thunderstorms later today into tonight with frequent deadly cloud to ground lightning likely, as well.
Over the weekend into early next week.. the upper air high will become a little stronger so I see a dry stable weather pattern for that part of the extended forecast period.
Based on the latest information from the NWS/National Hurricane Center, a tropical wave continues northwestward from the western Caribbean Sea and will move to near the Yucatan Peninsula and the southern Gulf of Mexico by late week with a high potential for development into a tropical cyclone. I’m still thinking, though, that the system will not be a big factor although guidance has shifted to putting the system ultimately into the north central Gulf of Mexico /perhaps then into southeast Louisiana.. Mississippi.. Alabama.. northwest Florida coasts/ by the weekend. I’ll continue to watch the system and the latest releases from our colleagues at the NWS/National Hurricane Center.
Regarding my forecast, my local forecast confidence: High forecast confidence today into tonight and continuing into tomorrow and Friday then my forecast confidence returns to very high for Saturday and Sunday into early next week.
Have a good Wednesday…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel