Updated 915am CT – Wednesday / 10 June 2015
.. Afternoon High Temperatures Rise as Ground Dries ..
.. Thunderstorm Chances Return Friday and Continue Through the Weekend ..
On this Wednesday…. a trough.. or line.. of low pressure extends south southwestward from a weak surface low pressure area over extreme western Kansas into the western Oklahoma panhandle and western Texas and eastern New Mexico. Surface high pressure is over the northern Gulf of Mexico and the lower Mississippi Valley. As a result of this surface weather pattern, our local surface winds are southerly.
In the upper levels of the atmosphere.. a weakened high pressure area, acting like a “lid” on the atmosphere, and shifted more southwestward and is centered over northern Mexico with weakened ridging into Texas and the northwestern Gulf of Mexico. A trough.. or line.. of low pressure is moving eastward over the eastern Great Lakes States with a stronger upper level disturbance just off the Pacific coast immediately south of the metropolitan San Francisco Bay area. As a result, our upper air winds at about 18,500 feet, as a result of a shifting of the upper high more to our southwest, have become northwesterly at 10 to 20 mph.
Even though the upper level high has weakened a bit and shifted more southwest of the area, I don’t see much change is seen in our weather pattern over the next 24 hours other than perhaps a few more clouds. A dry and stable weather pattern prevails. Even though weakened a bit, the upper level high pressure is still acting like a “lid” on the atmosphere generally keeping rising motion in the atmosphere at bay.
The ground is slowly drying and that has allowed afternoon high temperatures to rise a bit. With the upper high weakened a bit, yesterday’s high at Austin’s Camp Mabry of 95 degrees may have been the peak of the temperatures. Temperature highs over the next day or so should be down a degree or so.
By Friday and continuing through our upcoming weekend, our weather pattern will turn a little more unstable as the upper air high pressure area continues to shrink southwestward and weakens. I’m continuing a slim chance of afternoon or evening rain showers and thunderstorms on Friday with better rain and thunderstorm chances Saturday and Sunday and into the first part of next week. With lots of Friday and weekend outdoor activities, I remind everyone that frequent dangerous cloud-to-ground lightning will accompany any thunderstorms that do develop. National Weather Service rainfall guidance continues to suggest that we have the possibility of seeing up to 1/2 inch of rain starting Friday through early next week. Clouds and those precipitation chances will probably result in afternoon high temperatures being down closer to 90 degrees for the weekend into early next week.
Have a good Wednesday….
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel