Updated 845am CDT Tuesday / 30 April 2013
A Stable Weather Pattern with Warmer Temperatures ….
Strong Cold Front Still on Tap for Late Wednesday Night into Thursday ….
On this Tuesday morning…. surface high pressure is over the northeastern USA with a trough.. or line.. of surface low pressure developing from a surface low over southwestern Kansas extending southwestward to far west Texas to the east of El Paso. Given this surface pressure pattern, surface winds are south southeasterly across our area of the state.
In the upper levels of the atmosphere…. a broad weak trough.. or line.. of upper level low pressure is over the western half of USA. Within the flow, a strong upper level low pressure area.. that triggered our surprise thunderstorms yesterday.. is over southeast Texas and southern Louisiana. Given this upper air pattern, winds over south central Texas and the Austin metro area about 18,000 feet above the ground are northerly 10 to 20 mph.
Even after the surprise round of thunderstorms on Monday afternoon over parts of the area (triggered by the upper air disturbance that passed west-to-east to our south), a generally stable springtime weather pattern continues across our area. Surface high pressure.. to our east.. and developing low pressure.. to our west.. is combining to produce a southerly surface wind across the area. Low level moisture continues to increase with late night and early morning low cloudiness being the result along with afternoon high temperatures that will be above average over the next several days.
The strong cold front is still due to move into the area after midnight Wednesday night and move across the area with isolated to widely scattered rain showers and thunderstorms as the front completes its move over Austin by the end of the morning rush hour on Thursday morning. Unseasonably strong polar high pressure.. right out of Canada.. will usher in much cooler temperatures Thursday through Friday for our area. Some overnight low temperatures on Thursday night as well as on Friday night may reach into the upper 30s in some outlying low lying areas.
As the polar high moves east of the area.. southerly winds will return to the area by late Friday night through the weekend with warmer temperatures and increased low level moisture returning to the area.
Have a good Tuesday night and Wednesday…
Meteorologist Troy Kimmel