Updated 845am CDT Wednesday / 1 May 2013
Big Weather Changes in Store ….
Strong Cold Front Moving Through After Midnight ….
Unseasonably Cool Temperatures Arriving Tomorrow through Friday ….
On this Wednesday morning…. surface high pressure is over the northeastern USA with a trough.. or line.. of surface low pressure from a surface low over northeastern New Mexico extending southwestward to far west Texas to the east of El Paso. A southward moving cold front is over northwest Texas and Oklahoma. Given this surface pressure pattern, surface winds are south southeasterly across our area of the state.
In the upper levels of the atmosphere…. an eastward moving trough.. or line.. of upper level low pressure is over the western half of USA. Given this upper air pattern, winds over south central Texas and the Austin metro area about 18,000 feet above the ground are northerly 15 to 25 mph.
A 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 is producing late night and early morning low cloudiness and patchy fog along with afternoon high temperatures that will continue to be slightly above average today.
As the upper air trough over the western USA moves eastward, a strong cold front will move swiftly into the area after midnight tonight and move across the area with isolated to widely scattered rain showers and thunderstorms as the front completes its move over Austin before the morning rush hour tomorrow morning. Unseasonably strong polar high pressure.. right out of Canada.. will usher in much cooler temperatures tomorrow 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 Saturday through the remainder of the weekend into next week with warmer temperatures and increased low level moisture returning to the area.
Have a good Wednesday night and Thursday…
Meteorologist Troy Kimmel