Updated 915am CT – Thursday / 23 April 2015
.. A More Unstable Air Mass ..
.. Rain and Thunderstorm Chances Continue Through Early Saturday ..
.. A Little More Sunshine for the Weekend ..
On this Thursday…. a southward moving.. but weakening.. cold front extends westward from central Alabama.. Mississippi and northern Louisiana into north Texas then northwestward through west Texas and northeastern New Mexico and northward into Colorado. A weak low pressure are is over west and southwest Texas. As a result of this surface weather pattern, our local surface winds are south southeasterly.
In the upper levels of the atmosphere.. a counterclockwise rotating upper air low pressure area is located north of the St. Lawrence River and extends over the northeastern USA and southeastern Canada. Another upper level low pressure disturbance is over southern California.. western Arizona and southern Nevada. As a result, our upper air winds at about 18,500 feet are westerly at 60 to 70 mph.
With our return south southeasterly surface wind, we’ve seen low level moisture pick up quickly which is evidenced by the presence of fog this morning. We’re also seeing a moderate westerly upper level winds are bringing mid and high level Pacific moisture.. in the form of mid and high clouds.. to our local area.
A series of weak cold fronts.. including the one over north Texas this morning.. will approach the area from the north through the latter part of the week. Even though I don’t see the fronts making their way this far south through the end of the week, beginning today, we’ll be seeing the influence of passing upper air disturbances from the counter clockwise rotating system over the southwestern USA. This resultant increased upward motion in the atmosphere along with a more moist and unstable air mass will bring us increased clouds as well as rain and thunderstorms chances continuing through the remainder of the week and perhaps into early Saturday.
The latest NWS/Storm Prediction Center guidance suggests the possibility of stronger.. potentially severe.. thunderstorms for parts of Texas (including parts of our local area) for today through Friday. In addition, the latest NWS rainfall forecast guidance now shows the potential of 3/4 to 1 1/2 inch of rain between now and Saturday.
A drier and more stable air mass return Saturday into Sunday with more sunshine expected.
Another approaching front along with a passing upper air low pressure disturbance will result in the return of rain and thunderstorm chances to the forecast by Sunday night into Monday. Early indications suggest the possibility of severe thunderstorms again.
Have a good Thursday….
Meteorologist Troy Kimmel