Updated 845am CST Tuesday / 19 November 2013
…. Clouds Pick Up Tonight and Tomorrow Ahead of a Strong Late Week Cold Front ….
…. Overrunning Clouds and Rain with Much Cooler Temperatures by the Weekend ….
On this Tuesday morning…. a cold front extends westward across the Gulf of Mexico into far south Texas near Brownsville the northwestward as a stationary front into northern Mexico south of the Texas Big Bend. Surface high pressure.. behind the front.. is centered over the western Great Lakes and the middle Mississippi Valley. As a result of this surface weather pattern, surface winds are northeasterly over our area.
In the upper levels of the atmosphere… the wind pattern over the USA has become more zonal (west-to-east) with a weak upper level low pressure area moving eastward out of Texas. As a result of the overall upper level wind flow, the upper level winds over south central Texas and the Austin metro area about 18,000 feet above the ground are west northwesterly 30 to 40 mph.
As the surface high, to our north, continues to move eastward, we’re seeing a return to a southeasterly wind by later today into tonight and tomorrow. We’ll even see a slim chance of rain by tomorrow and into late week as moisture returns and deepens over our area.
By Friday, a strong upper air disturbance will pass by to our north and reshape the upper air wind pattern to allow for a strong cold front to move southward through the area about daybreak Friday. As the cold front moves offshore of the Texas coast by late Friday, another approaching upper air disturbance will keep moisture overrunning the colder air with rain chances and clouds persisting through next weekend and even into next week as well. Temperatures will cool to well below average levels by late Friday and through next weekend and into next week.
Latest guidance suggests that another upper air low pressure disturbance will move through the area next Tuesday and this will cause surface development of a low pressure off the Texas coast. As these systems move eastward, clouds will decrease and rain chances will drop from the forecast.
Regarding my forecast, my local forecast confidence: High to very high forecast confidence through the midweek.. then a moderate to high confidence forecast for the latter part of the week. Confidence falls to moderate for Friday through the weekend into next week (I have some questions regarding how much colder air will be with the cold front and if rain probabilities should be higher).
Have a good Tuesday…
Meteorologist Troy Kimmel