Updated 845am CT Wednesday / 18 December 2013
…. Clouds and Humidity Picks Up Tonight and Tomorrow Through Late Week ….
…. Upper Air Storm System and Cold Front Due Next Late Friday into the Weekend ….
On this Wednesday morning…. a surface high pressure area extends from the western Tennessee into east Texas with another surface high is over eastern Utah and western Colorado. A trough.. or line.. of low pressure separates the two and extends southward from western Kansas and west Texas into far southwest Texas. As a result of this surface weather pattern, surface winds are southerly across our area.
In the upper levels of the atmosphere… an upper level low pressure trough is moving off the eastern seaboard of the USA and southeastern Canada. Another upper level low pressure disturbance is over the Pacific Ocean just west of the San Francisco Bay area of northern California. As a result, the upper level winds over south central Texas and the Austin metro area about 18,000 feet above the ground are westerly 20 to 30 mph.
A dry and stable weather pattern continues with abundant sunshine expected through today with temperatures slowly warming up.
Southerly surface winds are returning and will be returning low level moisture with clouds becoming more common. This morning we did see some dense fog.. with visibilities as low as a quarter of a mile.. just to our south around the New Braunfels area. Late night and early morning low clouds and light drizzle will be possible tomorrow as well as Friday morning.
An upper air low pressure disturbance will move eastward into northern Mexico and the southwestern United States by late in the week and then pass over the area with a chance of rain showers and thunderstorms. As the disturbance moves by late Saturday, another cold front will settle southward through the area late Saturday night into early Sunday morning.
In the wake of the cold front, clouds will break with sunshine returning to the area by midday Sunday into early next week with slightly below average temperatures.
Regarding my forecast, my local forecast confidence: My confidence in my forecast is very high today. For tomorrow through Saturday, my forecast confidence falls to medium to high (exact timing of rain, exact rain chances and the timing of the cold front still a question). My forecast confidence returns to very high for Sunday into early next week.
Have a good Wednesday…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel