Updated 800am CT – Thursday / 11 December 2014
…. Rain Chances Decrease Tonight into Early Friday ….
…. Rain Shower and Thunderstorm Chances Again Sunday and Sunday Night ….
…. Cooler and Drier Weather for Early Next Week ….
On this Thursday morning…. a surface high pressure area is over southern Wisconsin. Another surface high pressure area is centered over Colorado and western Wyoming. As a result of this surface weather pattern, our local surface winds are very light.
In the upper levels of the atmosphere.. a strong upper level low pressure area is located over eastern New York state. Another weakening upper air low pressure disturbance is moving east across Texas. A third strong/dynamic upper level low pressure storm system is moving ashore of the Oregon and northern California coast. As a result, our upper air winds at about 18,500 feet are west northwesterly 20 to 30 mph.
The weakening upper air disturbance overhead is continuing to move east northeastward with clouds with a chance of rain continuing locally in the forecast. Rainfall amounts of less than 1/4 inch.. according to the latest NWS guidance.. are expected through tonight with this passage of this weather system.
We’ll see clouds break with some sunshine expected by tomorrow into Saturday before another stronger upper air disturbance and surface cold front moves into the area by Sunday into Sunday night. This second weather system appears to be a little more dynamic with increased clouds and rain shower and thunderstorm chances returning to the forecast for as early as Saturday night and then peaking Sunday and Sunday night. I expected, based on the current guidance, that the cold front will pass through our local area around midnight Sunday night. Isolated heavier thunderstorms may accompany this system with rainfall guidance suggesting upwards of 1/2 inch with the system.
It appears that a drier and cooler weather pattern will develop in the wake of the Sunday night/Monday morning upper air low pressure storm system and cold front.
Regarding my forecast, my local forecast confidence: My forecast confidence is medium to high today and tonight and again late Saturday through Sunday and Sunday night with precipitation chances and timing being the uncertainties. Otherwise.. I have high to very high forecast confidence through the seven day forecast.
Have a good Thursday….
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel