Updated 915am CT – Wednesday / 04 March 2015
… Here Comes the Arctic Cold Front …
… Computer Models Trend A Little Warmer Temperature Wise …
… Possible Round of Wintry Precipitation Tonight into Thursday …
On this Wednesday morning…. a strong arctic cold front extends southwestward from western Arkansas and extreme southeastern Oklahoma into northern areas of central Texas then westward into west Texas and New Mexico. Temperatures, behind the front, have into the 20s and 30s over the Texas panhandle and Oklahoma. As a result of this surface weather pattern, our local surface winds are light and variable or light southeasterly.
In the upper levels of the atmosphere.. a deep upper level trough.. or line of low pressure southwestward from the western Great Lakes Across the central and southern Rockies and into southern Arizona and northwestern Mexico. As a result, our upper air winds at about 18,500 feet are southwesterly at 55 to 65 mph.
Dense fog and light drizzle and light rain continues over our area this morning as a south southeasterly surface wind flow tries to reestablish in advance of the arctic cold front to our north. Clouds are likely to linger along with good chances of rain showers and thunderstorms, with an attendant lightning risk, as the front approaches and then moves through the area early to mid afternoon.
With the passage of the arctic cold front, there will be a rapid drop in temperatures with temperatures in the 60s falling quickly through the 40s into the evening rush hour today. The latest numerical computer guidance suggests temperatures overnight tonight into early tomorrow /Thursday/ will not be as cold as I had earlier predicted with lows overnight closer to 30 to 31 degrees. In other words, once again, we find ourselves in the difficult forecast situation being that we will be sitting on the freezing line locally which will define exact precipitation types. In any case, an overrunning pattern will persist on top of the advancing shallow layer of arctic air with light precipitation likely later this afternoon through tonight with precipitation tapering off a bit during the morning and midday hours tomorrow. It is likely, given the very latest forecast guidance, that parts of our south central Texas area could see either a wintry mix or a changeover to freezing/frozen wintry precipitation tonight into midday Thursday with possible ice accumulations and associated hazardous driving conditions in some areas. All local interests should stay in close touch with the latest weather information from the National Weather Service through tomorrow.
It appears that the overrunning pattern, even with some breaks in the clouds late Thursday into Thursday night and Friday, will linger late week into the weekend as temperatures only slowly warm just as we saw this past weekend.
Regarding my forecast, my local forecast confidence: My forecast confidence is lowered to medium today through tomorrow (as it relates to the extent and intensity of freezing temperatures and associated precipitation types) then back up to high tomorrow night through Friday and the weekend as it regards the basic weather pattern and precipitation occurrence, timing and amounts. Although it is a little lower than yesterday, I continue to have low to medium confidence of some type of freezing/frozen precipitation tonight into tomorrow.
Have a good Wednesday….
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel