[PBARC] Winter Storm Forecast

[WOLF, EARNEST G]

Winter Storm Forecast

    Issued:   09:15 AM Wednesday January 15, 2003

Freeze to Gulf Coast This Week - Much Colder Temperatures Possible Next Week 


In the short range, the Canadian front in the Central Plains will be moving southward to the Gulf coast by mid day on Thursday, bringing some of the coldest air of the season to the
Gulf coast. The air should be cold enough to produce low temperatures in the mid to upper 20s from the middle Texas coast, across south Louisiana, to the Florida Panhandle on Friday and
Saturday. The coldest temperatures for Texas and southwest Louisiana may be on Friday morning, as some modification of the cold air should occur there before Saturday morning. From
central Louisiana through the Florida Panhandle and northern Florida Peninsula, the coldest temperatures will be on Saturday. Farther north across Nebraska, Kansas, and Missouri, heavy
snow is likely tonight through Thursday morning. These areas could receive 6-12 inches of snow. We do not see any significant freezing rain threat across Oklahoma or Arkansas with this
event. The storm system will track eastward across the Tennessee Valley on Thursday evening, possibly producing another swath of heavy snow across western North Carolina through
Virginia early on Friday. 

Our concern today is for potentially much colder air across the deep south toward the middle to end of next week - January 23-26. The long range model has been indicating that this
event would be the coldest for several weeks, but wild fluctuations in day-to-day model runs have not given us very high confidence in next week's weather pattern. Recently, though, a
model consensus is growing for the development of what is called cross-Polar flow this weekend. This type of weather pattern would favor the movement of bitterly-cold Siberian-Arctic
air across the North Pole into northern Canada. We do agree that this cross-Polar flow is likely to develop by the weekend. This raises several questions. Just how cold will it get
across the Gulf Coast late next week? The models raise the possibility of a very hard freeze, with sub-20 degree temperatures down to the Gulf Coast from the mid Texas coast to the
Florida Panhandle by January 24-26. In fact, there are indications of the potential for afternoon high temperatures to be only in the lower 30s or colder along the Gulf Coast during
this period. This kind of cold air outbreak would be similar to the events of 1989 when the Gulf Coast experienced several days of sub-freezing temperatures. The next question involves
post-frontal cloud cover. We do see the potential for a southern stream disturbance late next week. Such a disturbance would support high temperatures remaining down near freezing or a
bit lower in the cold air. 

At ImpactWeather, we're not ready to accept the worst-case scenario of temperatures in the teens to the Gulf coast and highs below freezing for a day or two next week. Many factors
would have to come together perfectly for such an event to materialize. But we do think next week's temperatures will be significantly colder from Texas through Florida than the
temperatures with this week's cold front. We think there is a good possibility - 60-70% chance - of temperatures in the low 20s from the mid Texas coast to the Florida Peninsula next
week. We also think that there is the same chance for highs in the mid to upper 30s next Friday and Saturday. But everyone on the Gulf Coast should be aware that there is at least a
possibility that temperatures could be 5-10 degrees colder - teens for lows and upper 20s to low 30s for highs - toward the end of next week. 

The next Winter Storm Forecast will be issued near 10:00 AM Thursday. 

Chris Hebert 


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