Friday, January 7, 2011

1/7 - 8:15pm - Big Changes to Southern Winter Storm!

A day makes quite a difference when it comes to winter storm forecasting, and boy do we have some changes in the forecast to talk about. The major US-based computer models, the GFS and NAM, have both trended colder and wetter in today's runs compared to yesterday. Instead of talking about ice problems in Starkville and the Golden Triangle, we're now talking heavy snow. Jackson, TN has also seen a bump in snow totals on the models, with 2-4" now possible in the Hub City.

Jackson, TN
While no Winter Storm Watch is in effect for the Jackson area, snow totals could reach 2-4" by Monday midday. While this won't be a very heavy snowfall, it'll certainly cause travel problems across West Tennessee. The snow totals will increase as you head toward the Mississippi border, where up to 5 inches is possible. As you'll see in the graphic to the right, Winter Storm Watches begin with the Tennessee counties bordering Mississippi and go all the way south to just north of the Gulf Coast. I saw earlier this evening that brine has been applied to many roads across West Tennessee and that's certainly good news for travelers in the region on Sunday into Monday. I'll have the latest forecast for Jackson and West Tennessee tomorrow morning at 6am on WBBJ ABC 7's Good Morning West Tennessee!

Here's what the National Weather Service in Memphis has to say about this system:
GIVEN ALL OF THIS...IT SEEMS BEST TO CONTINUE WITH AROUND AN INCH NORTH OF JONESBORO TO PARIS...3 TO 4 INCHES ALONG AND SOUTH OF I-40...AND 5 TO 8 INCHES ACROSS MUCH OF NORTHERN MISSISSIPPI. DESPITE SOME HIGHER QPF SOUTH OF OXFORD AND TUPELO...WILL NOT PUSH TOTALS ABOVE 8 INCHES FOR NOW. LATER FORECASTS WILL CONTINUE TO FINE TUNE THESE TOTALS AS HOPEFULLY BETTER MODEL OUTPUT BECOMES AVAILABLE.

Starkville, MS
The shift from a couple inches of snow with ice accumulations to heavy snow accumulations of 4-8" in Starkville by Monday morning on the computer models has been remarkable today. Colder temperatures in the mid levels of the atmosphere and increased precipitation totals have really bumped up the snow totals across the Golden Triangle and I think this is a much better solution than an ice storm in the area. Unfortunately, that risk has shifted to Central Mississippi just south of Macon, MS and power outages and tree damage could be an issue down there. The most ambitious computer model today has been the 18z NAM run (on left), which gave Starkville over 9 inches of snow. I don't think we'll get quite that much snow, but the National Weather Service's 4-8" forecast looks on-par with what I'm thinking at this point. This will be the largest snow storm in quite a few years should this pan out, so get ready for some significant travel issues in North and Central Mississippi on Sunday night and Monday. I'll keep watch on the latest model runs and post tomorrow with the latest updates!

Here's what the National Weather Service in Jackson, MS says about Mississippi's winter weather chances:
AS FAR AS PRECIPITATION TYPE...MODEL SOUNDINGS AND SREF OUTPUT GENERALLY SUPPORT PRIMARILY SNOW...PERHAPS MIXED AT TIMES WITH SLEET AND A LITTLE FREEZING RAIN...ALONG AND N OF A BASTROP LA TO MACON LINE. GIVEN THE FORECAST QPF...THIS WOULD RESULT IN ABOUT 4 TO 8 INCHES OF SNOW ACCUMULATION IN THIS AREA. ACROSS THE I-20 CORRIDOR...A FULL WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN LOOKS TO BE POSSIBLE AT THIS POINT. DEPENDING ON WHAT THE DOMINANT PCPN TYPE ENDS UP BEING...THIS COULD RESULT IN SEVERAL INCHES OF SNOW...A COUPLE OF INCHES OF SLEET...OR A SIGNIFICANT LAYER OF GLAZE. ALONG THE HIGHWAY 84 CORRIDOR...PRECIP LOOKS TO POTENTIALLY BEGIN AS SNOW/SLEET THEN TRANSITION TO A MIX OF SLEET...FREEZING RAIN AND RAIN WITH SOME WINTRY ACCUMULATIONS POSSIBLE. ALL OF THESE AREAS WILL BE UNDER A WINTER STORM WATCH FROM 6 AM SUN TO 6 AM MON PER COORDINATION WITH SURROUNDING OFFICES.

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