NWS Sunday Evening Forecast Discussion – 10 p.m.

An extremely positively tilted but stretched trough in the Ohio Valley will drift slightly southward as the remnant upper level low ejects eastward in the trough. Cold advection at the surface with a high pressure system building eastward out of the Rockies, combined with rich low level moisture tonight will bring a fog potential to the area. However, evaporational cooling allowed by low clouds advecting southward and high clouds streaming from the gulf will keep the fog threat from being uniform.

The result will be variable clouds tonight with patchy fog depending on winds and cloud cover with temps near normal. After morning fog and low clouds expect improving conditions as surface high builds in from the west with seasonable temps.

Not quite as confident with the forecast through the week, but confidence in a dry forecast still remains good. On the other hand, by the weekend all bets are off. The overall pattern remains with active southern stream and a bit of a convoluted and evolving northern branch through the week.

A large upper low over the four corners area ejects as a new upper low undercuts the upper ridge on the west coast. This lead low then opens up and progresses eastward through the week dragging a poorly defined, dry cold front through the area Tuesday night through Wednesday morning. Main energy with this system skirts by to our north centered over the Ohio Valley. Models continue to keep any precipitation just north of the area, brushing extreme northern Alabama. A Strong surface high settles into the mid Mississippi Valley, which should keep us in a more or less continuous northerly flow Wednesday and Thursday.

Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather

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Developing Sub-Tropical Storm in the Gulf of Mexico! Strange Winter Continues… Sunday Evening Update 8:40 PM

Below is a discussion from the National Hurricane Center. There is a developing low pressure in the gulf that has a chance to become a sub-tropical storm. Either way, gusty winds and heavy rain will become likely across Florida over the next few days. The last time a tropical storm or sub tropical storm developed this early in the year was on February 2, 1952.

SPECIAL TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
645 PM EST SUN FEB 5 2012

FOR THE NORTH ATLANTIC…CARIBBEAN SEA AND THE GULF OF MEXICO…

 NON-TROPICAL LOW PRESSURE SYSTEM INTERACTING WITH AN UPPER-LEVEL TROUGH IS PRODUCING WIDESPREAD CLOUDINESS…SHOWERS…AND SCATTERED THUNDERSTORMS ACROSS MUCH OF WESTERN AND CENTRAL CUBA…THE LOWER FLORIDA KEYS…AND ADJACENT WATERS OF THE NORTHWESTERN CARIBBEAN SEA…SOUTHEASTERN GULF OF MEXICO…AND THE FLORIDA STRAITS. THE LOW IS CENTERED JUST WEST OF THE WESTERN TIP OF CUBA…AND A SURFACE CIRCULATION CENTER IS GRADUALLY BECOMING BETTER DEFINED. SHOWER ACTIVITY HAS BEEN SLOWLY INCREASING AND HAS BECOME BETTER ORGANIZED TODAY…AND IF THIS DEVELOPMENT TREND CONTINUES…THEN A SUBTROPICAL DEPRESSION OR A SUBTROPICAL STORM COULD FORM DURING THE NEXT DAY OR SO BEFORE THE DISTURBANCE MERGES WITH A COLD FRONT. THIS SYSTEM HAS A MEDIUM CHANCE…30 PERCENT…OF BECOMING A SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY NORTH-NORTHEASTWARD TONIGHT AND MONDAY MORNING…BEFORE TURNING NORTHEASTWARD AT 10 TO 15 MPH TOWARD SOUTH FLORIDA AND THE FLORIDA KEYS BY MONDAY AFTERNOON AND EVENING. REGARDLESS OF DEVELOPMENT… THIS SYSTEM WILL LIKELY BRING LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS TO PORTIONS OF THE FLORIDA KEYS AND SOUTH FLORIDA OVER THE NEXT COUPLE OF DAYS. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN OFFSHORE WATERS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE…UNDER AWIPS HEADER MIAOFFNT3 AND WMO HEADER FZNT24 KNHC…AND ALSO IN PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE. ADDITIONAL SPECIAL TROPICAL WEATHER OUTLOOKS WILL BE ISSUED AS NEEDED.

WVUA Chief Meteorologist Richard Scott

rscott@wvuatv.com