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AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 335 PM CST SAT JAN 20 2007 .SHORT TERM...CLOUDS HAVE FINALLY OVERSPREAD THE MID STATE WITH TEMPERATURES HAVE RISEN INTO THE LOWER TO MID 40S MOST AREAS. HOWEVER, THE SURFACE AIR REMAINS DRY, WITH DEW POINT DEPRESSIONS AVERAGING 20 DEGREES OR SO AREA-WIDE. THEREFORE, ALTHOUGH LIGHT PRECIPITATION HAS MOVED INTO WEST TENNESSEE, IT WILL BE A FEW HOURS BEFORE IT STARTS REACHING THE GROUND HERE. SURFACE ANALYSIS AT 20Z SHOWS THE SURFACE LOW STILL CENTERED OVER NORTHEASTERN NEW MEXICO, ALTHOUGH MOISTURE IS BEING PUSHED UP WELL AHEAD OF THE ACTUAL FRONTAL SYSTEM. BY 18Z TOMORROW, LOW CENTER WILL HAVE MOVED INTO CENTRAL MISSOURI, ALTHOUGH BY THEN THE DEEPEST MOISTURE WILL HAVE MOVED EAST OF NASHVILLE. IN THE MEANTIME, MODEL SOUNDINGS INDICATE THAT PRECIPITATION MAY MIX WITH SLEET THIS EVENING, ALTHOUGH THE LOW-LEVEL TEMPERATURE PROFILE (UP TO ABOUT 700 MB) WILL BE ALMOST ENTIRELY ABOVE FREEZING. EVAPORATIVE COOLING, OWING TO THE LARGE DEW POINT DEPRESSIONS, WILL PROBABLY FORCE TEMPERATURES DOWN ANOTHER COUPLE OF DEGREES WHEN THE PRECIPITATION BEGINS. BUT OVERALL, THE ENVIRONMENT IS JUST TOO WARM TO SUPPORT PURE WINTRY PRECIPITATION. SLEET WILL BE MOST PREVALENT IN AREAS NORTH OF NASHVILLE AND ALONG THE CUMBERLAND PLATEAU, WHERE ELEVATIONS ARE HIGHER AND SURFACE TEMPERATURES WILL BE SLIGHTLY COOLER. WHATEVER SLEET DOES MIX IN WILL LIKELY MELT SHORTLY AFTER DAYBREAK TOMORROW AS TEMPERATURES WARM, OWING TO AN INCREASING SOUTHERLY FLOW. AM LOOKING FOR ALL RAIN AFTER 14Z. .LONG TERM...PRECIPITATION WILL TAPER OFF TOMORROW AFTERNOON AND EVENING, BUT LOOK FOR CLOUDS TO REMAIN AT LEAST THROUGH MONDAY, AS THE 500 MB SHORTWAVE WON`T ACTUALLY PASS THROUGH MIDDLE TENNESSEE UNTIL MONDAY NIGHT. A RIDGE OF HIGH PRESSURE WILL KEEP TEMPERATURES DOWN IN THE NORMAL RANGE FOR THIS TIME OF YEAR. THE NEXT WEATHER SYSTEM WILL BEGIN TO AFFECT THE MID STATE ON WEDNESDAY, WITH SNOW POSSIBLE WEDNESDAY NIGHT AND THURSDAY, BUT AM STICKING WITH A RAIN/SNOW MIXTURE IN THOSE PERIODS SINCE IT`S SO FAR OUT.