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NWS Peachtree City, Ga » Text Product » MRX Area Forecast Discussion
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Surrounding: BMX MRX FFC CAE TAE Current Version Previous Versions: 1 2 3 4 5 6 7 8 9 Area Forecast Discussion234 FXUS64 KMRX 032027 AFDMRX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 327 PM EST SUN MAR 3 2013 .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)...AS UPPER TROUGH ACROSS THE NORTHEAST MOVES EAST...THEN LOW-CLOUDS AND FLURRIES WILL DISSIPATE THIS EVENING/TONIGHT ACROSS THE FORECAST AREA. FOR MONDAY... RIDGING WILL DOMINATE BOTH SURFACE AND ALOFT...BUT PLENTY OF HIGH AND MID-LEVEL CLOUDS WILL SPILL OVER THE RIDGE INCREASING CLOUDS ONCE AGAIN. FOR MONDAY NIGHT...A STRONG UPPER TROUGH WILL MOVE SOUTHEAST ACROSS THE PLAINS STATES WILL DEEPENING SURFACE LOW HEADING SOUTHEAST TOWARD THE TENNESSEE VALLEY. INCREASING SOUTHERLY WINDS WILL PRODUCE ISENTROPIC LIFT OVER THE TENNESSEE VALLEY. RAIN WILL SPREAD INTO THE REGION WITH HIGHEST POPS OVER THE PLATEAU AND SOUTHEAST TENNESSEE. FOR TUESDAY...STRONG UPPER TROUGH WILL MOVE INTO THE MID- MISSISSIPPI RIVER VALLEY WITH UPPER JET DIVING INTO THE NORTHERN GULF COAST STATES. THE JET WILL PLACE THE FORECAST AREA UNDER THE FAVORED RIGHT EXIT REGION OF THE JET. THE CIRCULATION AROUND THE JET WILL ENHANCE THE FRONTO-GENETIC FORCING WITH THE INCOMING FRONTAL BOUNDARY. ECMWF/GFS SHOW STRONG FRONTO-GENETIC FORCING OVER THE AREA DURING THE AFTERNOON. SINCE THE UPPER TROUGH HAS DEEP COLD AIR WITH 500MB TEMPERATURES BELOW -30 DEGREES CELCIUS...LAPSE RATES WILL STEEPEN WITH CAPES ALONG AND AHEAD OF FROPA TO WARRANT A CHANCE OF THUNDERSTORMS. FOR TUESDAY NIGHT AND WEDNESDAY...STRONG COLD AIR ADVECTION ALOFT ASSOCIATED WITH THE PASSAGE OF THE UPPER LOW OVER THE FORECAST AREA WILL CONTINUE TO STEEPEN THE LAPSE RATES. CAPES OF 100-150 J/KG WILL PRODUCE WIDESPREAD SHOWER ACTIVITY TUESDAY NIGHT DIMINISHING SLOWLY WEDNESDAY. FORECAST SOUNDINGS SHOW PRECIPITATION WILL QUICKLY CHANGED TO SNOW SHOWERS TUESDAY EVENING. ALONG WITH THE INSTABILITY...INCREASING NORTHWEST BOUNDARLY LAYER FLOW WILL PRODUCE GOOD OROGRAPHIC/NORTHWEST FLOW SNOWFALL INTO THE MOUNTAINS FOR TUESDAY NIGHT...THEN DIMINISHING WEDENSDAY NIGHT. HEAVY SNOW ACCUMULATIONS ARE POSSIBLE FOR THE FAR EASTERN TENNESSEE MOUNTAINS AND HIGHER ELEVATIONS OF SOUTHWEST VIRGINIA...SUCH AS HIGH KNOB. A WINTER STORM WATCH MAY BE NEEDED FOR THESE AREAS. WIDESPREAD SNOW SHOWER ACTIVITY TUESDAY AND WEDNESDAY MAY ALSO PRODUCE LIGHT SNOW ACCUMULATIONS FOR THE PLATEAU...SOUTHWEST NORTH CAROLINA MOUNTAINS AND PARTS OF NORTHERN AND CENTRAL TENNESSEE VALLEY. FOLLOWED GFS MOS NUMBERS THROUGH TUESDAY...BUT UNDERCUT DUE TO THE CLOUDS AND PRECIPITATION ON WEDNESDAY. .LONG TERM (THURSDAY THROUGH SUNDAY)...A FAIRLY BENIGN PERIOD WITH NICE SPRING WARMTH TO MAKE UP FOR ALL OF THE RECENT COLD. I WILL TRY TO HEDGE A BIT HIGHER ON MAX TEMPS LATE NEXT WEEK THAN THE 00Z MEX AND ENSEMBLE MEAN GUIDANCE GAVE...TIPPING THE HAT IN THE DIRECTION TOWARD THE WARMEST ENSEMBLE MEMBERS. THE ECMWF IS MORE CONSISTENT WITH ITS SOLUTION OF A SLOWER AND DEEPER ROCKIES TROUGH LATE IN THE PERIOD THAT WILL HELP US WARM A LITTLE MORE THAN THE 00Z EXTENDED GFS AND ENSEMBLE MOS WAS THINKING...AND THUS I WOULD EXPECT US TO REMAIN DRIER A LITTLE LONGER THAN GFS WANTS TOO. NO PRECIP MENTIONED THROUGH THE PERIOD. LOOKING AHEAD...THE GFS RUNS ARE A LITTLE BOUNCY WITH THE DAY 8-9 FORECAST...WHILE THE ECMWF IS MORE CONSISTENT WITH A FAIRLY SIGNIFICANT TROUGH SWEEPING THROUGH THE AREA MONDAY NIGHT OR TUESDAY MORNING. GIVEN THE WARMTH AHEAD OF IT TO WORK WITH...THE BIRD`S EYE VIEW MIGHT EXPECT A CONVECTIVE EVENT DURING THAT TROUGH PASSAGE. PROBABLY A QUICK RESUMPTION OF SPRING TIME TEMPS THE NEXT DAY FOLLOWING THE TROUGH PASSAGE. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 27 55 43 59 33 / 0 10 60 90 40 KNOXVILLE MCGHEE TYSON AIRPORT, TN 24 49 39 56 31 / 0 10 60 100 70 OAK RIDGE, TN 24 49 39 56 31 / 0 10 70 100 60 TRI CITIES AIRPORT, TN 19 47 33 56 30 / 0 10 40 100 80 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ |