406 FXUS64 KJAN 030912 AFDJAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 412 AM CDT THU OCT 3 2013 .SHORT TERM...THE FOCUS FOR THIS SHORT TERM WILL BE ON THE POTENTIAL TROPICAL SYSTEM (KAREN IF NAMED) EVOLVING ACROSS THE CENTRAL GULF. FOR US...THIS SYSTEM WILL NOT AFFECT THE CWA DURING THE NEXT 48 HRS (THU-FRI) BUT COULD HAVE SOME IMPACT OVER THE WEEKEND. MORE ON THAT PART OF THE FORECAST IN THE LONG TERM. FOR TODAY AND FRI...OUR REGION WILL BE ON THE WESTERN SIDE OF THE EVOLVING SE CONUS RIDGE. THIS WILL KEEP OUR AREA UNDER THE INFLUENCE OF SE/S LOW LEVEL FLOW...THUS IN A WARM/HUMID PATTERN. RECENT DAYS HAVE NOT BEEN REAL ACTIVE WITH CONVECTION DESPITE BEING VERY CLOSE TO A MID/UPPER LEVEL LOW AND HIGH MOISTURE AROUND. NOW...THE LACK OF A MID/UPPER LEVEL FEATURE WILL LIMIT OVERALL LIFT WHICH SHOULD RESULT IN LESS OVERALL CONVECTIVE ACTIVITY. LATEST PRECIP GUIDANCE SHOWS THIS WELL AND WILL FOLLOW THE 20-30% TYPE POPS OFFERED. INSTABILITY WILL BE LIMITED AND NOT REALLY EXPECTING MUCH IN THE WAY OF THUNDER...DUE TO THIS...ONLY MENTIONED SHOWERS IN THE FORECAST. WITH OVERALL LESS CLOUDS/PRECIP AROUND...TEMPS SHOULD BE WARMER THAN PREV DAYS. THE GFS INDICATES THIS AND ACTUALLY HAS SOME 90S FORECAST. THE NAM ON THE OTHER HAND IS MORE BULLISH WITH PRECIP...THUS HAS TEMPS MORE IN THE LOWER/MID 80S. I AGREE MORE WITH THE GFS BUT FEEL THAT IT IS TOO AGGRESSIVE FOR SOME LOCATIONS. DUE TO THIS...HAVE TRIMMED A COUPLE DEGREES OFF HIGHS. AS FOR LOW TEMPS...THE ABOVE AVG TREND WILL CONTINUE AND GUIDANCE IS GENERALLY ON TRACK. THE ONLY CHANGE WAS ON FRI NIGHT WHERE THE GFS SEEMED A BIT TOO LOW. VALUES WERE RAISED A BIT AS WARMER READINGS WERE PREFERRED DUE TO HIGHER SFC DEWPTS ON THE HEELS OF A MORE PERSISTENT S/SE SFC FLOW PATTERN. /CME/ .LONG TERM...SATURDAY THROUGH THURSDAY...THE EXTENDED FORECAST HINGES ON THE POTENTIAL TROPICAL SYSTEM IN THE SOUTHERN GULF. UPPER RIDGING WILL GIVE WAY TO A DEEP UPPER TROUGH AND ASSOCIATED COLD FRONT ON SATURDAY. THE GFS/ECMWF ARE IN PRETTY GOOD AGREEMENT THAT THE COLD FRONT WILL MOVE INTO THE DELTA BY EARLY SATURDAY EVENING AND MOVE ACROSS THE AREA SATURDAY NIGHT. THE TRACK OF THE TROPICAL SYSTEM WILL DICTATE OUR WEATHER AS IT INTERACTS WITH THE BOUNDARY. IF THE TRACK IS FURTHER EAST OVER SOUTHERN ALABAMA/NORTHWEST FLORIDA IT WILL CUT OFF MOST OF THE MOISTURE AND WE WILL PREDOMINATELY BE IN A DRY EAST TO NORTHEAST FLOW. IF IT TAKES A FURTHER WEST TRACK OVER SOUTHEAST LOUISIANA/SOUTHERN MISSISSIPPI THEN OBVIOUSLY WE WILL BE MUCH WETTER. MEX GUIDANCE HAS COME IN MUCH DRIER THAN PREVIOUS RUNS SINCE IT TRACKS THE SYSTEM FURTHER EAST SO WILL BUMP UP POPS FOR SATURDAY TO BE CONSISTENT WITH PREVIOUS FORECASTS. EITHER WAY IT LOOKS LIKE THE TROPICAL SYSTEM WILL BE EAST OF THE AREA BY SUNDAY...BUT EXPECT SOME LINGERING SHOWERS BEFORE COOLER DRIER AIR MOVES IN FOR MONDAY AND TUESDAY UNDER NORTHERLY FLOW. HIGHS BOTH DAY WILL BE AROUND 80 DEGREES WITH OVERNIGHT LOWS FALLING INTO THE 50S. THE SURFACE HIGH WILL MOVE FROM THE SOUTHERN PLAINS ON MONDAY TO THE OHIO VALLEY AND EVENTUALLY TO THE EAST COAST BY WEDNESDAY. AS IT DOES THE FLOW WILL SWING AROUND TO A MORE MOIST SOUTHEASTERLY DIRECTION AND THUS EXPECT AND INCREASED CHANCE FOR SHOWERS BY THURSDAY. /15/ && .AVIATION...MVFR AND IFR CEILINGS ARE DEVELOPING THIS MORNING AND LOOK FOR THESE TO CONTINUE TO EXPAND ACROSS THE CWA. IMPROVEMENT SHOULD OCCUR BETWEEN 15-17Z WITH CONDITIONS TRENDING TO VFR. THERE WILL BE THE POSSIBILITY FOR ISO SHRA DURING THE AFTERNOON...BUT WILL HOLD OFF ON INCLUDING IN THE OFFICIAL FORECAST FOR NOW. LOOK FOR MORE MVFR/IFR CEILINGS TO DEVELOP AFTER 08Z TONIGHT. /CME/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 88 69 89 70 / 26 7 18 8 MERIDIAN 88 66 89 67 / 16 8 19 9 VICKSBURG 88 69 90 68 / 28 8 17 8 HATTIESBURG 88 68 89 70 / 28 17 27 18 NATCHEZ 86 70 88 69 / 27 6 20 13 GREENVILLE 87 68 90 69 / 30 11 14 7 GREENWOOD 88 68 90 68 / 22 8 12 7 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ CME/15/