[Printable]
813 FXUS64 KJAN 190840 AFDJAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 340 AM CDT WED JUN 19 2013 .SHORT TERM...THE FOCUS OF THE FORECAST WILL CONTINUE TO REVOLVE AROUND PRECIP CHANCES...ESPECIALLY FOR TODAY AND THU...BUT THESE CHANCES WILL OVERALL LESS THAN WHAT THE AREA HAS SEEN THE PAST COUPLE DAYS. ONE OF THE KEY FEATURES THAT WILL INFLUENCE OUR WEATHER IS THE STALLED WEAK SFC FRONT ACROSS THE AREA. THIS BOUNDARY HAS BECOME BROAD/DIFFUSE...BUT IS GENERALLY SITUATED FROM TUP TO MLU. WHILE IT WOULD SEEM THAT AREAS ALONG AND SOUTH OF SAID BOUNDARY WOULD HAVE THE BEST PRECIP POTENTIAL TODAY...THIS NOT TRULY THE CASE. THE REASON IS THAT SOME DRIER AIR IN THE MID LEVELS IS PRESENT FOR AREAS JUST NORTH OF I-20. THIS IS IN PART TO NORTHERLY MID LEVEL FLOW DRAWING SOUTHWARD THAT DRIER AIR AS THE S/WV PASSED ACROSS THE SOUTHERN PARTS OF THE FORECAST AREA LAST EVENING. WITH ALL OF THIS...AREAS ALONG AND SOUTH OF I-20 WILL HAVE THE DEEPEST MOISTURE TO WORK WITH TODAY ALONG WITH SOME LOW LEVEL FOCUS FROM THE STALLED SFC BOUNDARY. ADDITIONALLY...WATER VAPOR IMAGERY SHOWS THE MID/UPPER TROUGH AXIS QUITE WELL AND IT IS SITUATED JUST TO OUR WEST. THIS FEATURE SHOULD ASSIST LIFT (ESP THIS MORNING) AND GENERATE PRECIP ACROSS THE SOUTHERN HALF OF THE AREA. THINKING THAT THE AIRMASS HAS BEEN WORKED OVER QUIET A BIT...OVER ALL LESS STORM COVERAGE IS EXPECTED. THUS...FOLLOWING THE 20-40% POPS FROM THE GFS SEEM VALID. WITH ANOTHER EARLY START TO ACTIVITY...WILL TREND POPS/WX DOWN FOR THE LATE AFTERNOON. LIKE YESTERDAY...TEMPS WILL BE HELD IN CHECK THANKS TO CLOUDS AND THE EARLY START TO PRECIP. GFS GUIDANCE INDICATES THIS WELL AND HAVE FOLLOWED. TONIGHT WILL BE GENERALLY QUIET WITH CLEARINGS SKIES. TEMPS WILL BE A BIT COOLER THAN WHAT WE HAVE SEE WITH UPPER 60S EXPECTED. THURSDAY WILL BE A TRICKIER FORECAST AS THE PREV MENTIONED SFC BOUNDARY WILL STILL BE IN THE GENERAL AREA BUT LIKELY SITUATED/ORIENTED IN A DIFFERENT MANNER. DEEP MOISTURE WILL BE OVERALL LOWER AREAWIDE WITH HIGHER MOISTURE CONTENT GENERALLY ACROSS THE SW/S HALF. WHAT MAKES THE FORECAST TRICKY IS THE PRESENCE OF A DISTINCT S/WV DROPPING SE. ASSOCIATED WITH THIS FEATURE WILL BE COOLER TEMPS IN THE MID LEVEL AND ALOFT. THE MID/UPPER LEVEL JET WILL ALSO BE SITUATED IN A WAY THAT SUPPORTS UPWARD MOTION. EVEN AS THESE FAVORABLE FEATURES EXIST...MODEL DATA IS NOT SHOWING MUCH DEVELOPMENT. I CAN`T ARGUE THAT THERE WILL BE LESS OVERALL POTENTIAL...BUT FEEL THAT ENOUGH INGREDIENTS WILL EXIST THAT ISOLATED STORMS WILL BE POSSIBLE DURING THE AFTERNOON. WITH THAT...HAVE INCREASED POPS FROM 10% TO 20% AND MENTIONED SLIGHT CHANCE FOR AFTERNOON ACTIVITY. AT THIS TIME...I WILL NOT MENTION ANY POSSIBILITY FOR STRONG STORMS...BUT THIS WILL HAVE TO BE MONITORED AS THE COOLER TEMPS ALOFT WILL LEAD TO BETTER LAPSE RATES AND A BIT HIGHER INSTABILITY AS SFC TEMPS WILL BE 2-4 DEGREES WARMER. /CME/ .LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...AN UPPER RIDGE WILL TRY BUILDING INTO THE WESTERN HALF OF THE FORECAST AREA FRIDAY INTO THE WEEKEND AS AN UPPER TROUGH PULLS OFF TO THE NORTHEAST AND UP THE EAST COAST. AS THIS HAPPENS...THE TROUGH WILL LEAVE BEHIND A PIECE OF ENERGY THAT`LL SET THE STAGE FOR SOME ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND STORMS OVER MAINLY EAST AND SOUTHEAST MISSISSIPPI THROUGH THE WEEKEND. RAIN CHANCES LOOK TO WANE HEADING INTO THE NEW WORK WEEK AS THE UPPER RIDGE BUILDS FURTHER EAST INTO THE CWA. OTHERWISE...LOOK FOR CONTINUED HOT AND HUMID CONDITIONS THROUGH THE FORECAST PERIOD. GUIDANCE SUGGESTED HIGHS AND LOWS LOOK REASONABLE THIS MORNING. HIGHS EACH AFTERNOON WILL RANGE IN THE LOW TO MID 90S...WHILE LOWS EACH NIGHT GENERALLY RANGE FROM THE UPPER 60S TO LOWER 70S. /19/ && .AVIATION...SOME MVFR VIS CONDITIONS ARE EXPECTED THIS MORNING WITH SOME POTENTIAL FOR IFR VIS NEAR GLH. THERE IS ALSO SOME POTENTIAL FOR A BRIEF PERIOD OF IFR CEILINGS BETWEEN 11-13Z FOR SITES ALONG I-20. THERE WILL ALSO BE SOME CHANCE FOR SHRA/TSRA TODAY FOR THE SOUTHERN HALF OF THE AREA AND WILL MENTION THAT WITH VC WORDING. OUTSIDE ANY CONVECTION...EXPECTING VFR CONDITIONS TO EXIST FROM 13-15Z INTO TONIGHT. MVFR VIS WILL BE POSSIBLE TONIGHT...MAINLY AFTER 07-08Z. /CME/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 89 68 91 69 / 41 12 17 6 MERIDIAN 87 66 91 68 / 38 9 15 12 VICKSBURG 88 67 91 68 / 36 12 17 4 HATTIESBURG 87 69 92 69 / 46 25 23 12 NATCHEZ 87 68 90 68 / 41 18 23 6 GREENVILLE 90 68 94 70 / 6 3 7 3 GREENWOOD 90 67 93 68 / 6 3 5 5 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ CME/19/
