118 FXUS62 KFFC 220540 AFDFFC AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PEACHTREE CITY GA 135 AM EDT WED MAY 22 2013 .UPDATE... UPDATED TO INCLUDE SOME POPS THROUGH MIDNIGHT FOR WEST CENTRAL GA AS WESTWARD MOVING OUTFLOW BOUNDARY LIKELY TO SPAWN A FEW MORE THUNDERSTORMS. WATCHING CLOSELY STORMS ACROSS NORTH GA FOR POSSIBLE LOCALIZED FF THREAT AS WELL. MOST STORMS HAVE BEEN PRODUCING PEA TO NICKEL SIZED HAIL THIS EVE AND EXPECT TREND TO CONTINUE THROUGH 4Z TO 5Z. OTHER UPDATE WAS TO GRIDS WED AFTN AND EVE TO INCLUDE SMALL HAIL AND GUSTY WINDS AS THERE APPEARS TO BE A MARGINAL SEVERE THREAT DUE TO SLIGHTLY INCREASING DEEP LAYER SHEAR PROFILES....PARTICULARLY ACROSS NW AND NE GA. WILL NEED TO MONITOR FOR POTENTIALLY INCREASING SEVERE THREAT AFTER 3 PM WED. && .PREV DISCUSSION... /ISSUED 805 PM EDT TUE MAY 21 2013/ PREV DISCUSSION... /ISSUED 314 PM EDT TUE MAY 21 2013/ SHORT TERM /TONIGHT THROUGH WEDNESDAY/... MODELS CONTINUE IN GOOD AGREEMENT THROUGH THE SHORT TERM. AIRMASS SHOWERS/TSTORMS DEVELOPING ACROSS THE CWA...MAINLY ACROSS THE EXTREME NORTH AND EASTERN PARTS OF THE CWA. THESE WILL DISSIPATE SHORTLY AFTER SUNSET THIS EVENING. THERE IS A POSSIBILITY THAT THE STORMS OVER NORTHWEST AL AND CENTRAL TN COULD MAKE IT TO EXTREME NORTHWEST GA BEFORE DIMINISHING THIS EVENING. THE H5 RIDGE OVER THE EASTERN U.S. WILL WEAKEN AS THE CENTRAL U.S. TROUGH MOVES INTO THE MISSISSIPPI VALLEY. THIS WILL PUSH A COLD FRONT INTO THE TENNESSEE VALLEY WEDNESDAY WHICH WILL BRING A BETTER CHANCE OF THUNDERSTORMS TO THE CWA...MAINLY ACROSS NORTH GA. INSTABILITY INCREASES WEDNESDAY ACROSS NORTH GA AND THIS COULD PRODUCE A FEW STRONG STORMS. GUIDANCE TEMPS LOOK GOOD FOR TONIGHT...ALTHOUGH TRICKY FOR WEDNESDAY WITH ADDITIONAL CLOUDS. WILL TREND TO THE COOLER SIDE OF GUIDANCE ACROSS NORTH GA FOR HIGHS ON WEDNESDAY DUE TO INCREASED CLOUDS AND PRECIP. 17 LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... BY WEDNESDAY EVENING...BOTH THE GFS AND ECMWF INDICATE THAT THE FRONT WILL BE WEAKENING SIGNIFICANTLY. GFS REMAINS AB IT ON THE STRONG SIDE WITH A SLIGHTLY MORE EAST WITH THE GREAT LAKES SURFACE LOW. BOTH ARE TRANSITIONING THE UPPER LOW TO MORE OF A SHARP OPEN TROUGH PHASING WITH THE LONGWAVE TROUGH IN CANADA. WEAK SHORTWAVE OFF THE SOUTH CAROLINA COAST WILL LIFT NORTHEAST AND BE ABSORBED BY THE LONGWAVE TROUGH AS WELL. SPC CONTINUES THE AREA IN GENERAL THUNDER FOR THURSDAY...WITH MUCAPE VALUES 500-1000 J/KG EARLY IN THE DAY...DECREASING BY MID-MORNING...AND INCREASING AGAIN IN EXTREME SOUTHERN ZONES JUST AHEAD OF THE FRONT AFTER 18Z TO OVER 1000 J/KG. WILL HAVE TO MONITOR THE AREA FOR THE POTENTIAL FOR ISOLATED STRONG STORMS BUT NOTHING TO SIGNIFICANT. COLD FRONT SHOULD BE PUSHED THROUGH THE AREA BY LATE THURSDAY... AND HAVE DECREASED TEMPS NORTHWEST SOMEWHAT TO LINE UP WITH THAT TIMING A LITTLE BETTER. SHOULD SEE A SIGNIFICANT DECREASE IN TEMPS TOWARD THE END OF THE WEEK WITH SURFACE HIGH PRESSURE BUILDING IN AND NORTHWEST FLOW ALOFT...CURRENT FORECAST HAS HIGHS ON FRIDAY ABOUT 5 DEGREES COOLER THAN HIGHS ON THURSDAY EXCEPT IN CENTRAL GEORGIA. SEE PREVIOUS LONG TERM DISCUSSION BELOW. TDP AVIATION... 06Z UPDATE... SOME MID/HIGH CLOUDS LINGERING INTO THE MORNING HOURS. VISIBILITY SHOULD REMAIN ABOVE 6SM...BUT MAY DROP TO MVFR MAINLY ATHENS AND MACON. VFR DURING THE DAY TODAY EXCEPT IN SHOWERS AND THUNDERSTORMS. THERE MAY BE CONVECTION AROUND THE FORECAST AREA MUCH OF THE DAY BUT THE BEST CHANCE FOR THUNDER AT ANY OF THE TAF SITES APPEARS TO BE 18Z AND INTO THE EARLY EVENING. VARIABLE TO LIGHT SOUTHEAST WINDS THIS MORNING BECOMING SOUTHWEST 10KT AFTER 14Z. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE ON TIMING OF CONVECTION. HIGH CONFIDENCE ON ALL OTHER ELEMENTS. 41 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 64 84 64 84 / 30 40 40 30 ATLANTA 67 83 66 82 / 20 40 40 30 BLAIRSVILLE 60 77 60 78 / 30 60 60 30 CARTERSVILLE 64 84 62 82 / 20 60 60 30 COLUMBUS 68 89 67 87 / 20 30 30 30 GAINESVILLE 65 83 64 81 / 20 50 50 30 MACON 63 87 65 86 / 20 30 30 30 ROME 64 84 61 83 / 30 60 60 30 PEACHTREE CITY 63 85 63 84 / 20 40 30 30 VIDALIA 68 89 69 88 / 40 30 30 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...30 LONG TERM....SNELSON AVIATION...41