429 FXUS62 KFFC 030221 AFDFFC AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 1021 PM EDT SUN JUN 2 2013 .UPDATE... SHOWERS AND THUNDERSTORMS HAVE LARGELY DISSIPATED ACROSS NORTH GEORGIA...WITH THE REMAINING ACTIVITY ACROSS CENTRAL GEORGIA. EXPECT THIS ACTIVITY TO CONTINUE THROUGH THE OVERNIGHT HOURS. HAVE MADE MORE SUBSTANTIAL CHANGES TO THE POPS FOR THE OVERNIGHT AND EARLY MORNING PERIODS TO REDUCE PRECIP CHANCES ACROSS THE NORTHERN PORTIONS OF THE CWA...WHILE KEEPING THE CENTRAL GEORGIA PORTIONS AS HIGH OR SLIGHTER HIGHER THAN THE PREVIOUS FORECAST. DIURNAL CONVECTION STILL EXPECTED MONDAY...AND HAVE ONLY MADE MINOR CHANGES TO POPS AND WEATHER. NO ADDITIONAL CHANGES ARE PLANNED AT THIS TIME. 31 && .PREV DISCUSSION... /ISSUED 801 PM EDT SUN JUN 2 2013/ .ISOLATED SEVERE STORMS POSSIBLE THIS EVENING... SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... /ISSUED 405 PM EDT SUN JUN 2 2013/ COLD FRONT STILL NORTHWEST OF THE STATE HOWEVER TWO LINES OF CONVECTION HAVE DEVELOPED ACROSS THE CWA AHEAD OF THIS FRONT. LOCAL WRF HAS PICKED UP ON BOTH LINES BUT WEAKENS THE EASTERN LINE AND LETS THE WESTERN LINE DOMINATE. ALTHOUGH HRRR ISNT AS CLEAR WITH BOTH LINES...IT DOES SHOW THE WEST LINE OF CONVECTION CONTINUING TO DOMINATE AND PUSH EAST. FORECAST IS IN LINE WITH THESE TWO HI-RES MODELS WITH THE FOCUS BECOMING ON THE WEST LINE. WILL CONTINUE TO MOVE EAST TONIGHT SO HAVE SHOWN CATEGORICAL POPS INTO THE EVENING FOR MUCH OF THE CWA. WITH 1500-2000 J/KG OF MUCAPE THIS AFTERNOON ISOLATED SVR STORMS ARE POSSIBLE WITH THE MAIN THREATS BEING WIND AND HAIL. BEHIND THIS LINE...COULD STILL SEE SCATTERED STORMS DEVELOP OVERNIGHT. CONFIDENCE IS LOW THOUGH ON FORECAST TONIGHT AS THERE ARE SOME DIFFERENCES IN THE MODELS /INCLUDING HI RES/...SOME SHOWING AN ACTIVE NIGHT WHILE OTHERS LIMITING ACTIVITY. HAVE BASICALLY GONE CHANCE POPS THROUGH THE NIGHT. COLD FRONT WILL PUSH THROUGH NORTH GEORGIA TONIGHT AND INTO CENTRAL GEORGIA ON MONDAY. WILL BE ENOUGH MOISTURE AND LIFT FROM THE FRONT THAT CONVECTION IS POSSIBLE AGAIN ON MONDAY BUT THE BETTER CHANCES WILL BE ACROSS THE SOUTHEAST PART OF THE CWA. PLENTY OF INSTABILITY /2000 J/KG OF MUCAPE/ MONDAY AFTERNOON TO SEE A FEW STRONG STORMS. STORMS LOOK TO CONTINUE WITH LAST IN A SERIES OF SHORTWAVES TO MOVE THROUGH MONDAY NIGHT. WILL INCREASE POPS TO HIGH END CHANCE RANGE THROUGH 12Z TUESDAY AS FRONT PUSHES THROUGH. TEMPS ARE NEAR A MODEL BLEND. 11 PREV DISCUSSION... /ISSUED 207 PM EDT SUN JUN 2 2013/ PREV DISCUSSION... UPDATE... /ISSUED 1025 AM EDT SUN JUN 2 2013/ SHOWERS AND THUNDERSTORMS HAVE BEEN SLOW TO DEVELOP ACROSS MUCH OF THE CWA THIS MORNING SO MAIN CHANGE TO THE FORECAST HAS BEEN TO REDUCE POPS FOR THE MORNING. BY EARLY AFTERNOON THOUGH...THE HRRR INCREASES COVERAGE GREATLY ACROSS THE NORTH AND WESTERN PART OF THE CWA AND THIS IS IN LINE WITH THE FORECAST. SOME INDICATION IN THE MODELS SUCH AS THE GFS AND ECMWF THAT THE BETTER COVERAGE WILL CONTINUE INTO TONIGHT AND MAY NEED TO ADJUST OUR POPS UPWARD OVERNIGHT IN FUTURE UPDATES. PORTIONS OF FANNIN AND GILMER COUNTY HAVE ALREADY SEEN AROUND 4 INCHES OF RAIN DURING THIS EVENT SO FAR. ALTHOUGH THEY HAVE RECEIVED A REPRIEVE FROM THE HEAVY RAIN...WILL HAVE TO CONTINUE TO MONITOR THIS AREA CLOSELY FOR POTENTIAL ISOLATED FLOODING AS HEAVY RAIN IS POSSIBLE AGAIN THIS AFTERNOON. 11 PREVIOUS LONG TERM... TUESDAY THROUGH SATURDAY/... /ISSUED 353 AM EDT SUN JUN 2 2013/ MODELS SHOW THE COLD FRONT PUSHING INTO SOUTH GA MONDAY NIGHT... WHERE IT MEANDERS... THEN DRIFTS BACK NORTH SLIGHTLY BY TUESDAY AFTERNOON. THIS WILL WARRANT HOLDING ONTO A SLIGHT CHANCE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE SOUTHERN REACHES OF THE FORECAST AREA ON TUESDAY. A SLIGHT CHANCE OF STORMS SPREAD BACK ACROSS NORTH GA BY WEDNESDAY AS AN EASTERLY WIND FLOW BEGINS TO ADVECT DEEP ATLANTIC MOISTURE BACK OVER THE AREA WHILE A SERIES OF UPPER DISTURBANCES BEGIN TO CARVE A BROAD LONG WAVE TROUGH THAT STRETCHES DOWN THE MS VALLEY REGION BY WEDNESDAY AFTERNOON. THIS UPPER TROUGH DEEPENS OVER THE SOUTH ON THURSDAY AND PROVIDES THE SUPPORT FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE FORECAST AREA THURSDAY AFTERNOON AND EVENING. AT THE SAME TIME... THE ECMWF AND GFS SHOW AN EARLY SEASON TROPICAL SYSTEM PUSHING INTO THE EASTERN GULF ON THURSDAY... ACROSS CENTRAL FL AND INTO THE WESTERN ATLANTIC ON FRIDAY...THEN UP THE EAST COAST ON SATURDAY AS HIGH PRESSURE BUILDING SOUTH OF CANADA HELPS HOLD THE SYSTEM OFF SHORE. AHEAD OF THIS SYSTEM ON FRIDAY... A CONTINUED MOIST EASTERLY FLOW AND UPPER TROUGH WILL SUPPORT DIURNALLY DRIVEN AFTERNOON AND EVENING CONVECTION ACROSS THE AREA AGAIN ON FRIDAY. AS THE TROPICAL SYSTEM PUSHES OFF TO THE NE ON SATURDAY... MODELS SHOW A COLD FRONT AND DRIER AIR SPREADING SOUTH IN ITS WAKE. DUE TO MUCH UNCERTAINTY ON TIMING AND TRACK... WILL CONTINUE TO SHOW A CHANCE OF CONVECTION ON SATURDAY FOR NOW AND MONITOR CHANGES IN THE MODEL RUNS CLOSELY OVER THE NEXT SEVERAL DAYS. 39 AVIATION... 00Z UPDATE... SHOWER AND THUNDERSTORM ACTIVITY STILL IMPACTING ATL AREA AND MCN TAF SITES. ANTICIPATE ACTIVITY TO DIMINISH AFTER 02Z...WITH LINGERING SHOWERS POSSIBLE THROUGH THE EARLY MORNING HOURS. CIGS EXPECTED TO DEGRADE TO LOW MVFR BY 08-09Z...WITH SOME IMPROVEMENT TO MID-HIGH MVFR BY 14-15Z. WINDS WILL BECOME W-WNW BEHIND THE CONVECTION TONIGHT...WITH SPEEDS GENERALLY 6 KT OR LESS. WINDS WILL INCREASE TO 6-8KT THROUGH MONDAY AFTERNOON. CONVECTION EXPECTED AGAIN MONDAY GENERALLY AFTER 18Z...AND HAVE INCLUDED A PROB30 -TSRA IN THE TAF FOR 19-23Z AT THIS TIME. //ATL CONFIDENCE...00Z UPDATE... MEDIUM CONFIDENCE ON MVFR CIGS AND VSBYS 08-14Z. HIGH CONFIDENCE ON ALL OTHER ELEMENTS. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 67 84 63 87 / 60 50 30 10 ATLANTA 69 84 68 86 / 80 30 10 10 BLAIRSVILLE 62 80 60 81 / 50 40 10 10 CARTERSVILLE 66 84 62 88 / 50 20 10 10 COLUMBUS 72 87 70 89 / 40 40 30 10 GAINESVILLE 67 83 65 85 / 90 40 20 10 MACON 69 86 68 90 / 100 50 40 20 ROME 67 83 61 88 / 40 20 10 10 PEACHTREE CITY 67 84 62 87 / 80 30 20 10 VIDALIA 72 86 71 89 / 70 60 40 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...31 LONG TERM....17 AVIATION...31