502 FXUS62 KFFC 111744 AFDFFC AREA FORECAST DISCUSSION...UPDATED AVIATION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 143 PM EDT TUE AUG 11 2015 .UPDATE... /ISSUED AT 1211 PM EDT TUE AUG 11 2015/ THE COLD FRONT IS STARTING TO PUSH INTO FAR NORTH GA EARLY THIS AFTERNOON. THE GREATER INSTABILITIES AND DEEPER MOISTURE IS MAINLY ALONG AND SOUTH OF A LA GRANGE TO WARRENTON LINE WHERE RADAR IS ALREADY SHOWING SCATTERED TO NUMEROUS SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS DEVELOPING. ALTHOUGH EXPECT ISOLATED TO SCATTERED SHOWERS WITH A FEW THUNDERSTORMS TO DEVELOP ALONG THE FRONT ACROSS NORTH GA THIS AFTERNOON... WILL KEEP THESE CHANCES TO AROUND 30 PERCENT FOR NOW AND SHOW THE 50-70 PERCENT ACROSS CENTRAL GA WHERE CONDITIONS ARE MORE FAVORABLE FOR GREATER COVERAGE OF STORMS. SPC CONTINUES TO SHOW MUCH OF THE AREA IN A MARGINAL RISK... AND A MODIFIED MORNING SOUNDING AT FFC SUPPORTS THIS POTENTIAL...WITH 2500- 2800 MUCAPE AND 1.8+ PW'S. STILL THINK THE GREATER CHANCES FOR ANY STRONG TO POSSIBLY SEVERE STORMS WILL BE SOUTH OF THAT LA GRANGE TO WARRENTON LINE... BUT CANNOT RULE OUT A STRONG TO EVEN SEVERE STORM ANYWHERE TODAY AHEAD OF THAT COLD FRONT. THE FRONT SHOULD PUSH THROUGH ATLANTA AREA BY LATE AFTERNOON... WITH DIMINISHING POPS EXPECTED THERE AND NORTHWARD BY THIS EVENING. STAY TUNED. /39 .PREV DISCUSSION... /ISSUED 425 AM EDT TUE AUG 11 2015/ SHORT TERM /TODAY THROUGH WEDNESDAY/... COLD FRONT CURRENTLY STRETCHES FROM THE OHIO VALLEY BACK THROUGH THE LOWER MISSISSIPPI RIVER VALLEY. THERE IS ALSO A LOW PRESSURE TROUGH SITUATED ACROSS CENTRAL GA. SHOWERS AND A FEW THUNDERSTORMS HAVE LINGERED OVERNIGHT...WORKING OFF THE REMAINING INSTABILITY...HIGH LOW LEVEL MOISTURE AND WITH A WEAK SHORTWAVE IN THE MID LEVELS. HI- RES MODELS KEEP THIS ACTIVITY GOING THROUGH THE REMAINDER OF THE OVERNIGHT HOURS. THE TROUGH AND FRONT SHOULD BE THE MAIN FOCI FOR CONVECTION TODAY. THE HI-RES MODELS DO SHOW A BRIEF LULL THIS MORNING IN ACTIVITY...BUT SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO FIRE UP AGAIN DURING PEAK HEATING. SURFACE CAPE REMAINS HIGH...BUT NOT SURE OF WHAT THE COVERAGE OF STORMS WILL ACTUALLY BE TODAY WITH ALL THE CLOUD DEBRIS LEFT BEHIND FROM THE OVERNIGHT ACTIVITY. WHERE CLOUDS BREAK OUT IN THE VICINITY OF THE TROUGH AND/OR FRONT IS WHERE STORMS SHOULD INITIATE TODAY. STRONG STORMS ARE LIKELY...WITH A FEW SEVERE STORMS POSSIBLE. DAMAGING WIND GUSTS WILL BE PRIMARY HAZARD FROM A SEVERE STORM. 00Z ATL SOUNDING SHOWS A VERY MOIST ENVIRONMENT IN PLACE WITH PWATS JUST UNDER 2 INCHES. NAM12 FORECAST SOUNDINGS SHOW PWATS INCREASING TO OVER 2 INCHES LATE THIS MORNING AND EARLY AFTERNOON. SO EVEN NON SEVERE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...AND WHERE THUNDERSTORMS REPEATEDLY MOVE...LOCALIZED FLOODING WILL BE POSSIBLE. THE FRONT SHOULD SETTLE JUST SOUTH OF THE CWFA BY LATE TONIGHT/EARLY WEDNESDAY. A DRIER AIRMASS WILL SETTLE ACROSS THE NORTH AND CENTRAL CWFA. MINIMAL POPS EXPECTED. NLISTEMAA LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... FCST PERIOD BEGINS IN A POST FRONTAL REGIME WITH DRY AIR ADVECTION AS NW FLOW ALOFT GRADUALLY WEAKENS. ANY CHANCE FOR SHOWERS OR STORMS THRU THURSDAY SHOULD REMAIN IN THE FAR NE HIGHER ELEVATIONS FROM OROGRAPHIC EFFECTS OR EAST CENTRAL GA DUE TO PROXIMITY WITH AFOREMENTIONED STALLED BOUNDARY FROM THE SHORT TERM. GUIDANCE HAVING SOME DISCONTINUITY ON THE EVOLUTION OF MAIN INFLUENCING FEATURES BY THE WEEKEND...THOUGH THE GFS HAS BEEN THE MORE CONSISTENT SOLUTION RECENTLY WITH HAVING A WEAK UPPER LOW ACROSS THE NORTHERN GULF AND ASSOCIATED LOW LEVEL ATLANTIC MOISTURE ADVECTION DRAWING FROM THE EAST. ASIDE FROM THE MOISTURE RETURN...THERE APPEARS TO BE NO PRONOUNCED FORCING MECHANISM OTHER THAN TYPICAL SUMMERTIME DIURNAL/TERRAIN INDUCED CONVECTIVE TRIGGERING AND HAVE GONE WITH SLIGHT TO LOW END CHANCE POPS THE REST OF THE PERIOD FOR MOST AREAS. ANY STORMS SHOULD BE LARGELY OUTFLOW DRIVEN IN THE PRESENCE OF A RATHER STAGNANT AIRMASS. TEMPS GENERALLY NEAR NORMAL TO SLIGHTLY BELOW THRU PERIOD AND WHILE RIDGING WEAKENS THRU PERIOD...GREATER CLOUD COVERAGE FROM RETURN OF MOISTURE SHOULD LIMIT DAYTIME MAX VALUES. BAKER && .AVIATION... 18Z UPDATE... COLD FRONT IS PUSHING INTO NORTH GA WITH RADAR SHOWING ISOLATED TO SCATTERED SHOWERS DEVELOPING AROUND THE ATLANTA TAF SITES AND NORTHWARD. EXPECT THE GREATER CHANCES OF THUNDER TO BE MAINLY SOUTH OF THE ATLANTA AIRPORTS AND WILL CONTINUE TO SHOW TEMPO 18-22Z -TSRA FOR CSG AND MCN... WHILE THINKING A TEMPO -SHRA WILL WORK FOR ATLANTA TAF SITES AND AHN THROUGH AROUND 22-23Z THIS EVENING. THE FRONT PUSHES SOUTH OF ATL BY 22-23Z...ENDING THE CONVECTIVE THREAT WITH VFR CONDITIONS ON TAP REST OF TAP PERIOD. CURRENT WNW WINDS WILL SHOW THE OCNL GUSTS THIS AFTERNOON... THEN A NW WIND AROUND 4- 7KTS WILL PREVAIL... POSSIBLY INCREASING TO AROUND 10KTS BY WED AFTN. /39 //ATL CONFIDENCE...18Z UPDATE... MED CONFIDENCE ALL ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 89 71 90 69 / 40 20 10 5 ATLANTA 88 71 88 69 / 40 20 10 5 BLAIRSVILLE 83 63 84 60 / 30 10 10 5 CARTERSVILLE 89 68 87 65 / 30 10 10 0 COLUMBUS 90 74 92 69 / 40 30 20 5 GAINESVILLE 87 70 88 69 / 30 20 10 5 MACON 90 72 92 71 / 40 30 20 10 ROME 89 69 88 65 / 30 10 10 0 PEACHTREE CITY 89 70 89 67 / 40 20 10 5 VIDALIA 90 74 93 73 / 40 40 30 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$