Area Forecast Discussion
Issued by NWS Atlanta, GA

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000
FXUS62 KFFC 211127
AFDFFC

AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
727 AM EDT THU AUG 21 2014

.SHORT TERM /TODAY THROUGH FRIDAY/...
/ISSUED AT 340 AM EDT THU AUG 21 2014/
MODELS IN GOOD AGREEMENT WITH STRONG MID AND UPPER LEVEL RIDGE
BUILDING OVER THE STATE FROM THE WEST TODAY... AND PUSHING THE
INFAMOUS RING OF FIRE FURTHER TO THE EAST. AS A RESULT... THE
INCREASED SUBSIDENCE SHOULD GREATLY DIMINISH THE THUNDERSTORM THREAT
FOR BOTH TODAY AND FRIDAY. NEVERTHELESS... IT IS AUGUST AND THE
RIDGE WILL HELP PUSH DAYTIME HIGHS WELL INTO THE 90S... AND EVEN
AROUND THE CENTURY MARK ACROSS PARTS OF CENTRAL GA TODAY AND AGAIN
ON FRIDAY. THESE WARM TEMPS... COUPLED WITH 70+ DEWPOINTS WILL PUSH
AFTERNOON SURFACE BASED CAPES INTO THE 3000 TO 4000+ J/KG RANGE...
AND DESPITE THE MID LEVEL RIDGE-INDUCED SUBSIDENCE CAP... ISOLATED
AFTERNOON AND EARLY EVENING THUNDERSTORMS CANNOT BE RULED OUT EACH
DAY. ADDITIONALLY... WITH THIS HEAT AND INSTABILITY... ANY STORM
THAT DOES DEVELOP WILL HAVE THE POTENTIAL TO REACH SEVERE LIMITS...
WITH DAMAGING WINDS BEING THE MAIN THREAT. NOT EXPECTING ANYTHING
WIDESPREAD OR ORGANIZED... JUST NEED TO BE ALERT FOR THIS ISOLATED
POTENTIAL EACH AFTERNOON AND EVENING.

AS FOR THE HEAT... STILL EXPECTING PARTS OF CENTRAL GA TO SEE
CRITICALLY HIGH HEAT INDEX VALUES TO AROUND THE 105 DEGREE MARK THIS
AFTERNOON... AND AGAIN FRIDAY AFTERNOON. THEREFORE... WILL CONTINUE
WITH THE HEAT ADVISORY AS POSTED FOR TODAY... GENERALLY ALONG AND
SOUTH OF A COLUMBUS TO MACON TO WARRENTON LINE... AND EXPECT THIS
THREAT TO REPEAT ON FRIDAY. DUE TO THE HEAT... PLEASE PLAY IT
SAFE... AND DRINK PLENTY OF FLUIDS... STAY IN AN AIR-CONDITIONED
BUILDING AND LIMIT OUTDOOR ACTIVITIES OVER THE NEXT FEW DAYS.

AS FOR TONIGHT... NO STORMS ARE EXPECTED WITH LOSS OF DAYTIME
HEATING AND CONTINUED RIDGE INFLUENCE. SHOULD SEE SOME PATCHY FOG
AFTER MIDNIGHT...  AND CONTINUED WARM LOW TEMPS IN THE 70S FOR MOST
AREAS. LEANED TOWARD A MAV AND MET BLEND FOR HIGHS AND LOWS THROUGH
THE PERIOD.

39


.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED AT 340 AM EDT THU AUG 21 2014/
MEDIUM RANGE MODELS CONTINUE TO SHOW LITTLE CHANGE IN THE LONG TERM
TRENDS ACROSS GEORGIA...AT LEAST REGARDING THE PERSISTENT UPPER
RIDGE EXPECTED TO DOMINATE FOR MUCH OF THE PERIOD. RIDGE IS DEPICTED
AT ITS STRONGEST FRIDAY THROUGH SUNDAY WITH SOME WEAKENING BY THE
FIRST HALF OF NEXT WEEK. CENTER OF THE RIDGE REMAINS WEST OF THE
STATE WHEN THE RIDGE IS AT ITS STRONGEST...AND I DO NOT BELIEVE WE
CAN ELIMINATE POPS COMPLETELY...ALTHOUGH FRIDAY THROUGH SUNDAY THE
CHANCES APPEAR TO BE SLIGHT AT BEST. BY MONDAY THROUGH THE END OF
THE PERIOD THE RIDGE WEAKENS ENOUGH FOR CHANCE POPS. ANY CONVECTION
WILL SHOW A DECIDEDLY DIURNAL BIAS. TEMPERATURES WILL BE WELL ABOVE
SEASONAL NORMALS INTO THE WEEKEND WITH SOME MODERATION BY THE
BEGINNING OF NEXT WEEK AS THE RIDGE WEAKENS AND THE LOW-LEVEL FLOW
TURNS EASTERLY.

BIG DIFFERENCES IN THE MODELS WITH RESPECT TO THE POTENTIAL TROPICAL
SYSTEM IN THE WESTERN ATLANTIC NEXT WEEK. 00Z/06Z RUNS FROM
YESTERDAY WERE PUSHING THE SYSTEM INTO THE GULF OF MEXICO BUT HAVE
DEVIATED SIGNIFICANTLY WITH THE 12Z/18Z AND NOW THE NEW 00Z RUNS.
THE TREND HAS BEEN PROGRESSIVELY MORE EASTERLY WITH THE MEDIUM RANGE
MODEL CONSENSUS NOW KEEPING THE SYSTEM EAST OF THE ATLANTIC COAST.
THIS IS STILL A LONG WAY OFF AND WE WILL LIKELY SEE QUITE A BIT OF
VARIABILITY IN THE HANDLING OF THIS POTENTIAL SYSTEM OVER THE NEXT
SEVERAL DAYS.

20


&&

.AVIATION...
12Z UPDATE...
SEEING SOME AREAS OF LIFR/IFR CIGS AND VSBY ACROSS FAR NORTH GA THIS
MORNING... BUT SO FAR NOTHING DEVELOPING AROUND THE ATLANTA TAF
SITES. WILL SHOW FEW010 AT 12Z... THEN SCT025 BY 14Z... AND SCT045
BY 17Z AS EXPECT MID LEVEL CU TODAY AS WET GROUND HEATS UP.
INCREASED UPPER RIDGE INFLUENCE SHOULD HOLD AFTERNOON CONVECTION
DOWN TO ISOLATED IN COVERAGE...SO NOT ENOUGH CONFIDENCE TO INCLUDE
IN TAFS AT THIS TIME. NW WINDS WILL PERSIST THROUGH THE TAF
PERIOD... WITH SPEEDS AROUND 6-8KTS TODAY... THEN LIGHT 4KTS OR LESS
TONIGHT. NO LOW CIG PROBLEMS EXPECTED TONIGHT.

//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON EARLY MORNING STRATUS. HIGH ON ALL OTHER ELEMENTS.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          97  72  99  73 /  30  20  20  20
ATLANTA         94  76  97  76 /  20  20  20  20
BLAIRSVILLE     89  67  90  69 /  30  20  20  20
CARTERSVILLE    95  70  97  71 /  20  20  20  20
COLUMBUS        97  74  98  77 /  20  20  20  20
GAINESVILLE     94  74  96  74 /  30  20  20  20
MACON           98  72  99  74 /  20  20  20  20
ROME            96  70  98  71 /  20  20  20  20
PEACHTREE CITY  95  70  96  72 /  20  20  20  20
VIDALIA         99  74 100  76 /  20  20  20  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: BALDWIN...BIBB...BLECKLEY...CHATTAHOOCHEE...
CRAWFORD...CRISP...DODGE...DOOLY...EMANUEL...GLASCOCK...
HANCOCK...HOUSTON...JEFFERSON...JOHNSON...JONES...LAURENS...
MACON...MARION...MONTGOMERY...MUSCOGEE...PEACH...PULASKI...
SCHLEY...STEWART...SUMTER...TAYLOR...TELFAIR...TOOMBS...
TREUTLEN...TWIGGS...WARREN...WASHINGTON...WEBSTER...WHEELER...
WILCOX...WILKINSON.

&&

$$

SHORT TERM...39
LONG TERM....20
AVIATION...39







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