262  
FXUS62 KFFC 201737 AAC  
AFDFFC  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE PEACHTREE CITY GA  
1237 PM EST SAT DEC 20 2014  
   
PREV DISCUSSION
 
/ISSUED 1036 AM EST SAT DEC 20 2014/  
 
UPDATE...  
 
MAIN CHANGES FOR THIS MORNING ARE WITH POPS...INCREASED POPS IN  
AREAS WHERE RAIN CONTINUES AND IS EXPECTED BUT ALSO SPEEDED UP  
THE EXIT ESPECIALLY FROM METRO ATLANTA AND OTHER NORTHERN ZONES  
BASED ON TRENDS. TEMPERATURES LOOK OKAY UNDER WIDESPREAD CLOUD  
COVER BUT WILL CONTINUE TO MONITOR IN CASE ANY BREAKS BEGIN TO  
DEVELOP. OTHERWISE GRIDS LOOK GOOD...PRODUCTS WILL BE REFRESHED  
SHORTLY.  
 
TDP  
 
PREV DISCUSSION... /ISSUED 627 AM EST SAT DEC 20 2014/  
 
PREV DISCUSSION... /ISSUED 310 AM EST SAT DEC 20 2014/  
 
SHORT TERM /TODAY THROUGH SUNDAY/...  
CURRENT RADAR LOOP SHOWS SHOWERS SPREADING EAST ACROSS  
THE STATE THIS MORNING. INSTABILITIES ARE VERY LOW THIS MORNING SO  
NO THUNDERSTORMS ARE OCCURRING WITH THESE SHOWERS. AFTER THE  
SHORTWAVE MOVING ACROSS THE AREA PUSHES EAST OF THE STATE THIS  
AFTERNOON...NEARLY ZONAL FLOW DEVELOPS ALOFT. THE SURFACE HIGH NOW  
OVER THE GREAT LAKES STATES SHIFTS EAST INTO EASTERN CANADA AND  
BEGINS WEDGING DOWN THE EASTERN SEABOARD THIS AFTERNOON THROUGH  
TONIGHT. THIS WILL KEEP CLOUD COVER OVER GA THROUGH SUNDAY NIGHT AS  
NEXT RAIN MAKER MOVES IN. NEXT SHORTWAVE IS BEGINNING TO DEVELOP  
ALONG THE EASTERN MEXICAN COAST AND WILL MOVE NE TONIGHT AND SUNDAY.  
RAIN WILL MOVE BACK INTO THE STATE FROM THE SOUTH BEGINNING SUN  
MORNING INCREASING NORTHWARD THROUGH SUNDAY NIGHT. WITH THE WEDGE IN  
PLACE ACROSS THE AREA AHEAD OF THIS SECOND SYSTEM INSTABILITIES WILL  
CONTINUE TO BE WEAK...SO NOT EXPECTING ANY THUNDERSTORMS WITH THIS  
SYSTEM EITHER.  
 
01  
 
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...  
AN ACTIVE WEATHER PATTERN LOOKS TO CONTINUE DURING THE LONG TERM.  
 
A DAMMED AIR MASS WILL BE IN PLACE SUNDAY NIGHT AND MONDAY WITH A  
STATIONARY FRONT TO THE SOUTH OF THE AREA. A SURGE OF DEEPER MOISTURE  
MOVES ACROSS THE AREA ALLOWING FOR LIKELY TO OCCASIONAL LIGHT RAIN  
AND OCCASIONAL DRIZZLE WITH POPS DECREASING SOME FOR MONDAY.  
FORECAST LOW TEMPERATURES SUNDAY NIGHT ARE RUNNING 5-10 DEGREES  
ABOVE NORMAL. FORECAST HIGH TEMPERATURES ON MONDAY ARE RUNNING NEAR  
TO 5 DEGREES BELOW NORMAL.  
 
THE MAIN CONCERN THEN BECOMES THE POTENTIAL FOR SEVERE WEATHER LATE  
TUESDAY AND TUESDAY NIGHT. LATEST RUNS OF THE GFS AND EUROPEAN ARE  
GENERALLY SIMILAR WITH THE GFS JUST SLIGHTLY FASTER BUT WITH BOTH  
MODELS SEEMING A LITTLE SLOWER THAN THE PREVIOUS RUNS. A STRONG COLD  
FRONT MOVES INTO AND POSSIBLY ACROSS THE AREA TUESDAY NIGHT. A 40-50  
KNOT 850MB JET WITH A STRONG UPPER JET. CAPES LOOK TO BE THE 200-800  
RANGE WITH LOW LEVEL SHEAR OF 30-40 KNOTS. THE CAPES DOES NOT A LINE  
ALL THAT WELL WITH THE BEST DYNAMICS BUT THE DYNAMICS ARE STRONG AS  
A WARM FRONT MOVES NORTH OVER THE AREA AHEAD OF THE COLD FRONT. THIS  
WILL LEAD TO STRONG TO POSSIBLY SEVERE THUNDERSTORMS WITH STRONG  
WINDS AND ISOLATED TORNADOES THE MAIN THREATS.  
 
DEPENDING ON TIMING SOME THREAT COULD LINGER ON THE EAST SIDE OF THE  
FORECAST AREA TO START WEDNESDAY...BUT FOR NOW...WILL LEAVE  
THUNDERSTORMS OUT ON WEDNESDAY. SOME CHANCE FOR SHOWERS WILL  
CONTINUE EARLY WEDNESDAY AS THE UPPER TROUGH APPROACHES...AND THE  
CHANCE FOR SHOWERS WILL CONTINUE OVER MAINLY N GA IN THE AFTERNOON.  
 
THE UPPER TROUGH WILL BE PASSING WEDNESDAY NIGHT WITH A MUCH COLDER  
AIRMASS MOVING OVER THE AREA. A CHANCE OF SHOWERS EARLY OVER N GA  
WILL BECOME A CHANCE OF FLURRIES LATE NIGHT. IT LOOKS THAT THE  
DEEPER MOISTURE WILL BE EXITING QUICKLY WEDNESDAY NIGHT SO NO MORE  
THAN FLURRIES ARE EXPECTED AT THIS TIME.  
 
THE FORECAST FOR CHRISTMAS IS EXPECTED TO BE DRY WITH TEMPERATURES  
CLOSE TO NORMAL.  
 
THE EUROPEAN AND GFS ARE SIGNIFICANT DIFFERENT FRIDAY INTO SATURDAY  
WITH THE EUROPEAN MUCH WETTER...ESPECIALLY FRIDAY NIGHT AND SATURDAY.  
 
BDL  
 

 
   
AVIATION
 
 
18Z UPDATE...  
WIDESPREAD MVFR THIS AFTERNOON WITH PATCHES OF IFR CIGS. WILL  
CONTINUE TREND WITH ONLY MINIMAL IMPROVEMENT THROUGH THE  
AFTERNOON...SHOULD SEE MVFR EVERYWHERE. CIGS DROP AGAIN OVERNIGHT  
WITH HINTS AT LIFR CONDITIONS AS WELL AS IFR FOG. SOME HINTS AT  
LIFR FOG. ONLY SLOW IMPROVEMENT LATE SUNDAY MORNING WITH LOW MVFR  
EXPECTED THROUGH THE END OF THE PERIOD. WINDS FAVORING THE E SIDE  
THROUGH THE PERIOD BUT CANNOT RULE OUT BRIEF NNW WINDS THIS  
AFTERNOON...BUT GENERALLY ALL 5KT OR LESS.  
 
//ATL CONFIDENCE...18Z UPDATE...  
MEDIUM-HIGH ON WIND DIRECTION THIS AFTERNOON.  
MEDIUM ON TIMING OF CIGS BUT HIGH ON GENERAL TRENDS.  
MEDIUM ON VSBY REMAINING 2SM OR GREATER.  
 
TDP  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
ATHENS 51 38 51 40 / 100 5 30 60  
ATLANTA 53 42 52 43 / 100 5 30 50  
BLAIRSVILLE 49 36 50 39 / 30 10 20 50  
CARTERSVILLE 53 37 52 40 / 50 10 20 30  
COLUMBUS 55 45 55 46 / 100 20 40 50  
GAINESVILLE 50 38 50 41 / 70 5 30 50  
MACON 55 43 54 46 / 100 20 50 60  
ROME 52 35 54 40 / 10 5 20 30  
PEACHTREE CITY 54 37 52 42 / 100 5 30 50  
VIDALIA 56 45 56 49 / 100 20 60 80  
 

 
   
FFC WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
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