619  
FXUS62 KFFC 221942  
AFDFFC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PEACHTREE CITY GA  
342 PM EDT MON MAY 22 2017  
 
   
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/
 
 
SURFACE BOUNDARY HAS BECOME NEARLY STATIONARY WITH CONVECTION  
DEVELOPING IN THE VICINITY OF THE FRONT AND ALSO AREAS SOUTHWARD.  
THESE SHOWERS AND TSTORMS APPEAR TO BE PRETTY EFFICIENT RAIN  
PRODUCERS WITH PWATS OF 1/5 TO 2 INCHES ACROSS MOST OF THE CWA  
THROUGH TONIGHT. WITH THE FRONT LINGERING AND THE SECOND SHORT WAVE  
MOVING ACROSS THE CWA TONIGHT, THINKING THAT THE QPF AMOUNTS MAY BE  
A BIT TOO LOW BUT CONFIDENCE IN RAISING THEM IS NOT QUITE THERE YET.  
HAVING SAID THAT, STILL THINK THERE IS A RISK OF ISOLATED FLASH  
FLOODING TONIGHT AND WILL THEREFORE MAINTAIN THE FLASH FLOOD WATCH.  
THE SHORT WAVE WILL EXIT THE CWA TUESDAY BRINGING A BRIEF RESPITE TO  
THE CWA. THE H5 TROUGH AND WILL CONTINUE TO DIG SOUTHWARD AND EJECT  
A STRONG COLD FRONT THAT WILL MOVE INTO THE CWA LATE TUESDAY  
NIGHT/EARLY WEDNESDAY MORNING. QPF AMOUNTS ARE NOT AS GREAT WITH  
THIS, HOWEVER INSTABILITIES INCREASE WITH CAPES INCREASING AHEAD OF  
THE COLD FRONT AS WELL AS LAPSE RATES AND 6KM BULK SHEAR. THIS  
SHOULD BRING A RISK OF ISOLATED SEVERE STORMS LATE TUESDAY NIGHT  
ACROSS MAINLY THE WESTERN PARTS OF THE CWA.  
 
17  
 
   
LONG TERM /WEDNESDAY THROUGH MONDAY/
 
 
NO CHANGES MADE TO THE EXTENDED FORECAST. THE EXTENDED PERIOD  
STARTS OFF WITH THE GFS AND NAM BOTH INCREASE DEEP LAYER SHEAR  
GOING INTO THE WED MORNING HOURS WHICH IS JUXTAPOSED WITH THE  
LEFT EXIT REGION OF THE 250MB JET. MODELS ARE MORE SPORADIC AND  
BROAD WITH QPF IN THIS PERIOD SO CONFIDENCE IS MEDIUM ON HOW  
THINGS WILL EVOLVE...ESPECIALLY GIVEN THE UNKNOWN IMPACT OF THE  
FIRST WAVE MOVING THROUGH TUESDAY AM. FOR NOW HAVE KEPT POPS IN  
THE LIKELY CATEGORY AND INCLUDED THUNDER AS WELL. MAY SEE A FAIRLY  
STOUT LINE OF CONVECTION DEVELOP IN THE EASTERN HALF OF THE STATE  
LATE WED AM INTO THE AFTERNOON AS MODELS FORECAST ADDITIONAL  
DESTABILIZATION DURING THE DAY.  
 
OF GREATER NOTE IS THE 00Z ECMWF SOLN WITH AN UPPER LOW CUTTING  
OFF MUCH FURTHER SOUTH THAN PREVIOUS SOLNS OVER CENTRAL AL AND  
SHIFTING EASTWARD ACROSS GA ON THU. GFS IS MUCH FURTHER NORTH WITH  
THE CUT OFF PORTION...BUT DOES EXTEND THE BASE OF THE TROF INTO  
THE SAME GENERAL AREA. GFS AND ECMWF 500 MB TEMPS WITH THE  
LOW/TROF DROP TO -21 TO -22 ACROSS THE REGION ON THU. SOUNDING  
CLIMATOLOGY SUGGESTS THAT THOSE TEMPS WOULD BE ONE OF AND VERY  
CLOSE TO THE COLDEST ON RECORD FOR MAY AT ATL SHOULD IT  
OCCUR...AND MOST CERTAINLY A RECORD FOR THE DATE. IN  
RESPONSE..AFTERNOON HIGHS BOTH WED AND THU ARE FORECAST TO REMAIN  
IN THE LOW 70S WHICH IS RIGHT AROUND RECORD LOW MAX TEMPS.  
OVERNIGHT LOWS DROP INTO THE LOW 50S THU AM AND FRI AM AS WELL AND  
WHILE MUCH BELOW NORMAL AND COOL...RECORDS ARE GENERALLY IN THE  
40S.  
 
NICE WEATHER ON TAP THROUGH SUNDAY BEFORE ANOTHER TROF DIGS INTO THE  
CENTRAL US AND RAIN CHANCES AGAIN INCREASE IN RESPONSE. MODELS VARY  
ON THE EVOLUTION OF THE TROF...BUT AGREE THAT ONE IS FORECAST TO  
RETURN.  
 
30/01  
 

 
   
AVIATION
 
 
18Z UPDATE...  
CONVECTION CONTINUES TO DEVELOP ALONG AND IN THE VICINITY OF THE  
STATIONARY FRONT DRAPED ACROSS NORTH GA FROM NEAR LGC TO ATL TO  
UPSTATE SOUTH CAROLINA. SCATTERED SHOWERS/TSTORMS WILL CONTINUE  
THROUGH THE AFTERNOON, BECOMING MORE WIDESPREAD TONIGHT AS THE  
NEXT WAVE OF CONVECTION MOVES ACROSS THE FORECAST AREA. THIS WAVE  
OF SHOWERS/TSRA WILL CONTINUE INTO TUESDAY. GENERALLY VFR CIGS  
THIS AFTERNOON, BECOMING IFR AFTER MIDNIGHT TONIGHT AND REMAINING  
IFR/MVFR INTO TUESDAY. WINDS WILL BE VARIABLE ALONG AND NORTH OF  
THE FRONT WHILE SOUTHWEST TO THE SOUTH OF THE FRONT. WINDS WILL  
BECOME SOUTHWEST TUESDAY MORNING AS THE FRONT LIFTS INTO NORTH GA.  
 
//ATL CONFIDENCE...18Z UPDATE...  
LOW TO MEDIUM ON TIMING OF WIND SHIFTS.  
MEDIUM ON REMAINING ELEMENTS.  
 
17  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
ATHENS 66 77 64 76 / 90 90 70 70  
ATLANTA 66 77 65 75 / 90 80 70 70  
BLAIRSVILLE 61 72 59 69 / 90 70 70 80  
CARTERSVILLE 65 78 64 74 / 90 70 70 70  
COLUMBUS 69 79 67 78 / 90 80 70 70  
GAINESVILLE 64 75 64 73 / 90 90 70 80  
MACON 68 77 67 79 / 90 90 70 70  
ROME 65 77 62 75 / 90 70 70 70  
PEACHTREE CITY 66 77 65 76 / 90 80 70 70  
VIDALIA 71 79 68 79 / 80 80 70 70  
 

 
   
FFC WATCHES/WARNINGS/ADVISORIES
 
 
FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH WEDNESDAY  
AFTERNOON FOR THE FOLLOWING ZONES: BALDWIN...BANKS...BARROW...  
BIBB...BLECKLEY...BUTTS...CARROLL...CHATTAHOOCHEE...CHEROKEE...  
CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...DEKALB...  
DOOLY...DOUGLAS...FAYETTE...FORSYTH...GLASCOCK...GREENE...  
GWINNETT...HALL...HANCOCK...HARALSON...HARRIS...HEARD...HENRY...  
HOUSTON...JACKSON...JASPER...JEFFERSON...JONES...LAMAR...MACON...  
MADISON...MARION...MERIWETHER...MONROE...MORGAN...MUSCOGEE...  
NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...  
PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...SCHLEY...SOUTH  
FULTON...SPALDING...STEWART...SUMTER...TALBOT...TALIAFERRO...  
TAYLOR...TROUP...TWIGGS...UPSON...WALTON...WARREN...WASHINGTON...  
WEBSTER...WILKES...WILKINSON.  
 

 
 

 
 
SHORT TERM...17  
LONG TERM....01  
AVIATION...17  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab GA Page Main Text Page