National Weather Service Weather Forecast Office

Area Forecast Discussion

793
FXUS62 KFFC 192350
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
750 PM EDT SUN MAY 19 2013

.PREV DISCUSSION... /ISSUED 312 PM EDT SUN MAY 19 2013/

SHORT TERM /TONIGHT THROUGH MONDAY/...
A RATHER MESSY UPPER LEVEL SYSTEM CONTINUES TO KEEP THE RISK OF
THUNDERSTORMS WITH HEAVY RAIN OVER MUCH OF THE CWA LATE THIS
AFTERNOON. REDEVELOPMENT OF THUNDERSTORMS ACROSS EASTERN TN/NORTH
GA IS REINFORCING THE FORECAST BY THE HRRR WHICH BRINGS ANOTHER
ROUND OT THUNDERSTORMS DOWN THE WEST SIDE OF GA THROUGH 00Z. THIS
WILL ALSO KEEP THE RISK OF FLASH FLOODING OVER THE WATCH AREA
THROUGH 00Z. THE PRECIP WILL SLOWLY EXIT FROM THE WEST TONIGHT
ALTHOUGH SOUTHEAST/EAST GA WILL STILL SEE SCATTERED
SHOWERS/TSTORMS INTO MONDAY. BY MONDAY AFTERNOON HIGH PRESSURE
WILL BE BUILDING OVER AL/GA WHICH SHOULD ALSO STABILIZE THE
ATMOSPHERE ENDING THE PRECIP BY MONDAY NIGHT/TUESDAY. MAV/MET
TEMPS LOOKING ALRIGHT...PERHAPS ON THE COOL SIDE TONIGHT AND HAVE
RAISE THEM A DEGREE OR TWO. WITH MORE SUNSHINE MONDAY
AFTERNOON...EXPECT TEMPS TO RISE WELL INTO THE 80S MOST AREAS.

17

LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
VERY FEW CHANGES TO THE EXTENDED. MADE SOME ADJUSTMENTS TO TEMPS
ON SATURDAY TO ACCOUNT FOR DRY CAD PROGGED TO DEVELOP. 12Z RUNS OF
GFS AND ECMWF STILL SIMILAR FOR THE SYSTEM AT THE END OF THE WEEK WITH
VERY LITTLE PRECIP EXPECTED AND THE FRONT MOVING THROUGH SOMETIME
EARLY FRIDAY. ALSO INCREASED CLOUD COVER A LITTLE FOR THE
WEDNESDAY SYSTEM AND ADJUSTED TEMPS ACCORDINGLY THERE AS
WELL...OTHERWISE NO SIGNIFICANT CHANGES.

TDP

PREV DISCUSSION... /ISSUED 357 AM EDT SUN MAY 19 2013/
PRECIP SHOULD END FROM WEST TO EAST TONIGHT AS THE SHORTWAVE
TROUGH SETS UP ALONG THE EASTERN SEABOARD. HAVE ONLY TWEAKED POPS
DURING THIS PERIOD.

FOR THE FIRST PART OF THE WEEK...THE 500MB TROUGH/SHEAR AXIS REMAINS
ACROSS THE SE COAST. THIS FEATURE WILL HELP FOCUS SCT DIURNAL
CONVECTION EACH DAY. PREVIOUS RUNS PUSHED THE FEATURE OFF THE COAST
ON TUESDAY...BUT IT SHOULD REMAIN IN PLACE UNTIL EARLY WEDNESDAY.

FOR THE LATTER PART OF THE WEEK...A COLD FRONT IS EXPECTED TO MOVE
INTO THE SOUTHEAST STATES. MODEL RUN TO RUN CONSISTENCY FOR THIS
FEATURE HAS BEEN LOW FOR THE PAST FEW DAYS. THE ECMWF NOW HAS THE
BOUNDARY APPROACHING NORTHERN GA ON FRIDAY...AND MOVING THROUGH THE
CWFA DURING THE DAY. THE GFS HAS CONTINUES TO BRING THE BOUNDARY
SOUTHWARD. NEITHER MODEL IS PRODUCING MUCH PRECIP WITH THIS FEATURE
FOR NOW...SO WILL LEAVE POPS IN THE SCT RANGE.

HIGH PRESSURE RETURNS FOR NEXT WEEKEND.

MAIN CHANGES TO THE EXTENDED WERE TO UP POPS SLIGHTLY IN THE EAST
FOR WEDNESDAY. MAINLY PERSISTENCE FOR THE LATTER HALF OF WEEK.

NLISTEMAA

&&

.AVIATION...
00Z UPDATE...
FIRST WAVE OF CONVECTION PUSHED SOUTH OF THE TERMINALS AND NEXT
WAVE HAS NOW DISSIPATED PRIOR TO ARRIVAL. THIS SHOULD LEAVE ALL
THE TERMINALS EXCEPT CSG AND MCN WITH JUST RESIDUAL -RA. CSG COULD
STILL SEE UPSTREAM CONVECTION OVER AL IMPACT THE TERMINAL THROUGH
06Z WITH MUCH LESSER CHANCES OVER MCN. OTHERWISE...REMAINS A
CHALLENGING FORECAST WITH CIGS THE BIG QUESTION AND UNCERTAINTY IS
GREAT WITH THE GUIDANCE. WITH THE AMOUNT OF RAIN MOST AREAS HAVE
SEEN...LEANING TOWARD THE MORE PESSIMISTIC PROJECTIONS OF IFR
DEVELOPMENT AT THE TERMINALS TONIGHT. WINDS WILL CONTINUE TO BE
TROUBLESOME AT ATL WITH MOST ACTIVITY OUTFLOW DRIVEN ALLOWING FOR
RAPID FLUCTUATIONS IN DIRECTIONS. WILL MAINTAIN LIGHT NORTHEAST
INITIALLY FOLLOWED BY LIGHT AND VARIABLE OVERNIGHT TONIGHT.

//ATL CONFIDENCE...00Z UPDATE...
LOW TO MEDIUM ON CIGS AND WINDS.
HIGH ON REMAINING ELEMENTS.

DEESE

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          63  86  65  86 /  80  20  10  30
ATLANTA         66  86  67  85 /  50  10  10  30
BLAIRSVILLE     60  83  60  82 /  80  10  10  40
CARTERSVILLE    63  87  65  87 /  80  10  10  20
COLUMBUS        66  89  67  89 /  30  10  10  10
GAINESVILLE     63  83  65  83 /  80  10  10  40
MACON           66  87  65  88 /  50  20  20  20
ROME            63  88  64  87 /  80  10  10  20
PEACHTREE CITY  64  86  65  86 /  40  10  10  20
VIDALIA         68  88  67  87 /  50  50  40  40

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BARTOW...BIBB...BUTTS...CARROLL...
CATOOSA...CHATTOOGA...CHEROKEE...CLARKE...CLAYTON...COBB...
COWETA...CRAWFORD...DADE...DAWSON...DEKALB...DOUGLAS...FANNIN...
FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...GORDON...
GREENE...GWINNETT...HALL...HANCOCK...HARALSON...HEARD...HENRY...
JACKSON...JASPER...JEFFERSON...JONES...LAMAR...LUMPKIN...
MADISON...MERIWETHER...MONROE...MORGAN...MURRAY...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PICKENS...PIKE...
POLK...PUTNAM...ROCKDALE...SOUTH FULTON...SPALDING...
TALIAFERRO...TOWNS...TROUP...UNION...UPSON...WALKER...WALTON...
WARREN...WASHINGTON...WHITE...WHITFIELD...WILKES...WILKINSON.

&&

$$

SHORT TERM...DEESE
LONG TERM....11
AVIATION...DEESE