294 
FXUS62 KFFC 280548 AAC
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
148 AM EDT SUN JUL 28 2013

.PREV DISCUSSION... 

UPDATE...
/ISSUED 1057 PM EDT SAT JUL 27 2013/ 
A FEW SHOWERS REMAIN ACROSS THE SOUTHEAST CORNER OF THE CWA AND WILL 
MAINTAIN POPS THERE FOR THE NEXT FEW HOURS. CURRENT FORECAST HAS A 
GOOD HANDLE ON THIS. NO CHANGES PLANNED.

SHORT TERM /TONIGHT THROUGH SUNDAY/...
/ISSUED AT 336 PM EDT SAT JUL 27 2013/
LOW PRESSURE CURRENTLY ACROSS SW MS WITH A WARM FRONT INTO CENTRAL 
AL. A COLD FRONT IS ALSO SITUATED ACROSS THE MID MS RIVER VALLEY. 
THE COLD FRONT WILL CONTINUE TO PUSH EAST OVER THE NEXT 24 HOURS AND 
BECOME DIFFUSE OVER CENTRAL/SOUTHERN GA LATE TOMORROW. 

SHOWERS HAVE DEVELOPED IN ASSOCIATION WITH A WEAK SHEAR AXIS ACROSS 
NORTH CENTRAL GA. THE DENSE CLOUD COVER ACROSS MUCH OF THE CWFA AND 
PATCHY LIGHT RAIN HAVE KEPT TEMPERATURES WELL BELOW NORMAL ACROSS 
THE NORTH AND CENTRAL AREAS. IN THE SOUTH...WHERE THE CLOUDS HAVE 
PARTIALLY CLEARED...TEMPS ARE WARMER AND A FEW THUNDERSTORMS HAVE 
DEVELOPED. IN ADDITION...IN THE FAR NORTH PART OF THE CWFA...A FEW 
BREAKS IN THE CLOUDS HAVE OCCURRED AND AN ISOLATED STORM IS 
POSSIBLE. A FEW STORMS COULD BE STRONG. ACROSS THE METRO 
AREAS...INSTABILITY WILL BE VERY LIMITED AND THE POTENTIAL FOR 
THUNDERSTORM DEVELOPMENT IS MINIMAL. DO EXPECT LOWER CIGS TO DEVELOP 
ACROSS THE CWFA OVERNIGHT...ESPECIALLY WHERE IT RAINS...AND BUMPED 
OVERNIGHT LOWS UP A DEGREE OR TWO. 

THE WEAK FRONT IS EXPECTED TO MOVE THROUGH THE REGION TOMORROW...BUT 
EVENTUALLY BECOME DIFFUSE. MODELS CONTINUE TO SHOW DRIER AIR BEHIND 
THE BOUNDARY...WITH THE MAIN FOCUS FOR CONVECTION TOMORROW ACROSS 
THE SOUTH. OVERALL...NO MAJOR CHANGES TO TOMORROWS FORECAST. 

NLISTEMAA

LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
/ISSUED AT 336 PM EDT SAT JUL 27 2013/
HAVE MADE MINOR CHANGES TO THE EXTENDED FORECAST...AS MODELS
CONTINUE TO SHOW SOME TIMING DIFFERENCES IN MID WEEK SHORTWAVE
ACTIVITY...WITH THE ECMWF SLIGHTLY AHEAD OF THE 12Z GFS TIMING.
HAVE OPTED TO CONTINUE WITH PREVIOUS FORECAST GIVEN THE RUN TO RUN
INCONSISTENCIES. HAVE ADJUSTED TEMPERATURES TO ACCOUNT FOR LATEST
MODEL TRENDS...WITH ONLY A FEW DEGREE CHANGES AT MOST. AS THE
PREVIOUS FORECAST DISCUSSION IS STILL APPLICABLE...HAVE INCLUDED
IT BELOW.

31

/ISSUED 434 AM EDT SAT JUL 27 2013/
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... WITH SFC RIDGING
BUILDING INTO THE CWA NEAR THE BEGINNING OF THE LONG TERM AND NO
STRONG WAVES PEGGED IN THE UPPER LEVELS...THIS MAY PROVIDE A SHORT
BREAK IN THE HIGHER THAN CLIMO POPS. WITH SFC RIDGE CENTERED OVER
THE OHIO VALLEY ON MONDAY...THE GFS KEEPS THE CWA DRY WHEREAS THE
ECMWF LINGERS SOME BETTER MOISTURE ACROSS CENTRAL GEORGIA.
FORECAST IS NEAR A BLEND OF THE TWO...WITH ONLY A SLIGHT CHANCE
MENTIONED ACROSS CENTRAL GEORGIA FOR THE AFTERNOON. WITH A SERIES
OF SHORTWAVES MOVING THROUGH MID-WEEK...WILL SEE A RETURN OF THE
ABOVE NORMAL POPS. GFS HAS BEEN FAIRLY CONSISTENT WITH TIMING
BETWEEN LAST NIGHT AND TONIGHT WHEREAS THE ECMWF HAS HAD SOME RUN
TO RUN DIFFERENCES. 00Z ECMWF HAS COME INTO BETTER AGREEMENT AGAIN
WITH THE 00Z GFS AS OPPOSED TO THE 12Z ECMWF. MAIN IMPACT WITH
THESE SHORTWAVES WILL BE AN INCREASE IN POPS FOR THE WEDNESDAY TO
THURSDAY TIME FRAME WITH THE BEST CHANCES ACROSS NORTH GEORGIA ON
WEDNESDAY. GIVEN SOME CONSISTENCY IN TIMING WITH THE GFS...HAVE
GONE AHEAD AND INTRODUCED LIKELY POPS FOR FAR NORTH GEORGIA ON
WEDNESDAY. PLENTY OF INSTABILITY WITH THE SYSTEM...BUT SHEAR IS
LACKING. STILL WITH INSTABILITY ALONE...ITS ENOUGH THAT SOME OF
THE STORMS COULD BECOME STRONG. GFS AND ECMWF ARE CONSISTENT WITH
HIGHER RAINFALL AMOUNTS ACROSS NORTH GEORGIA WITH BOTH MODELS
DEPICTING JUST UNDER 2 INCHES IN THE WEDNESDAY/THURSDAY TIME
FRAME. BY FRIDAY...UPPER DISTURBANCE IS EAST OF THE AREA AND THAT
WILL BRING US BACK INTO A MORE TYPICAL SUMMERTIME PATTERN...AT
LEAST IN TERMS OF CONVECTION.

11

&&

.AVIATION...
06Z UPDATE...
MAIN CHALLENGE IN THE TAFS THIS MORNING ARE THE CIG HEIGHTS AND
VSBYS. NOT CONFIDENT ON JUST HOW LOW CONDITIONS WILL GO...BUT WILL
CONTINUE TO SHOW MAINLY IFR CONDITIONS THIS MORNING. SOME SITES
COULD SEE VSBYS DECREASE MORE THAN ADVERTISED IN THE TAF...BUT
SHOULD BE SHORT LIVED. CONVECTIVE ACTIVITY TODAY SHOULD BE LIMITED
MORE TO CENTRAL GEORGIA THIS AFTERNOON WITH THE BEST CHANCES AT
MCN SO HAVE CONTINUED WITH PROB30 THERE. SLIGHT CHANCE AT ALL THE
OTHER SITES...BUT AGAIN CHANCE IS LOW.

//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ON WINDS. LOW CONFIDENCE ON CIGS AND VSBYS. 

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          87  67  89  67 /  20  10  10  10 
ATLANTA         85  67  86  70 /  20  10  10   5 
BLAIRSVILLE     80  58  82  61 /  10   5  10  10 
CARTERSVILLE    85  61  87  63 /  10  10  10  10 
COLUMBUS        87  71  91  72 /  20  10  20   5 
GAINESVILLE     84  65  86  68 /  10  10  10  10 
MACON           88  69  91  67 /  30  20  20  10 
ROME            85  61  88  63 /  10   5  10  10 
PEACHTREE CITY  86  64  88  63 /  20  10  10   5 
VIDALIA         88  72  90  73 /  40  30  20  10 

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...11
LONG TERM....SNELSON
AVIATION...11