Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 221756 AAC
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
156 PM EDT MON SEP 22 2014

.PREV DISCUSSION... /ISSUED 1128 AM EDT MON SEP 22 2014/

UPDATE...
COLD FRONT IS MARCHING ACROSS THE STATE THIS MORNING...WITH AN
ENHANCED LINE OF SHOWERS AND THUNDERSTORMS MOVING THROUGH MAINLY
CENTRAL GEORGIA RIGHT NOW. BIGGEST CONCERN WITH THE LINE IS HEAVY
RAIN AND LIGHTNING...BUT AS WITH PREVIOUS FORECAST...CANNOT RULE
OUT ISOLATED SEVERE THIS AFTERNOON AS INSTABILITY INCREASES. BEST
CHANCES WILL BE ACROSS EXTREME SOUTHEAST ZONES WHERE THE SPC
CONTINUES THE 5% WIND AND HAIL THREAT FOR THE DAY 1 OUTLOOK.

TEMPERATURES PRETTY MUCH IN LINE THIS MORNING BUT DRIER DEWPOINTS
ARE MOVING INTO NORTH GEORGIA A LITTLE FASTER THAN ORIGINALLY
PROGGED. HAVE MADE SOME UPDATES TO HOURLY GRIDS TO UPDATE TRENDS.
OTHER BIG CHANGES HAVE JUST BEEN TO KEEP UP WITH HOURLY POPS BASED
ON RADAR AND HIRES REFLECTIVITY FORECASTS. UPDATED PRODUCTS WILL
BE OUT SHORTLY.

TDP

PREV DISCUSSION... /ISSUED 739 AM EDT MON SEP 22 2014/

PREV DISCUSSION... /ISSUED 348 AM EDT MON SEP 22 2014/

SHORT TERM /TODAY THROUGH TUESDAY/...
LATEST REGIONAL SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY EXTENDING
FROM THE COAST OF NORTH CAROLINA THROUGH THE UPSTATE OF SOUTH
CAROLINA AND INTO ATHENS AND ATLANTA. HIGHER DEWPOINTS POOLING
NICELY ALONG THE FRONT WITH MID 60S VALUES WHILE TO THE
NORTH...DEWPOINTS HAVE ALREADY DROPPED INTO THE LOWER 50S. IN
ADDITION TO THE HIGHER DEWPOINTS...BAND OF SHOWERS AND AN
OCCASIONAL THUNDERSTORM MARK NICELY THE FRONT ACROSS THE AREA.
ALTHOUGH COVERAGE HAS BEEN SOMEWHAT LIMITED...CONTINUATION OF LOW
END CHANCE IS WARRANTED THROUGH DAYBREAK.

DIFFICULT CALL FOR THIS AFTERNOON AS MUCH DRIER AIR CONTINUES TO
RUSH INTO THE STATE BUT LAGGING VORT MAX IS ESPECIALLY STRONG FOR
THIS TIME OF YEAR AND GENERATES A HEALTHY AMOUNT OF LIFT AS IT
WORKS ITS WAY THROUGH. SOUTHERN SECTIONS OF THE FORECAST AREA WILL
BE AN EASY CALL AS ENOUGH MOISTURE REMAINS AS SHORT WAVE ARRIVES
AND CAPE VALUES INCREASE TO AROUND 2500 J/KG IN THE LATE
AFTERNOON. 500MB TEMPS WILL REALLY COOLED OFF DURING THIS TIME
PERIOD AS WELL WITH -11C TO -12C ANTICIPATED IN THE ZONE WITH
HIGHEST THUNDER CHANCES. FOR THIS REASON...FEEL A FEW STRONG TO
SEVERE STORMS ARE NOT OUT OF THE QUESTION FOR EXTREME SOUTH THIS
AFTERNOON AND EVENING. HAIL WILL BE THE PRIMARY THREAT ALTHOUGH
MODEST DOWNDRAFT CAPE COULD LEAD TO SOME STRONG WINDS WITH A FEW
OF THE STORMS.

FURTHER NORTH WILL BE A TOUGHER CALL AS DRY AIR COMPETES WITH
EXCELLENT SYNOPTIC LIFT. FOR MOST OF NORTH GEORGIA...LOOKS LIKE
50 TO .75 PWATS WILL BE JUST TOO LITTLE TO RESULT IN POPS BUT
VALUES CLOSER TO AN INCH ACROSS THE SOUTH METRO WARRANTS KEEPING
IN SLIGHT CHANCE AS SHORTWAVE MOVES THROUGH.

DRIER AIR AND PLEASANT TEMPS AND DEWPOINTS IN STORE FOR THE
REMAINING OF THE SHORT TERM.

DEESE

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
SURFACE HIGH PRESSURE AND COOLER TEMPERATURES WILL DOMINATE MUCH OF
THE LONG TERM PERIOD. HOWEVER THE MODELS ARE DIFFERING ON THE
DETAILS WITH A DRIER GFS AND WETTER EUROPEAN TO START UNTIL ABOUT
FRIDAY AND BEYOND.

FAVORING A DRIER GFS TUESDAY NIGHT WITH NO POPS OVER THE SE CWA AND
SORT OF A COMPROMISE ON WEDNESDAY WITH MAINLY SMALL POPS FOR THE SE
CWA. AFTER WEDNESDAY TENDING TO LEAN TOWARD THE WETTER EUROPEAN WITH
MAINLY SMALL POPS FOR SHOWERS ONLY INCREASING NORTH THROUGH SUNDAY
WHEN BOTH MODELS INCREASE DEEPER MOISTURE OVER THE AREA FROM SW
UPPER FLOW. SUNDAY IS THE FIRST DAY OF THE LONG TERM WHEN MAINLY
SMALL CHANCES FOR THUNDERSTORMS RETURN TO PORTIONS OF CENTRAL GA.

FORECAST TEMPERATURES CLOSE TO OR BELOW NORMAL THROUGH THE
PERIOD.

BDL

&&

.AVIATION...
18Z UPDATE...
LINE OF TSRA JUST SOUTH OF MCN/CSG...WITH TEMPO TSRA CONTINUING AT
MCN AND -SHRA FOR CSG. OTHERWISE MAINLY VFR ACROSS THE AREA WITH
FRONT PUSHING THROUGH. SOME UNCERTAINTY WITH TIMING OF WIND SHIFT
TO NE...CURRENT TIMING IS JUST AFTER 00Z TONIGHT. EXPECT LOW-END
GUSTS THIS AFTERNOON WITH WINDS DECREASING TO AROUND 5KT
OVERNIGHT. NE TO E WINDS WITH ANOTHER ROUND OF LOW-END GUSTS ON
TUESDAY. COULD SEE FEW-SCT LOW VFR CU TUESDAY AFTERNOON.

//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON TIMING OF WIND SHIFT.
HIGH ON ALL OTHER ELEMENTS.

TDP

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          82  58  77  56 /  20   5   0   0
ATLANTA         80  59  77  58 /  30   0   0   0
BLAIRSVILLE     75  51  75  51 /   0   5   0   0
CARTERSVILLE    80  55  79  56 /   5   0   0   0
COLUMBUS        84  63  80  61 /  60   0   0   0
GAINESVILLE     80  58  76  57 /  10   5   0   0
MACON           85  61  80  58 /  60  30   5   0
ROME            81  52  80  55 /   5   0   0   0
PEACHTREE CITY  81  56  79  56 /  50   0   0   0
VIDALIA         86  66  81  62 /  60  60  20  10

&&

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

$$




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