Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 281113 AAA
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
713 AM EDT THU AUG 28 2014


.PREV DISCUSSION...

SHORT TERM /TODAY THROUGH FRIDAY/...
/ISSUED 341 AM EDT THU AUG 28 2014/
ALTHOUGH THE UPPER RIDGE HAS BEEN WEAKENING...ITS STILL IN PLACE
ACROSS THE SOUTHEAST AND WILL LINGER THROUGH THE SHORT TERM.
ORIGINALLY THOUGHT THAT THE MOISTURE ACROSS THE OHIO VALLEY
YESTERDAY WOULD SINK SOUTHWARD ENOUGH TODAY TO ALLOW FOR ISOLATED
THUNDERSTORMS ACROSS THE MOUNTAINS TODAY...HOWEVER LATEST GUIDANCE
SUGGESTS THIS MOISTURE WILL REMAIN NORTH OF THE CWA. GUIDANCE HAS
BACKED OFF ON PRECIP ACROSS THE NE GA MOUNTAINS AND HI RES MODELS
ARE NOT PICKING UP ON DEVELOPMENT THIS AFTERNOON ACROSS THIS AREA.
THUS...HAVE TAKEN OUT THE SLIGHT CHANCE /20 PERCENT/ POPS ACROSS THE
NORTHEAST...BUT STILL MENTION 10 PERCENT CHANCE IN THE GRIDS.

FOR FRIDAY...START TO SEE THE EVIDENCE OF MOISTURE RETURN OFF THE
GULF ALONG THE GULF COAST BUT DOESNT QUITE MAKE IT INTO THE SOUTHERN
PORTIONS OF THE CWA. HAVE CONTINUED WITH A DRY FORECAST FOR FRIDAY.

THICKNESS VALUES CONTINUE TO INCREASE FOR TODAY SO EXPECT HIGH
TEMPERATURES TO BE ONE TO THREE DEGREES WARMER THAN YESTERDAY WITH
MOST AREAS MAKING IT INTO THE 90S...THE EXCEPTION BEING THE
MOUNTAINS. HIGH TEMPERATURES CONTINUE TO REMAIN ABOVE NORMAL WHILE
LOW TEMPERATURES CONTINUE TO REMAIN BELOW NORMAL.

11

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED 341 AM EDT THU AUG 28 2014/
EXTENDED PERIOD STILL CONTAINS QUITE A BIT OF UNCERTAINTY BUT AT
LEAST SOME MARGINAL IMPROVEMENTS TO MODEL CONSISTENCY NOTED THIS
RUN. WE BEGIN THE EXTENDED IN A TRANSITION PERIOD AS SURFACE HIGH
OVER THE OHIO VALLEY SHIFTS EAST OFF THE ATLANTIC COAST IN
RESPONSE TO UPPER LEVEL TROUGH KICKING OUT OF THE MIDWEST STATES
AND INTO THE OHIO VALLEY. THIS WILL BE A KEY COMPONENT IN OUR
LOCAL WX AS LOW LEVEL WINDS SHIFT TO A SOUTHERLY DIRECTION AND
PUMPS MOISTURE NORTHWARD OUT OF THE GULF OF MEXICO. THIS WILL
BRING PRECIPITABLE WATER VALUES BACK ABOVE 2 INCHES FOR MOST OF
THE AREA ON SATURDAY AND THIS COMBINED WITH MODEST SHORTWAVE
ENERGY OVER THE NORTHWEST ZONES SHOULD LEAD TO LIKELY COVERAGE OF
STORMS ALONG AND WEST OF THE INTERSTATE 75 CORRIDOR. WESTERLY
STEERING FLOW MAY BRING THESE STORMS FURTHER EAST THAN WHAT IS
CURRENTLY DEPICTED IN GRIDS AND WILL NEED TO MONITOR WITH
SUBSEQUENT MODEL RUNS FOR A POSSIBLE ADJUSTMENT UPWARD.

AFTER A FEW DAYS OF SUGGESTING SUNDAY AS THE WETTEST DAY OF THE
WEEKEND...MODELS NOW AGREE ON SLIGHTLY LESS COVERAGE. FIRST WAVE
OF SHORTWAVE ENERGY LIFTS NORTH OF THE AREA LEAVING LOCAL AREA
WITHOUT LARGE SCALE LIFT FOR SUNDAY. IN ADDITION...IN THE WAKE OF
THE SHORTWAVE...SOME DRIER MID LEVEL AIR WORKS IN WHICH THE ECMWF
REALLY PICKS UP ON. STILL FEEL FAR NW ZONES WILL SEE BETTER THAN
AVERAGE RAIN CHANCES GIVEN MOISTURE IN PLACE AND WILL GO WITH
LIKELY BUT TRANSITION WITH A SHARP GRADIENT TO JUST LOW TO MID
RANGE CHANCE FOR THE REMAINDER OF THE FORECAST AREA.

MID AND UPPER LEVEL RIDGE BUILD BACK OVER THE AREA THROUGH NEXT
WEEK BUT FEATURES ARE NOT PARTICULARLY STRONG. LIKEWISE...DEEP
LAYER MOISTURE NOT ANYTHING TO WRITE HOME ABOUT AND ALL THIS
POINTS TO CLIMO POPS FOR THE REMAINDER OF THE EXTENDED.

DEESE

&&

.AVIATION...
12Z UPDATE...
WINDS ARE FORECAST TO BE LIGHT TODAY. INITIALLY WINDS WILL BE
NORTHWEST TO WEST AND BECOME SOUTHWEST TONIGHT. SOME OF THE HIGHER
CLOUDS ACROSS ALABAMA MAY MAKE IT INTO THE CSG BUT
OTHERWISE...EXPECT CU TO DEVELOP FOR THE AFTERNOON WITH A FEW
CLOUDS.

//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON CIGS AND VSBYS. MEDIUM CONFIDENCE ON WIND.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          93  65  95  67 /   5   5   5   5
ATLANTA         90  69  92  71 /   5   5   5  10
BLAIRSVILLE     87  62  87  61 /  10  10  10  10
CARTERSVILLE    92  62  93  66 /   5   5   5  10
COLUMBUS        94  68  94  73 /   5   5  10  10
GAINESVILLE     90  68  91  68 /   5   5   5  10
MACON           93  62  95  68 /   5   5  10   5
ROME            92  62  93  66 /   5   5   5  10
PEACHTREE CITY  91  61  92  67 /   5   5   5  10
VIDALIA         94  67  94  72 /   5   5  10   5

&&

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

$$

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




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