Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 151533
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1133 AM EDT MON SEP 15 2014

.UPDATE...LOW CLOUDS FIRMLY ENTRENCHED ACROSS THE AREA AREA THIS
MORNING WITH AN EVEN WIDER EXPANSE THAN PREVIOUS MORNINGS. DESPITE
THIS...WE HAVE SEEN A LOW LEVEL JET AT 925MB TRAVERSING FRONTAL
BOUNDARY WHICH HAS ALLOWED JUST ENOUGH MECHANICAL LIFT TO GET
PARCELS ABOVE THE LFC. THIS HAS RESULTED IN ISOLATED THUNDERSTORMS
JUST NORTH OF THE BOUNDARY WHICH HAVE SINCE LARGELY DISSIPATED.
FOR THE REMAINDER OF THE AFTERNOON...DIFFICULT TO SAY HOW MUCH
INSOLATION WE WILL GET BUT NOT LOOKING PROMISING AS OF THIS
WRITING AND HAVE LOWERED MAX TEMPS A FEW MORE DEGREES AND DROPPED
LIKELY POPS THROUGH 00Z. HAVE INSTEAD GONE WITH LIKELY POPS
DURING THE OVERNIGHT PERIOD WHEN STRONGER SHORTWAVE MOVES THROUGH.

DEESE

&&

.PREV DISCUSSION... /ISSUED 743 AM EDT MON SEP 15 2014/

SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
/ISSUED AT 426 AM EDT MON SEP 15 2014/
LATEST SURFACE ANALYSIS SHOWS A WEDGE OF HIGH PRESSURE AND COOLER
AIR NOSING IN FROM THE NE AND A NEARLY STATIONARY FRONTAL BOUNDARY
ACROSS SOUTH GA. AN ACTIVE WEATHER PATTERN IS EXPECTED TODAY AS THE
STABLE WEDGE WEAKENS ITS GRIP AND THE FRONTAL BOUNDARY CREEPS
NORTHWARD... ALL WHILE A SERIES OF UPPER DISTURBANCES PUSH ACROSS
THE STATE DURING THE MID TO LATE AFTERNOON HOURS. ALTHOUGH IT
APPEARS THE GREATER INSTABILITY AND MOISTURE WILL BE MAINLY FOCUSED
ACROSS CENTRAL GA... IT APPEARS THE ADVANCING WARM FRONT COULD PUSH
AS FAR NORTH AS MAYBE A ROME TO ATLANTA TO WARRENTON LINE... AND
THIS IN ADVANCE OF THE APPROACHING DISTURBANCES. THIS WILL WARRANT
SHOWING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DURING THE
AFTERNOON AND EVENING FOR MOST AREAS. WILL HOLD ONTO SCATTERED
SHOWERS OVERNIGHT AS A COLD FRONT APPROACHES WITH AN ACTIVE WESTERLY
FLOW ALOFT. THE SHORT RANGE MODELS SHOW SIGNIFICANT TIMING
DIFFERENCES WITH THIS NEXT COLD FRONT... WITH THE FASTER GFS SHOWING
FROPA AT ATLANTA AROUND 8 AM TUESDAY MORNING WHILE THE SLOWER NAM
HOLDS OFF UNTIL AROUND NOON ON TUESDAY. WILL SHOW A SLIGHT LEAN
TOWARD THE FASTER GFS... BUT STILL HOLD ONTO A SLIGHT CHANCE OF
SHOWERS ACROSS NORTH GA ON TUESDAY WITH THE GREATER CHANCES FOR
SHOWERS AND THUNDERSTORMS MORE FOCUSED ACROSS CENTRAL GA THROUGH
TUESDAY AFTERNOON... THEN DIMINISHING CHANCES THERE TUESDAY EVENING.
ALTHOUGH CANNOT RULE OUT A STRONG OR EVEN ISOLATED SEVERE STORM WITH
TUESDAY`S COLD FRONT... EXPECT THIS THREAT TO BE MINIMAL AT BEST
WITH SUCH WEAK SHEAR VALUES AND EVEN MODEST INSTABILITIES. EXPECT
THE COLD FRONT TO PUSH SOUTH OF THE FORECAST AREA BY LATE TUESDAY
NIGHT WITH COOL/DRY HIGH PRESSURE BUILDING IN OVER THE AREA BY
WEDNESDAY MORNING.

TEMPS WILL BE TRICKY WITH AMPLE CLOUDS AND RAIN CHANCES TODAY...
THEN UNCERTAINTY ON TIMING OF COLD FRONT TONIGHT-TUESDAY. AS A
RESULT... DECIDED TO LEAN TOWARD A MAV AND MET BLEND THROUGH THE
PERIOD.

39

LONG TERM /WEDNESDAY THROUGH SUNDAY/...
/ISSUED AT 426 AM EDT MON SEP 15 2014/
THE EXTENDED FORECAST STARTS OUT WITH THE SECOND FRONT SWEEPING
INTO SOUTH GA AND USHERING IN A DRIER AIRMASS ACROSS NORTH GA.
STRONG HIGH PRESSURE RIDGE BUILDS IN BEHIND THE SECOND FRONT WHICH
WILL ALSO HELP TO SUPPRESS ANY PRECIPITATION THROUGH THE WEEKEND.
BOTH THE GFS AND ECMWF AGREE WITH THE DRIER AIR MASS MOVING IN...BUT
THEY ALSO AGREE THAT THERE WILL STILL BE A A BIT OF MOISTURE
LINGERING OVER EASTERN AND SOUTHERN SECTIONS OF THE STATE THROUGH
DAY 7. HAVE DECIDED TO CONTINUE WITH LOWERED POPS IN THE EXTENDED
AND KEEP JUST A SLIGHT CHANCE MAINLY SOUTH AND EAST. MODELS ALSO
CONTINUE TO INDICATE COOLER TEMPS ARE IN STORE FOR THE
STATE...ESPECIALLY WITH THE COOLER DRIER AIR MASS MOVING IN. BY
THE LATTER HALF OF THE WEEK WE COULD BE BELOW SEASONAL NORMALS.

01

AVIATION...
12Z UPDATE...
CURRENT WIDESPREAD LIFR/IFR CIGS ARE EXPECTED TO GRADUALLY IMPROVE
TO VFR CIGS BY 19-20Z THIS AFTERNOON. UPPER DISTURBANCES BY MID TO
LATE AFTERNOON WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS BETWEEN 20-02Z TODAY... WITH SCATTERED SHOWERS
PERSISTING OVERNIGHT AHEAD OF AN APPROACHING COLD FRONT. THE GFS IS
FASTER WITH THE FRONT...PUSHING IT ACROSS ATL BY 09-12Z TUE... WHILE
THE NAM SHOWS AROUND 15Z TUE. LEANING TOWARD A COMPROMISE OF 12Z TUE
FOR NOW. CURRENT EAST WINDS SWING SSW THIS AFTERNOON...THEN WEST
TONIGHT BEFORE SHIFTING NW BY 12 TUE. EXPECT MVFR CIGS TO SETTLE
BACK IN TONIGHT AROUND 06Z WITH VCSH. SHOULD SEE VFR CONDITIONS
RETURN AROUND 15Z TUE AFTER THE FROPA.

//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON ALL ELEMENTS TO INCLUDE... TIMING OF WIND SHIFT TO SW AND
VFR CIGS THIS AFTERNOON... AND TIMING OF TSRA LATE THIS AFTERNOON
AND EARLY EVENING... THEN RETURN OF MVFR CIGS TONIGHT.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          81  67  87  65 /  20  40  30  20
ATLANTA         80  69  86  68 /  30  60  30  20
BLAIRSVILLE     75  63  80  63 /  20  40  20  10
CARTERSVILLE    81  65  87  64 /  30  60  20  10
COLUMBUS        88  70  89  68 /  40  60  50  20
GAINESVILLE     79  66  85  66 /  20  40  20  20
MACON           86  69  89  67 /  40  60  50  20
ROME            82  66  88  63 /  30  60  20  10
PEACHTREE CITY  82  67  86  64 /  30  60  30  20
VIDALIA         88  72  88  70 /  40  60  60  40

&&

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

$$

SHORT TERM...DEESE
LONG TERM....BDL
AVIATION...DEESE




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