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000
FXUS62 KFFC 060837
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
337 AM EST FRI DEC 6 2013

...RECORD HIGHS IN JEOPARDY THIS AFTERNOON...
...AFTER A BRIEF RESPITE RAINS TO RETURN LATE TODAY...

.SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
CONTINUE TO SEE PERIODS OF SHRA WITH EMBEDDED TSRA ROLL THROUGH
ROUGHLY THE SAME AREAS OF WEST CENTRAL GEORGIA AND UP THROUGH THE
INTERSTATE 85 CORRIDOR. EARLIER ROTATION SEEN IN A FEW STORMS HAS
ABATED BUT NOW MID LEVEL WIND GUSTS MORE APPARENT AS ACTIVITY
REACHES THE NORTHEAST MOUNTAINS. ALL THIS HAS BEEN IN A ZONE OF
ENHANCED LOW AND MID LEVEL MOISTURE CHARACTERIZED BY PWATS IN THE
99TH PERCENTILE FOR THIS TIME OF YEAR. FORTUNATELY...ZONE DOES
LOOK TO BE LIFTING NORTHWARD SO AS TO ALLOW AREAS FROM CARROLLTON
THROUGH THE NORTHERN ATLANTA METRO TO DRY OUT A BIT.

MID AND UPPER LEVEL HEIGHTS WILL BUILD EVER SO SLIGHTLY THOUGH
THIS AFTERNOON WHICH SHOULD BE JUST ENOUGH TO SHUNT MOST
SIGNIFICANT PRECIP NORTH OF THE AREA FOR THE BALANCE OF TODAY.
HAVE KEPT NEAR CATEGORICAL IN FOR FAR NW COUNTIES BECAUSE OF THIS
BUT TAPERED VERY QUICKLY TO SILENT 10 POPS FOR THE SOUTHEAST
CORNER OF THE FORECAST AREA. TEMPS TODAY WILL BE HIGHLY DEPENDENT
ON HOW QUICKLY CLOUD COVER ERODES OR FOR THAT MATTER IF IT DOES.
FEEL WITH HEIGHTS BUILDING ALOFT...SHOULD SEE ENOUGH OF A BREAK IN
CLOUDS IN PRECIP AND CLOUDS TO WARRANT VALUES CLOSE TO GUIDANCE.
THIS WOULD BREAK A FEW A RECORDS ACROSS THE AREA PER CLIMATE
SECTION BELOW.

AS FAR AS SEVERE POTENTIAL...WILL BE A VERY CLOSE CALL TODAY AS
WIND CORE TRIES TO COME IN SYNC WITH BEST INSTABILITY. MODELS IN
GENERAL INDICATING THIS WILL NOT HAPPEN AS IMPRESSIVE 65KT 850MB
WIND CORE SHIFTS FROM ALABAMA AND MISSISSIPPI INTO THE TENNESSEE
VALLEY...LARGELY BYPASSING THE NW GA COUNTIES. IN ADDITION...305K
SURFACE INDICATES PRESSURE ALONG THAT SURFACE CONDUCIVE OF CAPPING
MUCH LIKE WHAT WAS DEPICTED THE LAST NONEVENT. DESPITE THESE
FACTORS...STILL CANNOT COMPLETELY RULE OUT AN ISOLATED SEVERE WIND
GUST OR BRIEF TORNADO.

FRONT PUSHES THROUGH FRIDAY NIGHT INTO SATURDAY WITH CONTINUED
MODERATE RAIN POTENTIAL BUT DOESNT GET ALL THAT FAR BEFORE NEXT
IMPULSE DIVES INTO THE CENTRAL PLAINS WITH SURFACE REFLECTION OVER
THE NORTHERN GULF OF MEXICO. RETURN MOISTURE ALOFT WILL RESULT IN
QUICKLY INCREASING POPS IN FAVORABLE ISENTROPIC UPGLIDE SETUP.
NORTH GEORGIA LOOKS TO BE TARGETED ONCE AGAIN WITH ANOTHER HALF AN
INCH TO INCH OF RAINFALL EXPECTED.

DEESE

.LONG TERM /SUNDAY THROUGH THURSDAY/...
EXTENDED BEGINS WITH SOUTHWEST FLOW CONTINUING ALOFT AS SURFACE
HIGH OVER THE GREAT LAKES CONTINUES RIDGING DOWN THE EASTERN
SEABOARD IN A DIABATICALLY ENHANCED CLASSICAL CAD SETUP.
ISENTROPIC UPGLIDE KEEPS HIGH POP-LOW QPF PRECIP ACROSS THE AREA
EARLY ON SUNDAY BUT AS A STRONG TROUGH AND SURFACE COLD FRONT
APPROACH SUNDAY NIGHT...PRECIPITATION INCREASES ACROSS THE AREA.
SEE HYDRO SECTION BELOW FOR MORE DETAIL.

SOUTH OF THE WEDGE FRONT...AS THE SYNOPTIC COLD FRONT APPROACHES
ON MONDAY...ALL MODELS HAVE MUCAPES INCREASING TO OVER 500 J/KG.
NOT TOO IMPRESSIVE BUT ENOUGH TO KEEP MENTION OF SLIGHT CHANCE
THUNDER IN THE AREA MONDAY AFTERNOON IN THAT WARM SECTOR...WHERE
HIGH TEMPS WILL BE IN THE MID 60S TO MID 70S. BEST SHEAR WILL BE
ALONG AND BEHIND THE COLD FRONT WHERE 0-1KM BULK SHEAR WILL BE
APPROACHING 35KT WHILE 0-6KM SHEAR IS UPWARDS OF 60-70KT. JUST
NOT SURE HOW WELL THESE TWO WILL LINE UP. SO FOR NOW...ISOLATED
THUNDER STILL LOOKS GOOD AND CANNOT RULE OUT STRONG TO ISOLATED
SEVERE STORMS BUT WILL MONITOR FORECAST TRENDS OVER THE NEXT
COUPLE OF DAYS.

COLD FRONT PUSHES THROUGH BY TUESDAY NIGHT BRINGING A MUCH COOLER
AIRMASS TO THE REGION. CURRENT GRIDS REFLECT ONLY A BRIEF OVERLAP
OF THE COLD AIRMASS AND LIGHT PRECIP...BRINGING A RAIN/SNOW MIX
INTO PORTIONS OF NORTH GEORGIA EARLY TUESDAY BEFORE THE MOISTURE
SWEEPS OUT. THIS WILL NEED TO BE REFINED WITH LATER FORECASTS. 00Z
GFS AND ECMWF ARE IN FAIRLY DECENT AGREEMENT THROUGH THE
EXTENDED...WITH HINTS OF THE BEGINNING OF A HYBRID DAMMING EVENT
JUST BEYOND THE END OF THE PERIOD.

TDP

&&

.HYDROLOGY...

WITH MAJORITY OF ACTIVITY WAITING UNTIL LATER THIS EVENING...AREA
CREEKS WILL HAVE SOMETIME TO RECOVER. WOULD NOT BE SURPRISED TO
SEE A FEW GO INTO FLOOD THIS EVENING WITH NEXT PRECIPITATION BATCH
BUT REDUCED TOTALS FROM HPC LEADS ME TO HOLD OFF ON ANY WATCH
PRODUCT AT THIS TIME.

COULD SEE SOME HEFTY AMOUNTS SUNDAY NIGHT AND MONDAY MORNING
ACROSS AREAS THAT WILL HAVE SEEN AT LEAST A COUPLE OF INCHES OF
RAIN UP TILL THEN...CANNOT RULE OUT THE POTENTIAL NEED FOR A FLOOD
WATCH BY THAT POINT. STORM TOTAL QPF THROUGH THE EXTENDED IS
ANOTHER 2-3 INCHES ACROSS NORTHWEST GEORGIA...WITH ALMOST AN INCH
OF THAT PROGGED TO COME BETWEEN 06-12Z MONDAY.

JTD/TDP

&&

.CLIMATE...

RECORDS FOR 12-06

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAHN      77 1998     37 1992     59 1912     20 1937
                            1962
   KATL      75 2001     25 1937     57 2011     14 1937
                                        1998
                                        1912
   KCSG      78 1951     42 1992     63 2011     24 1962
                            1962
   KMCN      78 1924     33 1937     63 1912     20 1937

&&

.AVIATION...
06Z UPDATE...
NEXT BATCH IN A SERIES OF SHOWERS AND EMBEDDED THUNDERSTORMS
CURRENTLY MOVING ACROSS THE NORTHERNMOST TAF SITES BUT REMAINING
GENERALLY NORTH OF ATL. EXPECT THIS TREND TO CONTINUE FOR THE
REMAINDER OF THE OVERNIGHT HOURS AND INTO MOST OF FRIDAY.
PERISTENT LOW LEVEL MOISTURE SHOULD RESULT IN A RETURN TO IFR
TONIGHT. TRENDS HAVE BEEN FOR IT TO REMAIN IFR AND NOT DIP TO LIFR
BUT CONFIDENCE IN THIS IS LOW AT THIS POINT. CIGS SHOULD GRADUALLY
IMPROVE THROUGH THE DAY...BECOMING MVFR FOR A BRIEF PERIOD. HAVE
PUSHED BACK SHRA/TSRA CHANCES BEYOND 00Z FOR THIS CYCLE. IN THE
WAKE OF THE SHRA...LOWERED CIG ARE EXPECTED WITH GOOD AGREEMENT ON
LIFR FOR A BRIEF PERIOD FRI NIGHT.

//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON LIFR POTENTIAL THIS MORNING AND SHRA/TSRA TIMING.
HIGH ON REMAINING ELEMENTS.

DEESE

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          75  57  59  47 /  40  70  60  60
ATLANTA         75  49  54  46 /  40  80  50  60
BLAIRSVILLE     67  46  52  43 /  50  90  60  80
CARTERSVILLE    72  45  50  44 /  50  90  60  70
COLUMBUS        80  55  59  52 /  30  80  60  30
GAINESVILLE     71  51  54  45 /  50  80  60  70
MACON           80  60  65  52 /  20  60  60  40
ROME            71  45  50  43 /  60 100  60  80
PEACHTREE CITY  76  50  55  47 /  30  80  60  50
VIDALIA         79  65  72  58 /  20  40  60  40

&&

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

$$

SHORT TERM...DEESE
LONG TERM....TDP
AVIATION...DEESE