FXUS62 KFFC 050348 AAC
AFDFFC
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1045 PM EST FRI DEC 4 2009
.UPDATE...
REVISED SNOW AMOUNTS IN FAR NE GA ZONES UP TO 1 TO 3 INCHES FOR THE
EVENT AS WRAPAROUND/UPSLOPE PRECIP MAY PERSIST INTO SAT AFTERNOON.
REST OF ADVISORY AREA STILL GOOD FOR AROUND AN INCH. MOST OF SNOW
WILL BE IN THE GRASSY/EXPOSED AREAS BUT MAY AFFECT SOME ROADWAYS FOR
A SHORT TIME SATURDAY MORNING MAINLY AREAS NORTH OF ROME TO
CLEVELAND LINE. THIS IS PRETTY CLOSE TO WHAT IS IN ADVISORY TEXT BUT
MAY SEND A MINOR CORRECTION BEFORE 11 PM.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 520 PM EST FRI DEC 4 2009/
UPDATE...
QUICK UPDATE TO TWEAK PRECIP AND CHANGEOVER TO SNOW TIMING TONIGHT
AND PRECIP TRENDS SATURDAY. SATELLITE/RADAR/SFC OBS TRENDS SHOW
PRECIP STREAKING ACROSS MISSISSIPPI INTO WESTERN ALABAMA IN THE
LAST FEW HOURS. 18Z GFS AND 21Z SREF STILL INDICATING LIGHT PRECIP
STREAMING INTO NORTH GA AROUND MIDNIGHT WHILE 00Z NAM SHOWS IT
COMING IN AROUND 09Z. HAVE TWEAKED POPS BASED ON LATEST GFS/SREF
TIMING AND OBSERVED TRENDS. OVERALL NOT MUCH CHANGE NOTED ON
OVERALL AMOUNTS SO HAVE NOT CHANGED ADVISORY AREA. MAY HAVE TO
WATCH SFC TEMP/DEWPOINT TRENDS AS SFC WETBULB TEMPS IN NORTH GA
APPEAR A TAD TOO WARM FOR MEASURABLE SNOW. WETBULB TEMP PROFILE
ALOFT ON NORTH GA MODEL SOUNDINGS APPEAR MORE FAVORABLE LATE
TONIGHT SO STILL FAIRLY CONFIDENT IN LOW END ADVISORY EVENT WITH
AMOUNTS AROUND AN INCH POSS. MEASURABLE PRECIP MAY CONTINUE INTO
THE AFTERNOON IN NE GA SO CONTINUED POPS THERE. MAY HAVE TO EXTEND
ADVISORY LATER IN THE DAY IF MEASURABLE SNOW PERSISTS THERE. ONLY
MINOR TWEAKS TO TEMP TRENDS AS MOS GUIDANCE TOO WARM NEAR KRMG AND
SOME NE GA AREAS AND TOO COOL IN TYPICAL RADIATIONAL COOLING SPOTS
IN WEST CENTRAL GA. SHOULD REMAIN CLOUDY TONIGHT. NO OTHER CHANGES
FOR NOW.
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AN UPPER LEVEL TROUGH DIPPING INTO WEST TEXAS WILL RACE EAST
ACROSS THE SOUTHERN STATES TONIGHT REACHING GEORGIA SATURDAY
MORNING. SURFACE LOW PRESSURE OVER THE CENTRAL GULF OF MEXICO IN
RESPONSE TO THIS TROUGH WILL SPREAD PRECIPITATION ACROSS AL/FL/GA
AND THE CAROLINAS TONIGHT AND SATURDAY. COLD AIR ADVECTION WILL
BRING 850 MB TEMPS DOWN TO ZERO TO MINUS 4 DEG C BY SATURDAY
MORNING OVER MUCH OF NORTH GEORGIA...NORTHWEST OF INTERSTATE
85. THE FORECAST SOUNDINGS SHOW A MIX OF RAIN...SLEET AND SNOW
AFTER MIDNIGHT THROUGH SATURDAY MORNING. THE PRECIPITATION TYPE
SHOULD BE PREDOMINANTLY SNOW OVER THE NORTH GA MOUNTAINS WHERE
TEMPERATURES (SURFACE&ALOFT) SHOULD BE COLD TO ENOUGH TO ALLOW
SOME ACCUMULATIONS. THIS MORNINGS NAM AND SREF MODEL RUNS ARE MORE
CONSISTENT WITH EACH OTHER NOW...WHILE THE GFS REMAINS THE WETTEST
WITH THE MOST SNOW ACCUMULATION. BEST BET IS TO REMAIN WITH
CURRENT THINKING THAT AN INCH OR TWO WILL BE POSSIBLE IN THE NORTH
GA MOUNTAINS AND LESS THAN ONE HALF ACCUMULATION ELSEWHERE IN THE
ADVISORY AREA...WHICH IS GENERALLY NORTH OF A CARROLLTON THROUGH
MARIETTA AND DAWSONVILLE TO CLEVELAND LINE. THE RAIN...SLEET AND
SNOW WILL END SATURDAY MORNING ...BUT THE LIGHT SNOW MAY LINGER
INTO EARLY SATURDAY AFTERNOON OVER THE NORTHEAST GA. HIGH PRESSURE
BUILDING IN FROM THE WEST LATE SATURDAY WILL ALLOW SKIES TO CLEAR
AND WINDS TO DROP OFF...BRINGING OPTIMAL RADIATIONAL COOLING
SATURDAY NIGHT. THE HIGH WILL SLIDE EAST OF GEORGIA ON SUNDAY. A
MET/MAV MOS BLEND WAS GENERALLY USED FOR TEMPS AND POPS.
LONG TERM /MONDAY THROUGH FRIDAY/...
THE UPPER LEVEL PATTERN BECOMES MORE ZONAL ACROSS THE EASTERN
U.S. EARLY NEXT WEEK ALLOWING A FEW WEAK SYSTEMS TO PUSH THROUGH
THE LOCAL AREA WITH OUR AIRMASS GRADUALLY WARMING AND MOISTENING.
AN UPPER TROUGH DIGGING INTO THE WESTERN STATES ON MONDAY/TUESDAY
WILL SPAWN A POWERFUL 970 MB SURFACE LOW WHICH TRACKS FROM THE
CENTRAL PLAINS TO THE GREAT LAKES BY WEDNESDAY...AS AN ASSOCIATED
COLD FRONT SURGES THROUGH GEORGIA. PRIOR TO THAT FRONTAL PASSAGE
THOUGH...APPEARS TO BE A RATHER EXTENDED PERIOD OF RAIN /POSSIBLY
HEAVY/ TUESDAY INTO WEDNESDAY.
AVIATION...
MVFR CEILINGS DEVELOPING BETWEEN 04Z AND 06Z AREAWIDE. IFR CEILINGS
EXPECTED ACROSS CENTRAL AND EAST GEORGIA BY 10Z. PRECIPITATION WILL
SPREAD NORTH BETWEEN 00Z AND 06Z...BUT SHOULD REMAIN RELATIVELY
LIGHT. RAIN MAY BECOME MIXED WITH SNOW BETWEEN 10Z AND 14Z AT
KATL...KFTY...KPDK...KRYY AND KAHN. VFR CONDITIONS WILL SPREAD FROM
NORTHWEST TO SOUTHEAST ACROSS THE FORECAST AREA BETWEEN 18Z AND 00Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 41 46 27 54 35 / 90 50 0 0 10
ATLANTA 36 43 28 54 37 / 80 20 0 0 20
BLAIRSVILLE 34 37 23 49 32 / 80 60 0 0 10
CARTERSVILLE 33 40 24 52 33 / 80 30 0 0 20
COLUMBUS 38 50 28 56 38 / 90 10 0 0 20
GAINESVILLE 37 43 28 50 35 / 80 40 0 0 10
MACON 40 52 27 58 37 / 90 20 0 0 10
ROME 32 41 24 53 33 / 80 40 0 0 20
PEACHTREE CITY 37 45 23 53 32 / 90 20 0 0 20
VIDALIA 42 54 30 57 40 / 100 60 0 0 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR THE FOLLOWING
ZONES: BARTOW...CARROLL...CATOOSA...CHATTOOGA...CHEROKEE...COBB...
DADE...DAWSON...DOUGLAS...FLOYD...GILMER...GORDON...HARALSON...MURRAY
...PAULDING...PICKENS...POLK...WALKER...WHITFIELD.
WINTER WEATHER ADVISORY FROM 4 AM TO 7 PM EST SATURDAY FOR THE
FOLLOWING ZONES: FANNIN...LUMPKIN...TOWNS...UNION...WHITE.
&&
$$
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