National Weather Service Weather Forecast Office

Area Forecast Discussion

061
FXUS62 KFFC 031957
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
257 PM EST SUN MAR 3 2013

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
SHORT WAVE THAT GAVE US THE CLOUDS AND FLURRIES/SNOW SHOWERS THIS
MORNING IS FINALLY LOSING ITS GRIP OVER THE CWA. SKIES ARE IN THE
PROGRESS OF BECOMING PARTLY CLOUDY ACROSS THE CWA. BY THIS EVENING
SKIES SHOULD BE CLEAR. THE NEXT SYSTEM COMES INTO THE CWA LATE
MONDAY NIGHT AND TUESDAY. SOME WARM ADVECTION MID LEVEL CLOUDS WILL
MOVE ACROSS NORTH GA LATE TONIGHT AND EARLY MONDAY BUT THEN HIGH
LEVEL CLOUDS WILL INCREASE THROUGH THE DAY. ENOUGH WARM ADVECTION AT
THE SURFACE WILL PUSH TEMPERATURES INTO THE 50S/L60S AFTER ANOTHER
COLD START. WILL CONTINUE THE FREEZE WARNING FOR THE ENTIRE CWA
TONIGHT AS WE SHOULD HAVE GOOD RADIATIONAL COOLING WHICH WILL ALLOW
TEMPS TO BOTTOM OUT. CLOUDS CONTINUE TO INCREASE MONDAY NIGHT WITH
PRECIP MOVING INTO NORTHWEST GA AFTER MIDNIGHT. MODELS KEEP THE
SURFACE LOW TO OUR NORTH KEEPING THE CWA IN THE WARM SECTOR. THIS
WILL KEEP TEMPS WELL ABOVE FREEZING MONDAY NIGHT SO DO NOT EXPECT
ANY FROZEN PRECIP NOR DO NOT EXPECT ANOTHER FREEZE WARNING. THERE
APPEARS TO BE ENOUGH INSTABILITY TUESDAY TO WARRANT THE MENTION IS
SLIGHT CHANCE OF THUNDERSTORMS. BASED ON THE MODEL WILL DEPEND ON
HOW FAST THE FRONT WILL PUSH THROUGH. AT THIS TIME ENOUGH
DISCREPANCY TO KEEP THE RISK OF THUNDER IN ALL DAY.

17

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GUIDANCE STILL SHOWING MINOR DISCREPANCIES WITH LOCATION OF LOW
PRESSURE SYSTEM AND ASSOCIATED MOISTURE. ECMWF IS MORE EXPANSIVE
WITH MOISTURE FIELD ON WRAP-AROUND BACK SIDE OF SYSTEM COMING
FARTHER SOUTHWARD INTO THE AREA...THOUGH THIS IS AN OUTLIER FROM
OTHER GUIDANCE MEMBERS. FORECAST SOUNDINGS STILL SHOW PORTIONS OF
NORTH GEORGIA COLD ALOFT TO SUPPORT SNOW SHOWER TRANSITION TUESDAY
NIGHT INTO WEDNESDAY MORNING...THEREFORE WILL CONTINUE MENTION BUT
DID NOT ADJUST COVERAGE. FUTURE UPDATES MAY WARRANT EXPANDING THE
SNOW SHOWER COVERAGE BASED ON TEMPS ALOFT EVEN THOUGH SFC TEMPS
MAY STRUGGLE TO GET TO FREEZING LATE. REST OF FORECAST LOOKS TO BE
ON TRACK AND DID NOT JUSTIFY CHANGES. PREVIOUS DISCUSSION FOLLOWS...

BAKER

PREV DISCUSSION... /ISSUED 635 AM EST SUN MAR 3 2013/

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MAIN STORY FOR THE LONG TERM REMAINS THE MONDAY NIGHT TO WEDNESDAY
SYSTEM. DESPITE SOME SLIGHT DIFFERENCES...MODELS ARE IN DECENT
AGREEMENT WITH TIMING AND POSITIONING OF FEATURES. BY MONDAY NIGHT
THE SFC LOW WILL SWEEP INTO THE TN VALLEY AND BRING THE CHANCE OF
PRECIP BACK TO THE CWA. FRONT WILL PUSH INTO GEORGIA ON TUESDAY
AND OUT OF THE STATE BY LATE TUESDAY NIGHT. GFS IS SLIGHTLY
FURTHER NORTH THAN PREVIOUS 00Z RUN WITH POSITIONING OF UPPER
LEVEL LOW AND OVERALL THE MODELS SUGGEST THE CLOSED UPPER LOW
TRACKING ACROSS THE TN VALLEY OR EXTREME NORTH GEORGIA TUESDAY
NIGHT. SOME WRAP AROUND MOISTURE WITH THIS SYSTEM WILL BE ENOUGH
TO LEAVE THE MENTION OF PRECIP IN ACROSS THE MOUNTAINS OF NORTH
GEORGIA ON WEDNESDAY.

UNCERTAINTY WITH THIS SYSTEM AS TO THE POSSIBILITY OF WINTER WEATHER
TUESDAY NIGHT INTO WEDNESDAY MORNING. WITH WRAP AROUND MOISTURE
STILL PROVIDING THE CHANCE OF PRECIP TUESDAY NIGHT INTO WEDNESDAY
ACROSS THE MOUNTAINS...GFS BUFR SOUNDING AT BRASSTOWN BALD
SUGGESTS THE RAIN COULD TRANSITION TO SNOW EARLY WEDNESDAY
MORNING. FORECAST CONTINUES TO MENTION RAIN AND SNOW DURING THIS
TIME TUESDAY NIGHT INTO WEDNESDAY MORNING ACROSS THE MOUNTAINS.
SOME LIGHT ACCUMULATIONS COULD BE POSSIBLE.

SOME INSTABILITY ASSOCIATED WITH THIS SYSTEM AS SHOWN BY MUCAPE
VALUES IN THE GFS AND NAM WHILE LIFTED INDICES ARE JUST BELOW ZERO.
COULD GO EITHER WAY ON MENTIONING ISOLATED TS IN THE GRIDS SO WILL
CONTINUE TREND TO LEAVE IT OUT FOR NOW.

BY THURSDAY...HIGH PRESSURE WILL BEGIN MOVING INTO THE CWA AND WILL
DOMINATE THROUGH THE REST OF THE EXTENDED...ALLOWING FOR DRY WEATHER
INTO THE WEEKEND.

11

&&

.AVIATION...
18Z UPDATE...
BROKEN VFR SKIES WILL SLOWLY BECOME SCATTERED THIS AFTERNOON LEAVING
CLEAR SKIES BY THIS EVENING. ALTO CU WILL MOVE INTO NORTH GA TOWARD
MORNING BUT A DENSER HIGHER LEVEL DECK WILL MOVE INTO THE CWA MID
MONDAY MORNING AND HOLD THROUGH THE DAY. WINDS WILL REMAIN
NORTHWEST...DIMINISHING TONIGHT...BECOMING WEST TO SOUTHWEST MONDAY
MORNING LESS THAN 10 KTS.

//ATL CONFIDENCE...18Z UPDATE...
HIGH ON ALL ELEMENTS.

17

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          26  58  40  60 /   0   5  10  70
ATLANTA         30  56  46  60 /   0   5  10  60
BLAIRSVILLE     23  53  37  52 /   0  10  30  80
CARTERSVILLE    26  56  42  59 /   5  10  30  70
COLUMBUS        32  60  46  67 /   0   5  10  50
GAINESVILLE     27  54  42  55 /   0   5  20  70
MACON           28  59  40  66 /   0   5  10  40
ROME            26  57  42  59 /   5  10  40  80
PEACHTREE CITY  26  58  42  61 /   0   5  10  60
VIDALIA         32  62  44  69 /   0   5   5  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EST MONDAY FOR THE
FOLLOWING ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...
BLECKLEY...BUTTS...CARROLL...CATOOSA...CHATTAHOOCHEE...
CHATTOOGA...CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...
CRAWFORD...CRISP...DADE...DAWSON...DEKALB...DODGE...DOOLY...
DOUGLAS...EMANUEL...FANNIN...FAYETTE...FLOYD...FORSYTH...
GILMER...GLASCOCK...GORDON...GREENE...GWINNETT...HALL...
HANCOCK...HARALSON...HARRIS...HEARD...HENRY...HOUSTON...
JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...
LAURENS...LUMPKIN...MACON...MADISON...MARION...MERIWETHER...
MONROE...MONTGOMERY...MORGAN...MURRAY...MUSCOGEE...NEWTON...
NORTH FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...
PICKENS...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...SCHLEY...
SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TOWNS...TREUTLEN...
TROUP...TWIGGS...UNION...UPSON...WALKER...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WHITE...WHITFIELD...WILCOX...
WILKES...WILKINSON.

&&

$$

SHORT TERM...17
LONG TERM....11/BAKER
AVIATION...17