-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KFFC 211147
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
735 AM EDT TUE MAY 21 2013

.SHORT TERM /TODAY THROUGH WEDNESDAY/...
UPPER RIDGE CONTINUES BUILDING OVER THE SOUTHEAST TODAY WITH AN
UPPER LOW NEAR SOUTHEAST GA/NORTHEAST FL. THE AIR MASS REMAINS
UNSTABLE HOWEVER WATER VAPOR SHOWS SOME DRIER AIR HAS WORKED INTO
NORTHWEST GA. HAVE KEPT A SLIGHT CHANCE/LOW CHANCE POPS MAINLY OVER
THE EASTERN HALF OF THE CWA THIS AFTERNOON AND EVENING...CLOSER TO
THE UPPER LOW AND BETTER MOISTURE. TONIGHT LOOKS LIKE A LULL BETWEEN
SYSTEMS AND HAVE ONLY INCLUDED SLIGHT CHANCE POPS ACROSS THE EXTREME
NORTH. THE GFS HINTS AT A SHORT WAVE CROSSING THE TN VALLEY
OVERNIGHT. A CLOSED UPPER LOW MOVING INTO THE GREAT LAKES REGION BY
WEDNESDAY SHOULD PUSH A FRONT INTO THE LOWER MISSISSIPPI VALLEY
TOWARD GEORGIA. THE MODELS WANT TO KEEP THE FRONT WEST OF THE CWA
DURING THE DAY...BUT AN INCREASE IN MOISTURE AND INSTABILITY SHOULD
SUPPORT BETTER CHANCES OF THUNDERSTORMS ACROSS THE CWA BY WEDNESDAY
AFTERNOON. MAV/MET TEMPERATURES ARE CLOSE AND HAVE TAKEN A
COMPROMISE.

41

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
WEAK COLD FRONT APPROACHING WITH AN UPPER LEVEL TROUGH/SHORT WAVE
FORECAST TO MOVE INTO THE AREA WEDNESDAY NIGHT AND WITH ASSOCIATED
MOISTURE AND INSTABILITY...SCATTERED SHOWERS AND THUNDERSTORMS
ARE REASONABLE...MOST SO FOR THE EVENING HOURS. THE WEAK COLD
FRONT MOVES INTO THE AREA ON THURSDAY. IT IS UNCLEAR HOW MUCH
CONVECTION WILL BE ASSOCIATED WITH THE FRONT. THE BEST INSTABILITY
IS FORECAST OVER CENTRAL GA WITH THE BEST UPPER SUPPORT OVER N GA.
AT THIS TIME IT SEEMS REASONABLE THAT THERE WILL BE A CHANCE OF
SHOWERS AND THUNDERSTORMS...MOST SO IN THE AFTERNOON. THE MAIN
UPPER TROUGH MOVES E FOR FRIDAY WITH A DRIER AIRMASS MOVING OVER
THE AREA BEHIND THE FRONT AS SURFACE HIGH PRESSURE BUILDS ALONG
WITH A MUCH DRIER NW FLOW. DRY CONDITIONS CONTINUE SATURDAY AS
HIGH PRESSURE MOVES ACROSS THE EASTERN STATES. SUNDAY LOOKS TO BE
MAINLY DRY AS WELL EXCEPT THE NW FLOW ALOFT BEGINS TO BECOME MORE
ACTIVE TO THE N WITH SOME MOISTURE SKIRTING BY THE AREA. MOISTURE
CONTINUES TO SKIRT BY MONDAY AND TUESDAY WITH A SHARP GRADIENT OF
SIGNIFICANT MOISTURE AT THE GA/SC LINE. FOR NOW WILL LEAVE A DRY
FORECAST FOR MONDAY/TUESDAY AND CONTINUE TO MONITOR THE PROGRESS
OF THE NW FLOW. TEMPERATURES GENERALLY RUNNING WITHIN 5 DEGREES OF
NORMAL THROUGH THE PERIOD EXCEPT SATURDAY AND SUNDAY MORNING LOWS
RUNNING 5-10 DEGREES BELOW NORMAL.

BDL

&&

.AVIATION...
-- Changed Discussion --
12Z UPDATE...
EXPECTING VFR TODAY WITH SCT TO BKN CLOUDS AT OR ABOVE 040. IFR
VISIBILITIES WILL IMPROVE QUICKLY THIS MORNING AS MOST AREAS OF FOG
ARE SHALLOW. WIDELY SCATTERED CONVECTION POSSIBLE THIS AFTERNOON AND
EVENING. PROBABILITY OF HAVING A THUNDERSTORM AFFECT THE TAF SITES
IS LOW SO HAVE LEFT THUNDER OUT OF FORECAST FOR NOW. WINDS EXPECTED
TO BECOME SOUTHWEST LATER THIS MORNING AROUND 5 TO 8KT. WINDS WILL
GRADUALLY SWITCH BACK AROUND TO THE SSE AGAIN BY 00Z THIS EVENING
BUT WILL BE GENERALLY LESS THAN 5KT. .

//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF SW WINDS. HIGH CONFIDENCE ON ALL
OTHER ELEMENTS.

41
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          87  64  86  64 /  30  30  40  40
ATLANTA         86  67  84  66 /  10  10  50  40
BLAIRSVILLE     82  60  81  60 /  30  30  50  50
CARTERSVILLE    86  64  85  63 /  10  10  50  40
COLUMBUS        90  68  88  68 /  10  10  30  30
GAINESVILLE     85  66  84  64 /  30  30  50  40
MACON           89  64  88  65 /  20  20  30  30
ROME            86  63  85  62 /  10  20  50  40
PEACHTREE CITY  87  61  86  63 /  10  10  50  30
VIDALIA         88  69  88  68 /  30  30  30  30

&&

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

$$

SHORT TERM...41
LONG TERM....BDL
AVIATION...41