National Weather Service Weather Forecast Office

Area Forecast Discussion

311
FXUS62 KFFC 030117 AAB
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
917 PM EDT WED OCT 2 2013

.UPDATE...
MADE A FEW TWEAKS TO THE GRIDS FOR THE OVERNIGHT PERIOD...MAINLY
INCREASED SKY COVER AND SUBSEQUENTLY RAISED LOWS A DEGREE OR TWO
AS SATELLITE TRENDS CONTINUE TO SHOW AMPLE MID/HIGH-LEVEL CLOUD
COVER. WITH THIS INCREASED CLOUD COVER I DO NOT EXPECT EARLY MORNING
FOG TO BE AS WIDESPREAD OR DENSE AS WEDNESDAY MORNING...BUT WE WILL
STILL LIKELY SEE AREAS OF FOG ONCE AGAIN.

20

&&

.PREV DISCUSSION... /ISSUED 800 PM EDT WED OCT 2 2013/

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
MAINLY A PERSISTENCE FORECAST THROUGH TONIGHT AND SHOULD AGAIN SEE
PATCHY TO AREAS OF FOG WITH PROGGED LOWER DEWPOINT DEPRESSIONS AND
CALM WINDS. MODELS IN GOOD AGREEMENT WITH UPPER RIDGE DAMPENING BY
TOMORROW AND MORE ENHANCED MOISTURE NOSING INTO FAR NORTHERN PORTION
OF CWA. SFC HIGH EAST OF THE AREA WILL ALLOW FOR WEAK SOUTH TO
SOUTHEASTERLY FLOW...SO THERE SHOULD BE ENOUGH OROGRAPHIC LIFT
INFLUENCE TO MUSTER OUT AT LEAST A SLIGHT CHANCE FOR SOME SHOWER
DEVELOPMENT IN THE FAR NORTH. MAIN FORECAST CONCERN REMAINS BEYOND
THE SHORT TERM WITH POTENTIAL INFLUENCE FROM A DEVELOPING TROPICAL
SYSTEM FROM THE SOUTH AND FRONTAL SYSTEM FROM THE WEST BY THE
WEEKEND.

GUIDANCE BLEND HAS CONTINUED TO VERIFY WELL FOR TEMPS WHICH RESULTS
IN VALUES AROUND 5 DEGREES ABOVE NORMAL FOR THURSDAY.

BAKER

LONG TERM /FRIDAY THROUGH WEDNESDAY/...
MAIN FOCUS OF THE EXTENDED REMAINS ON THE POTENTIAL TROPICAL
SYSTEM THAT IS IN THE CARIBBEAN THIS AFTERNOON. STILL CONSIDERABLE
DIFFERENCES BETWEEN THE GFS AND ECMWF WITH THE GFS BEING FURTHER
EAST THAN THE ECMWF AND ALSO STRONGER. THIS HAS AN IMPACT ON WHICH
DAY WE EXPECT THE BEST POPS ACROSS THE CWA. IN ADDITION...THE GFS
CLEARS THE FRONT OUT OF THE CWA BY TUESDAY WHEREAS THE ECMWF
LINGERS THE FRONT THROUGH THE LONG TERM. CURRENT FORECAST LEANS
TOWARD THE GFS AND MAIN CHANGE TO THE LONG TERM WAS TO INCREASE
POPS TO CATEGORICAL FOR SUNDAY AND SUNDAY NIGHT. HAVE ALSO TWEAKED
THE WINDS TO SHOW A SLIGHT INCREASE FOR SUNDAY. FEW CHANGES TO THE
FORECAST OUTSIDE THIS RAIN EVENT SO SEE THE PREVIOUS DISCUSSION
BELOW.

11

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

UPPER RIDGE SHOULD KEEP OUR CWA DRY THROUGH AT LEAST FRIDAY...WITH
THE DEEPER MOISTURE STAYING TO OUR WEST AND SOUTH. MODELS CONTINUE
TO PUSH DEEP UPPER TROUGH INTO THE CENTRAL STATES OVER THE
WEEKEND. ASSOCIATED COLD FRONT MAY NOT REACH GA UNTIL LATE SUNDAY
OR EARLY MONDAY. MAIN ISSUE IS TROPICAL SYSTEM FORECAST TO DEVELOP
IN THE CENTRAL GULF AND THE POSSIBLE TRACK. FOR NOW...HAVE
CONTINUED WITH BEST POPS FOR SATURDAY NIGHT INTO SUNDAY
NIGHT...AND DIMINISHING FROM THE WEST MONDAY AND MONDAY NIGHT.
LOOKS LIKE SOME OF THE TROPICAL MOISTURE SHOULD GET PULLED
NORTHWARD ACROSS THE CWA AHEAD OF THE FRONT. STILL SOME
DIFFERENCES ON FRONTAL PASSAGE AND CLEARING. ECMWF WANTS TO HANG
ON TO RAINFALL INTO TUESDAY...BUT HAVE BLENDED WITH NEIGHBORS AND
THE GFS BY ENDING ALL RAIN BY THEN.

41

AVIATION...
00Z UPDATE...
ONCE AGAIN VFR CONDITIONS ARE EXPECTED TO PREDOMINATE ACROSS THE
FORECAST AREA THROUGH THIS FORECAST PERIOD WITH SCATTERED MVFR...
AND LOCAL IFR...VISIBILITIES EXPECTED BETWEEN 06Z AND 14Z. ONLY TAF
SITES WHERE I AM CURRENTLY CARRYING ANY VISIBILITY RESTRICTIONS ARE
KPDK/KAHN/KMCN. WITH AMPLE MID AND HIGH LEVEL CLOUDS EXPECTED
THROUGH THE NIGHT I DO NOT EXPECT FOG TO BE QUITE AS WIDESPREAD OR
DENSE AS THE PREVIOUS COUPLE OF NIGHTS. WINDS WILL BE LIGHT SOUTH TO
EAST THROUGH 14Z...GENERALLY 3KTS OR LESS. INCREASING AND BECOMING
SOUTHEAST TO EAST AFTER BETWEEN 3-6KTS. ONLY CEILINGS EXPECTED
THROUGH AROUND 18Z WILL BE 15KFT OR HIGHER WITH SCATTERED CLOUDS
040-050FT...AND OCCASIONALLY BROKEN...AFTER 18Z.

//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.

20

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          58  84  60  85 /   5  10   5  10
ATLANTA         63  83  65  85 /   5  10  10  10
BLAIRSVILLE     54  79  56  81 /  10  20  10  10
CARTERSVILLE    58  84  60  85 /   5  10  10  10
COLUMBUS        63  85  67  87 /   5   5   5  10
GAINESVILLE     61  82  63  82 /   5  10  10  10
MACON           58  85  60  86 /   5   5   5  10
ROME            57  85  60  85 /   5  10  10  10
PEACHTREE CITY  56  83  58  85 /   5   5   5  10
VIDALIA         60  85  65  86 /   5   5   5  10

&&

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

$$

SHORT TERM...20
LONG TERM....NLISTEMAA
AVIATION...20