594 
FXUS62 KFFC 041823
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
223 PM EDT THU JUL 4 2013



.PREV DISCUSSION... /ISSUED 1051 AM EDT THU JUL 4 2013/ 

UPDATE...
WIDESPREAD SHOWERS CONTINUING ACROSS PORTIONS OF WESTERN AND
NORTHERN GEORGIA THIS MORNING...WITH SOME NEW DEVELOPMENT FIRING
ACROSS EASTERN GEORGIA. HAVE MADE SOME ADJUSTMENTS TO HOURLY POPS
AND WX GRIDS TO ACCOUNT FOR THE LATEST RADAR TRENDS...AND WITH THE
NEW WPC QPF GUIDANCE...HAVE ADJUSTED QPF AMOUNTS AS WELL. FOR
NOW...MODELS SUGGESTING THAT EARLY AFTERNOON THROUGH EVENING
ACTIVITY BE MORE CONVECTIVE IN NATURE THAN WHAT IS CURRENTLY
OCCURRING THIS MORNING. ADDITIONAL RAINFALL AMOUNTS THROUGH FRIDAY
MORNING ARE EXPECTED TO PEAK AT 2 OR MORE INCHES ACROSS FAR
NORTHWEST GEORGIA. FORTUNATELY...THIS AREA SAW LITTLE OF THE
ENHANCED PRECIP FROM THE LAST 24-36 HOURS...AND SHOULD BE ABLE TO
HANDLE 2 INCH AMOUNTS WITH LITTLE CONSEQUENCE. THAT BEING
SAID...LOCALLY HEAVIER AMOUNTS CAN BE EXPECTED...ESPECIALLY IF
STORMS TRAIN OVER THE SAME AREA. ACROSS A LARGE PORTION OF THE
AREA...AN ADDITIONAL 1-2 INCHES CAN BE EXPECTED...AND UP TO 1
INCH POSSIBLE IN THE FAR SOUTHEAST CWA.

AS A RESULT OF THE WET SOILS AND HEAVY PRECIPITATION...RIVERS AND
CREEKS CONTINUE TO RESPOND. ADDITIONAL RAINFALL TODAY WILL KEEP
THESE WATERS HIGH. IT IS IMPORTANT TO STAY ALERT TO CHANGING
CONDITIONS...AND USE EXTREME CAUTION IF HOLIDAY PLANS CENTER
AROUND STREAMS...CREEKS...OR RIVERS. PLEASE REFER TO LOCAL TV
MEDIA OUTLETS OR WWW.WEATHER.GOV/ATLANTA FOR THE LATEST
INFORMATION ON FLOODING CONDITIONS.

31

PREV DISCUSSION... /ISSUED 710 AM EDT THU JUL 4 2013/ 

SHORT TERM /TODAY THROUGH FRIDAY/... 
/ISSUED 438 AM EDT THU JUL 4 2013/ 
CURRENT RADAR LOOP SHOWS SHOWERS AND ISOLATED THUNDERSTORMS
CONTINUING TO MOVE NORTHWARD ACROSS THE STATE. THESE SHOWERS ARE
VERY MOISTURE LADEN WITH PW VALUES THIS MORNING IN THE 1.8 TO 2
INCH RANGE. MOST LOCATIONS ACROSS THE STATE HAVE RECEIVED 1 TO 2
INCHES OF PRECIPITATION OVER THE PAST 24 HOURS. A FEW ISOLATED
LOCATIONS HAVE SEEN 4 TO ALMOST 5 INCHES. THIS WEATHER PATTERN IS
SHAPING UP TO BE A DANGEROUS FLOODING THREAT. AS FOR THE WEATHER
PATTERN...THE MAIN UPPER LEVEL TROUGH TO THE WEST IS IN A FIGHT
WITH THE BERMUDA HIGH TO THE EAST. THIS IS PUTTING GA IN A VERY
MOIST TROPICAL FLOW REGIME. GUIDANCE SUGGESTS THAT THIS WILL
CONTINUE THROUGH THE WEEKEND AS THE TROUGH AND RIDGE DO NOT MOVE
VERY MUCH. MOST PLACES ACROSS THE STATE WILL SEE AN ADDITIONAL 2
TO 4 INCHES OF RAIN WITH ISOLATED HIGHER AMOUNTS THROUGH THE
BEGINNING OF NEXT WEEK. BY SUN-MON OF NEXT WEEK THE TROUGH TO OUR
WEST STARTS TO DE- AMPLIFY AND MOVES NE AS THE HIGH JUST OFF THE
CAROLINA COAST BUILDS WEST. THIS SHOULD HELP TO ROTATE THE AXIS OF
DEEP MOISTURE MORE EAST TO WEST. IF THIS HAPPENS THAT PLUME OF
DEEP MOISTURE WILL LOOSE ITS SOURCE OF MOISTURE...THE GULF OF
MEXICO...AND THE HEAVY PRECIP SHOULD DIMINISH BY MON-TUE.

01

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED 438 AM EDT THU JUL 4 2013/ 
LIMITED CHANGES MADE TO EXTENDED FORECAST DUE TO ONGOING WEATHER
AND FLOODING CONCERNS. 

PREVIOUS DISCUSSION FROM 430 AM EDT WED JUL 3 2012
VERY LARGE AND STRONG UPPER LEVEL TROUGH IN PLACE JUST WEST OF THE
MISSISSIPPI RIVER VALLEY WILL CONTINUE TO CONTROL THE WEATHER
PATTERN THROUGH MOST OF THE EXTENDED. THIS RETROGRADING UPPER
TROUGH IS EXPECTED TO BE CENTERED OVER THE CENTRAL PLAINS STATES BY
THU NIGHT AS A STRENGTHENING UPPER HIGH MOVES ONSHORE THE MID
ATLANTIC COAST. THIS PATTERN WILL KEEP GA IN VERY MOIST SOUTHERLY
FLOW THROUGH THE WEEKEND. THE FORECAST MODELS ARE SHOWING A PLUME
OF RICH MONSOONAL LIKE MOISTURE MOVING ONSHORE THE GA/SC/NC COAST
IN THE SHORT TERM THEN SPREADING WEST ACROSS THE REST OF THE
REGION THROUGH THE BEGINNING OF NEXT WEEK. THIS PATTERN WILL PUT
GA RIGHT UNDER THIS PLUME THU THROUGH SAT. THE MODELS ARE SHOWING
PW VALUES INCREASING TO NEAR 2 INCHES BY 00Z THU AND STAYING THERE
THROUGH 00Z TUE OF NEXT WEEK. THE WPC 3 TO 5 DAY QPF TOTALS ARE STILL
SHOWING 2 TO 4 INCH TOTALS ACROSS THE STATE WITH ISOLATED HIGHER
AMOUNTS. BOTH THE GFS AND ECMWF SHOW THE AXIS OF THIS PLUME
SHIFTING WEST OF THE STATE BY SUNDAY MORNING...BUT GA STILL STAYS
IN MOIST FLOW. BOTH THE GFS AND ECMWF HAVE BEEN ADVERTISING THIS
WEATHER PATTERN FOR ABOUT 5 DAY NOW SO CONFIDENCE IN THIS
OCCURRING IS VERY HIGH.

DEESE

HYDROLOGY...
/ISSUED 3 PM EDT WED JUL 3 2013/ 

POTENTIALLY DANGEROUS SITUATION DEVELOPING...

SINCE 8 AM EDT WEDNESDAY /THROUGH 3 PM WEDNESDAY/...WIDESPREAD
RAINFALL AMOUNTS OF 1.5 TO 2 INCHES HAVE FALLEN ACROSS NORTHERN
AND WESTERN GEORGIA. EXTREMELY HIGH RAINFALL AMOUNTS OF 3.5-6.5
INCHES HAVE FALLEN IN PORTIONS OF EXTREME WESTERN GEORGIA AND
PORTIONS OF THE WESTERN AND NORTHERN METRO ATLANTA AREAS. LATEST
MODEL CONSENSUS SUGGESTS THAT AN ADDITIONAL 3-4 INCHES OF RAINFALL
IS POSSIBLE IN NORTHERN AND WESTERN GEORGIA...AND 1-3 INCHES IS
POSSIBLE ACROSS EASTERN AND PORTIONS OF CENTRAL GEORGIA. IN
LOCATIONS WHERE STORMS TRAIN OVER THE SAME AREA...LOCALLY HIGHER
AMOUNTS CAN BE EXPECTED. THESE RAINFALL AMOUNTS WILL CONTINUE TO
CAUSE RIVERS AND CREEKS TO RISE...AND WIDESPREAD MINOR FLOODING
CAN BE EXPECTED. THE BIG CONCERN WILL BE CONTINUED FLOODING
OVERNIGHT AND INTO EARLY THURSDAY AND THE 4TH OF JULY ACTIVITIES
OCCURRING IN THE AREA. IT IS EXTREMELY IMPORTANT THAT ANYONE
DRIVING...ESPECIALLY IN THE DARK...REFER TO THE NWS ATLANTA
WEBSITE /WWW.WEATHER.GOV/ATLANTA/ OR LOCAL TV MEDIA OUTLETS BEFORE
HITTING THE ROADS. DO NOT DRIVE THROUGH FLOODED ROADWAYS OR AROUND
BARRICADES! AGAIN...THIS EVENT HAS THE POTENTIAL TO DEVELOP INTO A
DANGEROUS SITUATION. PLEASE STAY ALERT TO CHANGING
CONDITIONS...AND IF VISITING OR TRAVELING AROUND NORTH AND CENTRAL
GEORGIA...PLEASE BE FAMILIAR WITH THE COUNTY YOU ARE IN...AND BE
AWARE OF ANY CREEKS...RIVERS...OR STREAMS YOU MAY BE LOCATED NEAR.

31

&&

.AVIATION...
18Z UPDATE...
GENERALLY IFR TO MVFR CIGS EXPECTED IN CONVECTION...WITH SOME
BREAKS TO VFR OUTSIDE OF STORMS. EXPECT SHOWERS WITH ISOLATED TS
TO CONTINUE ACROSS THE AREA THROUGH 00Z...WITH SOME MODELS
INDICATING BEST CONVECTION WILL MOVE NORTH AND EAST OF TAF SITES
AT THAT TIME. WINDS EXPECTED TO BE ESE AT 7-12KT...WITH SOME
VARIABLE WINDS WITH GUSTS TO 20-25KT IN CONVECTION.
OVERNIGHT...CONDITIONS WILL DEGRADE TO IFR BY 06Z...WITH SLOW
IMPROVEMENTS TO GENERALLY MVFR THROUGH THE DAY. SCATTERED TS
EXPECTED AGAIN FRI 17-21Z...SO HAVE INCLUDED PROB30 GROUPS TO
ADDRESS THIS ACTIVITY.

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

31

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          81  70  83  69 / 100  80  80  60 
ATLANTA         77  69  79  70 / 100  90  80  70 
BLAIRSVILLE     72  66  76  66 / 100 100  90  70 
CARTERSVILLE    77  70  81  70 / 100 100  90  70 
COLUMBUS        80  70  83  71 / 100  70  80  70 
GAINESVILLE     76  68  80  68 / 100  90  90  60 
MACON           83  72  85  71 /  80  60  80  40 
ROME            78  71  81  70 / 100 100  90  70 
PEACHTREE CITY  78  69  81  69 / 100  80  80  70 
VIDALIA         87  73  88  73 /  40  30  40  30 

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING 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...31
LONG TERM....20
AVIATION...31