Special Weather Statement, NWS Atlanta, GA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
344 PM EDT MON OCT 1 2012

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
STARTING OUT WITH AN ACTIVE AFTERNOON WITH A TORNADO WATCH FOR MUCH
OF THE CWA AND THIS IS THE MAIN STORY FOR THE SHORT TERM. WARM FRONT
HAS LIFTED INTO NORTH GEORGIA...NORTH OF THE ATL TO AHN LINE. WEDGE
IS WORKING AGAINST THE WARM FRONT TO KEEP IT FROM PUSHING INTO
NORTHEST GA AT LEAST FOR NOW. THE MAJORITY OF THE CWA IS IN THE WARM
SECTOR WITH DEW POINTS IN THE LOW 70S. IN ADDITION...1500 TO 2000
J/KG OF SB CAPE HAS PUSHED INTO THE ATL AREA WITH AROUND 30KTS OF
LOW LEVEL SHEAR ACROSS MUCH OF THE CWA. THIS CONTINUES TO BE AN
ENVIRONMENT SUPPORTIVE OF ISOLATED TORNADOES AND DAMAGING WIND
HOWEVER ITS BEEN SLOW TO DEVELOP TODAY DUE TO THE DEEP MOISTURE
THROUGH THE MID LEVELS. ALTHOUGH ISOLATED SVR STORMS ARE POSSIBLE
WITHIN THE AREA OF SHOWERS CURRENTLY ACROSS THE CWA...ANOTHER AREA
OF CONCERN IS DEVELOPMENT OF STORMS WEST OF THIS LINE.

TREND OF POSSIBLE SVR STORMS WILL CONTINUE INTO THE EVENING BUT THE
THREAT DECREASES THE SECOND HALF OF THE NIGHT AS THE PRECIP CHANCES
SHFIT EASTWARD...WE LOOSE THE HEATING OF THE DAY AND THE INSTABILITY
DECREASES. BY TOMORROW MORNING...WILL KEEP LOW CLOUDS ACROSS THE
AREA WITH MAYBE SOME MIST AND SHOWERS ACROSS THE EASTERN HALF OF THE
CWA. AS THE SFC LOW LIFTS NORTHWARD TUESDAY INTO THE TENNESSEE AND
OHIO VALLEYS...THE DEEP MOISTURE DECREASES ACROSS OUR AREA AND WE
LOOSE MUCH OF THE INSTABILITY TOMORROW...THUS HAVE LIMITED WX TO
SHOWERS OR SLIGHT CHANCE THUNDER. DID DECREASE POPS SLOWER THAN THE
MODELS SINCE THE UPPER LEVEL LOW HANGS AROUND THE LOW TO MID
MISSISSIPPI VALLEY THROUGH TUESDAY NIGHT. HAVE TAKEN OUT ALL MENTION
OF POPS BY LATE TUESDAY NIGHT WITH DRIER AIR FINALLY MOVING INTO THE
CWA.

MIN TEMPS TONIGHT ARE ON THE HIGHER SIDE OF GUIDANCE BUT SLIGHTLY
COOLER THAN PERSISTENCE. REMAINDER OF THE SHORT TERM LEANS TOWARD A
BLEND.

11

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
NO MAJOR CHANGES TO THE EXTENDED WERE WARRANTED AT THIS TIME AS
MODELS CONTINUE TO SHOW HIGH PRESSURE DOMINATING WEDNESDAY THROUGH
FRIDAY... THEN A WEAK COLD FRONT PUSHING ACROSS THE AREA SATURDAY
NIGHT- SUNDAY.

39

PREVIOUS LONG TERM DISCUSSION...ISSUED 303 AM EDT MON OCT 1 2012
TUESDAY NIGHT THROUGH SUNDAY/...
THE DEEP TROUGH TO THE WEST OF THE CWA WEAKENS AND FILLS WITH THE
MAIN AREA OF ENERGY GOING NORTH OF THE STATE. THIS LEAVES US IN A
SOUTHWEST FLOW THAT BECOMES WEST BY THE END OF THE WEEK WITH THE
MAIN WESTERLIES TO OUR NORTH. ACCORDING TO THE GFS THE WESTERLIES
SINK INTO THE SOUTH WHILE THE ECMWF KEEP THE WESTERLIES OVER THE
OHIO VALLEY. THE GFS SOLUTION WOULD BRING LOW CHANCE POPS INTO THE
CWA FOR THE WEEKEND WHILE THE ECMWF WOULD KEEP US DRY. FOR AT
LEAST THE FIRST PART OF THE LONG TERM WE SHOULD SEE A DRYING TREND
ALTHOUGH WITH A SOUTHWEST FLOW THERE SHOULD BE AMPLE CLOUDS. FOR
THE WEEKEND WILL LEAN TOWARD THE GFS SOLUTION AND GO WITH LOW
CHANCE POPS...MAINLY FOR NORTH GA. AM CONCERNED ABOUT THE LOW
TEMPS FOR THE FIRST PART OF THE LONG TERM. FEEL WITH CLOUDS AND A
SOUTHWEST FLOW IT WILL BE HARD TO SEE LOWS IN THE 40S/50S AND WILL
RAISE MIN TEMPS A FEW DEGREES...ESPECIALLY ON WED AND THU MORNING.
REST OF THE TEMPS LOOK GOOD.

17

&&

.HYDROLOGY...
HAVE SEEN 1.5 TO 2.5 INCHES ACROSS NORTH GEORGIA WITH ISOLATED
HIGHER AMOUNTS NEAR 3 INCHES AND 0.5 TO 1 INCHES ACROSS CENTRAL
GEORGIA WITH ISOLATED AMOUNTS NEAR 2 INCHES. ANOTHER 0.5 TO 1 INCH
IS POSSIBLE...WITH THE HIGHEST AMOUNTS ACROSS NORTH GEORGIA. COULD
SEE SOME RISES ALONG THE CREEKS AND STREAMS...MAINLY ACROSS NORTH
GEORGIA...HOWEVER DO NOT EXPECT RIVER FLOODING AT THIS POINT.

&&

.AVIATION...
/ISSUED AT 201 PM EDT MON OCT 1 2012/
18Z UPDATE...
MAINLY IFR TO MVFR CONDITIONS ACROSS THE AREA THIS AFTERNOON AND
EXPECT TREND TO CONTINUE. ONE OF MAIN CHALLENGES IS CHANCE OF TS.
GREATER CHANCES ARE ACROSS MCN AND CSG AREA BUT THREAT DOES STILL
EXIST TO THE NORTH. EVEN WITH HEAVY SHRA ACROSS ATL SITES NOW...
THINK THE BIGGER THREAT OF TS IS WITH ISOLATED CELLS DEVELOPING
WEST OF THIS LINE. OVERNIGHT WILL SEE VLIFR TO LIFR CIGS AND VSBYS
AGAIN ACROSS THE SITES AND SOMEWHAT CONCERNED WE ARE ON THE
OPTIMISTIC SIDE OF VSBY/CIGS AT ATL. WINDS WILL BE A CHALLENGE TUESDAY
MORNING AND HOVER AROUND SOUTH AROUND SUNRISE AND THEN BECOME SW
DURING THE LATE MORNING TO AFTERNOON TIME FRAME.

//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON CIGS AND VSBYS. LOW CONFIDENCE ON TS TIMING.
HIGH CONFIDENCE ON WIND...BUT LOW AFTER 09Z TUESDAY DUE TO WIND
SHIFT FROM SE TO SW.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          67  77  58  78 /  80  40  20  10
ATLANTA         64  76  59  77 /  60  20  10  10
BLAIRSVILLE     60  70  51  74 /  80  40  10  10
CARTERSVILLE    64  75  53  77 /  60  20  10  10
COLUMBUS        65  78  58  81 /  40  20  10  10
GAINESVILLE     63  76  59  77 /  80  40  10  10
MACON           68  80  59  82 /  70  30  10  10
ROME            65  74  55  78 /  60  20  10  10
PEACHTREE CITY  64  76  54  77 /  60  20  10  10
VIDALIA         71  85  65  84 /  50  50  20  10

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
TORNADO WATCH UNTIL 9 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BALDWIN...BARROW...BARTOW...BIBB...BLECKLEY...BUTTS...
CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...CHEROKEE...
CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...DADE...
DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...FANNIN...FAYETTE...
FLOYD...FORSYTH...GILMER...GORDON...GWINNETT...HALL...HARALSON...
HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...JONES...
LAMAR...LUMPKIN...MACON...MARION...MERIWETHER...MONROE...
MORGAN...MURRAY...MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...
PAULDING...PEACH...PICKENS...PIKE...POLK...PULASKI...PUTNAM...
ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...STEWART...SUMTER...
TALBOT...TAYLOR...TROUP...TWIGGS...UPSON...WALKER...WALTON...
WEBSTER...WHITFIELD...WILCOX...WILKINSON.

&&

SHORT TERM...11
LONG TERM....39
AVIATION...11

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
249 PM EDT MON OCT 1 2012

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-020830-
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-
249 PM EDT MON OCT 1 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT...
ISOLATED SEVERE STORMS STILL POSSIBLE THIS AFTERNOON AND TONIGHT
ACROSS NORTH AND CENTRAL GEORGIA.

.SYNOPSIS...
AN AREA OF LOW PRESSURE OVER WEST CENTRAL ALABAMA WILL MOVE
NORTHEAST AND PULL A WARM FRONT...CURRENTLY ACROSS CENTRAL
GEORGIA...NORTHWARD INTO NORTH GEORGIA THIS AFTERNOON AND EVENING.
THIS WILL KEEP WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE REGION THROUGH TONIGHT. A FEW STORMS COULD BECOME SEVERE THIS
AFTERNOON AND EVENING.

.PRIMARY HAZARDS...
THE PRIMARY HAZARDS FROM THE SEVERE STORMS WILL BE ISOLATED
TORNADOES AND DAMAGING WINDS. LARGE HAIL MAY BE POSSIBLE LATER THIS
EVENING OVER NORTH GEORGIA. THE MORE FAVORABLE TIME FOR SEVERE STORM
DEVELOPMENT WILL BE FROM MID AFTERNOON THROUGH LATE THIS EVENING...
HOWEVER A FEW STRONG STORMS COULD LINGER AFTER MIDNIGHT.

.DISCUSSION...
THE STRONG UPPER TROUGH TO THE WEST WILL CONTINUE TO FEED WARM MOIST
AIR FROM THE GULF INTO THE REGION. DAYTIME HEATING HAS INCREASED
CAPES INTO THE 1500 TO 2000 J/KG RANGE ACROSS CENTRAL AND PARTS OF
NORTH GEORGIA THIS AFTERNOON. THIS COUPLED WITH STRONG LOW LEVEL
SHEAR WILL ALLOW FOR A FEW STORMS TO BECOME SEVERE. THE MAIN THREAT
WILL BE ACROSS THE WESTERN HALF OF THE STATE FROM MID AFTERNOON...
THROUGH THE EVENING HOURS. THE SEVERE WEATHER THREAT SHOULD GREATLY
DIMINISH AFTER MIDNIGHT TONIGHT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...
ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS THE EASTERN PARTS OF
THE REGION ON TUESDAY. HAZARDOUS WEATHER IS NOT EXPECTED WEDNESDAY
THROUGH SUNDAY.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS SHOULD MONITOR THE LATEST INFORMATION...ESPECIALLY THIS
AFTERNOON AND TONIGHT FOR POSSIBLE ACTIVATION ACROSS.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
259 PM EDT MON OCT 1 2012

GAZ034-045>048-056>058-068>070-011945-
259 PM EDT MON OCT 1 2012

...SIGNIFICANT WEATHER ADVISORY FOR HEAVY RAIN IN WALTON...
SPALDING...ROCKDALE...PIKE...NEWTON...LAMAR...UPSON...BUTTS...
DEKALB...GWINNETT AND HENRY COUNTIES UNTIL 345 PM EDT...

AT 253 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF HEAVY RAINFALL FROM ROSEBUD TO HANNAHS MILL...MOVING NORTHEAST AT 20
MPH.

RAINFALL AMOUNTS BETWEEN 1 AND 2 INCHES CAN BE EXPECTED ACROSS
WALTON...SPALDING...ROCKDALE...PIKE...NEWTON...LAMAR...UPSON...BUTTS.
..DEKALB...GWINNETT AND HENRY COUNTIES...INCLUDING AREAS AROUND
CENTERVILLE...KLONDIKE...HANNAHS
MILL...MEANSVILLE...WILLIAMSON...ZEBULON...EXPERIMENT...HIGHLAND
MILLS...TOWALAGA...ROVER...SUNNY SIDE...GRIFFIN...PANOLA MOUNTAIN
STATE PARK...RICHARDSON PARK AND LAKEVIEW ESTATES. DRIVERS SHOULD
USE CAUTION AS INTENSE RAINFALL WILL REDUCE VISIBILITIES. PONDING OF
WATER ON ROADWAYS IS ALSO LIKELY.

&&

LAT...LON 3390 8378 3367 8386 3355 8389 3338 8405
      3307 8414 3292 8436 3321 8438 3390 8404
TIME...MOT...LOC 1857Z 228DEG 17KT 3383 8393 3321 8424
          3299 8433

KS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
409 PM EDT MON OCT 1 2012

GAZ023-025-034-035-045>048-012045-
409 PM EDT MON OCT 1 2012

...SIGNIFICANT WEATHER ADVISORY FOR HEAVY RAIN IN WALTON...
ROCKDALE...NEWTON...BARROW...DEKALB...GWINNETT...HALL AND JACKSON
COUNTIES UNTIL 445 PM EDT...

AT 359 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE HEAVY RAINFALL FROM A CLUSTER OF STORMS NEAR
MILSTEAD...MOVING NORTHEAST AT 35 MPH.  THIS AREA HAS ALREADY
RECEIVED 1 TO 2 INCHES OF RAIN OVER THE PAST SEVERAL HOURS WITH ANOTHER
INCH POSSIBLE.  RAINFALL RATES WITH THIS STORM WILL BE NEAR 1 INCH
PER HOUR.

RUNOFF FROM THESE STORMS WILL CAUSE MINOR FLOODING OF SMALL CREEKS
AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES ACROSS
WALTON...ROCKDALE...NEWTON...BARROW...DEKALB...GWINNETT...HALL AND
JACKSON COUNTIES...INCLUDING AREAS AROUND CENTERVILLE...GUM CREEK...
GEORGIA INTERNATIONAL HORSE PARK...LAKEVIEW ESTATES...MILSTEAD...
CONYERS...BIG HAYNES CREEK PARK...YOUTH...WALNUT GROVE...ROSEBUD...
BETWEEN...SNELLVILLE...LOGANVILLE...WINDSOR AND GRAYSON.
ADDITIONALLY...COUNTRY ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS
AND STREAMS ARE SUBJECT TO MINOR FLOODING.

&&

LAT...LON 3407 8377 3407 8374 3405 8371 3406 8370
      3405 8369 3404 8358 3403 8356 3362 8392
      3370 8411 3411 8392 3410 8386 3412 8382
TIME...MOT...LOC 2004Z 204DEG 32KT 3375 8397

KS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
413 PM EDT MON OCT 1 2012

GAZ072-073-082>084-012045-
413 PM EDT MON OCT 1 2012

...SIGNIFICANT WEATHER ADVISORY FOR 45 MPH WINDS IN TWIGGS...JONES...
WILKINSON...BALDWIN AND BIBB COUNTIES UNTIL 445 PM EDT...

AT 409 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER JEFFERSONVILLE...MOVING NORTHWEST AT 30 MPH.

WIND GUSTS OF 45 MPH ARE LIKELY AS THIS STORM MOVES ACROSS TWIGGS...
JONES...WILKINSON...BALDWIN AND BIBB COUNTIES THROUGH 445 PM EDT.
SOME LOCATIONS IN THE PATH OF THE STORM INCLUDE JEFFERSONVILLE...
MARION...RIPLEY...FITZPATRICK...MYRICKS MILL...DRY BRANCH...IVEY...
GORDON...FRANKLINTON...CROSS KEYS...GRISWOLDVILLE...MOUNTAIN
SPRINGS...PANCRAS...COOPERS AND POSTELL.

&&

LAT...LON 3297 8369 3308 8326 3266 8314 3261 8346
TIME...MOT...LOC 2013Z 156DEG 27KT 3271 8336