Special Weather Statement, NWS Atlanta, GA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
745 AM EDT THU AUG 2 2012

.PREV DISCUSSION... /ISSUED 442 AM EDT THU AUG 2 2012/

SHORT TERM /TODAY THROUGH FRIDAY/...
BOUNTIFUL AVAILABLE MOISTURE THIS MORNING WITH DEWPOINTS STILL IN
THE 70S ACROSS MOST OF THE STATE. PATCHY FOG POSSIBLE UNTIL ABOUT
15Z WHEN HEATING AND MIXING SHOULD HELP ELIMINATE FOG. A SURFACE
BOUNDARY STRETCHING ALONG THE I-85 CORRIDOR MAY PROVIDE SOME FORCING
FOR CONVECTION FURTHER SOUTH TODAY. CURRENT INFRARED SATELLITE
IMAGERY SHOWS SOME CLOUD TOPS AROUND -30 C AHEAD OF THE BOUNDARY IN
THE SOUTHERN PORTIONS OF THE CWA. LEFT OVER BOUNDARIES FROM
YESTERDAYS CONVECTION MAY ALSO AID IN INITIATION AROUND METRO ATL
TODAY.

RAISED POPS HIGHER THAN GUIDANCE FOR MOST OF CWA...ALTHOUGH RIDGE OF
HIGH PRESSURE CENTERED OVER THE GULF OF MEXICO WILL FINGER INTO NW
GEORGIA...HELPING TO SUPPRESS CONVECTION THERE RELATIVE TO THE REST
OF THE CWA. SUMMER CONTINUES TO REIGN WITH WEAK 0-6KM BULK SHEAR
/VALUES BELOW 25 KTS/ AND MUCAPE VALUES ABOVE 2000 J/KG OVER MOST OF
THE CWA THURSDAY AFTERNOON. HEAT INDICES WILL BE ABOVE 105 IN THE
EXTREME SOUTHERN PORTIONS OF THE CWA THURSDAY AFTERNOON. WHILE THE
CRITERIA FOR A HEAT ADVISORY HAS NOT BEEN MET...IT IS STILL
ADVISABLE THAT PRECAUTIONS BE TAKEN FOR THOSE WHO MAY BE SENSITIVE
TO HEAT OR WORKING OUTDOORS. FRIDAYS HEAT INDICES FORECAST TO STAY
BELOW 105 OVER MOST AREAS.

UPPER LEVEL SHORTWAVE TROUGH WELL DEFINED IN THE 00Z GFS AND 00Z
NAM...EXITING SOUTH GEORGIA INTO NORTH FLORIDA THURSDAY INTO
FRIDAY...WILL AID RAIN CHANCES IN SOUTHERN PORTIONS OF THE CWA. GFS
IS SLIGHTLY DRIER THAN THE NAM OVER THE CWA THROUGH THE SHORT
TERM...ALTHOUGH BOTH HINT AT JUST ENOUGH MOISTURE AND FORCING TO
KEEP RAIN CHANCES MENTIONABLE CWA-WIDE ON THURSDAY AND FRIDAY. USED
A MODEL GUIDANCE BLEND FOR TEMPERATURES...RAISING POPS A BIT HIGHER
THAN GUIDANCE.

RAG

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LITTLE CHANGE IN THE PATTERN. A WEAK BOUNDARY CONTINUES OVER AREA
AS SHOWN BY BOTH GFS AND ECMWF. HOWEVER BY MONDAY...MODELS SHOW
SOME DIFFERENCE WITH GFS PUSHING A COLD FRONT SOUTHWARD INTO
GEORGIA AS HIGH PRESSURE BRINGS DRY AIR IN BEHIND IT. MEAN WHILE...
ECMWF HOLD DRIER AIR MASS NORTH OF AREA UNTIL WEDNESDAY WHEN DRIER
AIR FILTERS SOUTHWARD. THINKING IS TO MAINTAIN THE DIURNAL
CONVECTION THROUGH PERIOD. TEMPERATURES TO REMAIN NEAR NORMAL
THROUGH PERIOD.

37

&&

.AVIATION...
12Z UPDATE...
VFR THROUGH THE PERIOD WITH LIGHT SOUTHWESTERLY WINDS. BEST CHANCE
OF CONVECTION SOUTH OF INTERSTATE 85...MAINLY AT MCN AND
CSG...THIS AFTERNOON AND EVENING. CANNOT COUNT OUT AN ISOLATED
THUNDERSTORM IN THE METRO OR AHN...BUT NOT CONFIDENT ENOUGH TO
KEEP MENTION IN FORECAST FOR THE NORTHERN TAF SITES.

//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE FOR CONVECTION THURSDAY...
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
PREFERRED DRIER GFS SLIGHTLY OVER THE NAM.

RAG

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          94  72  94  72 /  40  20  30  40
ATLANTA         95  75  91  73 /  20  20  30  40
BLAIRSVILLE     88  68  85  69 /  20  20  30  50
CARTERSVILLE    96  71  92  70 /  20  20  30  40
COLUMBUS        97  75  93  74 /  30  20  20  20
GAINESVILLE     93  74  92  72 /  20  20  30  50
MACON           97  73  93  73 /  30  20  20  20
ROME            96  72  94  71 /  20  20  40  50
PEACHTREE CITY  94  70  90  70 /  20  20  20  30
VIDALIA         97  75  95  74 /  30  20  20  20

&&

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

SHORT TERM...RAG
LONG TERM....37
AVIATION...RAG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
604 AM EDT THU AUG 2 2012

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-031015-
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-
604 AM EDT THU AUG 2 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...TODAY AND TONIGHT...
SCATTERED THUNDERSTORMS THIS AFTERNOON AND TONIGHT WITH A FEW
POSSIBLY SEVERE.

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL SAG SLOWLY SOUTHWARD THROUGH THE
STATE AS WEAK UPPER LEVEL DISTURBANCES MOVE ACROSS THE AREA.

.PRIMARY HAZARDS...
THE PRIMARY HAZARD WILL BE GUSTY WINDS...SMALL HAIL AND FREQUENT
LIGHTNING.

.DISCUSSION...
A WEAK FRONTAL BOUNDARY OVER THE AREA WILL CONTINUE TO SLOWLY SAG
SOUTHWARD AS UPPER LEVEL DISTURBANCES MOVE ACROSS THE AREA. THIS
COMBINED WITH THE AFTERNOON HEATING AND CAPES RANGING FROM 2300 TO
2500...WILL BE THE TRIGGER FOR AFTERNOON THUNDERSTORM DEVELOPMENT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...
SCATTERED THUNDERSTORMS POSSIBLE EACH DAY.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ACTIVATION IS NOT REQUESTED BUT SPOTTERS ARE ENCOURAGED
TO SUBMIT REPORTS OF SEVERE WEATHER THROUGH THE WEB BY GOING TO
WEATHER.GOV/ATLANTA.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1244 PM EDT THU AUG 2 2012

GAZ104>106-021715-
1244 PM EDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR PEA SIZED HAIL AND 40 MPH WINDS
IN EASTERN SUMTER...CRISP AND DOOLY COUNTIES UNTIL 115 PM EDT...

AT 1242 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER DRAYTON...MOVING EAST AT 5 MPH.

THESE STORMS HAVE THE POTENTIAL TO PRODUCE PEA SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH AS THEY MOVE
ACROSS EASTERN SUMTER...CRISP AND DOOLY COUNTIES THROUGH 115 PM EDT.
HEAVY DOWNPOURS WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3221 8363 3182 8363 3196 8402 3220 8398
TIME...MOT...LOC 1643Z 260DEG 6KT 3206 8390

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1249 PM EDT THU AUG 2 2012

GAZ108>110-021715-
1249 PM EDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR PEA SIZED HAIL AND 40 MPH WINDS
IN WILCOX...TELFAIR AND DODGE COUNTIES UNTIL 115 PM EDT...

AT 1248 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER ABBEVILLE...MOVING EAST AT 5 MPH.

THESE STORMS HAVE THE POTENTIAL TO PRODUCE PEA SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH AS THEY MOVE
ACROSS WILCOX...TELFAIR AND DODGE COUNTIES THROUGH 115 PM EDT. HEAVY
DOWNPOURS WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3223 8309 3180 8296 3191 8334 3208 8337
TIME...MOT...LOC 1649Z 281DEG 5KT 3203 8327

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1255 PM EDT THU AUG 2 2012

GAZ097-098-111-112-021745-
1255 PM EDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 40 MPH WINDS
IN WHEELER...TREUTLEN...MONTGOMERY AND LAURENS COUNTIES UNTIL 145 PM
EDT...

AT 1254 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER BARNHILL...MOVING EAST AT 10 MPH.

THIS STORM HAS THE POTENTIAL TO PRODUCE DIME SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH AS IT MOVES ACROSS
WHEELER...TREUTLEN...MONTGOMERY AND LAURENS COUNTIES THROUGH 145 PM
EDT. SOME LOCATIONS IN THE PATH OF THIS STORM INCLUDE ORLAND...
ROCKLEDGE...LANDSBURG...BARNHILL...LOTHAIR...GLENWOOD...SOPERTON...
FIVE POINTS...KIBBEE...TARRYTOWN...AILEY...ZAIDEE AND MOUNT VERNON.
HEAVY DOWNPOURS WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3246 8242 3209 8250 3216 8279 3247 8274
TIME...MOT...LOC 1655Z 279DEG 7KT 3230 8270

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
115 PM EDT THU AUG 2 2012

GAZ104>106-021745-
115 PM EDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 40 MPH WINDS
IN SUMTER...CRISP AND DOOLY COUNTIES UNTIL 145 PM EDT...

AT 110 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER DRAYTON THE THUNDERSTORM WAS NEARLY
STATIONARY WITH A SLIGHT DRIFT TO THE WEST.

THIS STORM HAS THE POTENTIAL TO PRODUCE DIME SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH AS IT MOVES ACROSS
SUMTER...CRISP AND DOOLY COUNTIES THROUGH 145 PM EDT. SOME LOCATIONS
IN THE PATH OF THIS STORM INCLUDE DRAYTON...METHVINS...GEORGIA
VETERANS MEMORIAL STATE PARK...LAMAR...HUNTINGTON...COBB...LESLIE AND
DESOTO. HEAVY DOWNPOURS WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3191 8394 3191 8417 3214 8410 3213 8388
      3188 8391 3188 8394
TIME...MOT...LOC 1715Z 031DEG 1KT 3202 8398

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
127 PM EDT THU AUG 2 2012

GAZ076-086-021815-
127 PM EDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 35 MPH WINDS
IN EMANUEL AND JEFFERSON COUNTIES UNTIL 215 PM EDT...

AT 124 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER MOXLEY...MOVING EAST AT 5 MPH.

THIS STORM HAS THE POTENTIAL TO PRODUCE DIME SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 35 MPH AS IT MOVES ACROSS
EMANUEL AND JEFFERSON COUNTIES THROUGH 215 PM EDT. SOME LOCATIONS IN
THE PATH OF THIS STORM INCLUDE BARTOW...LOUISVILLE...THREE POINTS...
COLEMANS LAKE...MOXLEY AND WADLEY. HEAVY DOWNPOURS WILL CAUSE PONDING
OF WATER ON ROADWAYS.

&&

LAT...LON 3269 8221 3285 8252 3310 8248 3310 8228
      3304 8228 3301 8227 3293 8227 3284 8231
      3281 8221
TIME...MOT...LOC 1727Z 291DEG 3KT 3295 8246