Special Weather Statement, NWS Atlanta, GA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
741 AM EDT MON JUN 27 2011

.PREV DISCUSSION... /ISSUED 226 AM EDT MON JUN 27 2011/

SHORT TERM /TODAY THROUGH WEDNESDAY/...
BIGGEST CHALLENGE WITH TODAYS FORECAST IS THE TRAJECTORY OF THE MCS
NOW MOVING THROUGH IA/MO/IL. NONE OF THE MODELS PICK UP THAT THE MCS
EXISTS WHICH IS WHAT IS MAKING THIS A DIFFICULT FORECAST. IT APPEARS
THAT THE SOUTHEAST MOVING MCS IS FOLLOWING THE THERMAL WIND VECTOR
WHICH OVER THE NEXT 18 HOURS WOULD KEEP IT MOVING SOUTHEAST. THE
INHIBITING FACTOR IS THE BUILDING RIDGE OVER THE SOUTHERN THIRD OF
THE COUNTRY. ANOTHER INHIBITING FACTOR IS THAT OUR ATMOSPHERE GOT
WORKED OVER VERY WELL SUNDAY AFTERNOON AND EVENING. ALL MODELS HAVE
CAPES INCREASING TO OVER 2000 THIS AFTERNOON. HAVING SAID ALL OF
THIS...MAV AND MET POPS ARE GENERALLY LESS THAN 10 PERCENT. SEEING
THAT THE MODELS HAVE NOT PICKED UP ON THE MCS...WILL THROW OUT
GUIDANCE POPS AND CONTINUE WITH SLIGHT CHANCE TO CHANCE POPS THIS
MORNING AND CHANCE POPS THIS AFTERNOON WITH ISOLATED SEVERE POSSIBLE.

TUESDAY IS A DIFFERENT STORY. MODELS HAVE A COLD FRONT MOVING ACROSS
THE CWA TUESDAY AFTERNOON AND EVENING. GIVEN THE VOLATILITY OF THE
CURRENT STATE OF THE ATMOSPHERE...FEEL HIGH CHANCE POPS ARE IN
ORDER FOR TUESDAY AFTERNOON AND EVENING. MET GUIDANCE SEEMS TO HAVE
A BETTER HANDLE ON THIS THAN THE MAV GUIDANCE. DRIER AIR MOVES INTO
THE CWA WEDNESDAY WHICH SHOULD LIMIT CONVECTION IN THE AFTERNOON TO
SLIGHT CHANCE.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT THROUGH THE LONG TERM
FOR THE FIRST PART OF THE LONG TERM WITH DIFFERENCES DEVELOPING
TOWARD THE WEEKEND. A LARGE H5 RIDGE BUILDS OVER THE CENTRAL US.
THIS RIDGE WILL FLATTEN AS IT SHIFTS INTO THE EASTERN U.S. DURING
THIS TIME THE CWA WILL BE IN A WEAK UPPER FLOW. THE ONLY THING
KICKING OFF THUNDERSTORMS WILL BE DAYTIME HEATING AND OUTFLOW
BOUNDARIES...IN OTHER WORDS BACK TO CLIMO BY THE WEEKEND WITH
ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS.

&&

.AVIATION...
12Z UPDATE...
THERE ARE A FEW PATCHY AREAS OF FOG AND A FEW OF THE TAF SITES
VISIBILITIES HAVE GONE DOWN TO 5SM OR 6SM BUT NOTHING LOWER THAN
THAT YET. WITH THE SUN COMING UP LOOKS LIKE THIS WILL BE IT FOR
THIS MORNING. EXPECTING TSRA DEVELOPMENT AGAIN THIS AFTERNOON
BETWEEN 20-00Z AT THE TAF SITES. EXPECTED MVFR CEILINGS AND
VISIBILITIES IN AND AROUND TARS DEVELOPMENT. WINDS ARE OUT OF THE
WEST TO NORTHWEST AROUND 5KT THIS MORNING. WIND SPEEDS WILL INCREASE TO
NEAR 10KT BY 18Z.

//ATL CONFIDENCE...12Z UPDATE...
CONFIDENCE MEDIUM ON ALL ELEMENTS.

01

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          95  71  94  72 /  50  30  50  30
ATLANTA         93  73  92  74 /  50  30  50  30
BLAIRSVILLE     85  66  85  67 /  50  30  50  30
CARTERSVILLE    93  68  92  69 /  50  30  50  30
COLUMBUS        96  73  95  74 /  40  40  50  50
GAINESVILLE     90  71  91  72 /  50  30  50  30
MACON           97  71  95  72 /  40  50  50  50
ROME            92  71  92  70 /  50  30  50  30
PEACHTREE CITY  93  70  93  70 /  40  30  50  50
VIDALIA         94  73  95  74 /  40  50  50  50

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
453 AM EDT MON JUN 27 2011

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-280900-
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-
453 AM EDT MON JUN 27 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...TODAY AND TONIGHT
ISOLATED SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND TONIGHT

.SYNOPSIS...
A COMPLEX OF THUNDERSTORMS OVER NORTHERN MISSOURI AND CENTRAL ILLINOIS
WILL CONTINUE MOVING SOUTHEAST THROUGH TONIGHT. THESE
THUNDERSTORMS ARE EXPECTED TO MOVE INTO NORTH GEORGIA THIS
AFTERNOON.

.PRIMARY HAZARDS...
THE PRIMARY HAZARD FROM ISOLATED SEVERE THUNDERSTORMS WILL BE
FREQUENT CLOUD TO GROUND LIGHTNING AND GUSTY WINDS TO 60 MPH. THE
BEST LOCATION FOR ISOLATED SEVERE STORMS WILL BE ACROSS NORTH
AND CENTRAL GEORGIA THIS AFTERNOON AND TONIGHT.

.DISCUSSION...
A COMPLEX OF THUNDERSTORMS OVER NORTHERN MISSOURI AND CENTRAL ILLINOIS
WILL CONTINUE MOVING SOUTHEAST THROUGH TONIGHT. INSTABILITY
INDICES ARE EXPECTED TO BE STRONG TODAY WITH CAPES GETTING INTO
THE 2000-3000 RANGE AND LIFTED INDICES AROUND -4 TO -5 ACROSS GEORGIA.
THERE IS AN UPPER LEVEL RIDGE BUILDING IN ACROSS THE SOUTHERN
STATES WHICH WILL HELP CAP THE ATMOSPHERE BUT IT DOES NOT LOOK
STRONG ENOUGH TO KEEP ISOLATED SEVERE STORMS FROM DEVELOPING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
ISOLATED TO SCATTERED THUNDERSTORMS EXPECTED EACH DAY.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED THROUGH TONIGHT.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
900 AM EDT MON JUN 27 2011

GAZ079-091-271345-
900 AM EDT MON JUN 27 2011

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 40 MPH WINDS
IN TALBOT AND MARION COUNTIES UNTIL 945 AM EDT...

AT 859 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER BOX SPRINGS...MOVING SOUTH AT 20 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
TALBOT AND MARION COUNTIES THROUGH 945 AM EDT. SOME LOCATIONS IN THE
PATH OF THIS STORM INCLUDE OLIVE BRANCH...BAUGHVILLE...GENEVA...BOX
SPRINGS...JUNIPER...MARION ESTATES AND OAKLAND. BRIEF HEAVY DOWNPOURS
WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3249 8466 3250 8464 3253 8464 3252 8468
      3252 8469 3256 8467 3257 8469 3266 8469
      3269 8460 3245 8445 3239 8466
TIME...MOT...LOC 1300Z 339DEG 19KT 3253 8463

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
949 AM EDT MON JUN 27 2011

GAZ079-091-271415-
949 AM EDT MON JUN 27 2011

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 45 MPH WINDS
IN TALBOT AND MARION COUNTIES UNTIL 1015 AM EDT...

AT 948 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER JUNIPER...MOVING SOUTH AT 10 MPH.

WIND GUSTS OF 45 MPH ARE LIKELY AS THIS STORM MOVES ACROSS TALBOT AND
MARION COUNTIES THROUGH 1015 AM EDT. SOME LOCATIONS IN THE PATH OF
THE STORM INCLUDE BALDWINVILLE...BOX SPRINGS...BAUGHVILLE...JUNCTION
CITY...GENEVA...JUNIPER...MARION ESTATES...FIVE POINTS...OAKLAND...
BRANTLEY AND TAZEWELL.

DRIVERS SHOULD USE CAUTION AS INTENSE RAINFALL WILL REDUCE
VISIBILITIES. PONDING OF WATER ON ROADWAYS IS ALSO LIKELY.

&&

LAT...LON 3249 8466 3250 8464 3253 8464 3252 8468
      3252 8469 3255 8467 3257 8469 3267 8468
      3268 8440 3257 8441 3256 8444 3254 8445
      3243 8439 3233 8439 3233 8466
TIME...MOT...LOC 1349Z 358DEG 7KT 3254 8457

16

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1024 AM EDT MON JUN 27 2011

GAZ079-091-271445-
1024 AM EDT MON JUN 27 2011

...SIGNIFICANT WEATHER ADVISORY FOR HEAVY RAIN AND LIGHTNING IN
TALBOT AND MARION COUNTIES UNTIL 1045 AM EDT...

AT 1018 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS EXTENDING FROM 2 MILES SOUTH OF MANCHESTER...
THROUGH TALBOTTON...AND JUNIPER...MOVING SOUTH AT 10 MPH.

FREQUENT LIGHTNING...AND WIND GUSTS OF 45 MPH ARE LIKELY AS THESE
STORMS MOVE ACROSS TALBOT AND MARION COUNTIES THROUGH 1045 AM EDT.
SOME LOCATIONS IN THE PATH OF THESE STORMS INCLUDE PO BIDDY
CROSSROADS...OLIVE BRANCH...BAUGHVILLE...FLINT HILL...WOODLAND...
PLEASANT HILL...TALBOTTON...BALDWINVILLE...JUNCTION CITY...FIVE
POINTS...MARION ESTATES...OAKLAND...BRANTLEY...JUNIPER AND BOX
SPRINGS.

RAINFALL AMOUNTS BETWEEN 1 TO 2 INCHES CAN BE EXPECTED ACROSS TALBOT
AND MARION COUNTIES...INCLUDING AREAS AROUND OLIVE BRANCH...FLINT
HILL...TALBOTTON...AND JUNIPER. DRIVERS SHOULD USE CAUTION AS
INTENSE RAINFALL WILL REDUCE VISIBILITIES. PONDING OF WATER ON
ROADWAYS IS ALSO LIKELY.

&&

LAT...LON 3249 8466 3250 8464 3253 8464 3252 8468
      3284 8470 3285 8456 3288 8448 3286 8449
      3285 8446 3262 8439 3257 8441 3256 8444
      3254 8445 3248 8441 3239 8439 3234 8466
TIME...MOT...LOC 1419Z 348DEG 15KT 3268 8456

16/26

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1052 AM EDT MON JUN 27 2011

GAZ079-271515-
1052 AM EDT MON JUN 27 2011

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 45 MPH WINDS
IN TALBOT COUNTY UNTIL 1115 AM EDT...

AT 1048 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER WOODLAND...MOVING SOUTHEAST AT 5 MPH.

DIME SIZED HAIL AND WIND GUSTS OF 45 MPH ARE LIKELY AS THIS STORM
MOVES ACROSS TALBOT COUNTY THROUGH 1115 AM EDT. SOME LOCATIONS IN
THE PATH OF THE STORM INCLUDE FLINT HILL...WOODLAND...BIG LAZER
CREEK WMA...PO BIDDY CROSSROADS...PRATTSBURG...OLIVE BRANCH...
TALBOTTON AND PLEASANT HILL.

RAINFALL AMOUNTS AROUND 2 INCHES CAN BE EXPECTED ACROSS TALBOT
COUNTY...INCLUDING AREAS AROUND FLINT HILL...WOODLAND...BIG LAZER
CREEK WMA...PO BIDDY CROSSROADS...PRATTSBURG...OLIVE BRANCH...
TALBOTTON AND PLEASANT HILL.

DRIVERS SHOULD USE CAUTION AS INTENSE RAINFALL WILL REDUCE
VISIBILITIES. PONDING OF WATER ON ROADWAYS IS ALSO LIKELY.

&&

LAT...LON 3285 8464 3285 8456 3288 8451 3273 8432
      3272 8434 3270 8434 3257 8461 3279 8468
TIME...MOT...LOC 1450Z 310DEG 6KT 3281 8457

16