Severe Thunderstorm Warning 233, NWS Atlanta, GA

000 
WWUS52 KFFC 202019
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
420 PM EDT TUE MAY 20 2008

GAC083-295-202045-
/O.CON.KFFC.SV.W.0233.000000T0000Z-080520T2045Z/
DADE GA-WALKER GA-
420 PM EDT TUE MAY 20 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR WALKER AND SOUTHERN DADE COUNTIES...

AT 418 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZED
HAIL. THIS STORM WAS LOCATED NEAR RISING FAWN...MOVING SOUTHEAST AT
29 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
CLOUDLAND STATE PARK...CEDAR GROVE...DAVIS CROSSROADS...VILLNOW...
NAOMI...NOBLE...LINWOOD AND LA FAYETTE.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
TUESDAY EVENING FOR NORTHERN GEORGIA.

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL AFTER THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

LAT...LON 3477 8520 3477 8515 3472 8516 3471 8505
      3463 8504 3462 8506 3458 8507 3459 8553
      3490 8558
TIME...MOT...LOC 2020Z 293DEG 25KT 3479 8554

$$

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1204 PM EDT TUE MAY 20 2008

.UPDATE...
NO MAJOR CHANGES TO FORECAST UPDATE. TWEAKED POP AND WX GRIDS FOR
THIS AFTERNOON AND EVENING BUT KEPT POPS IN CHANCE CATEGORY.
BUMPED UP MENTION OF SVR STORMS THIS AFTERNOON AND EARLY EVENING.
COULD SEE THREAT OF SVR STORMS TO LATE EVENING.

WILL BE LAUNCHING AN 18Z RAOB...HOWEVER MODEL SOUNDINGS AND
MODIFIED MORNING RAOB STILL INDICATE STRONG INSTABILITY WILL BE
PRESENT THIS AFTERNOON AND EVENING. MLCAPE VALUES 1500-2000 J/KG
LIKELY. EVEN WITH SW TO WEST SFC WINDS...LOW LEVEL SHEAR ALSO
FORECAST TO BE SUFFICIENT FOR SUPERCELL STORMS AND POSSIBLY
TORNADOES. 0-6KM BULK SHEAR NEAR 40KTS AND 0-1KM SRH AROUND 150
M2/S2 AT 18Z-00Z. THE STRENGTH OF THESE PARAMETERS WERE NOT SEEN
WITH PREVIOUS MODEL RUNS AT THIS TIME YESTERDAY. HAVE ALREADY
BUMPED UP CONFIDENCE STATEMENTS IN HWO BUT STILL EXPECT ISOLATED
COVERAGE WITH DISCRETE SUPERCELLS. STRAIGHT-LINE HODOGRAPH ALSO
FAVORS SPLITTING SUPERCELLS SO WILL NEED TO BE ON OUR TOES WITH
POLYGON WARNINGS.

SNELSON

&&

.PREV DISCUSSION... /ISSUED 520 AM EDT TUE MAY 20 2008/

SHORT TERM /TODAY THROUGH THURSDAY/...
A COUPLE OF SHORT WAVES MOVING THROUGH OHIO VALLEY TODAY. SURFACE
LOW NOW OVER WEST VIRGINIA WILL MOVE OFF THE MID ATLANTIC COAST BY
AFTERNOON. THIS SHOULD PULL A FRONTAL BOUNDARY SOUTHWARD INTO
GEORGIA DURING THE AFTERNOON AND EVENING. INSTABILITY INCREASING
DURING THE DAY AND ISOLATED THUNDERSTORMS COULD BECOME SEVERE. SPC
HAS PLACED MOST OF THE CWA IN A SLIGHT RISK. STRONG LOW LEVEL JET
CROSSING NORTH GEORGIA TODAY SHOULD PRODUCE GUSTY WINDS OVER MUCH
OF THE CWA. HAVE ISSUED A WIND ADVISORY FOR THE NORTHERN
ZONES...WITH OTHER AREAS BORDER LINE. WESTERLY WINDS BRINGING
DRIER AIR INTO NORTH AND CENTRAL GEORGIA ON WEDNESDAY. HAVE LEFT
SLIGHT CHANCE POPS ACROSS SOUTHERN END OF CWA FOR WEDNESDAY IN
CASE SOME MOISTURE/INSTABILITY REMAINS IN THAT AREA. GEORGIA
REMAINING IN NORTHWEST FLOW ALOFT AND ANOTHER IMPULSE LOOKS LIKE
IT WILL SLIDE TO THE SOUTHEAST ON THURSDAY AND GIVE THE AREA
ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
OLD FRONTAL BOUNDARY ACROSS SOUTH GEORGIA AND INTO THE LOWER
MISSISSIPPI VALLEY COULD TRIGGER SOME CONVECTION FOR THE CWA
THROUGH FRIDAY. AFTER THAT...MODELS HAVE BEEN CONSISTENT IN
SHOWING HIGH PRESSURE BUILDING IN FROM THE NORTHERN STATES. THIS
SHOULD BRING A CHANGE TO A DRIER AIR MASS FOR THE CWA THROUGH THE
REMAINDER OF THE LONG TERM.

AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THIS FORECAST PERIOD
OUTSIDE OF AREAS OF CONVECTION. MOISTURE WAS BEGINNING TO RETURN
OVER THE REGION EARLY THIS MORNING AHEAD OF A COLD FRONT OVER THE
OHIO VALLEY. THIS FRONT WILL SAG SOUTHWARD INTO THE STATE BY THIS
AFTERNOON...CONTINUING INTO CENTRAL GEORGIA OVERNIGHT. SCATTERED
CONVECTION IS EXPECTED TO DEVELOP ALONG AND AHEAD OF THIS FRONT BY
18Z ACROSS NORTH GEORGIA WITH THE FOCUS SHIFTING INTO CENTRAL
GEORGIA AFTER 00Z. WINDS ARE ALREADY BEGINNING TO GUST UP OVER
15 KTS ACROSS NORTH GEORGIA. WEST WINDS IN THE 12 TO 15 KT RANGE ARE
EXPECTED TO SPREAD OVER NORTH AND CENTRAL GEORGIA BY 14Z...GUSTING
AS HIGH AS 25 TO 30 KTS BETWEEN 16Z AND 22Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          85  57  80  51  84 /  50  30  10  10  20
ATLANTA         84  58  78  55  82 /  40  30   5  10  20
BLAIRSVILLE     79  48  74  45  77 /  50  20  10  10  20
CARTERSVILLE    85  51  78  47  80 /  40  20   5  10  20
COLUMBUS        88  66  83  59  87 /  30  30  10  10  20
GAINESVILLE     83  56  77  53  79 /  40  20  10  10  20
MACON           89  63  86  55  90 /  30  30  10  10  20
ROME            85  54  81  50  83 /  40  20  10  10  20
PEACHTREE CITY  85  56  78  50  84 /  40  30  10  10  20
VIDALIA         91  68  90  59  89 /  20  30  20  10  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLARKE...COBB...DADE...DAWSON...DEKALB...DOUGLAS...
FANNIN...FLOYD...FORSYTH...GILMER...GORDON...GWINNETT...HALL...
HARALSON...JACKSON...LUMPKIN...MADISON...MURRAY...NORTH FULTON...
OCONEE...OGLETHORPE...PAULDING...PICKENS...POLK...SOUTH FULTON...
TOWNS...UNION...WALKER...WALTON...WHITE...WHITFIELD.

&&

13

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1030 AM EDT TUE MAY 20 2008

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-211000-
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-
1030 AM EDT TUE MAY 20 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.
ISOLATED TO A FEW SEVERE THUNDERSTORMS EXPECTED ACROSS NORTH AND
CENTRAL GEORGIA THIS AFTERNOON AND EVENING.

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO NORTH GEORGIA THIS AFTERNOON AND ACROSS
CENTRAL GEORGIA TONIGHT.

.PRIMARY HAZARDS...
THE PRIMARY HAZARDS FROM ANY SEVERE THUNDERSTORMS WILL BE DAMAGING
WINDS AND LARGE HAIL. ISOLATED TORNADOES WILL ALSO BE POSSIBLE. THE
MOST LIKELY LOCATION FOR SEVERE THUNDERSTORMS WILL BE SOUTH OF
DALTON AND NORTH OF COLUMBUS TO DUBLIN...THIS AFTERNOON AND EVENING.
HOWEVER...ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE NORTH OF
DALTON AND SOUTH OF COLUMBUS TO DUBLIN.

.OTHER HAZARDS...
A WIND ADVISORY IS ALSO IN EFFECT TODAY FOR NORTH GEORGIA NORTH OF A
LINE FROM CARROLLTON TO ATLANTA AND ATHENS. WEST WINDS OF 15 TO 25
MPH CAN BE EXPECTED OVER NORTH GEORGIA...WITH GUSTS TO 35 MPH OVER
THE HIGHER TERRAIN OF THE NORTH GEORGIA MOUNTAINS.

.DISCUSSION...
MOISTURE IS INCREASING AHEAD OF AN APPROACHING COLD FRONT. CAPES
WILL INCREASE TO 1500 TO 2000 WITH LIFTED INDICES OF MINUS 3 TO
MINUS 5. WHILE THE INSTABILITY WILL BE SUFFICIENT FOR SEVERE
THUNDERSTORMS...A LIMITING FACTOR WILL BE WEAK LOW LEVEL SHEAR.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.
THERE IS A CHANCE OF THUNDERSTORMS WEDNESDAY AND SATURDAY ACROSS
CENTRAL GEORGIA...AND ACROSS NORTH AND CENTRAL GEORGIA THURSDAY AND
FRIDAY. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS SHOULD REMAIN ALERT FOR POSSIBLE ACTIVATION THIS AFTERNOON.
EMERGENCY MANAGERS SHOULD MONITOR THE SITUATION.

BDL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
336 PM EDT TUE MAY 20 2008

GAZ053-202000-
336 PM EDT TUE MAY 20 2008

...SIGNIFICANT WEATHER ALERT FOR 1/4 TO 1/2 INCH DIAMETER SIZED HAIL
IN COWETA COUNTY UNTIL 400 PM EDT...

AT 332 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
DEVELOPING THUNDERSTORMS ACROSS NORTHERN COWETA COUNTY...NEAR HANDY
AND SARGENT. THIS THUNDERSTORMS WILL BE CAPABLE OF PRODUCING SMALL
HAIL AND WIND GUSTS TO 40 MPH.  THE STORMS WILL MOVE EAST AT 35 MPH.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT. CONTINUE TO MONITOR
NOAA WEATHER RADIO...WEATHER.GOV OR OTHER MEDIA OUTLETS FOR FURTHER
STATEMENTS OR POSSIBLE WARNINGS ON THESE STORMS.

19

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
349 PM EDT TUE MAY 20 2008

GAZ001-002-202015-
349 PM EDT TUE MAY 20 2008

...SIGNIFICANT WEATHER ALERT FOR PEA SIZED HAIL IN DADE AND WALKER
COUNTIES UNTIL 415 PM EDT...

AT 348 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER TRENTON...MOVING EAST AT 40 MPH.  OTHER
STRONG TO SEVERE STORMS ARE IN NORTHEAST ALABAMA AND WILL APPROACH
THE AREA BY 430 PM.  WARNINGS MAY BE NECESSARY WITH THIS ACTIVITY IF
THE STORMS MAINTAIN THEIR STRENGTH OR INCREASE.

WIND GUSTS OF 45 MPH AND PEA SIZED HAIL ARE LIKELY AS THIS STORM
MOVES ACROSS DADE AND WALKER COUNTIES THROUGH 415 PM EDT. SOME
LOCATIONS IN THE PATH OF THE STORM INCLUDE RISING FAWN...CLOUDLAND
STATE PARK...NEW ENGLAND...TRENTON...WILDWOOD...HINKLES...LOOKOUT
MOUNTAIN...ROSSVILLE...CHATTANOOGA VALLEY...HIGH POINT...DAVIS
CROSSROADS...FAIRVIEW...CHICKAMAUGA...NOBLE AND LINWOOD.