Damaging Winds in Georgia, July 20, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
216 PM EDT THU JUL 20 2006

.SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...

VERY SIMILAR SCENE THIS AFTERNOON COMPARED TO YESTERDAY AS SOME
ENHANCED CUMULUS CLOUDS HAVE FORMED ALONG A WEAK SURFACE TROUGH
EXTENDING FROM NEAR KFAY TO KGRD. EXPECT ISOLATED TO SCATTERED
CONVECTION WILL BE PRESENT LATE THIS AFTERNOON AND EVENING UNTIL
SUNSET WHEN LOSS OF DAYTIME HEATING SHOULD HELP STORMS TO
DISSIPATE.

GRADUAL HEIGHT FALLS WILL TAKE PLACE ON FRIDAY ACROSS THE OHIO
VALLEY AND MID ATLANTIC...IN ADVANCE OF AN APPROACHING SHORTWAVE
TROUGH. INCREASING SOUTHERLY FLOW WILL HELP TO MOISTEN THE
ATMOSPHERE MORE AS PRECIPITABLE WATER VALUES APPROACH 2 INCHES.
THIS ALONG WITH DAYTIME HEATING SHOULD LEAD TO BETTER COVERAGE OF
AFTERNOON CONVECTION ON FRIDAY. THE TROUGH AMPLIFIES ON SATURDAY
INTO SUNDAY AS A SURFACE LOW TRACKS ACROSS THE SOUTHERN OHIO
VALLEY INTO SOUTHERN NEW ENGLAND. AN ASSOCIATED COLD FRONT WILL
PUSH ACROSS THE MOUNTAINS LATE SATURDAY AND THEN STALL IN THE
VICINITY OF THE FORECAST AREA ON SUNDAY. THIS WILL RESULT IN
BETTER CHANCES OF PRECIPITATION FOR THE AREA. WILL CARRY HIGH
CHANCE POPS ON SAT/SUN AS THE TROUGH PUSHES THROUGH WITH SURFACE
BOUNDARY NEARBY.

MAX TEMPERATURES WILL BE A BIT COOLER ON FRIDAY THROUGH THE
WEEKEND WITH INCREASED CLOUD COVER AND INCREASED ATMOSPHERIC
MOISTURE. STAYED ON THE COOLER SIDE OF MOS FOR MAX TEMPS AND CLOSE
TO GUIDANCE ON OVERNIGHT LOWS.

&&

.LONG TERM (MONDAY THROUGH THURSDAY)...

PLENTY OF UNCERTAINTY IN THE EXTENDED REGARDING THE MEDIUM RANGE
MODELS...AS GFS AND ECMWF ARE OUT OF PHASE WITH ONE
ANOTHER...LEADING TO A LOW CONFIDENCE FORECAST. A LINGERING
FRONTAL BOUNDARY WILL BE THE MAIN FOCUSING FOR ANY CONVECTION NEXT
WEEK AS UPPER HEIGHTS SLOWLY BUILD AS 500H FLOW BECOMES MORE
ZONAL. THE BERMUDA HIGH RE-ESTABLISHES ITSELF PROVIDING CONTINUAL
FLOW OF LOW LEVEL MOISTURE FROM THE SOUTH/SOUTHEAST. PRECIPITABLE
WATER VALUES REMAIN AROUND 2 INCHES. THEREFORE EXPECTING DIURNALLY
INDUCED POPS THROUGHOUT THE WEEK WITH THE EMPHASIS ON LATE
AFTERNOON AND EARLY EVENING. TEMPERATURES WILL REMAIN AT OR
SLIGHTLY BELOW NORMAL WITH THE MOIST AIRMASS.

&&

.AVIATION...

SCATTERED TO BROKEN CLOUDS AROUND 6KFT WILL REMAIN ONCE AGAIN THIS
AFTERNOON...AND THEN DISSIPATE SHORTLY AFTER SUNSET.  ISOLATED
THUNDERSTORMS WILL ALSO BE POSSIBLE THIS AFTERNOON AND EVENING.
VISIBILITIES MAY DROP BORDELINE MVFR AT KAGS AND KOGB NEAR SUNRISE.

&&

.PREVIOUS DISCUSSION...
(ISSUED 247 AM EDT THU JUL 20 2006)

SHORT TERM (TODAY THROUGH SATURDAY)...
STRONG UPPER RIDGE CENTERED OVER THE CENTRAL US TO RETROGRADE TO THE
WEST THROUGH FRIDAY...WHILE TROFINESS DEVELOPS OVER THE EAST.
RELATIVELY LITTLE CHANGE ANTICIPATED FOR OUR FORECAST AREA (FA) FOR
TODAY. HOT TEMPS EXPECTED AGAIN...BUT HEAT INDEX VALUES NOT EXPECTED TO
REACH ADVISORY LEVELS WITH DEWPOINTS MIXING DOWN INTO THE MID TO
UPPER 60S THIS AFTERNOON. SOME INCREASE IN ATMOSPHERIC MOISTURE
MAY INCREASE CONVECTIVE COVERAGE A LITTLE FOR FRIDAY. THE RIDGE
WEST/TROUGH EAST UPPER PATTERN TO AMPLIFY BY SATURDAY. FRONTAL
BOUNDARY TO DRIFT DOWN INTO OUR FA SAT. CONTINUED INCREASE IN
MOISTURE PLUS THE FRONT TO EQUAL BETTER CONVECTIVE CHANCES...WITH
HIGH TEMPS NOT QUITE AS WARM.

LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
MADE NO CHANGES. FRONTAL BOUNDARY STALLS OVER THE FA SUNDAY. UPPER
TROUGH OVER THE EAST BEGINS TO WEAKEN AND SHIFT NORTH MONDAY...WITH
BERMUDA RIDGE BEGINNING TO BUILD WESTWARD OVER THE AREA FOR THE
REMAINDER OF THE FORECAST PERIOD.

AVIATION...
GENERALLY EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD WITH DRY HIGH
PRESSURE CONTINUING TO DOMINATE. THE ADDED MOISTURE ASSOCIATED WITH
THE NEARBY RIVERS SUPPORTS A PERIOD OF MVFR FOG AT AGS AND OGB AGAIN
EARLY THIS MORNING. THE AFTERNOON AND EVENING THUNDERSTORM CHANCE
APPEARS TOO LOW TO FORECAST AT THE TERMINALS AT THIS TIME.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

HC/HC/CAL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE COLUMBIA SC
539 AM EDT THU JUL 20 2006

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-210939-
AIKEN SC-BAMBERG SC-BARNWELL SC-BURKE GA-CALHOUN SC-CHESTERFIELD SC-
CLARENDON SC-COLUMBIA GA-EDGEFIELD SC-FAIRFIELD SC-KERSHAW SC-
LANCASTER SC-LEE SC-LEXINGTON SC-LINCOLN GA-MCCORMICK SC-MCDUFFIE GA-
NEWBERRY SC-ORANGEBURG SC-RICHLAND SC-RICHMOND GA-SALUDA SC-
SUMTER SC-
539 AM EDT THU JUL 20 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MIDLANDS OF SOUTH CAROLINA
AND THE CENTRAL SAVANNAH RIVER AREA OF GEORGIA.

.DAY ONE...TODAY AND TONIGHT
AFTERNOON HEAT INDEX VALUES WILL BE AROUND 103. THIS IS JUST BELOW
HEAT ADVISORY CRITERIA. AFTERNOON THUNDERSTORMS WILL BE ISOLATED.
A WIND GUST NEAR 60 MPH COULD POSSIBLY OCCUR WITH THE THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
ANY SEVERE WEATHER IS EXPECTED TO BE VERY ISOLATED.
THEREFORE...SPOTTER ACTIVATION IS NOT ANTICIPATED.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE COLUMBIA SC
318 PM EDT THU JUL 20 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0309 PM     HAIL             NW MCCORMICK            33.91N 82.29W
07/20/2006  E0.50 INCH       MCCORMICK          SC   FIRE DEPT/RESCUE

            PEA TO MARBLE SIZED HAIL ON HIGHWAY 28 NORTH OUTSIDE OF
            MCCORMICK...HEADING TOWARDS MOUNT CARMEL.

&&

CAL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
721 PM EDT THU JUL 20 2006

SCZ025-202345-

EDGEFIELD-
721 PM EDT THU JUL 20 2006

...STRONG THUNDERSTORMS WILL IMPACT EDGEFIELD COUNTY THROUGH 745 PM
EDT...

AT 721 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM CENTERED 3 MILES WEST OF EDGEFIELD...OR ABOUT 19
MILES NORTH OF BELVEDERE...MOVING SOUTHEAST AT 5 MPH. THIS STRONG
THUNDERSTORM WILL AFFECT AREAS IN AND AROUND EDGEFIELD AND TRENTON
THROUGH 745 PM EDT.

GUSTY WINDS OF 35 TO 45 MPH ALONG WITH BRIEF HEAVY RAIN CAN BE
EXPECTED.

LM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
729 PM EDT THU JUL 20 2006

GAZ064-210000-

COLUMBIA-
729 PM EDT THU JUL 20 2006

...STRONG THUNDERSTORMS WILL IMPACT COLUMBIA COUNTY THROUGH 800 PM
EDT...

AT 729 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
CENTERED 5 MILES WEST OF EVANS...MOVING SOUTHEAST AT 5 MPH. THIS WILL
AFFECT AREAS IN AND AROUND MARTINEZ...GROVETOWN AND EVANS THROUGH 800
PM EDT.

GUSTY WINDS OF 45 TO 55 MPH ALONG WITH BRIEF HEAVY RAIN CAN BE
EXPECTED.

LM