An area of showers and thunderstorms became anchored over the southeast slopes of the Appalachian Mountains during the afternoon hours. The storms produced very heavy rain which lead to a few instances of flash flooding over Rabun County.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS GSP wrote it up.
An area of showers and thunderstorms became anchored over the southeast slopes of the Appalachian Mountains during the afternoon hours. The storms produced very heavy rain which lead to a few instances of flash flooding over Rabun County.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before the first event at Aug 21, 12:18 PM EST, 42 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 118 PM EDT SAT AUG 21 2010 .SYNOPSIS... UNSETTLED WEATHER WILL CONTINUE THROUGH THE WEEKEND AS A WEAK COLD FRONT PUSHES SOUTH TOWARD THE AREA. THE FRONT WILL STALL OUT OR MAKE VERY LITTLE PROGRESS ON MONDAY...BUT IT SHOULD BE SOUTH OF THE AREA BY TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH TUESDAY AND REMAIN THROUGH THE END OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...POPS AND QPF HAVE BEEN INCREASED FOR THE UPPER SAVANNAH RIVER VALLEY INTO THIS AFTERNOON BASED ON RADAR TRENDS. THE UPPER VORT APPEARS TO BE MOVING JUST SOUTH OF THE BLUE RIDGE...WHICH SHOULD TAKE ADVANTAGE OF TERRAIN EFFECTS. UPPER LEVEL RIDING WAS ANALYZED OVER THE APPALACHIANS THIS MORNING...WITH A TROUGH UPSTREAM OVER FROM THE GREAT LAKES TO THE MID MS RIVER VALLEY. A LOW TO MID LEVEL TROUGH WAS LOCATED IN EASTERN GA AT 700 MB AND 850 MB...WHICH IS ASSOCIATED WITH THE LINE OF CONVECTION MOVING EAST INTO THE UPPER SAVANNAH RIVER VALLEY AT THIS TIME. A STATIONARY FRONT WAS LOCATED JUST SOUTHWEST OF THE SAVANNAH RIVER VALLEY...CLOSE TO WHERE THE CONVECTION WAS NOTED. THE NAM MOVES THIS UPPER FEATURE VERY SLOWLY EAST INTO SC BY TONIGHT...WITH MOST OF ITS INSTABILITY REMAINING WEST OF INTERSTATE 77. LIGHT NORTHEASTERLY SURFACE WINDS ARE EXPECTED TO VEER TO THE EAST TODAY...PROVIDING A BETTER UPSLOPE COMPONENT TO THE EAST OF THE UPPER LEVEL SYSTEM. POPS WILL BE RAISED IN THE WEST TODAY... PARTICULARLY IN SC AND GA...AND QPF RAISED AS WELL. SO FAR PRECIPITATION HAS BEEN MOVING ENOUGH TO KEEP RAINFALL AMOUNTS LIMITED...BUT AS THE UPPER SYSTEM SLOWS...AND INSTABILITY INCREASES WITH HEATING...RAINFALL AMOUNTS SHOULD COME UP. FORTUNATELY...THIS AREA HAS NOT HAS AS MUCH RECENT RAIN AS THE NC PIEDMONT...AND NO FLASH FLOOD OR FLOOD WATCH IS ANTICIPATED AT THIS TIME. TEMPERATURES BE SLIGHTLY ABOVE NORMAL DESPITE CLOUDS COVER...AS THE UPPER RIDGE AXIS CROSS THE AREA TODAY. CONVECTION WILL TAPER OFF TONIGHT...THOUGH THERE MAY BE AN INCREASE ALONG THE TN LINE LATE AS A NRN STREAM THROUGH AS IT/S ASSOCIATED COLD FRONT APPROACHES THE MTNS. I/M NOT LOOKING FOR WIDESPREAD ACTIVITY ALONG THE FRONT OWING TO THE TIME OF DAY A FAIRLY WEAK FORCING. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 240 AM SATURDAY...BETTER AGREEMENT IS SEEN THIS MORNING WRT TO THE ULVL PATTERN SUN THROUGH MON. THE 00Z GFS IS NOW CLOSING OFF THE UPPER LOW AND ACTUALLY DEEPENING AND KEEPING IT NORTH MORESO THAN EITHER THE NAM OR THE ECMWF BY SUN EVENING. THIS HAS A DISTINCT AFFECT ON THE TRANSITION OF THE SFC FRONT AND THE AMOUNT OF THETA/E AIRMASS MIXING EXPECTED DURING THE DAY MON. BASICALLY THE GFS STALLS THE FRONT OUT ACROSS REGION AND KEEPS THE AIRMASS STAGNANT...WHILE THE OTHER TWO OP MODELS SWEEP THE FRONT TO THE COAST AND MIX IN A DECENT AMOUNT OF LOWER THETA/E AIR. SINCE THE GFS IS BRAND NEW TO THIS IDEA...MORE WEIGHT WILL BE GIVEN TO THE IDEA OF A FROPA DURING THE DAY MON AND LITTLE IN THE WAY OF A PRECIP OR TSTM THREAT THEREAFTER. IN ANY SENSE...THE FRONT WILL NOT HAVE MUCH MOISTURE TO WORK WITH AS GOM TRANS VECTORS DONT REACH THE TN VALLEY UNTIL LATE SAT. ALSO WITH THE LLVL RIDGE PERSISTING AND WEAK FLOW AHEAD OF THE FRONT...NO EVIDENCE IS NOTED OF AN ERN GOM OR ATL MOISTURE FLUX INTO THE AREA SUN. MODEL SOUNDINGS INDICATE PW/S IN THE 1.5 TO 1.8 IN RANGE AHEAD OF THE FRONT...HOWEVER LOW INSTABILITY AND WEAK DYNAMICAL FORCING WILL NOT ALLOW FOR MUCH OF A HEAVY PRECIP THREAT. IN FACT...MOST OF THE PRECIP SHOULD BE ASSOCIATED WITH -SHRA AND A FEW TSTMS ACROSS THE NC MTN COUNTIES WHERE PERHAPS AN INCH OF PRECIP WILL FALL BTW 12Z SUN AND 12Z MON. OUTSIDE THE MTNS...MOST LIKELY AROUND A HALF INCH WILL FALL IN SCATTERED ACTIVITY. TEMPS ON SUN SHOULD STILL REACH A FEW DEGREES ABOVE NORMAL UNDER THE S/W RIDGE...AND RIGHT AROUND NORMAL MON...BUT PERHAPS A COUPLE DEGREES BELOW NORMAL ACROSS THE NC MTN VALLEYS WHERE THERE WILL BE MORE WIDESPREAD CLOUDINESS EARLY AND PERHAPS SOME DEGREE OF AIRMASS MIXING BY THE EARLY AFTERNOON. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 320 AM SATURDAY...THE UPPER LEVEL LOW AXIS SHIFTS TO THE EAST OF THE CWFA TUE AND SETS UP A RATHER STRONG SUBSIDENCE ZONE ACROSS THE REGION. THIS SHOULD LIMIT THE CONV POTENTIAL...HOWEVER A FEW ISOL -SHRA AND TSTMS ARE POSSIBLE WITH RESIDUAL LLVL MOISTURE POSSIBLY ENHANCED SOMEWHAT BY A WAVY SFC FRONT TO THE SOUTH. THE GFS LIKES THIS POSSIBILITY MORE THAN THE ECMWF...BUT GIVEN THE AMOUNT OF LARGE SCALE DOWNWARD MOTION EXPECTED...A NOD WILL BE GIVEN TO THE DRIER ECMWF. THE MODELS DO AGREE THAT AFT TUE THE UPPER PATTERN BECOMES QUASI/ZONAL WITH A LOW AMPLITUDE WAVE BRINGING A WEAK AND MOISTURE CHALLENGED SFC FRONT TO THE MTNS EARLY THU. MILDER CONDS COULD SET UP FRI THROUGH SAT AS A MID/ATL WEDGE LOOKS TO DEVELOP. THE DEGREE OF MOISTURE AFFECTING THIS WEDGE IS STILL UNCERTAIN...BUT LOWER THETA/E AIR COULD HOLD MAX TEMPS A COUPLE DEGREES BELOW NORMAL. HOWEVER BEFORE THEN...MAX TEMPS SHOULD AVG RIGHT AROUND NORMAL. && .AVIATION /17Z SATURDAY THROUGH WEDNESDAY/... AT KCLT...EAST SOUTHEAST WINDS WILL BECOME CALM THIS EVENING... ABOUT THE TIME LOW CLOUDS MOVE IN AHEAD OF THE SLOWLY ADVANCING VORT MAX IN THE SAVANNA RIVER VALLEY. GUIDANCE ONLY SUPPORTS BRIEF MVFR VISIBILITY IN FOG SUNDAY MORNING...WITH CEILINGS AT THE LOW END OF VFR. LIGHT WINDS COME UP FROM THE SOUTHWEST AFTER DAYBREAK...WITH A LOW VFR CEILING PERSISTING AS MOISTURE POOLS AHEAD OF AN APPROACHING COLD FRONT. ELSEWHERE...MVFR TO IFR CEILINGS AND VISIBILITY WILL BE INDUCED BY PRECIPITATION AND A GRADUALLY VEERING UPSLOPE FLOW COMPONENT AS A MID LEVEL VORT MAX CROSSES THE UPPER SAVANNAH RIVER VALLEY. LOW LEVEL MOISTURE IN THE WAKE OF THIS SYSTEM WILL KEEP RESTRICTIONS GOING OVERNIGHT...WITH WINDS GOING CALM. GUIDANCE SUPPORTS THE WORST RESTRICTIONS AT KAVL AND KAND...WHICH MAKES SENSE BASE ON WHERE THE TRACK OF THE VORT...THE STALLED SURFACE FRONT... AND TERRAIN EFFECTS COINCIDE. GUIDANCE SUPPORTS MVFR FOG BUT VFR CEILINGS AT KGSP AND KGMU...AS WELL AS KHKY WHERE IFR IS ONLY HINTED AT. LIGHT WEST SOUTHWEST WINDS COME UP AFTER DAYBREAK SUNDAY. LOW VFR CEILINGS ARE EXPECTED FROM MID MORNING THROUGH MID DAY AHEAD OF AN APPROACHING COLD FRONT. OUTLOOK...A COLD FRONT WILL BRING SCT SHRA/TSTMS AND ASSOCIATED RESTRICTIONS TO MOST OF THE REGION ON SUNDAY. BEHIND THE FRONT DRIER WEATHER IS EXPECTED MON-WED. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && SYNOPSIS...SBK NEAR TERM...JAT/MCAVOY SHORT TERM...SBK LONG TERM...SBK AVIATION...JAT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 526 AM EDT SAT AUG 21 2010 GAZ010-017-018-026-028-029-NCZ048-051>053-058-059-062>065-SCZ001>006- 010>012-019-220930- RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-MADISON-SWAIN-HAYWOOD- BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA- HENDERSON-OCONEE MOUNTAINS-PICKENS MOUNTAINS-GREENVILLE MOUNTAINS- GREATER OCONEE-GREATER PICKENS-GREATER GREENVILLE-ANDERSON-ABBEVILLE- LAURENS-GREENWOOD- 526 AM EDT SAT AUG 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA. .DAY ONE...TODAY AND TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE SOUTHWEST MOUNTAINS OF NORTH CAROLINA...NORTHEAST GEORGIA AND THE UPSTATE WEST OF GREENVILLE TODAY. BRIEF...HEAVY RAIN AND CLOUD TO GROUND LIGHTNING WILL BE THE MAIN THREAT FROM THUNDERSTORMS THIS AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... NONE. NCZ033-035>037-049-050-056-057-068>072-082-501>510-SCZ007>009-013- 014-220930- AVERY-ALEXANDER-IREDELL-DAVIE-YANCEY-MITCHELL-CATAWBA-ROWAN- CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC- CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE- MCDOWELL MOUNTAINS-EASTERN MCDOWELL-RUTHERFORD MOUNTAINS- GREATER RUTHERFORD-POLK MOUNTAINS-EASTERN POLK-SPARTANBURG-CHEROKEE- YORK-UNION SC-CHESTER- 526 AM EDT SAT AUG 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... NONE. 14
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1203 PM EDT SAT AUG 21 2010
GAZ010-017-018-026-028-029-SCZ001-004-010-211745-
ANDERSON-ELBERT-FRANKLIN-GREATER OCONEE-HABERSHAM-HART-OCONEE
MOUNTAINS-RABUN-STEPHENS-
1203 PM EDT SAT AUG 21 2010
...AN AREA OF HEAVY RAIN WILL AFFECT FRANKLIN...HABERSHAM...
HART...OCONEE... RABUN...SOUTHWESTERN ANDERSON...STEPHENS AND
WESTERN ELBERT COUNTIES THROUGH 145 PM EDT...
AT 1152 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LARGE AREA OF SHOWERS THAT WAS PRODUCING RAINFALL AMOUNTS UP TO 1
INCH PER HOUR. THE HEAVIEST RAIN WAS MOVE THROUGH STEPHENS AND RABUN
AND HART COUNTIES. RUNOFF FROM THESE STORMS WILL CAUSE MINOR
FLOODING OF SMALL CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...
STREETS AND UNDERPASSES AS THE RAIN BECOMES HEAVIER DURING THE
AFTERNOON.
HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK
HIGHER GROUND IF THREATENED BY FLOOD WATERS.
LAT...LON 3411 8304 3417 8311 3426 8312 3425 8334
3432 8340 3446 8340 3448 8356 3443 8362
3447 8365 3476 8363 3479 8368 3488 8366
3499 8355 3500 8309 3466 8284 3461 8286
3464 8282 3449 8271 3416 8273 3404 8289
PATPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
158 PM EDT SAT AUG 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0156 PM FLASH FLOOD 4 N MOCCASIN CREEK STAT 34.91N 83.58W
08/21/2010 RABUN GA LAW ENFORCEMENT
MUD SLIDE CAUSED BY HEAVY RAIN ON HIGHWAY 76 WEST NEAR
TOWNS COUNTY LINE.
&&
PTANNERPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
200 PM EDT SAT AUG 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0156 PM FLASH FLOOD CLAYTON 34.88N 83.40W
08/21/2010 RABUN GA LAW ENFORCEMENT
HIGHWAY 76 EAST IN CLAYTON GA CLOSED DUE TO FLOODING
&&
PTANNERThe Greer radar (KGSP), 106 km away, was scanning. The volume nearest the first event began at 17:59 UTC.
1 flash flood. Local standard time, as filed.
A portion of highway 76 was closed due to flooding about 2 miles southeast of Clayton. Also, a bridge over Ramey Rd was flooded in the Lakemont community and a creek flooded a portion of Lake Rabun Rd about 8 miles south southwest of Clayton.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Georgia in 2010Every state in 2010This day in weather historyWarnings in Georgia, August 2010
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 258263.