Alert archive / Georgia / Flash Flood Warnings in 2009

Flash Flood Warning 43, NWS Greenville-Spartanburg, SC

September 20, 2009Rabun County, Georgia; Oconee County, South Carolina

NWS Greenville-Spartanburg, SC issued this flash flood warning at Sep 20, 2009, 6:07 AM EDT for Rabun County, Georgia; Oconee County, South Carolina. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 20, 2009, 6:07 AM EDT (10:07 UTC)
Expired
Sep 20, 2009, 9:00 AM EDT
In force
3 hr
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Flood severity
None

Counties Rabun County, GA, Oconee County, SC

The radar

The Greer radar (KGSP), 103 km from the middle of the area, began a volume at 10:08 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Sep 20, 8:40 AM EDTFLASH FLOOD1 N Long Creek, SCCASSIDY BRIDGE ROAD FLOODED BY CREEK OVERFLOWING.
Sep 20, 8:40 AM EDTFLASH FLOOD3 N Long Creek, SCWHETSTONE ROAD FLOODED DUE TO STREAM OVERFLOWING BANK.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this flash flood warning; the first came 153 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 10.1 hours before the alert went out and 196 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Peachtre/Fal Fld, GA at 00:00Z on 2009-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1577 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 00:00Z on 2009-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1577 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
548 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS52 KGSP 201007
FFWGSP
GAC241-SCC073-201300-
/O.NEW.KGSP.FF.W.0043.090920T1007Z-090920T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
607 AM EDT SUN SEP 20 2009

THE NATIONAL WEATHER SERVICE IN GREENVILLE-SPARTANBURG HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN RABUN COUNTY IN NORTHEAST GEORGIA...
  WEST CENTRAL OCONEE COUNTY IN UPSTATE SOUTH CAROLINA...

* UNTIL 900 AM EDT

* AT 606 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM PERSISTENT HEAVY RAIN OVER THE WARNED AREA. RAIN 
WILL CONTINUE TO FALL AT THE RATE OF ONE TO TWO INCHES PER HOUR 
WHICH SHOULD CAUSE CREEKS AND STREAMS TO COME OUT OF THEIR BANKS. 

SPECIFICALLY...WARWOMAN CREEK...HOODS CREEK...LICK LOG CREEK...AND 
OTHER SMALL STREAMS THAT FEED INTO THE CHATTOOGA RIVER IN NORTHEAST 
RABUN COUNTY GEORGIA...AND WESTERN OCONEE COUNTY SOUTH CAROLINA... 
ARE EXPECTED TO COME OUT OF THEIR BANKS. ADDITIONAL RAIN IS EXPECTED 
TO MOVE INTO RABUN COUNTY. THIS COULD FORCE STEKOA CREEK AND THE 
HEADWATERS OF THE LITTLE TENNESSEE RIVER OUT OF THEIR BANKS AS WELL.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SKY VALLEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

WHEN DRIVING ALONG ROADS WHERE THE TERRAIN IS STEEP OR ROCKY...REMAIN
ALERT FOR POSSIBLE ROCK OR MUD SLIDES DUE TO THE HEAVY RAIN.

TO REPORT HIGH WATER...FLOODING...MUDSLIDES...LANDSLIDES OR OTHER
SEVERE WEATHER THROUGH OUR AUTOMATED REPORTING SYSTEM...CALL OUR TOLL
FREE NUMBER...1 8 7 7...6 3 3...6 7 7 2.

&&

LAT...LON 3499 8347 3500 8331 3492 8321 3493 8313
      3484 8318 3476 8326 3470 8335 3473 8339
      3472 8341 3475 8348 3485 8349

$$

MOORE
1 follow-up statement
000 
WGUS72 KGSP 201310
FFSGSP

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
910 AM EDT SUN SEP 20 2009

GAC241-SCC073-201311-
/O.EXP.KGSP.FF.W.0043.000000T0000Z-090920T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RABUN GA-OCONEE SC-
910 AM EDT SUN SEP 20 2009

...THE FLASH FLOOD WARNING HAS EXPIRED FOR WEST CENTRAL OCONEE AND
EASTERN RABUN COUNTIES...

AT 900 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE 
AREA OF HEAVIEST RAIN HAD MOVED NORTHEAST. LIGHT TO MODERATE RAIN 
WILL CONTINUE TO FALL WHICH WILL CAUSE MANY CREEKS AND STREAMS TO 
RUN BANKFULL...WITH MINOR FLOODING ALONG THE BANKS. THE WARNING WAS 
ALLOWED TO EXPIRE BUT A NEW WARNING MAY BE NEEDED IF HEAVIER RAIN 
REDEVELOPS OVER THE AREA.

LAT...LON 3499 8347 3500 8331 3492 8321 3493 8313
      3484 8318 3476 8326 3470 8335 3473 8339
      3472 8341 3475 8348 3485 8349

$$
RB

What forecasters said that day

The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Sep 20, 3:30 AM EDT, 2 hours 37 minutes earlier.

Area forecast discussion, Sep 20, 3:30 AM EDT, 2 hours 37 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
330 AM EDT SUN SEP 20 2009

.SYNOPSIS...
BROAD LOW PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL CONTINUE
TO BRING DEEP MOISTURE ACROSS THE SOUTHEAST TODAY AND TONIGHT. WEAK
HIGH PRESSURE WILL LINGER OVER THE REGION FOR MOST OF THE WORK WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
NUMEROUS TO WIDESPREAD SHOWER ACTIVITY CONTINUES AT 06Z ACROSS THE
WESTERN CAROLINAS IN A WARM ADVECTION UPGLIDE/SE UPSLOPE FLOW
REGIME. SOME OF THE SHOWERS HAVE BEEN CONCENTRATED/ANCHORED NEAR THE
BLUE RIDGE RESULTING IN WHAT SHOULD BE SOME IMPRESSIVE RAINFALL
TOTALS. FOR THE VERY NEAR TERM THIS WILL REQUIRE A CATEGORICAL POP
NEAR THE BLUE RIDGE AND OVER TOWARD METRO CLT...AND LIKELY
ELSEWHERE. THE INGREDIENTS FOR CONTINUED HEAVY RAIN REMAIN IN PLACE
THROUGH THIS MORNING WITH LOW LEVEL MOISTURE CONVERGENCE...HIGH
PW...AND ADDITIONAL FORCING ARRIVING FROM THE SW. HAVE GENERALLY
ACCEPTED THE HIGH MOSGUIDE POP WHICH KEEPS CATEGORICAL RAIN FORECAST
ON THE E SIDE OF THE HIGH TERRAIN...THEN TAPERING OFF ACROSS THE WRN
PIEDMONT. EXPECT TEMPS TO REMAIN COOL TODAY SO THE COOLER GUIDANCE
WAS FOLLOWED.

SUNDAY NIGHT LOOKS VERY SIMILAR TO THE SITUATION WE HAVE RIGHT
NOW...WITH CONINUED UPSLOPE/UPGLIDE. IF THIS GOES DOWN IN A SIMILAR
FASHION...THEN WE ARE GOING TO HAVE TO CONSIDER A FLOOD WATCH FOR
THE ZONES NEAR THE BLUE RIDGE. WOULD RATHER NOT ISSUE A WATCH RIGHT
NOW FOR ZONES THAT ALREADY HAVE A WARNING...SO IT WILL BE EVALUATED
LATER IN THE MORNING. TEMPS WERE KEPT CLOSE TO THE GUIDANCE FOR
LOWS.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 240 AM SUNDAY...ON MONDAY AND TUESDAY...BOTH THE 0Z GFS AND
ECMWF AGREE THAT A MID LEVEL LOW WILL CLOSE OFF OVER THE PLAINS AS A
RIDGE BUILDS OVER THE ATLANTIC COAST. AT THE SFC...WEAK HIGH
PRESSURE WILL LIKELY CONTINUE TO NOSE SE ACROSS THE CWA. THIS
PATTERN SHOULD FAVOR A CONTINUATION OF MOSTLY CLOUDY CONDITIONS WITH
TEMPERATURES AT OR SLIGHTLY LESS THAN NORMAL. ON MONDAY...IT APPEARS
THAT UPSLOPE FLOW AND DIURNAL INSTABILITY WILL SUPPORT LIKELY
COVERAGE OF SHRA AND POSSIBLY TSRA OVER THE MTNS...SCT COVERAGE
EAST. LI/S ON THE GFS INDICATE THAT THE SOUTHERN TIER OF THE CWA IS
FAVORED FOR INCREASED INSTABILITY. ON TUESDAY...ATLANTIC RIDGE AXIS
BEGINS TO SHIFT WEST...WITH THE CENTER PIVOTING OVER THE DEEP SOUTH.
THE RIDGE SHOULD REDUCE TUESDAY/S COVERAGE FROM MONDAY...DUE TO
DECREASED AFTERNOON INSTABILITY. I WILL FORECAST CHC POPS THROUGH
EARLY AFTERNOON...WITH LIKELY COVERAGE OVER THE MTN PEAKS DURING THE
MID TO LATE AFTERNOON.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...I WILL FAVOR THE ECMWF FOR ADJUSTMENTS WITHIN
THE EXTENDED PERIOD. WEAK MID LEVEL RIDGING WILL CONTINUE ACROSS THE
CWA FROM MID WEEK INTO THE EARLY WEEKEND. AT THE SFC...PRESSURES
SHOULD FAVOR SLIGHT HIGH PRESSURE...HOWEVER...A WEAK COLD FRONT
COULD SWEEP ACROSS THE REGION LATE IN THE WORK WEEK. TIMING AND
STRENGTH OF EXTENDED RANGE SFC FEATURES ARE TOO UNCERTAIN AT THIS
TIME. HOWEVER...THE CLOSED LOW OVER THE PLAINS WILL LIKELY MOVE
EAST...INCREASING MOISTURE AND LLVL RETURN FLOW ACROSS THE REGION.
OVERALL...DIURNAL SWINGS IN POPS ARE ANTICIPATED...PEAKING WITH CHC
DURING THE AFTERNOON AND EVENING WITH SCHC AT NIGHT. MOS GUIDANCE
AND PATTERN SUPPORT TEMPERATURES AT OR SLIGHTLY ABOVE NORMAL.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT...A LARGE AREA OF SLOW MOVING LIGHT TO MODERATE RAIN WILL
AFFECT THE TERMINAL FOR AT LEAST THE NEXT HOUR. THIS SHOULD KEEP A
PREVAILING MVFR VISIBILITY WITH CEILING COMING IN AND OUT OF LOW END
MVFR. WHEN THE RAIN FINALLY MOVES OUT...THERE COULD BE A BRIEF
PERIOD OF VFR...BUT THIS SHOULD FILL IN QUICKLY WITH FOG AND LOW
CLOUDS. GUIDANCE IS PESSIMISTIC WITH A TREND TOWARD IFR BY 09Z AND
WITH THE AIR MASS BEING FORCED BY MOIST UPGLIDE THIS SEEMS
REASONABLE. ONCE AGAIN...THESE CONDITIONS ARE EXPECTED TO IMPROVE
DURING THE MID TO LATE MORNING. CEILING SHOULD PROGRESS UPWARD
THROUGH MVFR AND PROBABLY TO LOW END VFR IN THE AFTERNOON. IF IT
DOES BREAK OUT...EXPECT A GREATER CHANCE OF SEEING SCATTERED
THUNDERSTORMS...BUT THIS WILL NOT BE PUT IN THE TAF FOR NOW.

ELSEWHERE...SHOWERS AIDED BY UPSLOPE/WARM ADVECTION SHOULD CONTINUE
TO DEVELOP ACROSS THE REGION THROUGH AT LEAST MID MORNING.
WIDESPREAD FLIGHT RESTRICTIONS ARE EXPECTED LATE TONIGHT WITH AREAS
OF IFR LIKELY TOWARD SUNRISE. DIURNAL IMPROVEMENT IS ALSO LIKELY ON
SUNDAY...WITH CIGS/VSBY IMPROVING FROM MID-MORNING ONWARD AND
PROBABLY BECOMING UNRESTRICTED ACRS MUCH OF THE FA DURING THE
AFTERNOON. HOWEVER...THIS SHOULD FILL RIGHT BACK IN DURING THE
EVENING HOURS.

OUTLOOK...A STAGNANT PATTERN WILL FAVOR PERIODS OF RAIN THROUGH MID
WEEK. EXPECT RESTRICTIONS...MAINLY MVFR...ESPECIALLY AT NIGHT...WITH
IFR POSSIBLE AROUND DAWN.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

SYNOPSIS...NED
NEAR TERM...PM
SHORT TERM...NED
LONG TERM...NED
AVIATION...PM
Hazardous weather outlook, Sep 20, 5:00 AM EDT, 1 hour 7 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
500 AM EDT SUN SEP 20 2009

GAZ010-017-018-026-028-029-NCZ033-048>053-058-059-062>065-501>510-
SCZ001>007-010-210900-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-MADISON-YANCEY-
MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-
SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-CALDWELL MOUNTAINS-
GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-MCDOWELL MOUNTAINS-
EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-GREATER RUTHERFORD-
POLK MOUNTAINS-EASTERN POLK-OCONEE MOUNTAINS-PICKENS MOUNTAINS-
GREENVILLE MOUNTAINS-GREATER OCONEE-GREATER PICKENS-
GREATER GREENVILLE-SPARTANBURG-ANDERSON-
500 AM EDT SUN SEP 20 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...WESTERN
NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.
PERIODS OF MODERATE TO HEAVY RAIN WILL CONTINUE ACROSS THE NORTH
CAROLINA MOUNTAINS AND ADJACENT FOOTHILLS THIS MORNING. SEVERAL INCHES OF
RAIN HAS ALREADY FALLEN ACROSS THE EAST FACING SLOPES EARLIER THIS
MORNING. ADDITIONAL RAINFALL TODAY COULD RESULT IN RAPID RISES
ALONG SMALL STREAM AND CREEKS AND POSSIBLY DEEP STANDING WATER
WITHIN AREAS OF POOR DRAINAGE. IN ADDITION...ISOLATED MUD SLIDES
MAY OCCUR DURING HEAVY RAINFALL RATES ACROSS STEEP TERRAIN.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF FLASH
FLOODING TO OUR OFFICE.

NCZ035>037-056-057-068>072-082-SCZ008-009-011>014-019-210900-
ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-
MECKLENBURG-CABARRUS-UNION NC-CHEROKEE-YORK-ABBEVILLE-LAURENS-
UNION SC-CHESTER-GREENWOOD-
500 AM EDT SUN SEP 20 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH
CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED TO NUMEROUS SHOWERS...A FEW HEAVY AT TIMES...WILL
CONTINUE ACROSS THE PIEDMONT THIS MORNING. HIGH RAINFALL RATES WILL
LIKELY LEAD TO STANDING WATER WITHIN AREAS OF POOR DRAINAGE.
OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF FLASH
FLOODING TO OUR OFFICE.

NED

In the hours before

Local storm report, Sep 20, 5:36 AM EDT, 31 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
536 AM EDT SUN SEP 20 2009

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

0500 AM     FLASH FLOOD      4 NE HENDERSONVILLE     35.37N 82.41W
09/20/2009                   HENDERSON          NC   OFFICIAL NWS OBS

            THE CLEAR CREEK STREAM GAUGE OBSERVED 8.1 FEET AT 9Z. A 8
            FEET...FRUITLAND ROAD AND LOW LYING AREAS NEAR THE RIVER
            BEGIN TO FLOOD.

&&

NED

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 20, 4:30 AM EDTFlash Flood WarningGSPRabun4 hr
Sep 20, 8:14 AM EDTAreal Flood WarningGSPRabun4 hr
Sep 20, 9:34 AM EDTAreal Flood AdvisoryGSPHabersham56 min
Sep 20, 10:28 AM EDTAreal Flood AdvisoryGSPStephens62 min
Sep 20, 10:39 AM EDTFlash Flood WarningGSPStephens3 hr
Sep 20, 11:59 AM EDTAreal Flood WarningGSPHabersham, Rabun6 hr
Sep 20, 2:31 PM EDTAreal Flood WarningGSPStephens3 hr
Sep 20, 5:32 PM EDTAreal Flood WarningGSPHabersham, Rabun, Stephens3 hr
Sep 20, 6:19 PM EDTFlood WatchGSPFranklin, Habersham, Rabun, Stephens36 hr
Sep 20, 6:19 AM EDTAreal Flood WarningGSPGreenville4 hr

Nearby

Flash Flood Warnings in Georgia, 2009Flash Flood Warnings in South Carolina, 2009Every flash flood warning in 2009

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.