Alert archive / South Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 44, NWS Greenville-Spartanburg, SC

October 7, 2021Greenwood County, South Carolina

NWS Greenville-Spartanburg, SC issued this flash flood warning at Oct 7, 2021, 10:21 AM EDT for Greenwood County, South Carolina. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Oct 7, 2021, 10:21 AM EDT (14:21 UTC)
Expired
Oct 7, 2021, 2:17 PM EDT
In force
4 hr
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Flood severity
None

County Greenwood County, SC

The radar

The Greer radar (KGSP), 71 km from the middle of the area, began a volume at 14:20 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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 12:00Z, 2.4 hours before the alert went out and 241 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 12:00Z on 2021-10-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 134 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 12:00Z on 2021-10-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 square meters per square second.193958Sfc1 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
134 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
660 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

217 
WGUS52 KGSP 071421
FFWGSP
SCC047-072015-
/O.NEW.KGSP.FF.W.0044.211007T1421Z-211007T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Greenville-Spartanburg SC
1021 AM EDT Thu Oct 7 2021

The National Weather Service in Greenville-Spartanburg has issued a

* Flash Flood Warning for...
  Northern Greenwood County in upstate South Carolina...

* Until 415 PM EDT.

* At 1021 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly.  The area of primary concern is the 
  Hodges and Cokesbury area, where 2-3 inches of rain has fallen 
  over the past 60-90 minutes.  Expect rapid flooding of low-water 
  crossings and other low-lying areas adjacent to small streams, 
  including the headwaters of Coronaca Creek near Cokesbury Rd and 
  Mulberry Creek near Sally White Rd.  Heavy rainfall will continue 
  across northern Greenwood County for the next 30-60 minutes.  
  Expect flooding to worsen over the next 1-2 hours before area 
  streams crest and flooding begins to recede.  Avoid all flooded 
  roadways and seek higher ground if you live next to a small stream.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Greenwood, Ware Shoals, Ninety Six, Cokesbury, Hodges, Lake 
  Greenwood, Shoals Junction, Greenwood State Park, Coronaca and 
  Dyson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3418 8190 3415 8205 3418 8216 3416 8224
      3422 8225 3426 8228 3428 8231 3432 8231
      3434 8233 3441 8225 3436 8218 3433 8217
      3432 8213 3430 8212 3430 8208 3424 8201
      3424 8198 3420 8194 3419 8192 3418 8192

FLASH FLOOD...RADAR INDICATED

$$

JMP
1 follow-up statement
055 
WGUS72 KGSP 071817
FFSGSP

Flash Flood Statement
National Weather Service Greenville-Spartanburg SC
217 PM EDT Thu Oct 7 2021

SCC047-071827-
/O.CAN.KGSP.FF.W.0044.000000T0000Z-211007T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Greenwood SC-
217 PM EDT Thu Oct 7 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHERN GREENWOOD COUNTY...

Flooding has receded from earlier heavy rainfall and no longer poses 
a threat.  Please continue to obey all barricades to allow engineers 
to assess road safety.  Additional heavy rainfall is possible later 
this afternoon and may cause new flooding to develop.  Please stay
weather aware and have multiple ways to receive warnings if 
additional flooding occurs.

LAT...LON 3418 8190 3415 8205 3418 8216 3416 8224
      3422 8225 3426 8228 3428 8231 3432 8231
      3434 8233 3441 8225 3436 8218 3433 8217
      3432 8213 3430 8212 3430 8208 3424 8201
      3424 8198 3420 8194 3419 8192 3418 8192

$$

JMP

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 Oct 7, 3:39 AM EDT, 6 hours 42 minutes earlier.

Area forecast discussion, Oct 7, 3:39 AM EDT, 6 hours 42 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
339 AM EDT Thu Oct 7 2021

.SYNOPSIS...
An upper level Low pressure over the lower Mississippi Valley will
focus a very moist southerly flow off the Gulf of Mexico into our
region for another day before it moves toward the Great Lakes.
Expect periods of widespread showers and locally heavy rainfall
through Friday especially for the mountains and foothills. As this
low and its associated front moves east of our area this weekend,
dry high pressure will be in place into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 335 AM EDT: A deep upper low will slowly move north from the
Mid-South into the Mid-West through the period. A series of short
waves will rotate around the low and across the area today. Much
weaker short waves are expected tonight. Good upper divergence
expected today as a jet streak rotates across the area. The
divergence weakens overnight as the jet streak moves away from the
area. Deep moisture remains in place over the area through the
period with PW values generally 1.5 inches or higher. Weak
instability remains in place as well along with good warm cloud
precip processes and isentropic lift. The one limiting factor is the
low level jet. While H85 winds will be southeasterly today, they
remain less then 30 kts. The synoptic and CAM guidance all respond
with widespread precip coverage over the western CWFA with lower
coverage over the east. The Flash Flood Watch looks well placed and
basically in line with QPF and Excessive Rainfall forecast from WPC.
That said, can't rule out flooding outside of the watch, especially
along the Upper Savannah River valley of the northern Blue Ridge.
Another warm and muggy day expected.

With forcing diminishing tonight as the upper low moves north,
expect precip coverage and intensity to diminish. This is in line
with both synoptic and CAM guidance. Deep moisture and weak upslope
flow will keep a chance of showers across the area overnight, but
the threat of new flooding greatly decreases. Therefore, the current
end time of the Watch still looks good. Will be another warm and
muggy night.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 300 am Thursday: Arcing upper trough associated with filling
upper low/transitioning open wave over the Midwest at the start of
the period will push steadily through the forecast area Fri into Fri
night. With in-situ cold air damming likely all but dissipated
during that time and plenty of lingering low level moisture...part
of which will be supplied from easterly flow north of tropical
disturbance off the Carolina Coast. Numerous showers and scattered
storms are therefore expected to flare up once again on Friday,
warranting likely PoPs across the entire area. There will be a
continued threat of locally excessive rainfall, with local antecedent
hydro conditions likely being the primary driver of any developing
runoff issues on Friday.

With low level moisture continuing to circulate around the
disturbance off the coast, PoPs will linger across primarily the
eastern half of the area Fri night into Saturday, but with a gradual
draw-down in probabilities to less than 20% by Saturday evening. Min
temps will remain above climo through the period, while maxes will
steadily warm to the tune of a couple of degrees above climo by
Saturday afternoon.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 245 am Thursday: Establishment of a long wave trough across
the western Conus will result in downstream ridging over the East by
the early part of the medium range, and this regime is forecast to
more or less persist into the middle part of next week. This will
result in dry and unseasonably warm conditions through much of the
period, with temps likely averaging around 5 degrees above climo.
Additionally, dewpoints will be anomalously high for early/mid
October, and in fact, wouldn't completely rule out some spotty
diurnal mountain showers early next week. Overall, it's not going to
feel especially fall-like.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Despite some VFR across the area, expect
deteriorating conditions this morning as moist upslope flow
continues, along with copious low level moisture. Expect MVFR cigs
to become widespread with IFR/LIFR cigs by daybreak then continuing
through the morning. Expect MVFR vsby to develop across much of the
area with TEMPO IFR vsby in heavier showers. NE wind continues
through the morning, S at KAVL. Expect slow improvement to MVFR cigs
and VFR vsby in the mid-afternoon. Showers will continue through the
period, so have prevailing or VCSH continues. TSRA will be possible
during the afternoon, so PROB30s have been included for that. Expect
cigs to drop back into the IFR range during the evening with some
MVFR vsby. NE wind, S at KAVL, continues through the period.

Outlook: A wet pattern is expected to continue into Friday, with
occasional periods of widespread showers and frequent occurrence of
flight restrictions expected. Finally, some drier air will try to
work in from the west this weekend, but low-level moisture may
linger, keeping a chance of low cigs and fog, especially late
night/early mornings.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Flash Flood Watch through this evening for GAZ010-017.
NC...Flash Flood Watch through this evening for NCZ052-053-059-
     062>065-505-507-509.
SC...Flash Flood Watch through this evening for SCZ001>003.

&&

SYNOPSIS...RWH
NEAR TERM...RWH
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...RWH
Hazardous weather outlook, Oct 7, 5:14 AM EDT, 5 hours 7 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
514 AM EDT Thu Oct 7 2021

GAZ018-026-028-029-NCZ033-048>051-058-068-501>504-506-508-510-
SCZ004>008-010>013-019-080915-
Stephens-Franklin-Hart-Elbert-Avery-Madison-Yancey-Mitchell-Swain-
Graham-Cleveland-Caldwell Mountains-Greater Caldwell-Burke Mountains-
Greater Burke-Eastern McDowell-Greater Rutherford-Eastern Polk-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-Anderson-Abbeville-Laurens-Union SC-Greenwood-
514 AM EDT Thu Oct 7 2021

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...Today and tonight.

Numerous to widespread showers along with isolated thunderstorms
are expected off and on through tonight. The main threat will be
from locally heavy rainfall. Isolated flash flooding could develop in
areas that see multiple rounds of heavy rainfall. Locations that have
received heavy rainfall in previous days will be most susceptible to
developing flash flooding. Occasional cloud to ground lightning will
also be possible with any thunderstorms.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-NCZ052-053-059-062>065-505-507-509-SCZ001>003-080915-
Rabun-Habersham-Haywood-Buncombe-Northern Jackson-Macon-
Southern Jackson-Transylvania-Henderson-McDowell Mountains-
Rutherford Mountains-Polk Mountains-Oconee Mountains-
Pickens Mountains-Greenville Mountains-
514 AM EDT Thu Oct 7 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

This Hazardous Weather Outlook is for northeast Georgia, western
North Carolina and upstate South Carolina.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ035>037-056-057-069>072-082-SCZ009-014-080915-
Alexander-Iredell-Davie-Catawba-Rowan-Lincoln-Gaston-Mecklenburg-
Cabarrus-Union NC-York-Chester-
514 AM EDT Thu Oct 7 2021

This Hazardous Weather Outlook is for piedmont North Carolina and
upstate South Carolina.

.DAY ONE...Today and tonight.

Isolated to widely scattered thunderstorms are expected across the
Piedmont today, mainly this afternoon and evening. The primary
threats from any storms will be from cloud to ground lightning and
locally heavy rainfall.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Lane

In the hours before

Local storm report, Oct 7, 9:15 AM EDT, 1 hour 6 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
915 AM EDT THU OCT 07 2021

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

0900 AM     FLASH FLOOD      4 WSW PIEDMONT          34.70N 82.54W
10/07/2021                   ANDERSON           SC   911 CALL CENTER

            911 CALL CENTER REPORTED ROAD CLOSURE DUE TO FLOOD ON
            HWY 17 AND DAVIS RD.

&&
Local storm report, Oct 7, 9:16 AM EDT, 1 hour 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
916 AM EDT THU OCT 07 2021

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

0900 AM     FLASH FLOOD      7 WNW WILLIAMSTON       34.65N 82.60W
10/07/2021                   ANDERSON           SC   911 CALL CENTER

            911 CALL CENTER REPORTED ROAD COMPLETELY WASHED OUT ON
            SHACKLEBURG RD.

&&
Local storm report, Oct 7, 9:20 AM EDT, 1 hour 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
920 AM EDT THU OCT 07 2021

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

0900 AM     FLASH FLOOD      4 SSW ANTREVILLE        34.26N 82.56W
10/07/2021                   ABBEVILLE          SC   911 CALL CENTER

            911 CALL CENTER REPORTED ROAD CLOSURE DUE TO FLASH
            FLOOD ON LAKE SECESSION RD NEAR DIAMOND HILL ELEMENTARY
            SCHOOL

&&
Local storm report, Oct 7, 9:21 AM EDT, 1 hour before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
921 AM EDT THU OCT 07 2021

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

0900 AM     FLASH FLOOD      2 SSW ANTREVILLE        34.28N 82.55W
10/07/2021                   ABBEVILLE          SC   911 CALL CENTER

            911 CALL CENTER REPORTED FLOODED ROADWAYS DUE TO HEAVY
            RAIN ON HIGHWAY 284

&&
Local storm report, Oct 7, 9:23 AM EDT, 58 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
923 AM EDT THU OCT 07 2021

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

0900 AM     FLASH FLOOD      2 SSW ABBEVILLE         34.15N 82.39W
10/07/2021                   ABBEVILLE          SC   911 CALL CENTER

            911 CALL CENTER REPORTED FLOOD ON HIGHWAY 28.

&&
Special weather statement, Oct 7, 9:42 AM EDT, 39 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
942 AM EDT Thu Oct 7 2021

SCZ012-019-071445-
Laurens SC-Greenwood SC-
942 AM EDT Thu Oct 7 2021

...A THUNDERSTORM WILL IMPACT SOUTHWESTERN LAURENS AND NORTHWESTERN
GREENWOOD COUNTIES UNTIL 1045 AM EDT...

At 942 AM EDT, Doppler radar was tracking a thunderstorm 6 miles
north of Greenwood, or near Cokesbury, moving east at 5 mph.

Locations to be impacted include...
Greenwood, Cokesbury, Hodges, Waterloo, Lake Greenwood and Coronaca.

Very heavy rainfall rates up to 2 inches per hour will be possible in
these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

&&

LAT...LON 3421 8224 3425 8227 3427 8230 3434 8231
      3438 8207 3421 8202
TIME...MOT...LOC 1342Z 270DEG 6KT 3429 8215

LANE

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 7, 5:47 AM EDTSpecial Weather StatementGSPGreenville43 min
Oct 7, 6:16 AM EDTFlash Flood WarningGSPAnderson3 hr
Oct 7, 7:08 AM EDTAreal Flood AdvisoryGSPOconee3 hr
Oct 7, 7:45 AM EDTAreal Flood AdvisoryGSPAbbeville3 hr
Oct 7, 8:59 AM EDTFlash Flood WarningGSPAbbeville3 hr
Oct 7, 9:16 AM EDTAreal Flood WarningGSPAnderson7 hr
Oct 7, 9:42 AM EDTSpecial Weather StatementGSPGreenwood63 min
Oct 7, 12:03 PM EDTAreal Flood WarningGSPAbbeville6 hr

Nearby

Flash Flood Warnings in South Carolina, 2021Every flash flood warning in 2021

Sources

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