Alert archive / North Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 20, NWS Greenville-Spartanburg, SC

August 17, 2021Transylvania County, North Carolina

NWS Greenville-Spartanburg, SC issued this flash flood warning at Aug 17, 2021, 1:25 PM EDT for Transylvania County, North 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
Aug 17, 2021, 1:25 PM EDT (17:25 UTC)
Expired
Aug 17, 2021, 5:15 PM EDT
In force
4 hr
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Flood severity
None

County Transylvania County, NC

The radar

The Greer radar (KGSP), 64 km from the middle of the area, began a volume at 17:25 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.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 5.4 hours before the alert went out and 260 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 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 259 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 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 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 square meters per square second.193958Sfc1 km3 km6 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
259 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
461 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
197 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

057 
WGUS52 KGSP 171725
FFWGSP
NCC175-172115-
/O.NEW.KGSP.FF.W.0020.210817T1725Z-210817T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Greenville-Spartanburg SC
125 PM EDT Tue Aug 17 2021

The National Weather Service in Greenville-Spartanburg has issued a

* Flash Flood Warning for...
  Transylvania County in western North Carolina...

* Until 515 PM EDT.

* At 125 PM EDT, With the threat of heavy tropical thunderstorms 
  expected to overspread the region this afternoon, as much as 5 
  inches of additional rainfall may occur. Renewed flooding is 
  expected to develop along many tributaries of the Upper French 
  Broad Valley and the highway 64 corridor from Rosman to Brevard to 
  Penrose.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3541 8274 3532 8266 3531 8264 3528 8262
      3518 8260 3515 8261 3513 8270 3510 8272
      3508 8276 3509 8278 3514 8288 3516 8290
      3516 8298 3518 8298 3519 8297 3524 8291
      3529 8291 3531 8283 3535 8279 3539 8277

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 2:22 AM EDTRiver Flood WarningGSPHenderson, Transylvania4 days
Aug 17, 3:01 AM EDTRiver Flood AdvisoryGSPBuncombe, Henderson79 min
Aug 17, 3:27 AM EDTRiver Flood AdvisoryGSPBuncombe26 hr
Aug 17, 3:59 AM EDTRiver Flood WarningGSPMadison40 hr
Aug 17, 4:12 AM EDTRiver Flood WarningGSPBuncombe31 hr
Aug 17, 4:20 AM EDTRiver Flood WarningGSPBuncombe, Henderson4 days
Aug 17, 11:36 AM EDTTornado Warning Tornado observedGSPAlexander, Iredell39 min
Aug 17, 12:05 PM EDTSpecial Weather StatementGSPIredell25 min
Aug 17, 12:06 PM EDTTornado WarningGSPIredell39 min
Aug 17, 12:33 PM EDTTornado WarningGSPAlexander12 min
Aug 17, 12:42 PM EDTTornado Warning Tornado observedGSPIredell18 min
Aug 17, 1:09 PM EDTFlash Flood WarningGSPJackson, Macon, Transylvania5 hr
Aug 17, 1:56 PM EDTSpecial Weather StatementGSPTransylvania34 min
Aug 17, 2:01 PM EDTSpecial Weather StatementGSPCatawba, Lincoln29 min
Aug 17, 2:02 PM EDTSpecial Weather StatementGSPIredell28 min
Aug 17, 2:02 PM EDTSpecial Weather StatementGSPAlexander28 min
Aug 17, 2:31 PM EDTTornado WarningGSPBurke, Caldwell44 min
Aug 17, 2:31 PM EDTTornado WarningGSPMacon19 min
Aug 17, 3:02 PM EDTTornado WarningGSPCaldwell43 min
Aug 17, 3:06 PM EDTTornado WarningGSPAlexander, Caldwell39 min
Aug 17, 3:12 PM EDTFlash Flood WarningGSPHaywood3 hr
Aug 17, 3:41 PM EDTFlash Flood WarningGSPBuncombe5 hr
Aug 17, 3:48 PM EDTTornado WarningGSPAlexander, Burke, Caldwell, Catawba42 min
Aug 17, 4:07 PM EDTTornado WarningGSPAvery, Burke, McDowell, Mitchell53 min
Aug 17, 4:08 PM EDTFlash Flood WarningGSPMadison9 hr
Aug 17, 4:16 PM EDTFlash Flood WarningGSPBuncombe, Henderson5 hr
Aug 17, 4:17 PM EDTTornado WarningGSPAvery, Burke, Caldwell43 min
Aug 17, 4:20 PM EDTTornado WarningGSPHenderson, Polk, Rutherford12 min
Aug 17, 4:24 PM EDTFlash Flood Warning Considerable damage threatGSPHaywood4 hr
Aug 17, 4:35 PM EDTFlash Flood WarningGSPBuncombe, Henderson, Polk, Rutherford8 hr
Aug 17, 4:50 PM EDTFlash Flood WarningGSPMcDowell9 hr
Aug 17, 4:58 PM EDTFlash Flood WarningGSPYancey4 hr
Aug 17, 4:59 PM EDTTornado WarningGSPAvery, Burke, McDowell, Mitchell, Yancey46 min
Aug 17, 5:14 PM EDTFlash Flood Warning Considerable damage threatGSPTransylvania4 hr
Aug 17, 5:17 PM EDTRiver Flood WarningGSPHaywood12 hr
Aug 17, 5:26 PM EDTTornado WarningGSPAvery, McDowell, Mitchell, Rutherford, Yancey49 min
Aug 17, 5:28 PM EDTTornado WarningGSPAvery, Burke, Caldwell47 min
Aug 17, 5:32 PM EDTFlash Flood WarningGSPMitchell4 hr
Aug 17, 5:48 PM EDTRiver Flood WarningGSPBuncombe26 hr
Aug 17, 6:00 PM EDTFlash Flood WarningGSPAvery, Burke, Caldwell9 hr
Aug 17, 6:16 PM EDTFlash Flood WarningGSPHenderson, Polk, Rutherford3 hr
Aug 17, 6:42 PM EDTTornado WarningGSPPolk, Rutherford48 min
Aug 17, 6:57 PM EDTFlash Flood WarningGSPBurke, McDowell6 hr
Aug 17, 7:59 PM EDTTornado WarningGSPCleveland46 min

Nearby

Flash Flood Warnings in North 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.