Alert archive / Georgia / Flash Flood Warnings in 2021

Flash Flood Warning 16, NWS Greenville-Spartanburg, SC

August 17, 2021Habersham County, Georgia

NWS Greenville-Spartanburg, SC issued this flash flood warning at Aug 17, 2021, 11:29 AM EDT for Habersham County, Georgia. It was in force for 5 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, 11:29 AM EDT (15:29 UTC)
Expired
Aug 17, 2021, 4:30 PM EDT
In force
5 hr
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Flood severity
None

County Habersham County, GA

The radar

The Greer radar (KGSP), 130 km from the middle of the area, began a volume at 15:30 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, 3.5 hours before the alert went out and 155 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°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.

284 
WGUS52 KGSP 171529
FFWGSP
GAC137-171830-
/O.NEW.KGSP.FF.W.0016.210817T1529Z-210817T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Greenville-Spartanburg SC
1129 AM EDT Tue Aug 17 2021

The National Weather Service in Greenville-Spartanburg has issued a

* Flash Flood Warning for...
  Southern Habersham County in northeastern Georgia...

* Until 230 PM EDT.

* At 1129 AM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 4 inches of rain have fallen. Flash flooding is ongoing or 
  expected to begin shortly.

  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.

* Some locations that will experience flash flooding include...
  Clarkesville, Cornelia, Baldwin, Demorest, Mount Airy, Alto, Raoul 
  and Hollywood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3467 8351 3462 8339 3448 8346 3449 8354
      3448 8356 3445 8359 3444 8361 3443 8361
      3450 8367 3452 8365 3453 8363 3454 8362
      3455 8362 3456 8362 3463 8359

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$
1 follow-up statement
710 
WGUS52 KGSP 171742
FFWGSP
GAC137-172030-
/O.EXT.KGSP.FF.W.0016.000000T0000Z-210817T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Greenville-Spartanburg has extended 
the

* Flash Flood Warning for...
  Southern Habersham County in northeastern Georgia...

* Until 430 PM EDT.

* At 142 PM EDT, Gauge reports of rainfall between 3 and 5 inches 
  were common across the warned area, and the threat of additional 
  heavy showers will continue this afternoon.  Areas of excessive 
  runoff and high water conditions will linger into late afternoon 
  countywide.


  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Gauges reported.

  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...
  Clarkesville, Cornelia, Baldwin, Demorest, Mount Airy, Alto, Raoul 
  and Hollywood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

When it is safe to do so, please report flooding or landslides 
threatening roads or property to the National Weather Service 
Greenville-Spartanburg by calling toll free, 1, 800, 2 6 7, 8 1 0 1, 
by posting on our Facebook page, or via Twitter using hashtag 
NWSGSP. Your message should describe the specific location where 
impacts occurred and the depth of flooding observed.

&&

LAT...LON 3467 8351 3462 8339 3448 8346 3449 8354
      3448 8356 3445 8359 3444 8361 3443 8361
      3450 8367 3452 8365 3453 8363 3454 8362
      3455 8362 3456 8362 3463 8359

FLASH FLOOD...GAUGE INDICATED

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 10:23 AM EDTSpecial Weather StatementGSPElbert37 min
Aug 17, 10:36 AM EDTTornado WarningGSPHabersham39 min
Aug 17, 10:58 AM EDTTornado WarningGSPElbert, Hart26 min
Aug 17, 11:19 AM EDTSpecial Weather StatementGSPHabersham26 min
Aug 17, 11:47 AM EDTTornado WarningGSPHabersham, Rabun, Stephens13 min
Aug 17, 11:52 AM EDTFlash Flood WarningGSPHabersham, Rabun5 hr
Aug 17, 1:58 PM EDTSpecial Weather StatementGSPRabun32 min
Aug 17, 2:31 PM EDTTornado WarningGSPRabun19 min
Aug 17, 4:28 PM EDTAreal Flood WarningGSPHabersham6 hr

Nearby

Flash Flood Warnings in Georgia, 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.