Alert archive / Georgia / Flash Flood Warnings in 2020

Flash Flood Warning 41, NWS Atlanta, GA

August 23, 2020Fannin County, Gilmer County, Union County, Georgia

NWS Atlanta, GA issued this flash flood warning at Aug 23, 2020, 2:14 AM EDT for Fannin County, Gilmer County, Union County, Georgia. It was in force for 6 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 23, 2020, 2:14 AM EDT (06:14 UTC)
Expired: Aug 23, 2020, 8:15 AM EDT
In force: 6 hr
Issued by: NWS Atlanta, GA
Area: Storm-based polygon
Flood severity: None

Counties Fannin County, GA, Gilmer County, GA, Union County, GA

The radar

The Atlanta radar (KFFC), 153 km from the middle of the area, began a volume at 06:14 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 00:00Z, 6.2 hours before the alert went out and 151 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 983 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 1160 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 94 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

191 
WGUS52 KFFC 230614
FFWFFC
GAC111-123-291-231215-
/O.NEW.KFFC.FF.W.0041.200823T0614Z-200823T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Peachtree City GA
214 AM EDT Sun Aug 23 2020

The National Weather Service in Peachtree City has issued a

* Flash Flood Warning for...
  Eastern Fannin County in north central Georgia...
  Southeastern Gilmer County in north central Georgia...
  Northwestern Union County in north central Georgia...

* Until 815 AM EDT Sunday.

* At 214 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2.5 and 3 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Margret, Hurst, Dial, Jones Creek, Hemp, Stover Creek Shelter, 
  Pisgah, Springer Mountain Shelter, Nottely Dam, Black Gap Shelter 
  and Ivy Log.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other low lying 
spots.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

Please report flooding to your local law enforcement agency when you 
can do so safely.

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 3457 8439 3499 8414 3499 8394 3497 8395
      3495 8393 3461 8419 3462 8420 3460 8422
      3460 8425 3457 8426 3458 8433 3456 8435

FLASH FLOOD...RADAR INDICATED

$$

The office that day

Everything else NWS Atlanta, GA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 23, 1:41 AM EDT	Special Weather Statement	FFC	Union	64 min

Nearby

Flash Flood Warnings in Georgia, 2020 Every flash flood warning in 2020

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.