Alert archive / Georgia / Flash Flood Warnings in 2021

Flash Flood Warning 38, NWS Atlanta, GA

October 4, 2021Banks County, Hall County, Georgia

NWS Atlanta, GA issued this flash flood warning at Oct 4, 2021, 4:59 PM EDT for Banks County, Hall County, Georgia. It was in force for 4 hr. 1 report 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: Oct 4, 2021, 4:59 PM EDT (20:59 UTC)
Expired: Oct 4, 2021, 9:00 PM EDT
In force: 4 hr
Issued by: NWS Atlanta, GA
Area: Storm-based polygon
Flood severity: None

Counties Banks County, GA, Hall County, GA

The radar

The Atlanta radar (KFFC), 124 km from the middle of the area, began a volume at 20:59 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

Time	Report	Where	Remark
Oct 4, 5:10 PM EDT	FLASH FLOOD	1 Se Gainesville, GA	THE EMERGENCY MANAGER REPORTED FLOODING AT SEVERAL LOCATIONS IN GAINESVILLE, INCLUDING CHESTATEE ROAD AT PEARL NIX PARKWAY, 1300 BLOCK OF CUMBERLAND DR, 1700 BLOCK OF MLK BLVD, WESSELL ROAD AT DIXON DR, HIGH STREET AT PINE STREET, AND RACE STREET BETWEEN JESSE

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

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 9.0 hours before the alert went out and 120 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: 443 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 597 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 46 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

122 
WGUS52 KFFC 042059
FFWFFC
GAC011-139-050100-
/O.NEW.KFFC.FF.W.0038.211004T2059Z-211005T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Peachtree City GA
459 PM EDT Mon Oct 4 2021

The National Weather Service in Peachtree City has issued a

* Flash Flood Warning for...
  Central Hall County in north central Georgia...
  West Central Banks County in northeastern Georgia...

* Until 900 PM EDT.

* At 459 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain in Gainesville. Flash flooding is already occurring.

  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...
  Gainesville, Flowery Branch, Oakwood, Lula and Gillsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3429 8393 3446 8366 3430 8362 3429 8362
      3414 8394 3428 8394 3428 8393

FLASH FLOOD...RADAR INDICATED

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 4, 11:01 AM EDT	Special Weather Statement	FFC	Harris, Muscogee, Talbot	44 min
Oct 4, 11:04 AM EDT	Flash Flood Watch	FFC	Baldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 90 more	4 days
Oct 4, 11:46 AM EDT	Special Weather Statement	FFC	Muscogee	44 min
Oct 4, 12:16 PM EDT	Flash Flood Warning	FFC	Harris, Muscogee	6 hr
Oct 4, 12:46 PM EDT	Special Weather Statement	FFC	Muscogee	44 min
Oct 4, 1:24 PM EDT	Flash Flood Warning	FFC	Muscogee	6 hr
Oct 4, 6:51 PM EDT	Special Weather Statement	FFC	Dawson	24 min

Nearby

Flash Flood Warnings in Georgia, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.