Alert archive / Georgia / Flash Flood Warnings in 2020

Flash Flood Warning 72, NWS Atlanta, GA

November 12, 2020Houston County, Georgia

NWS Atlanta, GA issued this flash flood warning at Nov 12, 2020, 4:16 AM EST for Houston 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: Nov 12, 2020, 4:16 AM EST (09:16 UTC)
Expired: Nov 12, 2020, 10:15 AM EST
In force: 6 hr
Issued by: NWS Atlanta, GA
Area: Storm-based polygon
Flood severity: None

County Houston County, GA

The radar

The Robins AFB radar (KJGX), 43 km from the middle of the area, began a volume at 09:19 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, 9.3 hours before the alert went out and 127 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: 410 J/kg
Mixed-layer CIN: -35 J/kg
Mixed-layer LCL: 759 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 127 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

825 
WGUS52 KFFC 120916
FFWFFC
GAC153-121515-
/O.NEW.KFFC.FF.W.0072.201112T0916Z-201112T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Peachtree City GA
416 AM EST Thu Nov 12 2020

The National Weather Service in Peachtree City has issued a

* Flash Flood Warning for...
  Houston County in central Georgia...

* Until 1015 AM EST.

* At 416 AM EST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 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...
  Perry, Warner Robins, Centerville, Unadilla, Robins Air Force 
  Base, Houston Lake, Clinchfield, Sand Bed, Grove Park, Meadowdale, 
  Moss Oak, Grovania, Kathleen, Hayneville, Elko, Bonaire, Henderson 
  and Elberta.

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.

&&

LAT...LON 3247 8379 3251 8377 3251 8375 3252 8375
      3253 8374 3252 8372 3256 8372 3265 8368
      3265 8361 3258 8357 3244 8360 3235 8363
      3229 8369 3229 8370 3228 8370 3228 8372
      3229 8372 3229 8373 3229 8383 3236 8383

FLASH FLOOD...RADAR INDICATED

$$

1 follow-up statement

515 
WGUS72 KFFC 121514
FFSFFC

Flash Flood Statement
National Weather Service Peachtree City GA
1014 AM EST Thu Nov 12 2020

GAC153-121524-
/O.EXP.KFFC.FF.W.0072.000000T0000Z-201112T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Houston GA-
1014 AM EST Thu Nov 12 2020

...FLASH FLOOD WARNING WILL EXPIRE AT 1015 AM EST THIS MORNING FOR 
HOUSTON COUNTY...

The heavy rain has ended. Flash Flooding is no longer expected to 
pose a threat. However, areas that are slow to drain may continue to 
have standing water for the next few hours and some creeks and 
streams will remain high. Motorists are cautioned to remain alert 
for water on roads.

LAT...LON 3247 8379 3251 8377 3251 8375 3252 8375
      3253 8374 3252 8372 3256 8372 3265 8368
      3265 8361 3258 8357 3244 8360 3235 8363
      3229 8369 3229 8370 3228 8370 3228 8372
      3229 8372 3229 8383 3236 8383

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Nov 11, 10:35 PM EST	Flash Flood Warning	FFC	DeKalb, Fulton, Gwinnett	6 hr
Nov 12, 12:05 AM EST	River Flood Warning	FFC	Forsyth, Fulton	6 hr
Nov 12, 12:20 AM EST	Special Weather Statement	FFC	Towns, Union, White	40 min
Nov 12, 1:37 AM EST	Flash Flood Warning	FFC	Towns, White	5 hr
Nov 12, 3:49 AM EST	Special Weather Statement	FFC	Houston, Twiggs	41 min
Nov 12, 4:13 AM EST	Flash Flood Warning	FFC	Greene, Oglethorpe, Putnam	6 hr
Nov 12, 4:27 AM EST	River Flood Warning	FFC	Forsyth	7 hr
Nov 12, 5:24 AM EST	Flash Flood Warning	FFC	Baldwin, Hancock	6 hr
Nov 12, 6:01 AM EST	Flash Flood Warning	FFC	Taliaferro, Warren, Wilkes	6 hr
Nov 12, 6:03 AM EST	Flash Flood Watch	FFC	Baldwin, Glascock, Hancock, Jefferson, Taliaferro, Warren and 3 more	5 hr
Nov 12, 6:40 AM EST	River Flood Warning	FFC	Forsyth, Fulton	30 hr

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.