Alert archive / Georgia / Flash Flood Warnings in 2021

Flash Flood Warning 35, NWS Tallahassee, FL

September 18, 2021Thomas County, Georgia

NWS Tallahassee, FL issued this flash flood warning at Sep 18, 2021, 6:42 PM EDT for Thomas County, Georgia. It was in force for 3 hr. 2 reports 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
Sep 18, 2021, 6:42 PM EDT (22:42 UTC)
Expired
Sep 18, 2021, 9:45 PM EDT
In force
3 hr
Issued by
NWS Tallahassee, FL
Area
Storm-based polygon
Flood severity
None

County Thomas County, GA

The radar

The Tallahassee radar (KTLH), 60 km from the middle of the area, began a volume at 22:42 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

TimeReportWhereRemark
Sep 18, 6:45 PM EDTFLOODThomasville, GASEVERAL VEHICLES STRANDED IN FLOOD WATERS DUE TO HEAVY RAINFALL.
Sep 18, 7:15 PM EDTFLASH FLOODThomasville, GAUPDATE: THERE WERE AT LEAST 15 VEHICLES STRANDED IN FLOOD WATERS IN THOMASVILLE. OFFICERS HAD TO ENTER THE WATER TO RESCUE CITIZENS FROM STALLED VEHICLES. PICTURES POSTED ON THE THOMASVILLE POLICE DEPARTMENT FACEBOOK PAGE SHOW SIGNIFICANT STREET FLOODING WITH

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

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 10.7 hours before the alert went out and 59 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, Tallahassee Rgnl, FL at 12:00Z on 2021-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 886 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 12:00Z on 2021-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.1939Sfc1 km3 km6 km9 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
886 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
714 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
5 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

609 
WGUS52 KTAE 182242
FFWTAE
GAC275-190145-
/O.NEW.KTAE.FF.W.0035.210918T2242Z-210919T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tallahassee FL
642 PM EDT Sat Sep 18 2021

The National Weather Service in Tallahassee has issued a

* Flash Flood Warning for...
  Central Thomas County in south central Georgia...

* Until 945 PM EDT.

* At 642 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen in the last 1 Hour. Flash flooding is ongoing or 
  expected to begin shortly.

  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...
  Thomasville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3087 8396 3087 8392 3084 8390 3080 8393
      3080 8396 3081 8401 3084 8402 3086 8402

FLASH FLOOD...RADAR INDICATED

$$
1 follow-up statement
637 
WGUS72 KTAE 190142
FFSTAE

Flash Flood Statement
National Weather Service Tallahassee FL
942 PM EDT Sat Sep 18 2021

GAC275-190152-
/O.EXP.KTAE.FF.W.0035.000000T0000Z-210919T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Thomas GA-
942 PM EDT Sat Sep 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 945 PM EDT THIS EVENING FOR 
CENTRAL THOMAS COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3087 8396 3087 8392 3084 8390 3080 8393
      3080 8396 3081 8401 3084 8402 3086 8402

$$

The office that day

Everything else NWS Tallahassee, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 18, 4:38 PM EDTAreal Flood AdvisoryTAECalhoun, Clay, Early4 hr
Sep 18, 5:20 PM EDTAreal Flood AdvisoryTAEEarly, Seminole4 hr
Sep 18, 5:39 PM EDTAreal Flood AdvisoryTAEEarly4 hr
Sep 18, 6:30 PM EDTAreal Flood AdvisoryTAEThomas3 hr
Sep 18, 6:37 PM EDTAreal Flood AdvisoryTAEBaker, Decatur, Grady, Miller, Mitchell, Thomas3 hr
Sep 18, 6:44 PM EDTFlash Flood WarningTAEEarly3 hr
Sep 18, 7:25 PM EDTAreal Flood AdvisoryTAEColquitt, Grady, Mitchell, Thomas3 hr
Sep 18, 7:47 PM EDTAreal Flood AdvisoryTAEBaker, Colquitt, Early, Miller, Mitchell3 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.