Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 37, NWS Tallahassee, FL

September 18, 2021Geneva County, Alabama

NWS Tallahassee, FL issued this flash flood warning at Sep 18, 2021, 6:49 PM CDT for Geneva County, Alabama. It was in force for 3 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
Sep 18, 2021, 6:49 PM CDT (23:49 UTC)
Expired
Sep 18, 2021, 10:00 PM CDT
In force
3 hr
Issued by
NWS Tallahassee, FL
Area
Storm-based polygon
Flood severity
None

County Geneva County, AL

The radar

The Eglin Afb radar (KEVX), 63 km from the middle of the area, began a volume at 23:49 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, 7:30 PM CDTFLASH FLOOD1 Sw Sellersville, ALPARTIAL ROAD WASHOUT DUE TO HEAVY RAIN ON COFFEE SPRINGS ROAD HEADING INTO SELLERSVILLE FROM SAMSON. PICTURE POSTED ON SOCIAL MEDIA.

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, 11.8 hours before the alert went out and 189 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.

233 
WGUS52 KTAE 182349
FFWTAE
ALC061-190300-
/O.NEW.KTAE.FF.W.0037.210918T2349Z-210919T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tallahassee has issued a

* Flash Flood Warning for...
  Northwestern Geneva County in southeastern Alabama...

* Until 1000 PM CDT.

* At 649 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 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...
  Samson, Logan Field Municipal A/P, Pera, Sellersville, Ganer, 
  Marl, Spears, Weeks, Earlytown and Hacoda.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3115 8616 3118 8596 3111 8585 3102 8619
      3106 8619 3112 8619

FLASH FLOOD...RADAR INDICATED

$$
1 follow-up statement
459 
WGUS72 KTAE 190300
FFSTAE

Flash Flood Statement
National Weather Service Tallahassee FL
1000 PM CDT Sat Sep 18 2021

ALC061-190310-
/O.EXP.KTAE.FF.W.0037.000000T0000Z-210919T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Geneva AL-
1000 PM CDT Sat Sep 18 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTHWESTERN GENEVA COUNTY...

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

LAT...LON 3115 8616 3118 8596 3111 8585 3102 8619
      3106 8619 3112 8619

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 3:38 PM CDTAreal Flood AdvisoryTAEHenry4 hr
Sep 18, 4:20 PM CDTAreal Flood AdvisoryTAEHouston4 hr
Sep 18, 4:39 PM CDTAreal Flood AdvisoryTAEDale, Henry, Houston4 hr
Sep 18, 4:46 PM CDTSpecial Weather StatementTAEHouston44 min
Sep 18, 5:36 PM CDTAreal Flood AdvisoryTAEGeneva3 hr
Sep 18, 5:44 PM CDTFlash Flood WarningTAEHenry, Houston3 hr
Sep 18, 5:47 PM CDTAreal Flood AdvisoryTAEHouston3 hr
Sep 18, 6:26 PM CDTAreal Flood AdvisoryTAEDale, Geneva, Houston3 hr

Nearby

Flash Flood Warnings in Alabama, 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.