Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 23, NWS Huntsville, AL

July 13, 2021DeKalb County, Alabama

NWS Huntsville, AL issued this flash flood warning at Jul 13, 2021, 6:31 PM CDT for DeKalb County, Alabama. It was in force for 89 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 13, 2021, 6:31 PM CDT (23:31 UTC)
Expired: Jul 13, 2021, 8:00 PM CDT
In force: 89 min
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Flood severity: None

County DeKalb County, AL

The radar

The Northeast Alabama radar (KHTX), 49 km from the middle of the area, began a volume at 23:35 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 12:00Z, 11.5 hours before the alert went out and 179 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: 123 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 876 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 88 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

332 
WGUS54 KHUN 132331
FFWHUN
ALC049-140100-
/O.NEW.KHUN.FF.W.0023.210713T2331Z-210714T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
631 PM CDT Tue Jul 13 2021

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Eastern DeKalb County in northeastern Alabama...

* Until 800 PM CDT.

* At 631 PM CDT, Local emergency management officials from Dekalb 
  County reported flash flooding occurring in Sylvania, Rainsville, 
  Powell, and Henagar. Up to 1 inch of rain has fallen. The expected 
  rainfall rate is 0.5 to 1 inch in 1 hour. Additional rainfall 
  amounts up to 0.5 inch are possible in the warning area. Flash 
  flooding is already occurring.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency management reported.

  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...
  Fort Payne, Rainsville, Henagar, Sylvania, Powell, Ider, Valley 
  Head, Hammondville, Mentone, Pine Ridge, Desoto State Park, 
  Adamsburg, Little River Canyon NP, Sulpher Springs, Collbran and 
  Dog Town.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3455 8552 3429 8574 3453 8592 3462 8579
      3474 8569 3474 8567 3476 8566 3481 8563
      3484 8560 3480 8557

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

70/DD

1 follow-up statement

798 
WGUS74 KHUN 140103
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
803 PM CDT Tue Jul 13 2021

ALC049-140113-
/O.EXP.KHUN.FF.W.0023.000000T0000Z-210714T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DeKalb AL-
803 PM CDT Tue Jul 13 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR EASTERN DEKALB COUNTY...

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

LAT...LON 3455 8552 3429 8574 3453 8592 3462 8579
      3474 8569 3474 8567 3476 8566 3481 8563
      3484 8560 3480 8557

$$

70/DD

The office that day

Everything else NWS Huntsville, AL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 13, 2:36 PM CDT	Special Weather Statement	HUN	Colbert	24 min
Jul 13, 3:01 PM CDT	Special Weather Statement	HUN	Cullman	29 min
Jul 13, 3:32 PM CDT	Special Weather Statement	HUN	Cullman	43 min
Jul 13, 3:48 PM CDT	Special Weather Statement	HUN	Lauderdale	42 min
Jul 13, 4:31 PM CDT	Special Weather Statement	HUN	Limestone	44 min
Jul 13, 5:16 PM CDT	Special Weather Statement	HUN	Colbert, Franklin	44 min
Jul 13, 6:06 PM CDT	Special Weather Statement	HUN	DeKalb	39 min
Jul 13, 6:49 PM CDT	Special Weather Statement	HUN	Jackson	26 min

Nearby

Flash Flood Warnings in Alabama, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.