Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 26, NWS Huntsville, AL

July 25, 2021Madison County, Alabama

NWS Huntsville, AL issued this flash flood warning at Jul 25, 2021, 6:11 PM CDT for Madison County, Alabama. It was in force for 105 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 25, 2021, 6:11 PM CDT (23:11 UTC)
Expired
Jul 25, 2021, 7:56 PM CDT
In force
105 min
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

County Madison County, AL

The radar

The Northeast Alabama radar (KHTX), 57 km from the middle of the area, began a volume at 23:12 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

Birmingham, AL (KBMX), launched 12:00Z, 11.2 hours before the alert went out and 160 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, Birmingham, AL at 12:00Z on 2021-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1352 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, Birmingham, AL at 12:00Z on 2021-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
1352 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
851 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

305 
WGUS54 KHUN 252311
FFWHUN
ALC089-260215-
/O.NEW.KHUN.FF.W.0026.210725T2311Z-210726T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
611 PM CDT Sun Jul 25 2021

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Southwestern Madison County in north central Alabama...

* Until 915 PM CDT.

* At 611 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across portions of Central Madison County, including 
  southeast Huntsville. 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...
  Southeast Huntsville, Redstone Arsenal, Owens Cross Roads, Farley, 
  Whitesburg and Hampton Cove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3473 8658 3465 8643 3451 8654 3454 8655
      3456 8655 3457 8656 3458 8659 3457 8662
      3463 8669

FLASH FLOOD...RADAR INDICATED

$$

12
1 follow-up statement
461 
WGUS74 KHUN 260056
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
756 PM CDT Sun Jul 25 2021

ALC089-260106-
/O.CAN.KHUN.FF.W.0026.000000T0000Z-210726T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison AL-
756 PM CDT Sun Jul 25 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN MADISON 
COUNTY...

Flood waters have receded and the heavy rain has ended. Flooding is 
no longer expected to pose a threat. Please continue to heed 
remaining road closures.

LAT...LON 3473 8658 3465 8643 3451 8654 3454 8655
      3456 8655 3457 8656 3458 8659 3457 8662
      3463 8669

$$

12

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 12:54 PM CDTHeat AdvisoryHUNColbert, Lauderdale5 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.