Alert archive / Alabama / Flash Flood Warnings in 2021
Flash Flood Warning 28, NWS Huntsville, AL
NWS Huntsville, AL issued this flash flood warning at Aug 11, 2021, 6:17 PM CDT for 4 counties in Alabama. It was in force for 79 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
- Aug 11, 2021, 6:17 PM CDT (23:17 UTC)
- Expired
- Aug 11, 2021, 7:36 PM CDT
- In force
- 79 min
- Issued by
- NWS Huntsville, AL
- Area
- Storm-based polygon
- Flood severity
- None
Counties Jackson County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL
The radar
The Northeast Alabama radar (KHTX), 47 km from the middle of the area, began a volume at 23:19 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
Birmingham, AL (KBMX), launched 12:00Z, 11.3 hours before the alert went out and 159 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.
- Mixed-layer CAPE
- 1557 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 940 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- -29 m²/s²
- 0-3 km storm-relative helicity
- -15 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
290
WGUS54 KHUN 112317
FFWHUN
ALC071-089-095-103-120115-
/O.NEW.KHUN.FF.W.0028.210811T2317Z-210812T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
617 PM CDT Wed Aug 11 2021
The National Weather Service in Huntsville has issued a
* Flash Flood Warning for...
Southern Madison County in north central Alabama...
East Central Morgan County in north central Alabama...
Southwestern Jackson County in northeastern Alabama...
Northern Marshall County in northeastern Alabama...
* Until 815 PM CDT.
* At 617 PM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 2 and 4 inches of rain
have fallen. The expected rainfall rate is 1 to 2 inches in 3
hours. 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...
Southern Huntsville, Scottsboro, Redstone Arsenal, Owens Cross
Roads, Grant, Section, Morgan City, Langston, Lim Rock,
Whitesburg, Farley, Laceys Spring and Valhermoso Springs.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3458 8668 3463 8667 3457 8645 3460 8624
3470 8619 3469 8613 3467 8607 3462 8593
3456 8598 3452 8611 3447 8627 3444 8654
3443 8657 3443 8672
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 3 HOURS
$$
KTW1 follow-up statement
730
WGUS74 KHUN 120036
FFSHUN
Flash Flood Statement
National Weather Service Huntsville AL
736 PM CDT Wed Aug 11 2021
ALC071-089-095-103-120046-
/O.CAN.KHUN.FF.W.0028.000000T0000Z-210812T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jackson AL-Madison AL-Marshall AL-Morgan AL-
736 PM CDT Wed Aug 11 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN MADISON, EAST
CENTRAL MORGAN, SOUTHWESTERN JACKSON AND NORTHERN MARSHALL
COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to be alert though for low lying areas where
water could still cover roadways and cause hydroplaning.
LAT...LON 3458 8668 3463 8667 3457 8645 3460 8624
3470 8619 3469 8613 3467 8607 3462 8593
3456 8598 3452 8611 3447 8627 3444 8654
3443 8657 3443 8672
$$
KTWThe office that day
Everything else NWS Huntsville, AL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 3:05 PM CDT | Special Weather Statement | HUN | Jackson | 40 min |
| Aug 11, 3:21 PM CDT | Special Weather Statement | HUN | Madison | 24 min |
| Aug 11, 3:32 PM CDT | Special Weather Statement | HUN | DeKalb | 28 min |
| Aug 11, 3:47 PM CDT | Special Weather Statement | HUN | Marshall | 28 min |
| Aug 11, 3:55 PM CDT | Special Weather Statement | HUN | Jackson | 35 min |
| Aug 11, 4:01 PM CDT | Severe Thunderstorm Warning | HUN | Jackson | 29 min |
| Aug 11, 4:07 PM CDT | Special Weather Statement | HUN | Lawrence | 38 min |
| Aug 11, 4:22 PM CDT | Severe Thunderstorm Warning | HUN | Franklin, Lawrence | 23 min |
| Aug 11, 4:35 PM CDT | Special Weather Statement | HUN | Morgan | 40 min |
| Aug 11, 4:43 PM CDT | Special Weather Statement | HUN | Madison | 47 min |
| Aug 11, 5:09 PM CDT | Special Weather Statement | HUN | Madison, Morgan | 21 min |
| Aug 11, 5:17 PM CDT | Special Weather Statement | HUN | Jackson | 28 min |
| Aug 11, 5:21 PM CDT | Severe Thunderstorm Warning | HUN | Jackson | 24 min |
| Aug 11, 5:38 PM CDT | Severe Thunderstorm Warning | HUN | Jackson, Madison | 25 min |
| Aug 11, 5:46 PM CDT | Special Weather Statement | HUN | Jackson | 29 min |
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.