Alert archive / Alabama / Flash Flood Warnings in 2021
Flash Flood Warning 19, NWS Huntsville, AL
NWS Huntsville, AL issued this flash flood warning at May 4, 2021, 10:47 AM CDT for DeKalb County, Marshall 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
- May 4, 2021, 10:47 AM CDT (15:47 UTC)
- Expired
- May 4, 2021, 2:00 PM CDT
- In force
- 3 hr
- Issued by
- NWS Huntsville, AL
- Area
- Storm-based polygon
- Flood severity
- None
Counties DeKalb County, AL, Marshall County, AL
The radar
The Northeast Alabama radar (KHTX), 64 km from the middle of the area, began a volume at 15:47 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
| Time | Report | Where | Remark |
|---|---|---|---|
| May 4, 10:50 AM CDT | FLASH FLOOD | Boaz, AL | PORTIONS OF SIX CITY STREETS WERE UNDER WATER, WITH AROUND 3 FEET OF WATER OVER THE ROADS AT ONE POINT. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Birmingham, AL (KBMX), launched 12:00Z, 3.8 hours before the alert went out and 156 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
- 2158 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 569 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 145 m²/s²
- 0-3 km storm-relative helicity
- 195 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 7.3
The text
As transmitted.
115
WGUS54 KHUN 041547
FFWHUN
ALC049-095-041900-
/O.NEW.KHUN.FF.W.0019.210504T1547Z-210504T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
1047 AM CDT Tue May 4 2021
The National Weather Service in Huntsville has issued a
* Flash Flood Warning for...
DeKalb County in northeastern Alabama...
Southeastern Marshall County in northeastern Alabama...
* Until 200 PM CDT.
* At 1047 AM CDT, Doppler radar indicated thunderstorms producing
heavy rain across portions of Marshall and Dekalb Counties.
Between 1 and 3 inches of rain have fallen. Flash flooding is
ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Doppler radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flash flooding include...
Albertville, Fort Payne, Boaz, Guntersville, Rainsville, Henagar,
Crossville, Sylvania, Fyffe, Powell, Geraldine, Ider, Douglas,
Valley Head, Hammondville, Mentone, Pine Ridge, Lakeview, Peeks
Corner and Guest.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 3422 8642 3447 8606 3450 8596 3461 8579
3474 8569 3478 8557 3452 8551 3447 8558
3444 8558 3436 8564 3436 8566 3426 8577
3424 8584 3420 8584 3420 8611 3419 8611
3418 8619 3410 8630
FLASH FLOOD...RADAR INDICATED
$$
AMP2 follow-up statements
510
WGUS74 KHUN 041705
FFSHUN
Flash Flood Statement
National Weather Service Huntsville AL
1205 PM CDT Tue May 4 2021
ALC049-095-041900-
/O.CON.KHUN.FF.W.0019.000000T0000Z-210504T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DeKalb AL-Marshall AL-
1205 PM CDT Tue May 4 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 2 PM CDT THIS
AFTERNOON FOR DEKALB AND SOUTHEASTERN MARSHALL COUNTIES...
At 1205 PM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the portions of Marshall and DeKalb Counties.
Between 2 and 3 inches of rain have fallen. Flash flooding has
already been reported, with runoff issues persisting even after the
rain has come to an end.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Doppler radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
Some locations that will experience flash flooding include...
Albertville, Fort Payne, Boaz, Guntersville, Rainsville, Henagar,
Crossville, Sylvania, Fyffe, Powell, Geraldine, Ider, Douglas,
Valley Head, Hammondville, Mentone, Pine Ridge, Lakeview, Peeks
Corner and Guest.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 3422 8642 3447 8606 3450 8596 3461 8579
3474 8569 3478 8557 3452 8551 3447 8558
3444 8558 3436 8564 3436 8566 3426 8577
3424 8584 3420 8584 3420 8611 3419 8611
3418 8619 3410 8630
FLASH FLOOD...RADAR INDICATED
$$
AMP298
WGUS74 KHUN 041855
FFSHUN
Flash Flood Statement
National Weather Service Huntsville AL
155 PM CDT Tue May 4 2021
ALC049-095-041905-
/O.EXP.KHUN.FF.W.0019.000000T0000Z-210504T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DeKalb AL-Marshall AL-
155 PM CDT Tue May 4 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 2 PM CDT THIS AFTERNOON FOR
DEKALB AND SOUTHEASTERN MARSHALL COUNTIES...
Flash flooding is no longer expected to pose a threat, though runoff
issues may remain through the afternoon. Please continue to heed
remaining road closures.
LAT...LON 3422 8642 3447 8606 3450 8596 3461 8579
3474 8569 3478 8557 3452 8551 3447 8558
3444 8558 3436 8564 3436 8566 3426 8577
3424 8584 3420 8584 3420 8611 3419 8611
3418 8619 3410 8630
$$
AMPThe office that day
Everything else NWS Huntsville, AL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 7:18 AM CDT | Special Weather Statement | HUN | Colbert | 42 min |
| May 4, 7:45 AM CDT | Special Weather Statement | HUN | Cullman | 60 min |
| May 4, 8:31 AM CDT | Special Weather Statement | HUN | Limestone, Madison, Morgan | 44 min |
| May 4, 9:01 AM CDT | Special Weather Statement | HUN | Jackson | 44 min |
| May 4, 9:04 AM CDT | Severe Thunderstorm Warning | HUN | Jackson | 26 min |
| May 4, 9:23 AM CDT | Special Weather Statement | HUN | DeKalb | 52 min |
| May 4, 9:25 AM CDT | Special Weather Statement | HUN | Cullman, Morgan | 50 min |
| May 4, 9:31 AM CDT | Severe Thunderstorm Warning | HUN | Cullman, Morgan | 39 min |
| May 4, 9:39 AM CDT | Severe Thunderstorm Warning | HUN | DeKalb, Jackson | 36 min |
| May 4, 9:51 AM CDT | Severe Thunderstorm Warning | HUN | DeKalb | 24 min |
| May 4, 10:17 AM CDT | Special Weather Statement | HUN | DeKalb | 58 min |
| May 4, 10:51 AM CDT | Special Weather Statement | HUN | Marshall | 39 min |
| May 4, 11:15 AM CDT | Special Weather Statement | HUN | Cullman | 45 min |
| May 4, 11:18 AM CDT | Severe Thunderstorm Warning | HUN | Cullman | 42 min |
| May 4, 3:37 PM CDT | Special Weather Statement | HUN | Franklin | 23 min |
| May 4, 4:18 PM CDT | Special Weather Statement | HUN | Lauderdale | 27 min |
| May 4, 5:10 PM CDT | Special Weather Statement | HUN | Cullman | 35 min |
| May 4, 5:56 PM CDT | Special Weather Statement | HUN | Madison | 49 min |
| May 4, 6:01 PM CDT | Special Weather Statement | HUN | Marshall | 44 min |
| May 4, 6:16 PM CDT | Special Weather Statement | HUN | Madison | 44 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.