Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 12, NWS Huntsville, AL

March 25, 2021DeKalb County, Alabama

NWS Huntsville, AL issued this flash flood warning at Mar 25, 2021, 6:22 PM CDT for DeKalb County, Alabama. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Mar 25, 2021, 6:22 PM CDT (23:22 UTC)
Expired
Mar 25, 2021, 9:05 PM CDT
In force
3 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County DeKalb County, AL

The radar

The Northeast Alabama radar (KHTX), 64 km from the middle of the area, began a volume at 23:23 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, 11.4 hours before the alert went out and 164 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 2021-03-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 54 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 12:00Z on 2021-03-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 613 square meters per square second.1939587897117Sfc1 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
54 J/kg
Mixed-layer CIN
-239 J/kg
Mixed-layer LCL
507 m above ground
0-6 km bulk shear
65 kt
0-1 km storm-relative helicity
613 m²/s²
0-3 km storm-relative helicity
713 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.6

Open this sounding in Storm Lab

The text

As transmitted.

375 
WGUS54 KHUN 252322
FFWHUN
ALC049-260230-
/O.NEW.KHUN.FF.W.0012.210325T2322Z-210326T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
622 PM CDT Thu Mar 25 2021

The National Weather Service in Huntsville has issued a

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

* Until 930 PM CDT.

* At 622 PM CDT, Emergency Management reported numerous roads along 
  Highway 35 in Fort Payne under as much as 2 feet of water. Dye 
  Branch has overflowed and is covering much of Highway 35 West of 
  Interstate 59. These are the same areas that flooded on Easter 
  Weekend in 2020, and the flash flooding lasted several hours in 
  the wake of the heavy rainfall that moved through the region. Do 
  not travel in these areas as there are numerous vehicles in the 
  floodwaters along this portion of Highway 35. TURN AROUND, DON'T 
  DROWN!

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Doppler radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Fort Payne, Rainsville, Henagar, Crossville, Sylvania, Fyffe, 
  Powell, Geraldine, Ider, Valley Head, Hammondville, Mentone, Pine 
  Ridge, Lakeview, Guest, Collbran, Lebanon, Peeks Corner, Dog Town 
  and Adamsburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3447 8602 3450 8596 3463 8577 3483 8558
      3452 8551 3447 8558 3444 8558 3440 8563
      3436 8563 3436 8566 3426 8577 3426 8581
      3424 8581 3424 8584 3420 8584 3420 8611
      3442 8610 3447 8606

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

12
1 follow-up statement
253 
WGUS74 KHUN 260205
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
905 PM CDT Thu Mar 25 2021

ALC049-260215-
/O.CAN.KHUN.FF.W.0012.000000T0000Z-210326T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DeKalb AL-
905 PM CDT Thu Mar 25 2021

...FLASH FLOOD WARNING FOR DEKALB COUNTY HAS BEEN REPLACED WITH A 
FLOOD WARNING...

A Flood Warning has replaced the original Flash Flood Warning due to 
water receding across Fort Payne. Additional rainfall tonight will 
aggravate flooding issues, but widespread flash flooding is not 
anticipated.

LAT...LON 3447 8602 3450 8596 3463 8577 3483 8558
      3452 8551 3447 8558 3444 8558 3440 8563
      3436 8563 3436 8566 3426 8577 3426 8581
      3424 8581 3424 8584 3420 8584 3420 8611
      3442 8610 3447 8606

$$

12

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 25, 3:01 AM CDTWind AdvisoryHUNColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more20 hr
Mar 25, 6:40 AM CDTSpecial Weather StatementHUNMarshall50 min
Mar 25, 7:37 AM CDTSpecial Weather StatementHUNColbert38 min
Mar 25, 7:55 AM CDTSpecial Weather StatementHUNCullman50 min
Mar 25, 8:20 AM CDTSevere Thunderstorm WarningHUNCullman, Morgan25 min
Mar 25, 8:38 AM CDTSevere Thunderstorm WarningHUNMarshall52 min
Mar 25, 8:50 AM CDTSpecial Weather StatementHUNCullman40 min
Mar 25, 9:13 AM CDTSevere Thunderstorm WarningHUNDeKalb, Jackson62 min
Mar 25, 9:16 AM CDTFlash Flood WarningHUNCullman, Marshall, Morgan4 hr
Mar 25, 10:22 AM CDTFlash Flood WarningHUNCullman, DeKalb, Jackson, Madison, Marshall, Morgan3 hr
Mar 25, 10:49 AM CDTSpecial Weather StatementHUNMarshall, Morgan41 min
Mar 25, 2:21 PM CDTFlash Flood WarningHUNCullman, Lawrence, Marshall, Morgan3 hr
Mar 25, 2:35 PM CDTFlash Flood WarningHUNLawrence, Limestone, Morgan3 hr
Mar 25, 2:37 PM CDTSpecial Weather StatementHUNColbert, Lauderdale38 min
Mar 25, 2:45 PM CDTFlash Flood WarningHUNColbert, Franklin, Lauderdale, Lawrence3 hr
Mar 25, 2:53 PM CDTTornado WarningHUNColbert, Franklin, Lauderdale21 min
Mar 25, 2:56 PM CDTSpecial Weather StatementHUNJackson34 min
Mar 25, 3:07 PM CDTFlash Flood WarningHUNCullman, DeKalb, Jackson, Madison, Marshall, Morgan3 hr
Mar 25, 4:08 PM CDTSpecial Weather StatementHUNMarshall37 min
Mar 25, 4:44 PM CDTSpecial Weather StatementHUNDeKalb46 min
Mar 25, 5:01 PM CDTSpecial Weather StatementHUNCullman29 min
Mar 25, 5:16 PM CDTAreal Flood WarningHUNColbert, Franklin, Lauderdale, Lawrence4 hr
Mar 25, 5:21 PM CDTAreal Flood WarningHUNLawrence, Limestone, Morgan5 hr
Mar 25, 5:23 PM CDTAreal Flood WarningHUNCullman, Lawrence, Marshall, Morgan5 hr
Mar 25, 6:13 PM CDTAreal Flood WarningHUNCullman, DeKalb, Jackson, Madison, Marshall, Morgan3 hr
Mar 25, 6:24 PM CDTSpecial Weather StatementHUNDeKalb, Marshall51 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.