Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 7, NWS Huntsville, AL

March 25, 20216 counties in Alabama; Franklin County, Tennessee

NWS Huntsville, AL issued this flash flood warning at Mar 25, 2021, 10:22 AM CDT for 6 counties in Alabama; Franklin County, Tennessee. 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, 10:22 AM CDT (15:22 UTC)
Expired
Mar 25, 2021, 1:30 PM CDT
In force
3 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

Counties Cullman County, AL, DeKalb County, AL, Jackson County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Franklin County, TN

The radar

The Northeast Alabama radar (KHTX), 47 km from the middle of the area, began a volume at 15:24 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, 3.4 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 2021-03-25Temperature 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.

348 
WGUS54 KHUN 251522
FFWHUN
ALC043-049-071-089-095-103-TNC051-251830-
/O.NEW.KHUN.FF.W.0007.210325T1522Z-210325T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
1022 AM CDT Thu Mar 25 2021

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Northeastern Cullman County in north central Alabama...
  Southeastern Madison County in north central Alabama...
  Southeastern Morgan County in north central Alabama...
  DeKalb County in northeastern Alabama...
  Jackson County in northeastern Alabama...
  Marshall County in northeastern Alabama...
  Southern Franklin TN County in middle Tennessee...

* Until 130 PM CDT.

* At 1022 AM CDT, Emergency management reported thunderstorms 
  producing heavy rain across the warned area. Several roads across 
  this area have water over them, with several roads on Sand 
  Mountain reported closed. 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...Emergency management and doppler radar estimates.

  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, Scottsboro, Fort Payne, Boaz, Guntersville, Arab, 
  Rainsville, Bridgeport, Henagar, Stevenson, Crossville, Sylvania, 
  Owens Cross Roads, Fyffe, Hollywood, Powell, Geraldine, Grant, 
  Skyline and Section.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

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 3432 8663 3444 8659 3461 8638 3475 8625
      3483 8621 3490 8613 3499 8596 3500 8586
      3497 8560 3454 8552 3447 8558 3443 8558
      3439 8562 3424 8596 3418 8619 3411 8630
      3419 8637 3427 8640 3427 8650

FLASH FLOOD...OBSERVED

$$

AMP

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, 10:49 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, 6:22 PM CDTFlash Flood Warning Considerable damage threatHUNDeKalb3 hr
Mar 25, 6:24 PM CDTSpecial Weather StatementHUNDeKalb, Marshall51 min
Mar 25, 2:42 PM CDTSpecial Weather StatementHUNMoore48 min
Mar 25, 3:04 PM CDTSpecial Weather StatementHUNLincoln41 min

Nearby

Flash Flood Warnings in Alabama, 2021Flash Flood Warnings in Tennessee, 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.