Alert archive / Alabama / Areal Flood Warnings in 2021

Areal Flood Warning 21, NWS Huntsville, AL

March 31, 20215 counties in Alabama

NWS Huntsville, AL issued this areal flood warning at Mar 31, 2021, 11:35 AM CDT for 5 counties in Alabama. It was in force for 6 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
Mar 31, 2021, 11:35 AM CDT (16:35 UTC)
Expired
Mar 31, 2021, 5:24 PM CDT
In force
6 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

Counties DeKalb County, AL, Jackson County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL

The radar

The Northeast Alabama radar (KHTX), 57 km from the middle of the area, began a volume at 16:38 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

TimeReportWhereRemark
Mar 31, 12:32 PM CDTFLASH FLOOD1 Ene Stevenson, ALOLD MOUNT CARMEL ROAD HAS BEEN CLOSED DUE TO FLASH FLOODING.

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, 4.6 hours before the alert went out and 152 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 2021-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 455 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 2021-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 273 square meters per square second.19395878Sfc1 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
455 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
527 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
273 m²/s²
0-3 km storm-relative helicity
283 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

510 
WGUS44 KHUN 311635
FLWHUN

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Huntsville AL
1135 AM CDT Wed Mar 31 2021

ALC049-071-089-095-103-312230-
/O.NEW.KHUN.FA.W.0021.210331T1635Z-210331T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DeKalb AL-Jackson AL-Madison AL-Marshall AL-Morgan AL-
1135 AM CDT Wed Mar 31 2021

The National Weather Service in Huntsville has issued a

* Flood Warning for...
  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...

* Until 530 PM CDT.

* At 1135 AM CDT, emergency management had reported heavy rain had 
  caused areas of flooding. Between 2 and 4 inches of rain have 
  fallen.

Some locations that will experience flooding include...
  Southern Huntsville, Albertville, Scottsboro, Fort Payne, Boaz, 
  Guntersville, Arab, Rainsville, Bridgeport, Henagar, Stevenson, 
  Crossville, Sylvania, Owens Cross Roads, Fyffe, Hollywood, Powell, 
  Grant, Geraldine and Skyline.

Though rain is ending, flooding problems will likely continue to 
linger for the next several hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Warning means that flooding is imminent or occurring. All 
interested parties should take necessary precautions immediately.

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

&&

LAT...LON 3431 8682 3447 8678 3456 8654 3472 8633
      3499 8593 3497 8560 3452 8551 3447 8558
      3444 8558 3436 8564 3426 8577 3424 8584
      3420 8584 3420 8611 3418 8619 3410 8631
      3429 8648

$$

McCoy
1 follow-up statement
613 
WGUS84 KHUN 312224
FLSHUN

Flood Statement
National Weather Service Huntsville AL
524 PM CDT Wed Mar 31 2021

ALC049-071-089-095-103-312234-
/O.CAN.KHUN.FA.W.0021.000000T0000Z-210331T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DeKalb AL-Jackson AL-Madison AL-Marshall AL-Morgan AL-
524 PM CDT Wed Mar 31 2021

...FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN MADISON, SOUTHEASTERN 
MORGAN, DEKALB, JACKSON AND MARSHALL COUNTIES...

Heavy rainfall has ended and flood waters have receded, except along 
the Big Wills Creek basin in Fort Payne. Minor flooding will 
continue along Big Wills Creek this evening, and a separate Flood 
Warning will be issued for just this location.

LAT...LON 3431 8682 3447 8678 3456 8654 3472 8633
      3499 8593 3497 8560 3452 8551 3447 8558
      3444 8558 3436 8564 3426 8577 3424 8584
      3420 8584 3420 8611 3418 8619 3410 8631
      3429 8648

$$

12

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 31, 3:38 AM CDTSpecial Weather StatementHUNMarshall52 min
Mar 31, 3:56 AM CDTSpecial Weather StatementHUNMorgan49 min
Mar 31, 4:59 AM CDTAreal Flood WarningHUNJackson3 hr
Mar 31, 6:21 AM CDTAreal Flood WarningHUNCullman3 hr
Mar 31, 7:21 AM CDTFlash Flood WarningHUNCullman6 hr
Mar 31, 7:30 AM CDTFlash Flood WarningHUNJackson, Marshall4 hr
Mar 31, 7:36 AM CDTSpecial Weather StatementHUNCullman39 min
Mar 31, 8:49 AM CDTFlash Flood WarningHUNMadison, Marshall, Morgan3 hr
Mar 31, 9:41 AM CDTFlash Flood WarningHUNDeKalb, Jackson, Marshall119 min
Mar 31, 1:06 PM CDTAreal Flood WarningHUNCullman5 hr
Mar 31, 1:42 PM CDTRiver Flood WarningHUNMadison, Marshall, Morgan55 hr
Mar 31, 1:52 PM CDTFreeze WatchHUNColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more13 hr
Mar 31, 1:52 PM CDTFreeze WarningHUNColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more42 hr
Mar 31, 5:29 PM CDTAreal Flood WarningHUNDeKalb3 hr
Mar 31, 6:18 PM CDTAreal Flood WarningHUNCullman18 hr

Nearby

Areal Flood Warnings in Alabama, 2021Every areal 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.