Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 5, NWS Huntsville, AL

March 17, 2021Jackson County, Marshall County, Alabama

NWS Huntsville, AL issued this flash flood warning at Mar 17, 2021, 11:10 PM CDT for Jackson County, Marshall County, Alabama. It was in force for 4 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 17, 2021, 11:10 PM CDT (04:10 UTC)
Expired
Mar 18, 2021, 3:00 AM CDT
In force
4 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Jackson County, AL, Marshall County, AL

The radar

The Northeast Alabama radar (KHTX), 38 km from the middle of the area, began a volume at 04:08 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 00:00Z, 4.2 hours before the alert went out and 168 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 00:00Z on 2021-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 188 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 00:00Z on 2021-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 336 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
188 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
669 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
336 m²/s²
0-3 km storm-relative helicity
465 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted.

936 
WGUS54 KHUN 180410
FFWHUN
ALC071-095-180800-
/O.NEW.KHUN.FF.W.0005.210318T0410Z-210318T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
1110 PM CDT Wed Mar 17 2021

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  West Central Jackson County in northeastern Alabama...
  Northern Marshall County in northeastern Alabama...

* Until 300 AM CDT.

* At 1110 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 3 and 6 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  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...
  Woodville, Paint Rock and Lim Rock.

Runoff from previous rainfall has produced flash flooding in and 
north of the Woodville area, particularly near the intersection of 
CR  and CR 30. In this location water almost up to the top of 
mailboxes was reported by emergency management.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3461 8634 3463 8635 3467 8635 3470 8623
      3471 8618 3465 8614 3460 8624 3460 8630
      3460 8632 3461 8632

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

$$

KTW
1 follow-up statement
124 
WGUS74 KHUN 180420
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
1120 PM CDT Wed Mar 17 2021

ALC095-180430-
/O.CAN.KHUN.FF.W.0005.000000T0000Z-210318T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marshall AL-
1120 PM CDT Wed Mar 17 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHERN MARSHALL COUNTY...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

A Flash Flood Watch remains in effect until 700 AM CDT Thursday for 
portions of north Alabama and southern middle Tennessee.

LAT...LON 3461 8634 3463 8635 3467 8635 3470 8623
      3471 8618 3465 8614 3460 8624 3460 8630
      3460 8632 3461 8632

$$

ALC071-180800-
/O.CON.KHUN.FF.W.0005.000000T0000Z-210318T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jackson AL-
1120 PM CDT Wed Mar 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 3 AM CDT THURSDAY FOR 
WEST CENTRAL JACKSON COUNTY...

At 1120 PM CDT, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Between 3 and 6 inches of rain 
have fallen. Flash flooding is ongoing or expected to begin shortly.

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...
  Woodville, Paint Rock and Lim Rock.

Runoff from previous rainfall has produced flash flooding in and 
north of the Woodville area, particularly near the intersection of 
CR 8 and CR 30. In this location water almost up to the top of 
mailboxes was reported by emergency management.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3461 8634 3463 8635 3467 8635 3470 8623
      3471 8618 3465 8614 3460 8624 3460 8630
      3460 8632 3461 8632

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

$$

BCC

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 17, 7:40 PM CDTAreal Flood WarningHUNColbert, Lauderdale6 hr
Mar 17, 7:54 PM CDTSpecial Weather StatementHUNColbert, Lauderdale36 min
Mar 17, 8:16 PM CDTAreal Flood WarningHUNDeKalb, Jackson, Madison, Marshall, Morgan6 hr
Mar 17, 8:17 PM CDTSpecial Weather StatementHUNColbert, Franklin43 min
Mar 17, 8:26 PM CDTSpecial Weather StatementHUNLauderdale34 min
Mar 17, 8:47 PM CDTAreal Flood WarningHUNMadison11 hr
Mar 17, 8:50 PM CDTSpecial Weather StatementHUNColbert, Lauderdale, Lawrence25 min
Mar 17, 9:06 PM CDTRiver Flood WarningHUNLawrence24 hr
Mar 17, 9:07 PM CDTFlash Flood WarningHUNColbert, Lauderdale3 hr
Mar 17, 9:14 PM CDTSpecial Weather StatementHUNCullman31 min
Mar 17, 9:19 PM CDTFlash Flood WarningHUNJackson, Madison, Marshall, Morgan3 hr
Mar 17, 9:34 PM CDTAreal Flood WarningHUNDeKalb6 hr
Mar 17, 9:45 PM CDTSpecial Weather StatementHUNMarshall, Morgan30 min
Mar 17, 10:09 PM CDTAreal Flood WarningHUNCullman, Madison, Morgan6 hr
Mar 17, 10:13 PM CDTSpecial Weather StatementHUNDeKalb, Jackson47 min
Mar 17, 10:44 PM CDTTornado WarningHUNDeKalb13 min
Mar 17, 11:03 PM CDTSpecial Weather StatementHUNDeKalb27 min
Mar 18, 12:03 AM CDTAreal Flood WarningHUNMarshall117 min
Mar 18, 1:30 AM CDTAreal Flood WarningHUNCullman, DeKalb, Jackson, Madison, Marshall, Morgan8 hr
Mar 18, 8:35 AM CDTAreal Flood WarningHUNMadison2 hr
Mar 18, 10:15 AM CDTRiver Flood WarningHUNJackson, Madison, Marshall67 hr
Mar 18, 10:45 AM CDTRiver Flood WarningHUNColbert, Lauderdale4 days

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.