Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 15, NWS Huntsville, AL

March 31, 2021Jackson County, Marshall County, Alabama

NWS Huntsville, AL issued this flash flood warning at Mar 31, 2021, 7:30 AM CDT for Jackson County, Marshall County, Alabama. It was in force for 4 hr. 2 reports 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, 7:30 AM CDT (12:30 UTC)
Expired
Mar 31, 2021, 11:41 AM CDT
In force
4 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

Counties Jackson County, AL, Marshall County, AL

The radar

The Northeast Alabama radar (KHTX), 25 km from the middle of the area, began a volume at 12:31 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, 7:45 AM CDTFLASH FLOOD7 Ne Woodville, ALAPPROXIMATELY 6 INCHES OF WATER COVERING COUNTY ROAD 30 IN MULTIPLE LOCATIONS, INCLUDING COUNTY ROAD 119.
Mar 31, 7:50 AM CDTFLASH FLOOD3 W Hollywood, ALAPPROXIMATELY 6 TO 8 INCHES OF WATER COVERING COUNTY ROAD 105 NEAR COUNTY ROAD 21.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 0.5 hours before the alert went out and 166 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, Nashville Metro, TN at 12:00Z on 2021-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Nashville Metro, TN at 12:00Z on 2021-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
498 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

366 
WGUS54 KHUN 311230
FFWHUN
ALC071-095-311830-
/O.NEW.KHUN.FF.W.0015.210331T1230Z-210331T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
730 AM CDT Wed Mar 31 2021

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Jackson County in northeastern Alabama...
  Northeastern Marshall County in northeastern Alabama...

* Until 130 PM CDT.

* At 730 AM CDT, gauge reports indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Gauges.

  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...
  Scottsboro, Bridgeport, Stevenson, Hollywood, Grant, Skyline, 
  Section, Woodville, Pisgah, Pleasant Groves, Hytop, Dutton, 
  Langston, Paint Rock, Martintown, Fackler, Larkinsville, Bass, 
  Fabius and Rosalie.

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.

&&

LAT...LON 3463 8635 3472 8635 3499 8593 3497 8560
      3486 8558 3483 8563 3477 8565 3461 8592
      3447 8619 3458 8630 3459 8630 3460 8633
      3461 8633

FLASH FLOOD...GAUGE INDICATED

$$

McCoy
1 follow-up statement
782 
WGUS74 KHUN 311641
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
1141 AM CDT Wed Mar 31 2021

ALC071-095-311651-
/O.CAN.KHUN.FF.W.0015.000000T0000Z-210331T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jackson AL-Marshall AL-
1141 AM CDT Wed Mar 31 2021

...FLASH FLOOD WARNING IS CANCELLED FOR JACKSON AND NORTHEASTERN 
MARSHALL COUNTIES...

This flash flood warning has been replaced with an Areal Flood 
Warning.  Even though the heavy rain has ended, flooding will 
continue to cause problems for the next several hours. Please 
continue to heed remaining road closures.

LAT...LON 3463 8635 3472 8635 3499 8593 3497 8560
      3486 8558 3483 8563 3477 8565 3461 8592
      3447 8619 3458 8630 3459 8630 3460 8633
      3461 8633

$$

McCoy

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, 7:36 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, 11:35 AM CDTAreal Flood WarningHUNDeKalb, Jackson, Madison, Marshall, Morgan6 hr
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

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.