Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 4, NWS Huntsville, AL

March 17, 20214 counties in Alabama; Franklin County, Lincoln County, Tennessee

NWS Huntsville, AL issued this flash flood warning at Mar 17, 2021, 9:19 PM CDT for 4 counties in Alabama; Franklin County, Lincoln County, Tennessee. It was in force for 3 hr. 5 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 17, 2021, 9:19 PM CDT (02:19 UTC)
Expired
Mar 18, 2021, 12:30 AM CDT
In force
3 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

Counties Jackson County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Franklin County, TN, Lincoln County, TN

The radar

The Northeast Alabama radar (KHTX), 44 km from the middle of the area, began a volume at 02:22 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 17, 9:22 PM CDTFLOOD7 E Huntsville, ALDUG HILL ROAD AND ROBINSON DRIVE INTERSECTION UNDER WATER.
Mar 17, 9:36 PM CDTFLASH FLOOD2 Wnw Owens Crossroads, ALHIGH WATER RESCUE UNDERWAY WITH AN SUV IN FOUR FEET OF WATER NEAR A CREEK ON SOUTH GREEN MOUNTAIN ROAD AND OLD BIG COVE ROAD. BOTH OCCUPANTS WERE SUCCESSFULLY RESCUED.
Mar 17, 10:00 PM CDTFLASH FLOOD5 Nnw Owens Crossroads, ALSIGNIFICANT FLOODING IN COVE SUBDIVISION AT JACKS CREEK LANE AND PALE DAWN. WATER COVERS MAILBOXES AND THERE WERE WAVES IN THE RUSHING WATER DOWN THE STREET. REPORT RECEIVED VIA SOCIAL MEDIA.
Mar 17, 10:01 PM CDTFLASH FLOOD4 Sw Owens Crossroads, ALHOBBS ISLAND AND HYATT INTERSECTION FLOODED WITH FURNITURE FLOATING IN THE ROADWAY.
Mar 17, 11:11 PM CDTFLASH FLOOD1 W Gurley, ALCAR SUBMERGED AT ROCK CUT ROAD AT HWY 72. WATER WAS FLOWING OVER THE ROADWAY.

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 00:00Z, 2.3 hours before the alert went out and 158 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 00:00Z on 2021-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 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, Nashville Metro, TN at 00:00Z on 2021-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 249 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
51 J/kg
Mixed-layer CIN
-123 J/kg
Mixed-layer LCL
623 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
249 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

036 
WGUS54 KHUN 180219
FFWHUN
ALC071-089-095-103-TNC051-103-180530-
/O.NEW.KHUN.FF.W.0004.210318T0219Z-210318T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Central Madison County in north central Alabama...
  East Central Morgan County in north central Alabama...
  Northwestern Jackson County in northeastern Alabama...
  Northern Marshall County in northeastern Alabama...
  Southwestern Franklin TN County in middle Tennessee...
  Southeastern Lincoln County in middle Tennessee...

* Until 1230 AM CDT.

* At 919 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 3 and 4 inches of rain 
  have fallen. Flash flooding is already occurring.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  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...
  Southern Huntsville, Moores Mill, Redstone Arsenal, Owens Cross 
  Roads, Huntland, Skyline, Gurley, New Market, Pleasant Groves, 
  Hytop, Paint Rock, Maysville, Garth, Brownsboro, Hollytree, 
  Ryland, Trenton, Princeton, Hampton Cove and Larkin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3459 8670 3472 8660 3490 8642 3499 8634
      3510 8623 3502 8607 3484 8611 3447 8647
      3451 8654 3456 8656 3458 8659 3454 8664
      3454 8674

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-3 INCHES IN 4 HOURS 

$$

KTW
1 follow-up statement
768 
WGUS74 KHUN 180528
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
1228 AM CDT Thu Mar 18 2021

ALC071-089-095-103-TNC051-103-180538-
/O.EXP.KHUN.FF.W.0004.000000T0000Z-210318T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jackson AL-Madison AL-Marshall AL-Morgan AL-Franklin TN TN-Lincoln
TN-
1228 AM CDT Thu Mar 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1230 AM CDT EARLY THIS MORNING 
FOR EAST CENTRAL MORGAN COUNTY IN NORTH CENTRAL ALABAMA, 
NORTHWESTERN JACKSON AND NORTHERN MARSHALL COUNTIES IN NORTHEASTERN 
ALABAMA AND SOUTHWESTERN FRANKLIN TN AND SOUTHEASTERN LINCOLN 
COUNTIES IN MIDDLE TENNESSEE...

The heavy rain has ended and flash flooding has transitioned to 
areal flooding.

LAT...LON 3459 8670 3472 8660 3490 8642 3499 8634
      3510 8623 3502 8607 3484 8611 3447 8647
      3451 8654 3456 8656 3458 8659 3454 8664
      3454 8674

$$

KTW

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, 9:34 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 17, 11:10 PM CDTFlash Flood Warning Considerable damage threatHUNJackson, Marshall4 hr
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, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.