Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 54, NWS Nashville, TN

August 21, 20214 counties in Tennessee

NWS Nashville, TN issued this flash flood warning at Aug 21, 2021, 5:07 PM CDT for 4 counties in Tennessee. It was in force for 4 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
Aug 21, 2021, 5:07 PM CDT (22:07 UTC)
Expired
Aug 21, 2021, 9:00 PM CDT
In force
4 hr
Issued by
NWS Nashville, TN
Area
Storm-based polygon
Flood severity
None

Counties Dickson County, TN, Houston County, TN, Montgomery County, TN, Stewart County, TN

The radar

The Ft Campbell radar (KHPX), 51 km from the middle of the area, began a volume at 22:10 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
Aug 21, 6:00 PM CDTFLASH FLOOD5 Nnw Slayden, TNREPORT OF SWIFT WATER RESCUSES ONGOING AND MULTIPLE ROADS UNDERWATER IN SOUTHERN MONTGOMERY COUNTY.

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, 10.1 hours before the alert went out and 105 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 2021-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1243 joules per kilogram.LCLEL10008507005003002001001 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 2021-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.193958Sfc1 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
1243 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
488 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted.

522 
WGUS54 KOHX 212207
FFWOHX
TNC043-083-125-161-220115-
/O.NEW.KOHX.FF.W.0054.210821T2207Z-210822T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
507 PM CDT Sat Aug 21 2021

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Northwestern Dickson County in middle Tennessee...
  Northern Houston County in middle Tennessee...
  Southwestern Montgomery County in middle Tennessee...
  Stewart County in middle Tennessee...

* Until 815 PM CDT.

* At 507 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Dover, Erin, Tennessee Ridge, Big Rock, Vanleer, Cumberland City, 
  Slayden, Indian Mound, Palmyra, Cunningham and Land Between The 
  Lakes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3664 8806 3661 8783 3644 8725 3636 8727
      3635 8728 3632 8729 3632 8727 3621 8730
      3626 8768 3633 8791 3644 8806 3647 8805
      3649 8806 3651 8804 3654 8803

FLASH FLOOD...RADAR INDICATED

$$

Schaper
2 follow-up statements
728 
WGUS54 KOHX 212242
FFWOHX
TNC043-083-125-161-220200-
/O.EXT.KOHX.FF.W.0054.000000T0000Z-210822T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
542 PM CDT Sat Aug 21 2021

The National Weather Service in Nashville has extended the

* Flash Flood Warning for...
  Northwestern Dickson County in middle Tennessee...
  Northern Houston County in middle Tennessee...
  Southwestern Montgomery County in middle Tennessee...
  Stewart County in middle Tennessee...

* Until 900 PM CDT.

* At 542 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Dover, Erin, Tennessee Ridge, Big Rock, Vanleer, Cumberland City, 
  Slayden, Indian Mound, Palmyra, Cunningham and Land Between The 
  Lakes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3664 8806 3661 8783 3644 8725 3636 8727
      3635 8728 3632 8729 3632 8727 3621 8730
      3626 8768 3633 8791 3644 8806 3647 8805
      3649 8806 3651 8804 3654 8803

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

$$

Schaper
270 
WGUS74 KOHX 212312
FFSOHX

Flash Flood Statement
National Weather Service Nashville TN
612 PM CDT Sat Aug 21 2021

TNC043-083-212322-
/O.CAN.KOHX.FF.W.0054.000000T0000Z-210822T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dickson TN-Houston TN-
612 PM CDT Sat Aug 21 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN DICKSON AND 
NORTHERN HOUSTON COUNTIES...

A new Flash Flood Warning has been issued for the affected area, 
with numerous reports of flash flooding ongoing.

A Flash Flood Watch remains in effect until 1200 AM CDT for a 
portion of Middle Tennessee.

LAT...LON 3664 8806 3661 8783 3644 8725 3638 8759
      3637 8759 3637 8772 3635 8774 3634 8790
      3635 8794 3644 8806 3647 8805 3649 8806
      3651 8804 3654 8803

$$

TNC125-161-220200-
/O.CON.KOHX.FF.W.0054.000000T0000Z-210822T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery TN-Stewart TN-
612 PM CDT Sat Aug 21 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM CDT THIS EVENING 
FOR WEST CENTRAL MONTGOMERY AND STEWART COUNTIES...

At 612 PM CDT, Emergency management reported flash flooding ongoing 
across the warned area with numerous water rescues in progress in 
southern Montgomery County. Between 3 and 6 inches of rain have 
fallen so far today.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Emergency management reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Dover, Big Rock, Cumberland City, Indian Mound, Land Between The 
  Lakes and Palmyra.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 3664 8806 3661 8783 3644 8725 3638 8759
      3637 8759 3637 8772 3635 8774 3634 8790
      3635 8794 3644 8806 3647 8805 3649 8806
      3651 8804 3654 8803

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Shamburger

The office that day

Everything else NWS Nashville, TN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 21, 2:48 AM CDTAreal Flood AdvisoryOHXDickson, Hickman, Humphreys, Lewis2 hr
Aug 21, 3:29 AM CDTFlash Flood WarningOHXDickson, Hickman, Humphreys5 hr
Aug 21, 4:10 AM CDTAreal Flood AdvisoryOHXGiles, Lawrence, Lewis, Maury3 hr
Aug 21, 4:29 AM CDTAreal Flood AdvisoryOHXMontgomery, Stewart3 hr
Aug 21, 4:49 AM CDTFlash Flood WarningOHXDickson, Hickman, Houston, Humphreys3 hr
Aug 21, 6:24 AM CDTFlash Flood WarningOHXHouston, Humphreys, Stewart5 hr
Aug 21, 7:47 AM CDTFlash Flood Warning EmergencyCatastrophic damage threatOHXDickson, Hickman, Houston, Humphreys9 hr
Aug 21, 8:39 AM CDTRiver Flood WarningOHXHickman13 hr
Aug 21, 9:41 AM CDTAreal Flood AdvisoryOHXHickman, Lewis, Maury3 hr
Aug 21, 10:12 AM CDTFlash Flood WarningOHXHickman, Humphreys, Lewis, Maury, Perry3 hr
Aug 21, 10:17 AM CDTRiver Flood AdvisoryOHXHickman52 hr
Aug 21, 11:39 AM CDTAreal Flood AdvisoryOHXGiles, Lawrence, Marshall3 hr
Aug 21, 12:33 PM CDTRiver Flood WarningOHXHumphreys44 hr
Aug 21, 4:40 PM CDTAreal Flood AdvisoryOHXHouston, Stewart3 hr
Aug 21, 4:55 PM CDTFlash Flood WarningOHXDickson, Hickman, Houston, Humphreys6 hr
Aug 21, 5:10 PM CDTSpecial Weather StatementOHXHouston, Stewart50 min
Aug 21, 5:30 PM CDTSpecial Weather StatementOHXDickson, Houston45 min
Aug 21, 5:43 PM CDTSpecial Weather StatementOHXLawrence47 min
Aug 21, 5:57 PM CDTTornado WarningOHXDickson16 min
Aug 21, 5:58 PM CDTFlash Flood WarningOHXCheatham, Dickson, Houston, Montgomery3 hr
Aug 21, 6:17 PM CDTSpecial Weather StatementOHXDickson43 min
Aug 21, 6:29 PM CDTSpecial Weather StatementOHXHickman31 min
Aug 21, 6:53 PM CDTSpecial Weather StatementOHXWilliamson37 min

Nearby

Flash 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.