Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 52, NWS Nashville, TN

August 21, 20215 counties in Tennessee

NWS Nashville, TN issued this flash flood warning at Aug 21, 2021, 10:12 AM CDT for 5 counties in Tennessee. It was in force for 3 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, 10:12 AM CDT (15:12 UTC)
Expired
Aug 21, 2021, 1:15 PM CDT
In force
3 hr
Issued by
NWS Nashville, TN
Area
Storm-based polygon
Flood severity
None

Counties Hickman County, TN, Humphreys County, TN, Lewis County, TN, Maury County, TN, Perry County, TN

The radar

The Ft Campbell radar (KHPX), 105 km from the middle of the area, began a volume at 15:16 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, 10:52 AM CDTFLASH FLOOD1 Ssw Waverly, TN911 CALL CENTER IS DOWN IN HUMPHREYS COUNTY DUE TO BEING FLOODED.

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, 3.2 hours before the alert went out and 109 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.

957 
WGUS54 KOHX 211512
FFWOHX
TNC081-085-101-119-135-211815-
/O.NEW.KOHX.FF.W.0052.210821T1512Z-210821T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
1012 AM CDT Sat Aug 21 2021

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Hickman County in middle Tennessee...
  Western Humphreys County in middle Tennessee...
  Northern Lewis County in middle Tennessee...
  Western Maury County in middle Tennessee...
  Northeastern Perry County in middle Tennessee...

* Until 115 PM CDT.

* At 1012 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 5 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...
  Columbia, Waverly, Hohenwald, Centerville, Camden, Mount Pleasant, 
  New Johnsonville, Hurricane Mills, Lobelville, Kimmins, 
  Pleasantville, Bucksnort, Gordonsburg, Hampshire, Williamsport, 
  I-40 Near The Tennessee River and Santa Fe.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3585 8795 3588 8794 3594 8793 3595 8801
      3598 8802 3600 8800 3603 8800 3612 8792
      3614 8792 3617 8787 3587 8760 3580 8712
      3551 8711 3549 8742 3556 8765

FLASH FLOOD...RADAR INDICATED

$$

10

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, 10:17 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, 5:07 PM CDTFlash Flood WarningOHXDickson, Houston, Montgomery, Stewart4 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.