Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 42, NWS Nashville, TN

July 25, 2021Montgomery County, Tennessee

NWS Nashville, TN issued this flash flood warning at Jul 25, 2021, 5:19 PM CDT for Montgomery County, Tennessee. It was in force for 116 min. 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
Jul 25, 2021, 5:19 PM CDT (22:19 UTC)
Expired
Jul 25, 2021, 7:15 PM CDT
In force
116 min
Issued by
NWS Nashville, TN
Area
Storm-based polygon
Flood severity
None

County Montgomery County, TN

The radar

The Ft Campbell radar (KHPX), 16 km from the middle of the area, began a volume at 22:21 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
Jul 25, 5:45 PM CDTFLASH FLOOD5 Nnw Red River Estates, TNMULTIPLE TWITTER IMAGES OF FLASH FLOODING EAST OF CLARKSVILLE

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, 10.3 hours before the alert went out and 76 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 2021-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 961 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 12:00Z on 2021-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.1939Sfc1 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
961 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1017 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

655 
WGUS54 KOHX 252219
FFWOHX
TNC125-260015-
/O.NEW.KOHX.FF.W.0042.210725T2219Z-210726T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
519 PM CDT Sun Jul 25 2021

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Northeastern Montgomery County in middle Tennessee...

* Until 715 PM CDT.

* At 519 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. 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...
  Clarksville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3663 8712 3663 8713 3662 8713 3658 8717
      3654 8726 3651 8737 3659 8736 3664 8730
      3664 8721 3664 8714 3664 8711

FLASH FLOOD...RADAR INDICATED

$$

Whitehead

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 12:41 PM CDTHeat AdvisoryOHXDickson, Hickman, Houston, Humphreys, Lawrence, Lewis and 4 more6 hr
Jul 25, 3:59 PM CDTSpecial Weather StatementOHXRobertson31 min
Jul 25, 4:56 PM CDTAreal Flood AdvisoryOHXDavidson2 hr
Jul 25, 5:00 PM CDTAreal Flood AdvisoryOHXMontgomery2 hr
Jul 25, 5:15 PM CDTFlash Flood WarningOHXDavidson2 hr

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.