Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 37, NWS Nashville, TN

July 18, 2021Davidson County, Tennessee

NWS Nashville, TN issued this flash flood warning at Jul 18, 2021, 4:31 PM CDT for Davidson County, Tennessee. It was in force for 89 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 18, 2021, 4:31 PM CDT (21:31 UTC)
Expired: Jul 18, 2021, 6:00 PM CDT
In force: 89 min
Issued by: NWS Nashville, TN
Area: Storm-based polygon
Flood severity: None

County Davidson County, TN

The radar

The Nashville radar (KOHX), 23 km from the middle of the area, began a volume at 21:34 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.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 9.5 hours before the alert went out and 14 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 949 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 588 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

018 
WGUS54 KOHX 182131
FFWOHX
TNC037-182300-
/O.NEW.KOHX.FF.W.0037.210718T2131Z-210718T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
431 PM CDT Sun Jul 18 2021

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Central Davidson County in middle Tennessee...

* Until 600 PM CDT.

* At 431 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across 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...
  Downtown Nashville including West End and Metro Center, East 
  Nashville including Inglewood, Browns Creek including Oak Hill, 
  Berry Hill, and South Nashville, and areas near Grassmere, 
  Woodbine, and Antioch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3602 8676 3617 8685 3620 8682 3623 8671
      3612 8666 3602 8675

FLASH FLOOD...RADAR INDICATED

$$

LaRosa

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 7:16 PM CDT	Areal Flood Advisory	OHX	Wilson	119 min
Jul 17, 7:38 PM CDT	Areal Flood Advisory	OHX	Lawrence	112 min
Jul 17, 8:00 PM CDT	Flash Flood Warning	OHX	Lawrence	3 hr
Jul 17, 8:40 PM CDT	Areal Flood Advisory	OHX	Lawrence, Wayne	3 hr
Jul 17, 9:03 PM CDT	Flash Flood Warning	OHX	Lawrence	117 min
Jul 17, 9:07 PM CDT	Areal Flood Advisory	OHX	Montgomery, Robertson, Sumner	113 min
Jul 17, 10:09 PM CDT	Areal Flood Advisory	OHX	Davidson, Sumner, Trousdale, Wilson	2 hr
Jul 17, 11:19 PM CDT	Areal Flood Advisory	OHX	Smith, Trousdale	116 min
Jul 18, 3:54 PM CDT	Special Weather Statement	OHX	Davidson	51 min
Jul 18, 4:03 PM CDT	Areal Flood Advisory	OHX	Davidson, Williamson	117 min
Jul 18, 4:27 PM CDT	Areal Flood Advisory	OHX	Davidson, Rutherford, Williamson, Wilson	2 hr
Jul 18, 4:42 PM CDT	Areal Flood Advisory	OHX	Cumberland	3 hr
Jul 18, 6:08 PM CDT	Areal Flood Advisory	OHX	Giles	112 min
Jul 18, 6:11 PM CDT	Areal Flood Advisory	OHX	DeKalb	2 hr
Jul 18, 6:14 PM CDT	Areal Flood Advisory	OHX	Sumner, Wilson	2 hr
Jul 18, 6:17 PM CDT	Areal Flood Advisory	OHX	Perry	118 min

Nearby

Flash Flood Warnings in Tennessee, 2021 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.