Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 65, NWS Nashville, TN

September 20, 20215 counties in Tennessee

NWS Nashville, TN issued this flash flood warning at Sep 20, 2021, 6:51 PM CDT for 5 counties in Tennessee. It was in force for 114 min. 3 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: Sep 20, 2021, 6:51 PM CDT (23:51 UTC)
Expired: Sep 20, 2021, 8:45 PM CDT
In force: 114 min
Issued by: NWS Nashville, TN
Area: Storm-based polygon
Flood severity: None

Counties Giles County, TN, Lawrence County, TN, Lewis County, TN, Maury County, TN, Wayne County, TN

The radar

The Northeast Alabama radar (KHTX), 121 km from the middle of the area, began a volume at 23:54 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

Time	Report	Where	Remark
Sep 20, 7:05 PM CDT	FLASH FLOOD	5 W Ethridge, TN	PHOTO SHOWS HUDSON ROAD FLOODED NEAR KIRK ROAD
Sep 20, 7:25 PM CDT	FLASH FLOOD	Iron City, TN	WATER COVERING HIGHWAY 242 IN IRON CITY
Sep 20, 8:20 PM CDT	FLASH FLOOD	Summertown, TN	FLOODING REPORTED AROUND SUMMERTOWN MARKET ON HIGHWAY 20

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, 11.9 hours before the alert went out and 112 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: 323 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 758 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 149 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

827 
WGUS54 KOHX 202351
FFWOHX
TNC055-099-101-119-181-210145-
/O.NEW.KOHX.FF.W.0065.210920T2351Z-210921T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
651 PM CDT Mon Sep 20 2021

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Northwestern Giles County in middle Tennessee...
  Lawrence County in middle Tennessee...
  Southeastern Lewis County in middle Tennessee...
  Southern Maury County in middle Tennessee...
  Southeastern Wayne County in middle Tennessee...

* Until 845 PM CDT.

* At 651 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2.5 inches of 
  rain have fallen. Additional rainfall amounts up 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...
  Columbia, Lawrenceburg, Mount Pleasant, Loretto, Collinwood, 
  Summertown, St. Joseph, Ethridge, Lynnville, Henryville, Leoma, 
  Westpoint, Iron City, Culleoka and Cypress Inn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3501 8782 3551 8754 3551 8746 3561 8689
      3542 8696 3542 8695 3535 8706 3500 8741

FLASH FLOOD...RADAR INDICATED

$$

Whitehead

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 19, 8:09 PM CDT	River Flood Warning	OHX	Bedford, Marshall	40 hr
Sep 20, 6:25 AM CDT	Areal Flood Advisory	OHX	Dickson, Hickman, Lewis, Maury	2 hr
Sep 20, 7:08 AM CDT	Areal Flood Advisory	OHX	Dickson, Montgomery	112 min
Sep 20, 8:29 AM CDT	Areal Flood Advisory	OHX	Cheatham, Davidson, Hickman, Lewis, Marshall, Maury and 1 more	2 hr
Sep 20, 9:53 AM CDT	Areal Flood Advisory	OHX	Bedford, Davidson, Marshall, Rutherford, Williamson	112 min
Sep 20, 10:10 AM CDT	Areal Flood Advisory	OHX	Dickson, Hickman, Lewis, Maury, Williamson	2 hr
Sep 20, 10:25 AM CDT	Flash Flood Warning	OHX	Dickson, Hickman, Lewis, Maury, Williamson	5 hr
Sep 20, 10:32 AM CDT	Areal Flood Advisory	OHX	Davidson, Robertson, Rutherford, Sumner, Williamson, Wilson	118 min
Sep 20, 10:48 AM CDT	Areal Flood Advisory	OHX	Bedford, Rutherford	4 hr
Sep 20, 11:44 AM CDT	Areal Flood Advisory	OHX	Rutherford, Wilson	3 hr
Sep 20, 12:23 PM CDT	Areal Flood Advisory	OHX	Davidson, Rutherford, Sumner, Williamson, Wilson	3 hr
Sep 20, 1:02 PM CDT	Areal Flood Advisory	OHX	Macon, Sumner, Trousdale, Wilson	3 hr
Sep 20, 3:25 PM CDT	Flash Flood Warning	OHX	Cheatham, Dickson, Hickman, Lewis, Maury, Williamson	5 hr
Sep 20, 3:56 PM CDT	Areal Flood Advisory	OHX	Giles, Marshall, Maury, Williamson	2 hr
Sep 20, 4:10 PM CDT	Flash Flood Warning	OHX	Giles, Marshall, Maury, Williamson	3 hr
Sep 20, 4:26 PM CDT	River Flood Advisory	OHX	Hickman	4 hr
Sep 20, 4:34 PM CDT	River Flood Advisory	OHX	Bedford	11 hr
Sep 20, 5:59 PM CDT	Areal Flood Advisory	OHX	Giles, Lawrence, Lewis, Maury, Wayne	3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.