Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 62, NWS Nashville, TN

September 20, 20215 counties in Tennessee

NWS Nashville, TN issued this flash flood warning at Sep 20, 2021, 10:25 AM CDT for 5 counties in Tennessee. It was in force for 5 hr. 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, 10:25 AM CDT (15:25 UTC)
Expired: Sep 20, 2021, 3:30 PM CDT
In force: 5 hr
Issued by: NWS Nashville, TN
Area: Storm-based polygon
Flood severity: None

Counties Dickson County, TN, Hickman County, TN, Lewis County, TN, Maury County, TN, Williamson County, TN

The radar

The Nashville radar (KOHX), 65 km from the middle of the area, began a volume at 15:29 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, 10:28 AM CDT	FLASH FLOOD	2 Wsw Hampshire, TN	MINOR FLOODING IN THE HAMPSHIRE AREA.
Sep 20, 11:16 AM CDT	FLASH FLOOD	Bon Aqua, TN	WATER OVER OLD HWY 46 AND MISSIONARY RIDGE ROAD.
Sep 20, 3:23 PM CDT	FLASH FLOOD	4 Nw Williamsport, TN	LEATHERWOOD ROAD NEAR HWY 50 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, 3.4 hours before the alert went out and 56 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.

326 
WGUS54 KOHX 201525
FFWOHX
TNC043-081-101-119-187-201830-
/O.NEW.KOHX.FF.W.0062.210920T1525Z-210920T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
1025 AM CDT Mon Sep 20 2021

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Southeastern Dickson County in middle Tennessee...
  Eastern Hickman County in middle Tennessee...
  Northeastern Lewis County in middle Tennessee...
  Western Maury County in middle Tennessee...
  Northwestern Williamson County in middle Tennessee...

* Until 130 PM CDT.

* At 1025 AM CDT, emergency management reported flooding from 
  prolonged heavy rainfall across the warned area. Between 1.5 and 
  3.5 inches of rain have fallen with additional heavy rainfall 
  possible. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Emergency management reported.

  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...
  Dickson, Centerville, Mount Pleasant, Fairview, Primm Springs, 
  Williamsport, Lyles, Santa Fe, Bon Aqua, Hampshire, Gordonsburg 
  and Natchez Trace At Highway 96.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3605 8743 3601 8705 3600 8704 3599 8704
      3599 8703 3600 8702 3600 8700 3600 8697
      3545 8727 3555 8752

FLASH FLOOD...OBSERVED

$$

Adcock

1 follow-up statement

167 
WGUS54 KOHX 201813
FFWOHX
TNC043-081-101-119-187-202030-
/O.EXT.KOHX.FF.W.0062.000000T0000Z-210920T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Nashville has extended the

* Flash Flood Warning for...
  Southeastern Dickson County in middle Tennessee...
  Eastern Hickman County in middle Tennessee...
  Northeastern Lewis County in middle Tennessee...
  Western Maury County in middle Tennessee...
  Northwestern Williamson County in middle Tennessee...

* Until 330 PM CDT.

* At 113 PM CDT, emergency management reported heavy rain across the 
  warned area. Between 1.5 and 3.5 inches of rain have fallen and 
  additional showers are moving across the area. Flash flooding is 
  ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Emergency management reported.

  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...
  Dickson, Centerville, Mount Pleasant, Fairview, Primm Springs, 
  Williamsport, Lyles, Santa Fe, Bon Aqua, Hampshire, Gordonsburg 
  and Natchez Trace At Highway 96.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3605 8743 3601 8705 3600 8704 3599 8704
      3599 8703 3600 8702 3600 8700 3600 8697
      3545 8727 3555 8752

FLASH FLOOD...OBSERVED

$$

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, 10:32 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
Sep 20, 6:51 PM CDT	Flash Flood Warning	OHX	Giles, Lawrence, Lewis, Maury, Wayne	114 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.