Alert archive / Tennessee / Flash Flood Warnings in 2020

Flash Flood Warning 34, NWS Nashville, TN

September 13, 2020Davidson County, Rutherford County, Williamson County, Tennessee

NWS Nashville, TN issued this flash flood warning at Sep 13, 2020, 10:29 AM CDT for Davidson County, Rutherford County, Williamson County, Tennessee. It was in force for 7 hr. 2 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 13, 2020, 10:29 AM CDT (15:29 UTC)
Expired: Sep 13, 2020, 5:30 PM CDT
In force: 7 hr
Issued by: NWS Nashville, TN
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Davidson County, TN, Rutherford County, TN, Williamson County, TN

The radar

The Nashville radar (KOHX), 33 km from the middle of the area, began a volume at 15:31 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 13, 10:48 AM CDT	FLASH FLOOD	1 Ssw La Vergne, TN	SIGNIFICANT FLASH FLOODING HAS MOVED AND FLIPPED SHIPPING CONTAINERS UP TO BRIDGESTONE PKWY.
Sep 13, 10:55 AM CDT	FLASH FLOOD	1 Sse Antioch, TN	I-24 CLOSED AT BELL RD DUE TO WATER OVER THE INTERSTATE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this flash flood warning; the first came 19 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 3.5 hours before the alert went out and 19 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: 642 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 639 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

659 
WGUS54 KOHX 131529
FFWOHX
TNC037-149-187-131830-
/O.NEW.KOHX.FF.W.0034.200913T1529Z-200913T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
1029 AM CDT Sun Sep 13 2020

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Southeastern Davidson County in middle Tennessee...
  Northwestern Rutherford County in middle Tennessee...
  Northeastern Williamson County in middle Tennessee...

* Until 130 PM CDT.

* At 1029 AM CDT, emergency management reported ongoing significant 
  flash flooding. Between 3 and 5 inches of rain have fallen.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Emergency management.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Franklin, Smyrna, Brentwood, La Vergne, Nolensville, Antioch, 
  Rural Hill, Triune and Percy Priest Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 3604 8676 3614 8656 3608 8651 3591 8656
      3581 8673 3582 8687 3593 8677

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

10

2 follow-up statements

956 
WGUS54 KOHX 131812
FFWOHX
TNC037-149-187-132030-
/O.EXT.KOHX.FF.W.0034.000000T0000Z-200913T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
112 PM CDT Sun Sep 13 2020

The National Weather Service in Nashville has extended the

* Flash Flood Warning for...
  Southeastern Davidson County in middle Tennessee...
  Northwestern Rutherford County in middle Tennessee...
  Northeastern Williamson County in middle Tennessee...

* Until 330 PM CDT.

* At 112 PM CDT, emergency management reported that flash flooding 
  continues, but water is starting to recede. Between 3 and 6 inches 
  of rain have fallen.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency management.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Franklin, Smyrna, Brentwood, La Vergne, Nolensville, Antioch, 
  Rural Hill, Triune and Percy Priest Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 3604 8676 3614 8656 3608 8651 3591 8656
      3581 8673 3582 8687 3593 8677

FLASH FLOOD...OBSERVED

$$

10

414 
WGUS54 KOHX 132024
FFWOHX
TNC037-149-187-132230-
/O.EXT.KOHX.FF.W.0034.000000T0000Z-200913T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
324 PM CDT Sun Sep 13 2020

The National Weather Service in Nashville has extended the

* Flash Flood Warning for...
  Southeastern Davidson County in middle Tennessee...
  Northwestern Rutherford County in middle Tennessee...
  Northeastern Williamson County in middle Tennessee...

* Until 530 PM CDT.

* At 324 PM CDT, emergency management reported thunderstorms 
  producing heavy rain across the warned area. Between 3 and 6 
  inches of rain have fallen. Flash flooding is ongoing.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency management.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Franklin, Smyrna, Brentwood, La Vergne, Nolensville, Antioch, 
  Rural Hill, Triune and Percy Priest Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 3604 8676 3614 8656 3608 8651 3591 8656
      3581 8673 3582 8687 3593 8677

FLASH FLOOD...OBSERVED

$$

LaRosa

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Nashville, TN wrote its last area forecast discussion before this flash flood warning went out at Sep 13, 6:49 AM CDT, 3 hours 40 minutes earlier.

Area forecast discussion, Sep 13, 6:49 AM CDT, 3 hours 40 minutes before

Area Forecast Discussion
National Weather Service Nashville TN
649 AM CDT Sun Sep 13 2020

.UPDATE...
FOR 12Z AVIATION DISCUSSION.

&&

.DISCUSSION...

Tweaked hourly temperature, dewpoint, and wind speed/direction
grids. Freshened up wording in zone forecast product for flash
flood watch. Remainder of forecast continues to be on track.

&&

.AVIATION...
12Z TAF DISCUSSION.

MVFR to IFR conditions persist at BNA/MQY with SHRA/TSRA this
morning. CKV/CSV vary between VFR and MVFR CIGs. More SHRA/TSRA is
on the way for BNA/MQY in the next several hours, while CSV will
have to wait until 18z for any activity. Heavier rain will reduce
VIS/CIGs to MVFR or IFR at times.

Activity will taper off around 00z or a little sooner. Light
south winds become northerly/variable this afternoon and evening.
MVFR CIGs are possible at BNA/MQY/CSV and may need further
adjustment in later TAF cycles.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through this evening for Bedford-Clay-Davidson-
Giles-Hickman-Jackson-Lawrence-Lewis-Macon-Marshall-Maury-
Overton-Perry-Pickett-Putnam-Rutherford-Smith-Sumner-Trousdale-
Wayne-Williamson-Wilson.

&&

DISCUSSION......JB Wright
AVIATION........Schaper

Hazardous weather outlook, Sep 13, 5:18 AM CDT, 5 hours 11 minutes before

Hazardous Weather Outlook
National Weather Service Nashville TN
518 AM CDT Sun Sep 13 2020

TNZ005>011-023>034-056>066-075-077>080-093>095-141000-
Stewart-Montgomery-Robertson-Sumner-Macon-Clay-Pickett-Houston-
Humphreys-Dickson-Cheatham-Davidson-Wilson-Trousdale-Smith-Jackson-
Putnam-Overton-Fentress-Perry-Hickman-Lewis-Williamson-Maury-
Marshall-Rutherford-Cannon-De Kalb-White-Cumberland-Bedford-Coffee-
Warren-Grundy-Van Buren-Wayne-Lawrence-Giles-
518 AM CDT Sun Sep 13 2020

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

A good portion of the mid state will experienced between two
to three inches, with locally higher amounts of around five
inches, of rainfall today. Heavy rainfall could fall within
a short period of time causing flooding of streets and low
lying areas.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Currently, the greatest rainfall amounts associated the remants
of Tropical Storm Sally will be across southeastern portions of
the mid state region later this work week where two to four
inches of rainfall could be possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Please relay any
information about observed severe weather to the NWS while following
all local, state, and CDC guidelines.

JB Wright

In the hours before

Local storm report, Sep 13, 8:50 AM CDT, 1 hour 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
850 AM CDT SUN SEP 13 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0845 AM     FLASH FLOOD      NOLENSVILLE             35.95N  86.65W
09/13/2020                   WILLIAMSON         TN   LAW ENFORCEMENT

            MULTIPLE ROADS FLOODED AROUND NOLENSVILLE.

&&

EVENT NUMBER OHX2000531

MR3

Local storm report, Sep 13, 9:22 AM CDT, 1 hour 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
922 AM CDT SUN SEP 13 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 AM     FLASH FLOOD      3 SSW ANTIOCH           36.02N  86.69W
09/13/2020                   DAVIDSON           TN   EMERGENCY MNGR

            WATER RESCUE ONGOING AT CULBERTSON RD.

&&

EVENT NUMBER OHX2000532

MR3

Local storm report, Sep 13, 9:31 AM CDT, 58 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
931 AM CDT SUN SEP 13 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0929 AM     FLASH FLOOD      2 NE LA VERGNE          36.02N  86.55W
09/13/2020                   RUTHERFORD         TN   SOCIAL MEDIA

            WATER APPROACHING HOMES ON MERCURY DRIVE IN LA VERGNE

&&

EVENT NUMBER OHX2000533

JB

Local storm report, Sep 13, 10:16 AM CDT, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
1016 AM CDT SUN SEP 13 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 AM     FLASH FLOOD      5 NE GALLATIN           36.43N  86.39W
09/13/2020                   SUMNER             TN   TRAINED SPOTTER

            DESHA CREEK IS OVER WRIGHTS LN AND THE ROAD IS
            IMPASSABLE.

&&

EVENT NUMBER OHX2000534

MR3

Local storm report, Sep 13, 10:21 AM CDT, 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
1021 AM CDT SUN SEP 13 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1012 AM     FLASH FLOOD      SPRING HILL             35.74N  86.92W
09/13/2020                   MAURY              TN   TRAINED SPOTTER

            ROAD FLOODED AND CLOSED AT MILES JOHNSON PKWY AND
            DUPLEX RD

&&

EVENT NUMBER OHX2000535

MR3

Local storm report, Sep 13, 10:24 AM CDT, 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
1024 AM CDT SUN SEP 13 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1018 AM     FLASH FLOOD      MOUNT PLEASANT          35.55N  87.19W
09/13/2020                   MAURY              TN   EMERGENCY MNGR

            SEVERAL ROADS BECOMING FLOODED AND ARE BEING CLOSED.

&&

EVENT NUMBER OHX2000536

MR3

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 13, 4:07 AM CDT	Flash Flood Watch	OHX	Bedford, Clay, Davidson, Giles, Hickman, Jackson and 16 more	13 hr
Sep 13, 6:28 AM CDT	Areal Flood Advisory	OHX	Hickman, Lewis, Perry, Wayne	3 hr
Sep 13, 7:00 AM CDT	Areal Flood Advisory	OHX	Davidson, Rutherford, Williamson, Wilson	3 hr
Sep 13, 7:32 AM CDT	Flash Flood Warning	OHX	Davidson, Rutherford, Williamson, Wilson	6 hr
Sep 13, 7:37 AM CDT	Areal Flood Advisory	OHX	Hickman, Lewis, Maury, Williamson	113 min
Sep 13, 8:26 AM CDT	River Flood Warning	OHX	Davidson	10 hr
Sep 13, 9:16 AM CDT	Areal Flood Advisory	OHX	Macon, Sumner, Trousdale, Wilson	119 min
Sep 13, 9:51 AM CDT	Flash Flood Warning	OHX	Giles, Lawrence, Lewis, Maury	8 hr
Sep 13, 9:55 AM CDT	Flash Flood Warning	OHX	Sumner, Trousdale	3 hr
Sep 13, 10:42 AM CDT	River Flood Warning	OHX	Davidson	13 hr
Sep 13, 11:19 AM CDT	River Flood Warning	OHX	Davidson	14 hr
Sep 13, 11:50 AM CDT	Areal Flood Advisory	OHX	Lawrence, Lewis, Wayne	4 hr
Sep 13, 11:54 AM CDT	Flash Flood Warning	OHX	Giles, Marshall, Maury	3 hr
Sep 13, 3:09 PM CDT	Areal Flood Advisory	OHX	Giles, Lawrence, Marshall, Wayne	4 hr

Nearby

Flash Flood Warnings in Tennessee, 2020 Every flash flood warning in 2020

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.