Alert archive / Tennessee / Flash Flood Warnings in 2026

Flash Flood Warning 70, NWS Nashville, TN

August 20, 20266 counties in Tennessee

NWS Nashville, TN issued this flash flood warning at Aug 20, 2026, 4:15 AM CDT for 6 counties in Tennessee. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 20, 2026, 4:15 AM CDT (09:15 UTC)
Expired
Aug 20, 2026, 8:15 AM CDT
In force
4 hr
Issued by
NWS Nashville, TN
Area
Storm-based polygon
Flood severity
None

Counties Hickman County, TN, Humphreys County, TN, Lewis County, TN, Maury County, TN, Perry County, TN, Williamson County, TN

The radar

The Ft Campbell radar (KHPX), 108 km from the middle of the area, began a volume at 09:15 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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 00:00Z, 9.3 hours before the alert went out and 109 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 00:00Z on 2026-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 310 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 00:00Z on 2026-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 square meters per square second.193958Sfc1 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
310 J/kg
Mixed-layer CIN
-212 J/kg
Mixed-layer LCL
1337 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
209 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

764 
WGUS54 KOHX 200915
FFWOHX
TNC081-085-101-119-135-187-201215-
/O.NEW.KOHX.FF.W.0070.260820T0915Z-260820T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
415 AM CDT Thu Aug 20 2026

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Hickman County in Middle Tennessee...
  Southern Humphreys County in Middle Tennessee...
  Lewis County in Middle Tennessee...
  Western Maury County in Middle Tennessee...
  Perry County in Middle Tennessee...
  West Central Williamson County in Middle Tennessee...

* Until 715 AM CDT.

* At 415 AM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 2 inches of rain
  have fallen. The expected rainfall rate is 2 to 3 inches in 1 hour.
  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 indicated.

  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, Hohenwald, Centerville, Linden, Mount Pleasant, New
  Johnsonville, Hurricane Mills, Lobelville, Nunnelly, Kimmins,
  Pinewood, Pleasantville, Bucksnort, Gordonsburg, Lyles, Hampshire,
  Bon Aqua, Primm Springs and Williamsport.

This includes the following highways...
Interstate 40 between mile markers 136 and 162. Interstate 840
between mile markers 6 and 20.

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 3607 8797 3606 8769 3604 8755 3602 8755
      3600 8754 3598 8749 3594 8706 3557 8696
      3550 8718 3550 8798 3553 8798 3561 8803
      3568 8802 3572 8803 3577 8798 3583 8797
      3587 8794 3593 8793 3595 8801 3603 8800

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...2-3 INCHES IN 1 HOUR

$$

Dirkes
3 follow-up statements
212 
WGUS74 KOHX 201040
FFSOHX

Flash Flood Statement
National Weather Service Nashville TN
540 AM CDT Thu Aug 20 2026

TNC101-119-187-201050-
/O.CAN.KOHX.FF.W.0070.000000T0000Z-260820T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lewis TN-Maury TN-Williamson TN-
540 AM CDT Thu Aug 20 2026

...FLASH FLOOD WARNING IS CANCELLED FOR LEWIS, WESTERN MAURY AND WEST
CENTRAL WILLIAMSON COUNTIES...

Rainfall rates have come down and flash flooding is no longer
expected to pose a threat.

&&

LAT...LON 3607 8797 3606 8769 3604 8755 3600 8754
      3598 8749 3595 8720 3594 8720 3572 8723
      3572 8725 3565 8776 3569 8802 3572 8803
      3577 8798 3583 8797 3587 8794 3591 8793
      3594 8793 3595 8801 3603 8800

$$

TNC081-085-135-201215-
/O.CON.KOHX.FF.W.0070.000000T0000Z-260820T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hickman TN-Humphreys TN-Perry TN-
540 AM CDT Thu Aug 20 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 AM CDT THIS
MORNING FOR HICKMAN, SOUTHERN HUMPHREYS AND NORTHERN PERRY
COUNTIES...

At 540 AM CDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1 and 2 inches of rain have
fallen. The expected rainfall rate is 2 to 3 inches in 1 hour.
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 indicated.

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...
  Centerville, New Johnsonville, Hurricane Mills, Lobelville,
  Bucksnort, Pinewood, Nunnelly, Pleasantville, Lyles, Bon Aqua and
  Primm Springs.

This includes the following highways...
Interstate 40 between mile markers 136 and 162. Interstate 840 near
mile marker 6.

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 3607 8797 3606 8769 3604 8755 3600 8754
      3598 8749 3595 8720 3594 8720 3572 8723
      3572 8725 3565 8776 3569 8802 3572 8803
      3577 8798 3583 8797 3587 8794 3591 8793
      3594 8793 3595 8801 3603 8800

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...2-3 INCHES IN 1 HOUR

$$

Dirkes
923 
WGUS54 KOHX 201154
FFWOHX
TNC081-085-135-201315-
/O.EXT.KOHX.FF.W.0070.000000T0000Z-260820T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
654 AM CDT Thu Aug 20 2026

The National Weather Service in Nashville has extended the

* Flash Flood Warning for...
  Hickman County in Middle Tennessee...
  Southern Humphreys County in Middle Tennessee...
  Northern Perry County in Middle Tennessee...

* Until 815 AM CDT.

* At 654 AM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 2.5 and 3.5 inches of
  rain have fallen. The expected rainfall rate is 1 inch in 1 hour.
  Additional rainfall amounts up to 0.5 inches are possible in the
  warned area. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  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...
  Centerville, Lobelville, Bucksnort, Pinewood, Nunnelly, Lyles, Bon
  Aqua and Primm Springs.

This includes Interstate 40 between mile markers 136 and 162.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3595 8801 3598 8749 3595 8720 3594 8721
      3594 8720 3593 8720 3574 8725 3574 8732
      3569 8778 3572 8803 3577 8798 3583 8797
      3586 8794 3587 8794 3591 8793 3594 8793

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1 INCH IN 1 HOUR

$$

Dirkes
799 
WGUS74 KOHX 201306
FFSOHX

Flash Flood Statement
National Weather Service Nashville TN
806 AM CDT Thu Aug 20 2026

TNC081-085-135-201316-
/O.EXP.KOHX.FF.W.0070.000000T0000Z-260820T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hickman TN-Humphreys TN-Perry TN-
806 AM CDT Thu Aug 20 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 815 AM CDT THIS MORNING FOR
HICKMAN, SOUTHERN HUMPHREYS AND NORTHERN PERRY COUNTIES...

Flood waters have receded. The heavy rain has ended. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.

&&

LAT...LON 3595 8801 3598 8749 3595 8720 3594 8721
      3594 8720 3593 8720 3574 8725 3574 8732
      3569 8778 3572 8803 3577 8798 3583 8797
      3586 8794 3587 8794 3591 8793 3594 8793

$$

Dirkes

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 Aug 20, 12:29 AM CDT, 3 hours 46 minutes earlier. Its key messages:

  • Updated at 1229 AM CDT Thu Aug 20 2026
  • Slight risk (level 2 out of 5) for severe storms late tonight into early Thursday morning along and north of I-40. Damaging winds and heavy rain are the main concerns.
  • Scattered thunderstorms develop again in the afternoon and evening with a low severe weather threat for areas south of I-40.
  • Near normal temperatures are expected this weekend.
Area forecast discussion, Aug 20, 12:29 AM CDT, 3 hours 46 minutes before
Area Forecast Discussion
National Weather Service Nashville TN
1229 AM CDT Thu Aug 20 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1229 AM CDT Thu Aug 20 2026

- Slight risk (level 2 out of 5) for severe storms late tonight
  into early Thursday morning along and north of I-40. Damaging
  winds and heavy rain are the main concerns.

- Scattered thunderstorms develop again in the afternoon and
  evening with a low severe weather threat for areas south of
  I-40.

- Near normal temperatures are expected this weekend.

&&

.SHORT TERM...
(Tonight through Friday Night)
Issued at 1045 PM CDT Wed Aug 19 2026

Short range models have been a complete mess handling upstream
storms over MO and this has complicated our storm forecast for
tonight. Latest trends bring storms in later than our previous
forecast, perhaps as late as 2 or 3 AM CDT in our northwest. How
far south storms develop is also a bit uncertain, but even if the
main MCS tracks up in KY, it should still push some outflow storms
down into the Mid State. Our far southern counties may not see
any rain through the night.

A severe risk continues with the storms, mainly damaging wind gusts.
A brief tornado cannot be fully ruled out, but storms should be
outflow dominant with relatively stable boundary conditions here
compared to upstream areas. Local heavy rain will be a concern,
mainly in the northwest.

Pockets of showers and storms will linger into the morning as a
diffuse frontal zone approaches the area. Much of midday will be
rain-free. Then, after the atmosphere recovers, additional
scattered storms will form along the weak frontal zone as another
impulse crosses the area. This time the greatest severe storm and
heavy rain potential will be located across our southern and
Plateau counties. Local damaging wind gusts will be the concern
in the afternoon as capes climb above 2000 with dcape values over
1k.

Some additional shortwave energy will cross the area Thursday and
Friday with a low chance for more showers and storms, mainly south
and Plateau.

&&

.LONG TERM...
(Saturday through next Thursday)
Issued at 1045 PM CDT Wed Aug 19 2026

Slightly less humid air will move in with temperatures staying
around normal through the weekend and into early next week. Rain
chances look very low for the weekend. The upper high will push
eastward early next week which means temperatures and humidity
will start to creep up toward mid next week.

&&

.AVIATION...
(06Z TAFS)
Issued at 1229 AM CDT Thu Aug 20 2026

Conditions will deteriorate into this morning, with all sites
seeing -TSRA through this morning. Afterwards, winds will begin to
turn northerly, with ceilings rising. FG will become an issue
after 00z on the 21st, slowly settling in as winds go calm.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      91  69  90  65 /  40  30  10   0
Clarksville    89  70  89  66 /  50  10   0   0
Crossville     86  66  84  63 /  50  30  30   0
Columbia       93  70  91  67 /  40  30   0   0
Cookeville     86  68  85  65 /  60  30  20   0
Jamestown      85  67  84  64 /  60  40  30   0
Lawrenceburg   92  69  89  66 /  40  30  10   0
Murfreesboro   93  70  91  67 /  40  40  10   0
Waverly        90  70  89  67 /  30  10   0   0

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&

SHORT TERM...13
LONG TERM....13
AVIATION.....Holley

In the hours before

Special weather statement, Aug 20, 2:53 AM CDT, 1 hour 22 minutes before
Special Weather Statement
National Weather Service Nashville TN
253 AM CDT Thu Aug 20 2026

TNZ007-008-200830-
Robertson TN-Sumner TN-
253 AM CDT Thu Aug 20 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN SUMNER AND
NORTHEASTERN ROBERTSON COUNTIES THROUGH 330 AM CDT...

At 253 AM CDT, Doppler radar was tracking a strong thunderstorm near
Cross Plains, or 12 miles northeast of Springfield, moving southeast
at 35 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Gallatin, White House, Cross Plains, Portland, Orlinda,
Mitchellville, Cottontown, and Black Jack.

This includes Interstate 65 between mile markers 109 and 121.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 600 AM CDT for
Middle Tennessee.

&&

LAT...LON 3665 8638 3638 8650 3654 8681 3665 8677
      3665 8659 3663 8656 3664 8655 3664 8654
      3665 8651
TIME...MOT...LOC 0753Z 295DEG 29KT 3659 8669

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Holley
Special weather statement, Aug 20, 3:17 AM CDT, 58 minutes before
Special Weather Statement
National Weather Service Nashville TN
317 AM CDT Thu Aug 20 2026

TNZ026-027-059-200845-
Williamson TN-Davidson TN-Cheatham TN-
317 AM CDT Thu Aug 20 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN DAVIDSON...
WILLIAMSON AND SOUTH CENTRAL CHEATHAM COUNTIES THROUGH 345 AM CDT...

At 317 AM CDT, Doppler radar was tracking a strong thunderstorm near
Fairview, or 12 miles west of Franklin, moving east at 45 mph.

HAZARD...Wind gusts up to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Franklin, Brentwood, Spring Hill, Forest Hills, Oak Hill, Belle
Meade, Kingston Springs, Thompson's Station, Pegram, Bellevue,
Fairview, Natchez Trace At Highway 96, and Leipers Fork.

This includes the following highways...
 Interstate 40 between mile markers 188 and 198.
 Interstate 65 between mile markers 55 and 78.
 Interstate 24 near mile marker 57.
 Interstate 840 between mile markers 10 and 17, and between mile
markers 22 and 34.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 600 AM CDT for
Middle Tennessee.

&&

LAT...LON 3588 8718 3611 8709 3608 8668 3574 8680
TIME...MOT...LOC 0817Z 282DEG 41KT 3598 8705

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

Holley

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 12:43 AM CDTSevere Thunderstorm Warning Considerable damage threatOHXHouston, Stewart47 min
Aug 20, 1:23 AM CDTSevere Thunderstorm Warning Considerable damage threatOHXHouston, Montgomery, Stewart67 min
Aug 20, 2:00 AM CDTSevere Thunderstorm WarningOHXCheatham, Dickson, Houston, Montgomery, Robertson60 min
Aug 20, 2:53 AM CDTSpecial Weather StatementOHXSumner37 min
Aug 20, 3:17 AM CDTSpecial Weather StatementOHXWilliamson28 min
Aug 20, 6:02 AM CDTSpecial Weather StatementOHXHickman, Maury, Perry43 min
Aug 20, 6:11 AM CDTSpecial Weather StatementOHXMontgomery34 min
Aug 20, 6:52 AM CDTFlash Flood WarningOHXMontgomery3 hr
Aug 20, 8:30 AM CDTSpecial Weather StatementOHXRutherford, Williamson45 min

Nearby

Flash Flood Warnings in Tennessee, 2026Every flash flood warning in 2026

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.