Special Weather Statement, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
253 PM CDT Wed Aug 18 2021

.DISCUSSION...

Radar is showing some good bands of thunderstorms where CAPE is
3000+ J/KG. One of those bands happens to be sitting over the
office and radar is estimating at least 2 inches of rain has
fallen. Any place that gets these training storms will have the
potential for heavy rainfall and localized flash flooding.

A broad front will move through the Ohio Valley today and
tomorrow. This will give southerly winds for the area. PW value
from the 18Z sounding was almost 2" and PW/s from soundings to
the south and southwest have been 2" and higher so the potential
for periods of heavy rainfall will be possible. Storm total
precipitation values for today through Sunday night range from 3+
inches Wayne county to 1" Picket and Fentress Counties. Will keep
watching this just in case more than localized flash flooding
becomes a potential.

A ridge builds in from the lower Mississippi Valley for the
weekend. Still have chance to likely rain on Saturday and down to
slight chance/chance starting on Sunday. With the influence of
this ridge mainly a diurnal pop situation with Monday and Tuesday
being the driest days.

Temperatures will be on the cooler side due to clouds and rain for
the next couple of day...but still very much summertime.

&&

.AVIATION...
18Z TAF DISCUSSION.

Scattered showers and t'storms will effect much of the area
through the afternoon and again overnight into tomorrow morning.
Expect periods with decreased visibilities if a storm moves
directly over a terminal. Winds will remain light and calm through
the TAF period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      72  85  72  88  72 /  70  80  60  80  40
Clarksville    71  84  70  86  71 /  70  70  50  70  40
Crossville     68  79  67  81  66 /  60  80  60  70  30
Columbia       71  84  71  86  71 /  70  80  60  80  40
Lawrenceburg   71  83  70  86  70 /  70  80  60  80  40
Waverly        70  84  70  87  70 /  60  80  60  80  40

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

DISCUSSION......12
AVIATION........Adcock

Hazardous Weather Outlook
National Weather Service Nashville TN
716 AM CDT Wed Aug 18 2021

TNZ005>011-023>034-056>066-075-077>080-093>095-191030-
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-
716 AM CDT Wed Aug 18 2021

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

There is a marginal risk of severe storms today, particularly during
the afternoon. The primary risk is strong to severe wind gusts.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

There is a high probability of showers and thunderstorms lasting
through Saturday night. Significant rainfall accumulations are
possible in areas that are affected by multiple rounds of storms, and
some flooding may occur, especially in areas near the Alabama state
line.

.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.

12

Special Weather Statement
National Weather Service Nashville TN
1206 PM CDT Wed Aug 18 2021

TNZ027-028-181745-
Davidson TN-Wilson TN-
1206 PM CDT Wed Aug 18 2021

...A strong thunderstorm will impact portions of east central
Davidson and central Wilson Counties through 1245 PM CDT...

At 1206 PM CDT, Doppler radar was tracking a strong thunderstorm over
Mount Juliet, or 9 miles west of Lebanon, moving east at 15 mph.

HAZARD...Winds in excess of 30 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Lebanon, Mount Juliet, Belinda City, Rural Hill, Green Hill and
Gladeville.

Wilson County Fair Matrix will also be impacted.

This includes the following highways...
 Interstate 40 between mile markers 222 and 244.
 Interstate 840 between mile markers 67 and 76.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3630 8617 3603 8619 3608 8649 3610 8652
      3609 8652 3610 8659 3627 8657 3628 8656
      3628 8652 3629 8643
TIME...MOT...LOC 1706Z 273DEG 13KT 3619 8650

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH

FB

Special Weather Statement
National Weather Service Nashville TN
152 PM CDT Wed Aug 18 2021

TNZ008-027-028-181930-
Davidson TN-Wilson TN-Sumner TN-
152 PM CDT Wed Aug 18 2021

...A strong thunderstorm will impact portions of east central
Davidson, southwestern Sumner and northwestern Wilson Counties
through 230 PM CDT...

At 152 PM CDT, Doppler radar was tracking a strong thunderstorm over
Hermitage, or 10 miles east of Nashville, moving northeast at 20 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Gallatin, Lebanon, Hendersonville, Mount Juliet, Lakewood, Hermitage,
Old Hickory, Rural Hill, Belinda City, Green Hill and Percy Priest
Lake.

This includes Interstate 40 between mile markers 217 and 234.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3607 8658 3619 8673 3644 8656 3623 8626
TIME...MOT...LOC 1852Z 221DEG 19KT 3619 8659

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

13

Special Weather Statement
National Weather Service Nashville TN
259 PM CDT Wed Aug 18 2021

TNZ008-182030-
Sumner TN-
259 PM CDT Wed Aug 18 2021

...A strong thunderstorm will impact portions of northeastern Sumner
County through 330 PM CDT...

At 258 PM CDT, Doppler radar was tracking a strong thunderstorm near
Portland, or 9 miles north of Gallatin, moving north at 20 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Portland, Mitchellville and Oak Grove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3665 8635 3664 8625 3642 8637 3647 8658
      3664 8655 3664 8654 3665 8651
TIME...MOT...LOC 1958Z 194DEG 18KT 3652 8646

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

13

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
303 PM CDT WED AUG 18 2021

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

0301 PM     FLASH FLOOD      2 SW NASHVILLE          36.15N  86.81W
08/18/2021                   DAVIDSON           TN   SOCIAL MEDIA

            FLOODING ON STREETS ACROSS VANDY CAMPUS INCLUDING 24TH
            AVENUE SOUTH AND OUTSIDE OF THE 25TH SOUTH AVENUE
            GARAGE.

&&

EVENT NUMBER OHX2100597

CMA

Special Weather Statement
National Weather Service Nashville TN
338 PM CDT Wed Aug 18 2021

TNZ057-058-093-094-182130-
Hickman TN-Lawrence TN-Wayne TN-Lewis TN-
338 PM CDT Wed Aug 18 2021

...Strong thunderstorms will impact portions of Lewis, northeastern
Wayne, northwestern Lawrence and south central Hickman Counties
through 430 PM CDT...

At 338 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Hohenwald to near Waynesboro. Movement was
east at 15 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Hohenwald, Waynesboro, Collinwood, Gordonsburg and Kimmins.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3518 8779 3555 8767 3557 8765 3560 8766
      3566 8764 3580 8733 3518 8745
TIME...MOT...LOC 2038Z 255DEG 14KT 3561 8759 3527 8770

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

13

Special Weather Statement
National Weather Service Nashville TN
340 PM CDT Wed Aug 18 2021

TNZ026-027-182115-
Davidson TN-Cheatham TN-
340 PM CDT Wed Aug 18 2021

...Strong thunderstorms will impact portions of northwestern Davidson
and east central Cheatham Counties through 415 PM CDT...

At 340 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Ashland City to near Joelton. Movement was
north at 15 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Ashland City, Joelton, Whites Creek and Beaman Park.

This includes Interstate 24 between mile markers 31 and 44.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3619 8680 3617 8714 3635 8707 3636 8683
      3635 8682 3636 8680 3636 8673
TIME...MOT...LOC 2040Z 193DEG 14KT 3622 8707 3625 8684

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

13