Special Weather Statement, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
222 PM CDT Thu Aug 12 2021

.DISCUSSION...

Hot temps again are the story today, with dewpoints a few degrees
higher than yesterday, but thats helping keep temps a few degrees
lower than yesterday as well. Still seeing heat index values up to
around 107 in the west, and the heat advisory will remain in
effect until 8 pm. Some isolated thunderstorms have developed in
the southwest and tried to pop up elsewhere with diurnal help. As
we get into the day Friday, the Midwest trough will move eastward
and bring a cold front down near the region. As we stay in the
warm sector, showers and thunderstorms will develop over the mid
state around mid day, but also to our north. Instability will be
high thanks to the hot temps and moisture sticking around, however
with the absence of any strong shortwave trough activity, deep
layer shear will be weak. Still, with enough instability in the
area Friday, some strong to severe storms will be possible,
especially in the afternoon and evening with the main threat being
damaging wind gusts. CAMs do have isolated storms developing in
the early afternoon, and a line of storms moving through as early
as the mid afternoon, with another push of convection in the
evening moving in from the north. Any one of the rounds of showers
and storms will have the potential to be strong to severe and
produce damaging wind gusts, and will definitely be monitoring for
any trends in CAMs later today and tonight.

On Saturday the trough will continue moving east towards New
England, and the front will be further south and east over the mid
state. Kept in mention of precip overnight Friday night into
Saturday morning as isolated to scattered showers and storms will
be possible with the front nearby. Better chances will be in the
south and east Saturday afternoon with diurnal help. Sunday will
be about the same, with best chances in the afternoon south and
east. As for the remnants of the tropical storm, models decided to
change up solutions a bit once the low makes landfall on the
Panhandle late Sunday/early Monday. The ECMWF has it linger for
6-12 hours over the Panhandle then move off to the northeast,
clipping our far east with some rain Tuesday. The GFS keeps the
low along the Gulf Coast through Thursday before high pressure
takes over. With the new solutions and uncertainty, mainly kept in
the summertime diurnal trend with pops next week with best chances
for rain during the afternoon/evening. Some showers may linger
into the overnight hours especially if the ECMWF is correct
Monday through Wednesday with the tropical low. Did not have
confidence to increase pops next week much from the previous
forecast otherwise.

&&

.AVIATION...
18Z TAF DISCUSSION.

Tafs at CKV/BNA/MQY will be VFR. Vis at CSV may drop to MVFR near
dawn on Friday. Storms will be isolated today, so the probability
of a terminal being affected is too small to include in the tafs.
Additional storms may develop late Friday morning, but the bulk
of the activity will be after 18z. Winds will generally be out of
the SSW/SW today at 5 kts.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      76  93  73  89  70 /  20  50  50  50  20
Clarksville    74  92  70  88  65 /  20  50  40  40  10
Crossville     68  86  67  83  65 /  20  50  30  60  30
Columbia       74  93  72  89  69 /  20  50  40  50  30
Lawrenceburg   72  90  72  88  69 /  20  50  30  60  30
Waverly        73  91  72  88  69 /  20  50  30  50  30

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT this evening for Bedford-Cannon-
Cheatham-Clay-Coffee-Davidson-De Kalb-Dickson-Giles-Hickman-
Houston-Humphreys-Jackson-Lawrence-Lewis-Macon-Marshall-Maury-
Montgomery-Perry-Putnam-Robertson-Rutherford-Smith-Stewart-
Sumner-Trousdale-Wayne-Williamson-Wilson.

&&

DISCUSSION......Barnwell
AVIATION........Reagan

Hazardous Weather Outlook
National Weather Service Nashville TN
452 AM CDT Thu Aug 12 2021

TNZ005>011-023>034-056>066-075-077>080-093>095-131000-
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-
452 AM CDT Thu Aug 12 2021

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

Heat Index values of 100 to 110 degrees are likely across most of
Middle TN today. Please take the necessary precautions to protect
yourself and loved ones from heat related illnesses.

Very isolated thunderstorms are possible south of I-40 this
afternoon. Wind gusts of 40 mph and heavy rainfall are the main
concerns.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Scattered thunderstorms are possible Friday and Saturday. Storms both
days will carry the potential for strong wind gusts and heavy
rainfall.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

27

Special Weather Statement
National Weather Service Nashville TN
421 PM CDT Thu Aug 12 2021

TNZ034-122200-
Fentress TN-
421 PM CDT Thu Aug 12 2021

...A strong thunderstorm will impact portions of central Fentress
County through 500 PM CDT...

At 420 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Jamestown, moving northeast at 5 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...
Jamestown, Allardt and Grimsley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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 3637 8471 3638 8472 3637 8473 3635 8473
      3635 8474 3634 8474 3633 8477 3630 8480
      3629 8484 3629 8487 3628 8488 3623 8490
      3621 8496 3636 8508 3653 8486 3646 8471
      3640 8466
TIME...MOT...LOC 2120Z 237DEG 6KT 3633 8495

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

FB