Special Weather Statement, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
246 AM CDT Sat Mar 27 2021

.DISCUSSION...

Some convection just now beginning to fire across nrn AL and nrn MS.
This is in response to a warm front which will be lifting northward
through the mid state today. Showers and thunderstorms will be
rapidly increasing over the next few hours with this activity
spreading northward and continuing into your Saturday.
Destabilization will be rather rapid with sfc based capes between
1000-1500 j-kg and LI values approaching -5C by 18Z. An examination
of upcoming lapse rates and mid level capes do support the
potential for some hail today, with perhaps the severe threshold
of 1 inch being surpassed. 850 mb wind speeds are not overly
impressive and the organized lift is somewhat sub-par. Helicities
are between 100-200, but the Hrrr does indicate a little
reflectivity wrapped signatures by afternoon. Overall looks like
some strong to severe storms with high winds and hail possible
with some cell rotation also possible. Storm direction looks like
from 250 deg at 40 mph or so.

Tonight, the slow approach of a strengthening frontal boundary will
provide well organized and strong forcing. However, phasing with the
better instability parameters is a little off with the instability
outrunning the forcing just a bit. Nevertheless, SPC has the entire
area in an enhanced risk. The threats will be damaging winds and
large hail but cannot rule out an isolated tornado or two. In
addition, flash flooding looks to be a big threat. For that reason,
the flash flood watch remains in effect. Latest storm total precip
shows 2-3 inches for most areas through tonight, with the bulk of
the heavy rainfall, of course, occurring overnight. localized 4 inch
amounts cannot be ruled out. Qpf gradients drop off rather markedly
to our north and south, but we are close enough to the event now
where we see the heavier rainfall is going to occur across our area.
Moving on, some shower activity will linger into your Sunday
morning. Clearing will commence in the afternoon.

For the near term temps, despite the clouds and rainfall, we will
see our temps warm into the lower 70s for today with humidities on
the upswing for sure. Cooler on Sunday and low temps will be in the
35 to 40 degree range by Monday morning.

In the ext fcst, a mid week frontal boundary will move through. The
feature looks weaker than our previous boundaries and instabilities
look marginal at best. Anyhow, shower chances return Tuesday and
Wednesday. It will be turning noticeably cooler on Wednesday and the
models are leaning toward slowly falling daytime temperatures.
Thursday and Friday are looking dry.

For our extended temps, it looks seasonal on Tuesday and then
turning colder Wednesday, as mentioned previously. Low temps for
Thursday through Saturday look like 30s.

Note that our growing season has begun and thus, the freeze warnings
and or frost advisories may begin to fly by late next week.

&&

.AVIATION...
06Z TAF DISCUSSION.

Poor flying conditions expected this TAF period as SHRA/TSRA
develop and affect all airports. No problems early this morning
with light winds and VFR conditions, but showers and storms will
rapidly develop and impact airports from 12Z onward with MVFR/IFR
conditions. Some improvement is possible this afternoon at
airports, before deteriorating again Saturday evening. Light
southeast winds early this morning will increase and become
southerly later today.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      73  57  63  38  66 /  80  90  60   0  10
Clarksville    73  52  60  35  63 /  30  90  20   0   0
Crossville     69  57  60  35  60 /  80  70  70   0  10
Columbia       75  59  64  37  66 /  80  80  60   0  10
Lawrenceburg   75  59  64  37  65 /  70  70  70   0  10
Waverly        73  53  62  36  64 /  50 100  30   0  10

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from 7 AM CDT this morning through Sunday
evening for Bedford-Cannon-Cheatham-Clay-Coffee-Cumberland-
Davidson-De Kalb-Dickson-Fentress-Giles-Grundy-Hickman-Houston-
Humphreys-Jackson-Lawrence-Lewis-Macon-Marshall-Maury-Montgomery-
Overton-Perry-Pickett-Putnam-Robertson-Rutherford-Smith-Stewart-
Sumner-Trousdale-Van Buren-Warren-Wayne-White-Williamson-Wilson.

&&

DISCUSSION......21
AVIATION........Shamburger

Hazardous Weather Outlook...UPDATED
National Weather Service Nashville TN
711 PM CDT Fri Mar 26 2021

TNZ005>011-023>034-056>066-075-077>080-093>095-271000-
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-
711 PM CDT Fri Mar 26 2021

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Tonight.

Some strong to severe thunderstorms will be possible late tonight for
locations generally south of I-40 and around and west of I-24.
Large hail will be primary threat.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Severe thunderstorms will be possible Saturday and Saturday night
across all of Middle Tennessee. Damaging winds, large hail, and
isolated tornadoes will all be possible. Multiple rounds of heavy
rainfall expected from mid morning hours on Saturday through at least
morning hours on Sunday. Rainfall amounts of 1 to 3 inches, with
locally higher amounts of 4 to 5 inches, expected on already
saturated ground conditions. Runoff impacts could last through
afternoon hours on Sunday.

.SPOTTER INFORMATION STATEMENT...

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

Spotter Thunderstorm Reporting Criteria...
Tornado
Funnel Cloud
Flooding
Hail >= 1/2 Inch
Winds > 50 MPH (Measured)
Structural Damage
Trees or Power Lines Down

JB Wright

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
715 AM CDT SAT MAR 27 2021

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

0715 AM     HAIL             1 NE LEBANON            36.22N  86.31W
03/27/2021  M1.00 INCH       WILSON             TN   NWS EMPLOYEE

&&

EVENT NUMBER OHX2100327

BW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
734 AM CDT SAT MAR 27 2021

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

0733 AM     HAIL             FAIRVIEW                35.98N  87.12W
03/27/2021  E0.88 INCH       WILLIAMSON         TN   NWS EMPLOYEE

&&

EVENT NUMBER OHX2100328

21

Special Weather Statement
National Weather Service Nashville TN
742 AM CDT Sat Mar 27 2021

TNZ027-028-030-057-059>062-271330-
Hickman TN-Rutherford TN-Williamson TN-Davidson TN-Wilson TN-
Maury TN-Marshall TN-Smith TN-
742 AM CDT Sat Mar 27 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN SMITH...SOUTHEASTERN
DAVIDSON...NORTH CENTRAL MARSHALL...NORTHERN RUTHERFORD...NORTHERN
MAURY...WILLIAMSON...WILSON AND EAST CENTRAL HICKMAN COUNTIES UNTIL
830 AM CDT...

At 741 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Rural Hill to 8 miles southeast of
Centerville. Movement was northeast at 45 mph.

Half inch hail will be possible with these storms.

Locations impacted include...
Murfreesboro, Franklin, Columbia, Lebanon, Carthage, Smyrna,
Brentwood, La Vergne, Spring Hill, Mount Juliet, Nolensville, Oak
Hill, Thompson's Station, Watertown, Gordonsville, Walterhill, Rural
Hill, Antioch, Belinda City and South Carthage.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3627 8584 3625 8582 3562 8677 3571 8740
      3626 8640 3628 8584
TIME...MOT...LOC 1241Z 238DEG 40KT 3615 8657 3573 8732

Whitehead

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
812 AM CDT SAT MAR 27 2021

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

0805 AM     HAIL             3 NW SPRING HILL        35.77N 86.96W
03/27/2021  M1.00 INCH       MAURY              TN   TRAINED SPOTTER

0804 AM     HAIL             SPRING HILL             35.74N 86.92W
03/27/2021  M1.00 INCH       MAURY              TN   TRAINED SPOTTER

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
817 AM CDT SAT MAR 27 2021

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

0805 AM     HAIL             THOMPSON'S STATION      35.81N  86.91W
03/27/2021  M1.00 INCH       WILLIAMSON         TN   PUBLIC

&&

EVENT NUMBER OHX2100329

DH

Special Weather Statement
National Weather Service Nashville TN
839 AM CDT Sat Mar 27 2021

TNZ031>034-066-271430-
Putnam TN-Cumberland TN-Fentress TN-Overton TN-Jackson TN-
839 AM CDT Sat Mar 27 2021

...SIGNIFICANT WEATHER ADVISORY FOR OVERTON...NORTH CENTRAL
CUMBERLAND...SOUTHEASTERN JACKSON...CENTRAL PUTNAM AND SOUTHWESTERN
FENTRESS COUNTIES UNTIL 930 AM CDT...

At 839 AM CDT, Doppler radar was tracking a strong thunderstorm near
Baxter, or near Cookeville, moving east at 55 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Cookeville, Livingston, Jamestown, Algood, Monterey, Allardt,
Grimsley, Clarkrange, Crawford, Rickman and Cummins Falls State Park.

This includes Interstate 40 between mile markers 283 and 303.

LAT...LON 3613 8558 3636 8555 3643 8483 3629 8481
      3630 8482 3628 8488 3624 8488 3621 8491
      3618 8490 3615 8491 3613 8487 3609 8483
      3610 8482 3608 8480 3609 8488
TIME...MOT...LOC 1339Z 266DEG 46KT 3621 8560

Whitehead