Special Weather Statement, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
1153 AM CST Tue Feb 7 2017

.UPDATE...
FOR 18Z AVIATION DISCUSSION.

&&

.DISCUSSION...

An interesting day is in store for us here in Middle Tennessee.
At forecast time, other than a few showers streaming across the
area, it's relatively quiet.  However, if we look upstream, the
action is already under way.  Showers and thunderstorms have already
crossed over the Mississippi River and are headed across West
Tennessee.  These storms will likely break into our northwest
counties over the next couple of hours and with little to no surface
based instability present, these storms should pass through Middle
Tennessee with little to no fanfare.  As we get into the daylight
hours, the activity that is further upstream (currently over
Arkansas) will start to near the mid-state and it's these storms
we'll have to start watching for the potential of severe weather.
Parsing the forecast soundings, not much has changed in regards
to our forecast thinking. There will be at least a marginal chance
for damaging straight line winds and hail, especially during the
morning hours. This is when the wind fields are their strongest. A
50-60 kt 850mb LLJ will provide 0-3km helicities potent enough to
help sustain updrafts. As we get into the afternoon hours, these
wind fields begin to weaken. That 850mb jet weakens to 30 kts and
while that's nothing to sneeze at with surface instability
climbing near 1000 J/Kg, it's not what it could be. So, as we get
into the afternoon, we'll start looking for much more isolated
instances of sustained updrafts. Latest HRRR suggests there's just
enough deep layer shear to organize a weak line as the bulk of
the precip pushes across I-65 early this afternoon. This is most
likely where the afternoon threat of severe weather will be
concentrated. Again, with surface winds out of the southwest, the
tornado threat will be low -- though not zero -- throughout this
event.

Outside of today's thunderstorms, it's going to be breezy.  Gusts of
30 to 35 mph will be possible until that LLJ weakens later this
afternoon.

As advertised, today's thunderstorms will be pre-frontal.  The
actual front still isn't expected to push through Middle Tennessee
until Wednesday afternoon.  This means that while we'll probably
have a decent lull in activity tonight, we could see some more
convective development on Wednesday just ahead of the front.
Instabilities will be lower than today, but there could be just
enough deep layer shear to organize some of this convection, so a
few strong storms will be possible late Wednesday morning into the
early afternoon hours, especially south of I-40.

Behind the front, some precipitation will linger into Wednesday
night. There's still plenty of model inconsistencies regarding
how quickly the cold air will push in behind the front. Because of
this, I'm still only going to carry a chance of some light snow
on the northern Plateau early Thursday morning. QPFs are still
very light, so this should be of little to no consequence.

We'll dry out starting Thursday.  Temperatures will be much more
seasonal, but this won't last long as the surface ridge following
tomorrow's frontal passage will get east of us quickly and provide
southerly flow as early as Friday. This will allow us to warm up
once again, with afternoon highs back into the upper 50s and 60s
Friday and Saturday. Another front is still progged to push
through Sunday, but the latest extended guidance has weakened this
front considerably. Because of this, I'm still only going to
carry a chance PoP for Sunday.

&&

.AVIATION...
18Z TAF DISCUSSION.

Poor flying conditions will continue over the next 24 hrs. RA will
move out during the afternoon hours but low ceilings and reduced
vis will continue to be an issue overnight. Only included tempo
tsra group at CSV for the next couple of hours as lightning has
been scarce with this activity. Winds will calm overnight and
with ample low level moisture fog may become an issue along with
IFR cigs. Cigs should improve to MVFR by mid to late morning at
all three terminals.

&&

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

&&

DISCUSSION......Unger
AVIATION........Reagan

Hazardous Weather Outlook
National Weather Service Nashville TN
554 AM CST Tue Feb 7 2017

TNZ005>011-023>034-056>066-075-077>080-093>095-081200-
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-
554 AM CST Tue Feb 7 2017

This Hazardous Weather Outlook is for portions of Middle
Tennessee.

.DAY ONE...Today and Tonight.

Strong to severe thunderstorms will be possible today across all
of Middle Tennessee. While the tornado threat will be low,
damaging straight line winds and large hail will be the main
threats. The main focus areas will be west of I-65 this morning
and east of I-65 this afternoon.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

A couple of strong storms will be possible during the late morning
and early afternoon hours Wednesday. Strong gusty winds and small
hail will be possible, especially south of I-40.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is requested today. Please report any storm
damage in Middle Tennessee to the National Weather Service in
Nashville.

THUNDERSTORM SPOTTER REPORTING CRITERIA...
Tornado
Funnel Cloud
Flooding
Hail >= 1/2 inch
Winds > 50 MPH (measured)
Structural Damage
Tress or Power Lines Down

27

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
1208 PM CST TUE FEB 07 2017

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

0920 AM     TSTM WND DMG     6 W SLAYDEN             36.28N  87.57W
02/07/2017                   HOUSTON            TN   EMERGENCY MNGR

            EMERGENCY MANAGER REPORTED DAMAGE TO HOUSE WITH CARPORT
            BLOWN DOWN AND DAMAGE TO WINDOWS FROM DEBRIS. MULTIPLE
            TREES REPORTED DOWN.

&&

EVENT NUMBER OHX1700073

FBORDEN

Special Weather Statement
National Weather Service Nashville TN
1221 PM CST TUE FEB 7 2017

TNZ032>034-064>066-071915-
Putnam TN-Cumberland TN-Fentress TN-Overton TN-De Kalb TN-White TN-
1221 PM CST TUE FEB 7 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN OVERTON...
CUMBERLAND...SOUTHEASTERN DE KALB...WHITE...SOUTHEASTERN PUTNAM AND
FENTRESS COUNTIES UNTIL 115 PM CST...

At 1220 PM CST, Doppler radar was tracking strong thunderstorms
along a line extending from near Livingston to near Doyle. Movement
was east at 35 mph.

Half inch hail and wind gusts up to 50 mph will be possible with
these storms.

Locations impacted include...
Cookeville, Crossville, Sparta, Jamestown, Fairfield Glade, Monterey,
Crab Orchard, Allardt, Pleasant Hill, Doyle, Grimsley, Hamptons
Crossroads, Cumberland Mountain State Park, Slate Springs, Bakers
Crossroads, Virgin Falls State Natural Area, Rock Island State Park,
Lake Tansi, Indian Rock Lake and Clarkrange.

LAT...LON 3638 8472 3630 8480 3629 8487 3621 8491
      3615 8491 3606 8479 3577 8505 3577 8525
      3581 8528 3582 8527 3580 8537 3582 8546
      3581 8552 3579 8552 3579 8560 3584 8572
      3585 8579 3637 8522 3650 8472 3640 8466
TIME...MOT...LOC 1820Z 255DEG 33KT 3633 8520 3585 8563

Shamburger

Special Weather Statement
National Weather Service Nashville TN
1255 PM CST TUE FEB 7 2017

TNZ066-077>080-071930-
Cumberland TN-Coffee TN-Van Buren TN-Grundy TN-Warren TN-
1255 PM CST TUE FEB 7 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN CUMBERLAND...
SOUTHEASTERN COFFEE...VAN BUREN...SOUTHEASTERN WARREN AND GRUNDY
COUNTIES UNTIL 130 PM CST...

At 1255 PM CST, Doppler radar was tracking strong thunderstorms along
a line extending from near Spencer to near Cowan. Movement was east
at 50 mph.

Half inch hail and wind gusts up to 50 mph will be possible with
these storms.

Locations impacted include...
Spencer, Gruetli-Laager, Tracy City, Monteagle, Altamont, Coalmont,
Palmer, Beersheba Springs, Hillsboro, Indian Rock Lake, Pelham, Fall
Creek Falls State Park and Fiery Gizzard S.p..

LAT...LON 3583 8478 3576 8492 3576 8526 3557 8542
      3553 8561 3549 8554 3543 8554 3538 8549
      3532 8556 3529 8571 3524 8569 3522 8574
      3522 8587 3529 8592 3535 8604 3581 8557
      3580 8536 3582 8527 3579 8526 3582 8523
TIME...MOT...LOC 1855Z 272DEG 45KT 3575 8541 3517 8606

Shamburger

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
137 PM CST TUE FEB 07 2017

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

1016 AM     TSTM WND DMG     2 E BERRY HILL          36.12N  86.72W
02/07/2017                   DAVIDSON           TN   EMERGENCY MNGR

            TREE BLOWN DOWN ON OLD GLENROSE AVENUE BETWEEN I-24 AND
            BRILEY PARKWAY

&&

EVENT NUMBER OHX1700074

SHAMBURGER

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE NASHVILLE TN
145 PM CST TUE FEB 07 2017

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

0430 AM     HAIL             5 NW ASHLAND CITY       36.33N  87.12W
02/07/2017  E0.88 INCH       CHEATHAM           TN   FACEBOOK

            BRIEF PEA TO NICKEL SIZE HAIL REPORTED 5 MILES
            NORTHWEST OF ASHLAND CITY

0920 AM     TSTM WND DMG     6 W SLAYDEN             36.28N  87.57W
02/07/2017                   HOUSTON            TN   EMERGENCY MNGR

            EMERGENCY MANAGER REPORTED STRUCTURAL DAMAGE AT THIS
            LOCATION...AROUND THE HIGWAY 49 AND ELLIS MILLS ROAD
            INTERSECTION. HOUSE WAS DAMAGED WITH CARPORT BLOWN DOWN
            AND WINDOWS BLOWN OUT FROM DEBRIS WITH MULTIPLE TREES
            DOWN. IN ADDITION THERE WERE TREES BLOCKING THE ROAD ON
            TOWN BRANCH ROAD AND PROCTOR ROAD IN THE SAME AREA.

1010 AM     TSTM WND DMG     2 E BERRY HILL          36.12N  86.73W
02/07/2017                   DAVIDSON           TN   911 CALL CENTER

            ONE TREE REPORTED DOWN.

1016 AM     TSTM WND DMG     2 E BERRY HILL          36.12N  86.72W
02/07/2017                   DAVIDSON           TN   EMERGENCY MNGR

            TREE BLOWN DOWN ON OLD GLENROSE AVENUE BETWEEN I-24 AND
            BRILEY PARKWAY

&&

EVENT NUMBER OHX1700069 OHX1700070 OHX1700072 OHX1700074

SHAMBURGER

Special Weather Statement
National Weather Service Nashville TN
211 PM CST TUE FEB 7 2017

TNZ075-072045-
Bedford TN-
211 PM CST TUE FEB 7 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN BEDFORD COUNTY UNTIL 245
PM CST...

At 211 PM CST, Doppler radar was tracking a strong thunderstorm near
Petersburg, or 10 miles southeast of Lewisburg, moving east at 50
mph.

Dime size hail will be possible with this storm.

Locations impacted include...
Shelbyville, Wartrace, Normandy and Raus.

LAT...LON 3534 8647 3536 8649 3535 8653 3536 8654
      3537 8662 3543 8666 3547 8666 3559 8624
      3546 8625 3545 8624 3545 8625 3541 8625
      3541 8629 3539 8630 3538 8633 3536 8633
      3535 8637 3535 8641 3533 8641 3532 8643
TIME...MOT...LOC 2011Z 256DEG 42KT 3538 8662

Shamburger