Severe Thunderstorm Warning 2, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
536 AM CST Sat Jan 1 2022

.UPDATE...
FOR 12Z AVIATION DISCUSSION.

&&

.DISCUSSION...

Airmass attempting to destabilize this morning. Still expecting
some convective development to commence toward 4 or 5 am. Shear
parameters should continue to climb through 12Z and thus, the
tornado watch shall continue. After sunrise, convection through
early afternoon should be mostly isolated to scattered. Pressure
gradient will be on the upswing and we can expect southerly winds
of 15 to 25 mph with gusts to 35 mph. Will issue an SPS to address
this by 4 am or so.

Severe threat for this afternoon and evening still looms. SPC still
carries an enhanced risk for the entire mid state area. Timing still
looks like early afternoon across our northwest, mid to late
afternoon for Nashville and central areas, early evening for the
Plateau. Damaging winds, large hail and isolated tornadoes are still
all in play as viable threats.

As for the flood watch, it will remain in effect for northern
portions of our area. The stalled out boundary to our north will
serve as the focus for the heaviest rainfall. Looks as though around
2 inches or so is still expected across the watch area.

Shower activity will continue into the overnight and on into Sunday
morning. At that point, the boundary will be located a considerable
distance to our southeast. Upper level energy will begin to amplify
to our west with the aforementioned slowing down. Cyclogenesis will
pick up along the boundary with the sfc low moving along it.
Moisture will wrap around on the back side with some further
enhancement from the upper level trough. With freezing levels
continuing to drop, the showers should turn over to snow late Sunday
afternoon and into the evening. The ground is rather warm but a
dusting to a quarter of an inch of snowfall cannot be ruled out on
grassy surface to the west of the Plateau. Along the Plateau, a half
inch or so will be possible. The snow will end across the Plateau
around sunrise Monday.

For the near term temps, very warm today with mid perhaps upper 70s
expected. The record high to today for BNA is 77F so that may get
beaten. Turning colder tonight and noticeably colder on Sunday with
temperatures falling into the 30s in the afternoon. Lows Monday
morning look like lower 20s for the bulk of the area.

In the ext fcst, models lean toward a late week cold front with
moisture along and behind the passing boundary. Rain and snow will
again be in the forecast starting on Thursday. Otherwise, after a
brief pre frontal moderating trend, temperatures will lean toward
running below normal. Noting too horrible but we could see some
teens for lows by the tail end of the extended period.

&&

.AVIATION...
12Z TAF DISCUSSION.

VFR/MVFR conditions are expected at airports this morning with
VCSH/-SHRA and gusty south to southwest winds. TSRA will move over
all terminals this afternoon with IFR vis and strong tstorm wind
gusts. IFR conditions will continue overnight with continued SHRA
and winds becoming northwesterly.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through this evening for Cheatham-Clay-Davidson-
Dickson-Houston-Humphreys-Jackson-Macon-Montgomery-Robertson-
Smith-Stewart-Sumner-Trousdale-Wilson.

&&

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

Hazardous Weather Outlook
National Weather Service Nashville TN
520 AM CST Sat Jan 1 2022

TNZ005>011-023>034-056>066-075-077>080-093>095-021130-
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-
520 AM CST Sat Jan 1 2022

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

As a stationary boundary just to our north continues to encounter
some increasingly unstable air, a few strong to severe thunderstorms
will be possible across far northern and northwestern middle
Tennessee through this morning. Strong to damaging winds, isolated
tornadoes, and some hail will be possible.

A Flood Watch remains in effect through 9 PM this evening mainly for
areas along and north of I-40 where heavy rain may lead to isolated
flooding. Up to 2 inches of rainfall will be possible across the
watch area.

A cold front will begin to approach the area late in the day. This
cold front will be working across a very warm and unstable airmass.
As a result, Severe thunderstorms will be possible from mid afternoon
and continue into this evening. Straight line damaging winds, large
hail and a few tornadoes will all be possible.

Look for wind speeds to average from 10 to 15 mph today. By
afternoon, some wind gusts of up to 35 mph will also be possible.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

On Sunday, the rainshower activity will change over to snow showers
as colder air moves into the region. At this time, only very light
accumulation is possible to the west of the Cumberland Plateau.
Along the Cumberland Plateau however, a half inch or so of
accumulation will be possible, mainly on grassy areas. The warm
ground temperatures should prevent any major driving problems.

.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.

21