747
FXUS64 KOHX 101108
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
508 AM CST Fri Jan 10 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 453 AM CST Fri Jan 10 2025

 - Significant snow accumulation and major travel impacts today
   into early Saturday.

 - Cold temperatures into next week with lows in the teens and
   20s.

 - Temperatures below freezing during nighttime hours next week
   will re-freeze any melted snow, resulting in black ice and
   continued hazardous travel especially on secondary roads.

&&

.SHORT TERM...
(Today through Saturday)
Issued at 219 AM CST Fri Jan 10 2025

We can see the whites of the eyes of what will be a major winter
storm for Middle TN today that will bring major travel impacts to
the region. A surface low is sitting south of LA over the Gulf of
Mexico and this will pass to our south today. Warm air advection
and light precip has pushed into western TN early this morning. We
are starting to see light radar returns in our far SW but there
is abundant dry air below 700 mb. This will saturate over the
next several hours as warm air advection increases and moisture
gets advected into the area. Light snow should start in the
southwest between 4 and 6 AM with light snow continuing to push
northeast reaching Nashville between 7 and 9 AM and the Plateau
between 8 and 11 AM.

Warm air advection and frontogenesis will amp up in the late
morning and afternoon with a 50+ knot low level jet to our south.
This will set up a good overrunning zone over Middle TN and bring
us moderate to locally heavy snow with snow rates approaching
0.50-0.80" per hour for a time. The strong low level jet will try
to push a nose of warm air into Middle TN but overall models are
confident in keeping it to our south with ensembles and the HREF
only putting a ~10% of 850 mb temps going above 0C. I do think we
will see temps aloft approach and maybe go just above 0C along our
southern counties. This would bring a mix of sleet and rain along
with the snow for a time in the afternoon mainly between noon and
5 PM but most areas should see just snow for this event.

Snow will diminish form west to east during the evening and looks
to be out of here by midnight. Strong subsidence will develop
aloft as the snow pushes out and we will see the dendritic growth
zone dry out. Low level moisture will remain in place and we
could see some light freezing drizzle overnight along with some
flurries from time to time.

Snow totals across the area will generally be between 3 and 6
inches with the lowest totals towards the TN/AL boarder where some
mix will be possible. Snow ratios will also be much lower towards
the boarder with the warmer air likely in the 6:1 to 8:1 range
while they will be 10:1 to 12:1 in the northern part of our area.
We will likely see a band of higher snow totals that will set up
somewhere between Lawrenceburg to Clarksville and in that area
snow totals could approach 8". We will see major travel issues
today with snow covered roads and difficult travel conditions,
travel is not advised. Issues will likely linger into Saturday.

Subsidence aloft will keep low clouds in place for Saturday with
some flurries from time to time. Highs both today and tomorrow
will be in the low to mid 30s.

&&

.LONG TERM...
(Saturday Night through next Friday)
Issued at 219 AM CST Fri Jan 10 2025

As we head into Saturday night short wave ridging will be in place
but there is some uncertainty on if we can clear out with the
strong subsidence aloft. If clouds stick around our MinTs will
remain a bit warmer but if we clear out it will get down right
cold with lows well into the teens and maybe some single digits.
If we don`t clear out Saturday night we will get some clearing and
sun on Sunday with warmer highs in the upper 30s to lower 40s.
This will bring snow melt during the day. We will drop below
freezing Sunday night and that will freeze over any snow melt and
will likely bring some travel issues especially on secondary
untreated roads and walkways. Flow becomes more zonal on Tuesday
as a trough digs into the Great Lakes but it will be similar
conditions for us with afternoon temps above freezing and snow
melt during the day. Troughing then develops over the Northeast
and that will bring another push of cold air into Middle TN.
Starting Tuesday night into the end of the week we will see lows
fall into the teens with highs in the 30s. A trough will dig into
the Great Lakes next weekend and that will bring us some rain
chances.

&&

.AVIATION...
(12Z TAFS)
Issued at 453 AM CST Fri Jan 10 2025

12Z tafs will begin with VFR, but conditions will deteriorate
rapidly as a winter storm moves across the region. Cigs will
lower through the morning with widespread IFR to LIFR conditions
developing. Snow will become heavier with visibility reduced
frequently to 1/2SM, and occasionally 1/4SM in the heavier
bursts. The window for the heaviest snowfall is between roughly
15Z to 00Z.

Snow will taper off to flurries at KCKV, KBNA, and KMQY by 02Z.
Snow will linger til 06Z for CSV and SRB. Despite the snow coming
to an end, widespread IFR/LIFR cigs will remain through the end of
the taf period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      35  28  36  21 / 100  30   0   0
Clarksville    33  26  34  21 / 100  40   0   0
Crossville     32  23  30  13 / 100  70   0   0
Columbia       34  27  35  16 / 100  20   0   0
Cookeville     33  26  31  16 / 100  60   0   0
Jamestown      32  24  30  14 / 100  70   0   0
Lawrenceburg   35  27  34  16 / 100  30   0   0
Murfreesboro   35  27  35  16 / 100  40   0   0
Waverly        33  25  34  20 / 100  20   0   0

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 AM CST Saturday for TNZ005>009-
023>030-056>064-075-077>079-093>095.

Winter Storm Warning from 9 AM this morning to 6 AM CST Saturday
for TNZ010-011-031>034-065-066-080.

&&

$$

SHORT TERM...Mueller
LONG TERM....Mueller
AVIATION.....13