415
FXUS63 KLMK 100506
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1206 AM EST Mon Nov 10 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Colder air will filter into the region this evening with scattered
  rain showers changing over to snow showers. More widespread snow
  showers and possible snow squalls expected on Monday with minor
  accumulations possible in the Bluegrass region of Central Kentucky.

* Very cold weather is expected Monday and Tuesday mornings with
  lows in the upper teens to lower 20s and wind chill values in the
  teens.

&&

.UPDATE...
Issued at 907 PM EST Sun Nov 9 2025

Temperatures continue a gradual fall into the low to mid 30s this
evening. Spotty light precipitation has been a mix of rain and snow
up to this point. Radar currently shows a broad area of very light
returns, with isolated embedded areas of 20+ dBZ. Brief, spotty
light snow showers are possible over the next 1-2 hours or so.
However, a lead mid-level impulse will quickly shift east of the
area late this evening. Moisture depth will drop quickly, resulting
in the light snow shutting off by 11 pm. The potential for snow
accumulation and impacts is minimal this evening, though a quick
dusting on rooftops is possible.

Overnight, steady CAA continues via stout NW flow. Temperatures are
forecast to drop into the mid 20s during the early to mid-morning
hours of Monday. NW winds of 10-20 mph will continue during this
time, dropping wind chills into the teens. Bundle up for the ride to
work or school!

Deep upper level troughing will continue to descend over the Ohio
Valley tonight and on Monday. A potent mid-level vort max will
rotate south from the Great Lakes, along with an induced sfc trough.
These features will drop south over southern IN and central KY from
Monday morning into the afternoon hours. These features will bring
another surge of moisture, along with enhanced lift and colder
temperatures aloft (steeper mid-level lapse rates).

Scattered to numerous snow showers are expected from mid-morning
Monday through the afternoon hours. Steep lapse rates, and
the presence of weak instability, will support brief intense
snowfall rates. Snowfall totals of a dusting up to around an inch
are expected. However, snowfall totals could be a bit uneven with
swaths of higher totals. In general, snowfall of around an inch
looks most likely along and northeast of a line from Scottsburg IN
to Liberty KY. Parts of southeastern IN and the KY Bluegrass have
the best chance at seeing slightly more than 1 inch, though
confidence is not high in anyone seeing more than 1 inch (highest
probability would be around a 48% chance for more than 1 inch in
Madison IN).

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 358 PM EST Sun Nov 9 2025

=== Precip Switch Over This Afternoon and Evening ===

The early morning cold front has now moved east of the entire state
of Kentucky, and will continue to surge eastward through the mid-
Atlantic region this evening. We have been dealing with gusty NW
gradient winds and strong CAA regime behind the cold front, which
has allowed our sfc temps to fall throughout the day. We started off
this morning in the mid to upper 50s, but KY Mesonet obs now show
the entire area already in the upper 30s and low 40s. We will
continue to drop the rest of the afternoon and evening, possibly
into the mid-30s across southern IN by 00z.

Regional radar shows light rain shield moving across southwestern IN
and into central KY, with more light precip over east-central IN
that is already being reported as light snow in Lafayette and Terre
Haute. This is being driven by a healthy mid-level vorticity wing
that is pinwheeling around the primary upper trough. While we will
initially see light rain, or even drizzle, we expect our precip to
switch over to light snow later this afternoon and especially this
evening as the precip shield drives south.


=== Break in Activity Tonight, Cold Wind Chills ===

As we get deeper into the overnight, we expect to see a lull in
precip activity due to a brief loss in upper level forcing and
weaker moisture transport off of Lake Michigan. Due to this, will
have a period of mostly dry PoPs for the forecast area tonight.

While the first snowflakes of the season bring a lot of attention,
the main story for tonight will actually be the bitter wind chills.
With continued strong CAA, and gusty NW winds persisting through the
overnight, our forecast temps plunge into the low 20s by tomorrow
morning. NW wind gusts up to 20 mph through the night, combined with
the sfc temps in the 20s, will likely yield wind chills dropping
into the teens by early tomorrow morning.

=== Snow Showers and Possible Snow Squalls Tomorrow ===

By 12z tomorrow morning, the well-advertised upper level low will
deepen as it drops southward into the Ohio Valley. Guidance
continues to indicate a healthy moisture plume will advect off the
Great Lakes and southward into our region by mid-morning and
afternoon. As our mid-level forcing increases again, the core of the
cold airmass will sink into the Ohio Valley, leading to even more
steepening of lapse rates. The combination of upper and mid-level
forcing, very steep lapse rates, and plenty of deep moisture
extending well above the DGZ all add to high chances for streaks of
snow showers across the region tomorrow. In addition to the snow
chances, tomorrow will be quite raw, with gusty NW winds and temps
remaining in the 30s.

The snow showers will likely have a convective nature to them, as hi-
res CAMs have been hinting at in their respective reflectivity
products. Snow squall parameters have continued to be between 2-4 on
today`s model runs. Convective snow squalls certainly seem possible
tomorrow, as guidance suggests approximately 50-100 J/kg of SBCAPE,
mainly for central KY and the Bluegrass region. According to the
NBM, the probability to exceed 100 J/kg of SBCAPE tomorrow afternoon
is around 25% between the I-65 and I-75 corridors. The HREF is not
far off either, with roughly a 20% chance for the same area. While
some model soundings have indicated upwards to 150-200 J/kg, the
overall probabilities for SBCAPE reaching those levels seem much
lower. Regardless, confidence continues to increase on snow squall
potential for tomorrow, especially for areas east of I-65.

=== Potential Winter Weather Impacts ===

Winter weather impacts for this evening and tonight are expected to
be minimal, as any snow will be light and scattered. We could see a
tenth or two of snow tonight, but with how gusty the winds are, will
likely blow any light snow around. A very minor dusting on elevated
or grassy surfaces remains the expected outcome for tonight.

Winter weather impacts on tomorrow remain a bit uncertain. While we
are beginning to hone in on broad snow accumulations for majority of
the region, the convective nature of these snow showers tomorrow
could lead to narrow swaths of higher amounts. The NWS Probabilistic
Precip Portal paints a 25% chance of at least 1 inch of snow on a
line from Jasper, IN to Louisville, to Richmond and northward.
Better chances exist to the northeast, where a line from Madison, IN
to Lexington has a 35-40% chance of at least 1 inch.

In general, up to an inch of snow accumulation will be possible in
areas east of I-65, though some locations east of I-75 could see
upwards of 1-2 inches. Some travel impacts will be possible on
Monday, especially on bridges and overpasses.

One impeding factor to the snow amounts will be the warm soil
temperatures, which are in the low 50s. This event will be based on
snow rates and if they can overcome the warm ground. The best chance
for minor accumulations will be in those heavier snow bands or snow
squalls, where the snowfall rates will overcome the ground and sfc
temps. Though the heavy snow rates will likely be brief and more
isolated. Additional impacts with any of those snow squalls will be
brief reduced visibility and quick accumulations, which can be quite
hazardous on roadways.

=== Additional Comments ===

As mentioned in the previous discussion, there is increasing
confidence on snow showers, perhaps briefly heavy at times. However,
the overall confidence on seeing impacts remain somewhat low given
the ground temps and overall snow amounts. Because of this, will
continue with the Special Weather Statement highlighting the
upcoming weather, and will give tonight`s forecast another chance to
comb through the data before making a decision on the need for a
Winter Weather Advisory for tomorrow. Regardless, the best chance
for an advisory will be for the Bluegrass region, where an inch of
snow will be most likely.

By Monday evening, upper level support for snow showers will push
east of the region and snow will quickly taper off from west to
east.  Gusty northwest winds will continue across the area with lows
dropping into the teens/lower 20s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 358 PM EST Sun Nov 9 2025

Monday night - We`ll begin to see heights aloft rise as the closed
upper low spins northeast across the eastern Great Lakes. Strong sfc
high pressure is forecast to slide east along the central Gulf
Coast. Besides a few lingering flurries east of I-75, Monday night
will be dry with clearing skies. Westerly winds will stay up around
5-10 mph, helping to keep temps from dropping too far. However, with
lows in the lower 20s in most places, those winds will also produce
wind chills in the teens early Tuesday morning.

Tuesday - A mid-level impulse is forecast to dive southeast across
portions of IL/IN and spread increasing mid and upper level clouds
across the northern 2/3 of the forecast area. Meanwhile, a deeper
wave will rotate southeast over Ontario, with an attendant cold
front draped southwest through the Upper Midwest and central Plains.
A 50+ kt WSW low-level jet is forecast to overspread the Lower OH
Valley Tuesday afternoon into the overnight hours. We`ll see healthy
WAA during this stretch, and we`ll slowly start to push the cold air
mass out of here. However, increasing mid-level clouds will temper
sfc heating. Highs Tuesday afternoon will range from the lower 40s
in the Bluegrass Region to around 50 degrees in Bowling Green.

Tuesday night, we`ll remain sandwiched in a fairly strong pressure
gradient between a Canadian low and Florida high. A stout low-level
westerly jet will continue to advect warmer air into the region.
Look for a mostly clear and somewhat breezy night, with lows in the
30s.

Wednesday and Thursday look fairly quiet and warmer with sfc high
pressure building in from the west. An amplifying upper level ridge
is forecast to translate eastward across the Rockies and eventually
the Plains. Highs should range from the mid 50s to lower 60s. Lows
Wednesday night will be cool with the sfc high overhead or nearby.
Lows should be in the low to mid 30s. Thursday night lows may be a
touch warmer, in the mid 30s to lower 40s.

For Friday and Saturday, the upper level ridge will move overhead in
response to a deep upper level trough moving over the Rockies and
central Plains. Southerly low-level flow and continued WAA will push
temperatures back into the 60s and 70s for highs. Could see a threat
for severe weather materialize by Saturday across Missouri and parts
of the MS Valley, if medium range guidance remains relatively
consistent. The CSU ML severe probabilities certainly highlight an
elevated risk for severe weather off to our west Saturday into
Saturday night. Based on the timing from the latest 12Z model
guidance, this would bring us a chance for showers and thunderstorms
by Sunday. Cannot rule out some stronger thunderstorms, but it`s
much too early to get into the details.

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 1206 AM EST Mon Nov 10 2025

Breezy northwest winds will be seen across the region overnight.  A
few light snow showers will move southeast within the northwest
flow, but most of the night will remain rather dry with VFR
conditions expected.

Strong upper level wave and slug of moisture will rotate southward
out of Indiana and into Kentucky around 10/14-15Z or so.  This will
bring snow showers to the region and some of them may be convective
in nature.  Overall, MVFR conditions look likely through the day,
but within the heavier snow showers, reductions to IFR cigs/vsbys
are possible.  Worst of the snow at KSDF/KHNB looks to be between
10/14-20Z and over at KLEX/KRGA between 10/15Z-22Z.  Further south
at KBWG, snow is expected to be much lighter in nature and not
overly impactful to aviation.  Look for improving conditions from NW
to SE after 10/22Z with VFR conditions returning for Monday night
and into Tuesday.  Northwest gusty winds will continue through the
day with gusts of 20-25kts at times, but winds will diminish
considerably after sunset.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

UPDATE.......EBW
SHORT TERM...CJP
LONG TERM....EBW
AVIATION.....MJ