925
FXUS63 KLMK 062341
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
641 PM EST Sat Dec 6 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Cloudy, cool, damp and dreary with possible drizzle during the day
  Sunday.

* Cold front Sunday night will briefly change rain showers over to
  snow early Monday morning. Could created some isolated slick spots
  on untreated and elevated surfaces for the Monday morning commute.

* A series of systems will pass across the Ohio Valley Wednesday and
  Thursday with the potential of some wintry precipitation Thursday
  morning into the afternoon.

* Very cold air by the end of the week into the weekend with highs
  in the 30s to even 20s by the weekend and lows into the teens and
  single digits.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 323 PM EST Sat Dec 6 2025

Low-level moisture trapped under a temperature inversion between 900-
700mb has kept stubborn low stratus over much of central KY and even
southern IN most of the day. While visible satellite imagery has
shown the stratus trying to break and thin out here this afternoon,
history has shown us that given the time of year and when sunset
occurs, that we will likely see this area of stratus start to fill
back in as we lose daytime heating, mixing allowing for the
inversion to strengthen overnight. While some light drizzle/mist
can`t be ruled out late this afternoon and tonight, I think the
better chance comes tomorrow as a mid-level shortwave, inverted sfc
trough and approaching sfc cold front work into the Ohio Valley.

Given the cloud cover, decided to go a little above guidance leaning
more on the NBM 75th percentile for minT overnight. While winds will
become light to calm, the lack of clearing should keep temperatures
fairly steady to just a couple degrees cooler than where they were
after sunset. Lows will range from near 30 to the upper 20s along
and east of the I-75 corridor while temperatures along and west of
I-65 will range from the low/mid 30s.

Model soundings going into tomorrow continue to keep near sfc
moisture trapped under a strong temperature inversion around 850mb
along with dry air. The profile saturates at around 700mb into the
DGZ setting up a but of a seeder-feeder situation. Due to the amount
of dry air between the saturated sfc later under 950mb and the
saturated upper layer, am leaning more towards seeing mainly just
pockets of drizzle out ahead of the approaching system during the
day tomorrow. As was the situation with overnight lows, went below
guidance for high due to the persistent cloud cover, with highs
ranging from the low 40s to the north and mid/upper 40s further
south. It will likely be another cool damp and overall dreary day.

PoPs increase as the sfc cold front and associated shortwave axis
slide across the Ohio Valley tomorrow night into early Monday
morning. Initially most of the precipitation should fall as rain or
even a possible rain/snow mix along the Ohio River before changing
over briefly to all snow in the pre-dawn hours of Monday. Likely
only get a quick coating on grassy and elevated surfaces as well as
any roads or sidewalks that haven`t been treated. Most of the
activity should be out before the Monday morning commute but not
going to rule out any isolated slick spots as temperatures fall into
the low/mid 20s across most of KY with near 30 closer to the KY/TN
border.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 323 PM EST Sat Dec 6 2025

Canadian sfc high builds in over the region on Monday along with
strong CAA. Skies will clear from the NW to the SE during the day as
highs in the low/mid 30s across the northern half of the CWA with
just shy of 40 as you get close to the KY/TN border. While we remain
dry for Tuesday, sfc high will have quickly moved eastward allowing
winds to veer from the NNE to the SW by Tuesday afternoon. Return
flow on the backside of the departing sfc high will increase WAA and
push afternoon temperatures nearly 10 degrees warmer than Monday
with low/mid 40s to near 50 across the south.

A quick moving Alberta Clipper will track across the Great Lakes
during the day Wednesday along with another cold front. Light rain
showers, with the highest chances across our northern CWA from
southern IN, north central KY into the Bluegrass. Wednesday into
Wednesday evening. A second system, tracking farther south, will
arrive across the region by Thursday morning. Given the more
southern track right into southern IN and central KY along with CAA
associated with the passing cold front Wednesday evening, we will
need to watch this system for potential wintry precipitation.
Currently the forecast is calling for a mix of rain and snow, mainly
norther of the WK/BK Parkways with rain to the south. While both
deterministic models agree on this scenario there remains enough
differences that confidence is not real high on exact p-type and
location at this time.

High pressure will follow these two systems for late week and into
the weekend with a blast of some very cold air. Highs only in the
20s by the start of the weekend and lows in the teens and possibly
single digits in spots. As of now, we look to be dry with this onset
of much colder air.

&&

.AVIATION /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 640 PM EST Sat Dec 6 2025

Pretty tricky overnight forecast as we try to forecast this stubborn
stratus deck. As previously mentioned, model guidance continues to
not handle things well, and as result feel that more of a
persistence forecast is the way to go. Tried to show some optimism
at a few sites later tonight as the edges of the low cloud deck
erode a bit, but overall expect more MVFR ceilings than not. May
even see some IFR creep into HNB and SDF tomorrow morning. RGA/LEX
have the best chance for a return to VFR overnight if the southern
edge of the stratus deck continues its trend of eroding northward.
Winds will be light and variable through the period before they take
on a steady NW to N component by later Sunday.

&&

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

&&

$$

SHORT TERM...BTN
LONG TERM...BTN
AVIATION...BJS