543
FXUS63 KLMK 082344
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
644 PM EST Mon Dec 8 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Milder temperatures and sunshine return on Tuesday.

* Windy conditions are expected Tuesday night into Wednesday, with
  widespread wind gusts of 25-35 mph and isolated gusts to 40 mph
  likely.

* Several chances for light precipitation return during the second
  half of the week. Light wintry precipitation is possible Thursday
  night into Friday, but significant impacts are not expected at
  this time.

* Cold temperatures are likely this weekend, but forecast
  temperatures have trended less cold.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 346 PM EST Mon Dec 8 2025

This afternoon, cool and cloudy conditions are left in the wake of
this morning`s system which left anywhere from a dusting to 2 inches
of snow as well as light rain across southern IN and central KY.
Visible satellite shows that stratus clouds are beginning to clear
across southern IN and western KY. The clearing process will
gradually continue from north to south later this evening and
tonight as high pressure moves over the area and cold advection
subsides in the lower troposphere.

As the high pressure moves across the region tonight, northerly
winds should go light and variable this evening before becoming
southerly early Tuesday morning as another low pressure system
begins to approach from the northwest. Low clouds could linger
tonight, especially across south central KY, and how much cooling we
see will be dependent on how quickly clouds clear. Where clouds
clear, temperatures should be able to fall into the low-to-mid 20s,
and upper teens would be likely in areas which have greater snow
cover. Additionally, some patchy fog can`t be ruled out, though this
should be limited as winds increase early Tuesday morning. On the
other hand, if low clouds hang on, lows would only be expected to
fall into the mid-to-upper 20s, and temperatures will likely rise or
be stagnant in the immediate pre-dawn hours Tuesday as southerly
winds increase.

Tuesday should give us our first decent warm return flow day in a
while as southwest winds strengthen ahead of an approaching sfc low
pressure system. This warm advection should help to scour out any
lingering low clouds, with scattered mid- and upper-level clouds
expected throughout the day. Still, there should be at least
filtered sunshine for most of the day on Tuesday, which when
combined with warm breezes, should allow temperatures to warm into
the mid- and upper-40s across the area. While the peak low- and mid-
level winds will remain to the northwest of the area during the day
on Tuesday, by the afternoon, we should be able to achieve 10-15 mph
sustained SW winds with widespread wind gusts of 20-25 mph.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 346 PM EST Mon Dec 8 2025

The synoptic pattern during the second half of the upcoming week is
expected to feature deep NW flow across much of the CONUS as an
upper low spins over eastern Canada while upper ridging remains
entrenched off the west coast. Shortwaves along the southwestern
flank of the upper trough will bring several clipper systems across
the central and eastern CONUS, providing several chances for light
precipitation across the Ohio Valley.

The first of these clipper systems should develop over the Dakotas
Tuesday afternoon, with 990 mb sfc low pressure swinging across the
Great Lakes Tuesday night into Wednesday. With our region sandwiched
between the deep low pressure to the north and high pressure to the
south, a strong pressure and height gradient will be in place across
the region Tuesday night into Wednesday. As a result of the strong
height gradient, a 60-65 kt H85 jet will swing across the Ohio
Valley Tuesday night into Wednesday morning. While nighttime low-
level stability should keep the strongest winds aloft, windy
conditions are expected Tuesday night into Wednesday morning, with
gusts of 25-35 mph likely.

As is typical with clipper systems, moisture will be fairly limited
and mostly confined to the north side of the system. With that being
said, as a sfc cold front passes through the region Wednesday, there
should be enough combination of lift and moisture to squeeze out
scattered rain showers. Rainfall amounts should be light, with most
areas receiving less than 0.10".

Behind the Wednesday clipper system, temperatures should drop for
Wednesday night into Thursday. While there could be a few scattered
flurries on Thursday, it is more likely that Thursday will end up
being dry across the area as we remain in between systems.

Thursday night into Friday, there is pretty good agreement in a
second shortwave and clipper system sliding across the Ohio Valley.
Exact timing and precipitation types and amounts are a bit more
variable between different model solutions. Given the modest cold
air intrusion behind the mid-week system and limited moderation in
temperatures, wintry p-types are more likely with this system. For
example, of ECMWF ensemble members which have precipitation, roughly
80% show snow for Louisville. Once again, moisture with this system
will be limited as the disturbance will be blocked from accessing
Gulf moisture. As a result, while there is a reasonably good chance
in wintry precipitation Thursday night into Friday, impacts are
generally expected to be limited at this time.

As we head from Friday into the coming weekend, there has been a
notable shift in the model guidance with respect to the magnitude of
the cold air over the past several model runs. Most recent guidance
has trended milder, with less amplification of the upper wave
pattern and less southward progression of the arctic air mass. As a
result, temperatures with this forecast update have come up about 5-
10 degrees across the area on Saturday, though there is still a
relatively large spread in temperature guidance. Below normal
temperatures are still likely this weekend, though there should be a
stronger north-south temperature gradient given the trend toward a
more baroclinic/zonal flow pattern. Another effect of this change in
the expected pattern would be increased chances for precipitation,
though p-types and amounts are highly uncertain.

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 644 PM EST Mon Dec 8 2025

MVFR stratus is slowly scouring out from the north and west this
evening, and SDF and BWG will likely see skies become FEW-SCT within
the first 2-3 hours of this forecast period. Confidence is lower on
the exact timing of clearing at LEX/RGA. LEX is slightly above the
VFR threshold, but BKN ceilings could linger a bit deeper into the
overnight period while flirting with MVFR conditions. Or, some
brief/TEMPO MVFR conditions are not out of the question at LEX early
Tuesday morning.

VFR conditions are expected to return by Tuesday morning, with winds
picking up out of the south by mid-to-late morning. 20-25 kt wind
gusts are likely Tuesday afternoon, with scattered mid-level clouds
expected through the day.

&&

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

&&

$$

SHORT TERM...CSG
LONG TERM...CSG
AVIATION...EBW