754
FXUS63 KLMK 090601
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
101 AM EST Tue Dec 9 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.

&&

.UPDATE...
Issued at 900 PM EST Mon Dec 8 2025

Chilly, calm conditions are being observed this evening as high
pressure drifts overhead. Most of southern Indiana (except for
Harrison/Floyd counties) and western Kentucky now have mostly clear
skies, which has allow temps to dip into the mid 20s already.
Stratus continues to slowly scour out from the west and north across
central KY, but we`re also seeing the lower clouds thin a bit faster
now over the Bluegrass.

Expect a patch of SCT-BKN low clouds over central KY to gradually
move off to the east over the next several hours. Temperatures will
dip further into the upper teens to mid 20s during that time frame.
Winds will remain light overnight, only beginning to increase out of
the SSW toward dawn.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
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 /WEDNESDAY 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 /06Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 100 AM EST Tue Dec 9 2025

There is a finger or stratus cutting north across central Kentucky
over SDF. This layer drops south and wraps around very close to RGA,
and south of LEX. Currently, believe SDF is about to improve to
clear skies before an approaching mid-layer deck arrives later
tonight from the northwest. Southwest winds are going to increase
during the period before gusts begin during the day. Tuesday night,
might see gusts to around 30 knots.

&&

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

&&

$$

UPDATE...EBW
SHORT TERM...CSG
LONG TERM...CSG
AVIATION...KDW