878
FXUS63 KLMK 291747
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1247 PM EST Sat Nov 29 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Precipitation, mostly in the form of rain, will arrive late
  Saturday afternoon, early evening with a few location across
  southern IN seeing a quick burst of snow or rain snow mix. Little
  to no impacts expected

* Another shot of cold air for Sunday with gusty winds making it
  feel rather blustery.

* Winter storm system Monday night into Tuesday will bring a wide
  spread of wintry weather types to the area ranging from impactful
  accumulating snow, wintry mix with some locations seeing only rain.

&&

.UPDATE...
Issued at 1127 AM EST Sat Nov 29 2025

Light radar returns continue to train across our southern IN
counties; however, sfc obs continue to suggest that most/all of the
snow aloft is sublimating before reaching the ground. SDF ACARS
soundings continue to show a stout dry layer below 700 mb, with
little in the way of top-down saturation taking place over the past
few hours. RAP mesoanalysis continues to show the best LLJ/moisture
advection over the Mississippi Valley and into southern IL, though
this should begin to shift east later this afternoon. Until better
moisture can saturate the lowest 10 kft, it will be difficult to get
much precipitation to the ground.

No major changes to the forecast at this time. Where the mid-level
deck is located this morning, temps have run a few degrees below the
previous forecast, so have blended to short-range consensus guidance
which is handling this better.

Issued at 848 AM EST Sat Nov 29 2025

A mid-level stratus deck has overspread most of the area this
morning, with the exception of areas around Lake Cumberland and
points along the TN border. As this stratus deck has moved overhead,
temperatures have gradually risen into the upper 20s east of I-65
and into the low 30s west of I-65. Regional radars do show light
returns beginning to work into SW and central Indiana, but obs
indicate that most of this is not reaching the ground until you get
west of the Wabash Valley.

As we head through the rest of the morning hours, winds will
steadily increase out of the E/SE, and temperatures are expected to
warm above freezing, particularly across southern and central KY.
Greater saturation over IN may eventually lead to pockets of
flurries and light snow showers by around midday, and some of these
flurries could make it into north central KY this afternoon. It
still looks like no significant impacts are expected with this, and
there are no major changes to the forecast at this time. Did make
some minor adjustments to PoP trends for this evening and tonight to
incorporate preliminary 12Z hi-res data.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 419 AM EST Sat Nov 29 2025

The main focus for the short term will be the arrival of a strong
storm system coming out of the central plains moving through the
Ohio Valley and into the Great Lakes by Sunday morning. Short range,
hi-resolution guidance is doing a good job this morning with the
main main precipitation shield that is currently stretches from IA
through most of MO into western AR, with mainly snow falling north
of a line from St. Louis to Kansas City.

As this system approaches during the morning, we will initially see
high clouds as the main precipitation shield will be to our west
through IL into MO and AR. A very strong 60-65kt LLJ behind the
precipitation will continue to advect warm and moist air northward
into the Ohio Valley. It appears the hi-res short range guidance is
showing a much clearer picture on where this storm system is headed
and where most of the precipitation will fall today into tonight.
Current guidance takes the sfc low as well as the best overall
dynamics and lift and keeps it to our west over IL and then
northward through the northern half of Indiana. As warm and moist
air advection increases ahead of this system during the day, dry air
associated with the colder air at the surface will initially keep
most if not all of the precipitation from reaching the ground. Model
sounding show a good dry layer between 800-900mb and any snow that
may try to form this morning or early afternoon will initially
sublimate as it works through this dry layer. At best, we may see a
few flurries or flakes across southern IN and parts of norther KY
through the first half of the day.

Our best chance for precipitation arrives late afternoon into early
evening as band of precipitation associated with leading edge of the
LLJ will work along the Ohio River northward between 22z to 01z.
There may be enough cold air north of the Ohio River that we could
see an initial burst of snow or rain/snow mix but the trend in
guidance seems to be that the warm layer wins out scouring out the
near sfc cold air before the main precipitation arrives. While it is
still possible that a few of our far northern southern IN counties
could see a quick burst of accumulating snow, the likelihood of that
happening have been dropping since yesterday as most of the forcing
works north and the WAA wins out. Most will just see rain as the
precipitation arrives later this afternoon and early evening.

Scattered light to moderate rain showers are expected through the
evening and overnight Saturday into Sunday morning with temperatures
holding fairly steady in the 40s to upper 30s. Wind gusts of 20-30
mph are expected as the LLJ pushes through the Ohio Valley this
evening and a tight sfc gradient associated with the passing storm
system.

Strong cold front works in from the west to the east quickly Sunday
morning, with winds shifting from the south to the west behind the
front. This will also be followed by strong reinforcing shot of cold
air behind it. Temperatures will quickly drop into the mid 30s and
then hold steady and slowly drop through the day. Sunday will be
cold and blustery under mostly cloudy skies with winds still gusting
to around 20-25 mph, making it feel like it is in the mid 20s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 419 AM EST Sat Nov 29 2025

In the long term our attention turns to the next system that will
impact the region late Monday into Tuesday. Shortwave trough working
out of the Four Corners and through the southern Plains Monday night
will interact with a developing sfc low coming out of the western
Gulf. As the shortwave trough axis works across the OH and TN
Valleys, the sfc low tracks across the southeast towards the
Carolinas/Mid-Atlantic coast by Tuesday afternoon.

This will advect Gulf moisture Northwest into the Ohio Valley during
the day Monday. The combination of isentropic lift associated with
the warm and moist air advection and a mid level jet streak ahead of
the mid-level trough axis, we will not be lacking for lift and
forcing allowing for widespread moderate to potentially heavy
precipitation to develop over the area Monday night into Tuesday.

As was mentioned in the previous forecast, while this would normally
be a classic setup for a winter storm over the Ohio Valley, we will
be lacking a strong deep cold airmass to keep the precipitation as
mostly snow. While the deterministic guidance of the GFS and EURO
ensembles agree that we will likely see a wide variety of p-types
over the CWA, the confidence on where it will snow, where it it will
be a wintry mix of snow, sleet and even freezing rain to even just
plain rain remains the main challenge. We continue to see consensus
in the models suggesting we will see a NE to SW snow/mix/rain line
bisect the Common Wealth but where does this boundary sets up
remains the main challenge in the forecast. The latest 00z run of
the deterministic had the ECMWF keeping that line along the WK/BG
Parkways while the GFS had shifted the warmer air further north the
wintry mix line along the Ohio River. As we go through the weekend
we will start to see the the guidance between the deterministic
models to come together on a common solution helping us increase
overall confidence. For now, to help with messaging of potential
impacts, we will stay away from specific numbers and focus more on
potential impacts and general placement for the various p-type
associated with this system.


Once we get through this system on Tuesday, the rest of the week
looks to be dry as our forecast will be dominated by sfc high
pressure through the region. Temperatures will remain below normal
with highs mainly in the mid/upper 30s with the possibility of some
40s. We could see the next potential system arrive by the start of
next weekend.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 1247 PM EST Sat Nov 29 2025

A low pressure system and an associated cold front will move across
the region later today through Sunday morning, bringing rain
showers, gusty winds, and MVFR ceilings. This afternoon, VFR
conditions should continue at all sites as mid-level clouds
gradually build down. Winds should veer to the southeast and
increase in strength later this afternoon and evening. The first few
bands of rain showers should begin to move from west to east across
the area after 21Z this afternoon. While there could be a very short
period of a mix with sleet or snow (particularly at HNB),
precipitation should change to all rain within an hour of onset.
Tonight, as the cold front moves into the area, winds should
strengthen and continue to veer to the south-southwest. 20-25 kt
wind gusts are possible later tonight, especially if low-level
stability is weaker than expected. CIGs should gradually drop to
MVFR levels from west to east tonight, and the exact timing of
category changes is a bit uncertain. Around sunrise Sunday, the cold
front should move through the area, with breezy west winds and MVFR
CIGs expected behind the front Sunday.

&&

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

&&

$$

UPDATE...CSG
SHORT TERM...BTN
LONG TERM...BTN
AVIATION...CSG