105
FXUS63 KLMK 210939
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
439 AM EST Fri Nov 21 2025

.KEY MESSAGES...

* Waves of rain showers, with a few embedded storms, are expected
  today through Saturday morning. Severe weather and flooding remain
  unlikely with this system.

* The late weekend and into early next week will see drier
  conditions, before another chance for rain arrives by next
  Tuesday. Temperatures turn cooler by Thanksgiving Day.

&&

.UPDATE...
Issued at 439 AM EST Fri Nov 21 2025

Over the past hour, there have been a couple ASOS/AWOS obs of 1/2 SM
or less across southern KY, with KY Mesonet and traffic cameras also
showing very low visibility across southern KY. Given the proximity
to the developing warm front, think that these lower visibilities
may persist for a while. A dense fog advisory has been issued until
9 AM CST to account for these reductions in visibility.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 333 AM EST Fri Nov 21 2025

This morning, a renewed push of low clouds and moisture is working
into the area from the southwest. Pockets of drizzle and fog have
been observed across southern KY as low-level moisture settles in
the presence of weak boundary-layer winds. Even though pockets of
drizzle and persistent near-sfc saturation have kept things wet
across the area last night into this morning, most of the actual
rain shower activity has stayed south and west of the area through
08Z. A notable north-south gradient in temperatures is observed in
latest obs, ranging from the upper 40s north of I-64 to the mid-to-
upper 50s along the TN border.

As we head through the rest of the morning hours, an upper-level
shortwave over the southern Plains will eject to the northeast
across KS before moving to the east along the I-70 corridor this
afternoon and evening. Mid-level frontogenesis over the lower
Missouri Valley should support the development of a band of rain
showers which will extend to the ESE across the lower Ohio Valley.
This band of rain showers should move from SW to NE across the area
later today, with rainfall rates generally being light, with a few
embedded pockets of moderate rain. At the sfc, a stationary front
over TN this morning will lift to the north as a warm front, with
the front expected to end up near the I-64 corridor by this evening.
To the north of the warm front, low clouds and showers will
continue, with temperatures remaining fairly steady in the upper 40s
and low-to-mid 50s. South of the warm front, warm advection via
southerly winds should allow temperatures to warm into the 60s this
afternoon, with showers becoming much more isolated.

By this evening, the shortwave energy and its associated sfc low
will turn more to the east as it gets picked up by a departing
northern stream trough. With the sfc low expected to track across
southern IN and northern KY tonight, a trailing cold front will move
across the southern half of the CWA during the late evening and
overnight hours. While the warm sector with this system will not be
particularly robust, sfc dewpoints climbing into the low 60s this
evening should allow for around 500 J/kg of SBCAPE across southern
KY, with similar amounts of MUCAPE located further north. With the
combination of modest instability within the warm sector and forcing
along the cold front, think that a line of showers and storms will
move across the region late this evening into early Saturday
morning. While deep-layer shear is sufficient for organized
convection, lacking instability and fairly unidirectional shear
profiles should limit the overall severe threat. However, given the
proximity to better instability across the TN valley, a strong storm
can`t be completely ruled out along and south of the Cumberland
Parkway tonight (note the SPC Day 1 marginal risk).

Otherwise, a drying trend is expected from NW to SE behind the front
after midnight tonight, though low clouds and patchy drizzle/mist
will likely continue into early Saturday morning. NW winds will
bring in weak cold advection behind the front, with lows ranging
from the mid 40s (NW) to the mid 50s (SE) Saturday morning.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 333 AM EST Fri Nov 21 2025

Saturday through Sunday Night...

The upper level shortwave and its associated sfc low will cross the
Appalachians into the mid-Atlantic on Saturday, with drier northerly
flow working into the region in its wake. Low-level moisture will be
a bit slow to clear, so while most areas should remain dry during
the day on Saturday, a stratus layer may stick around through much
of the day before clearing from north to south during the afternoon
and evening hours. A spotty shower can`t be ruled out south of the
Parkways on Saturday where the low-level moisture will be a bit
deeper. Highs on Saturday in most locations should warm into the
upper 50s and low 60s, fairly seasonable for this time of year.

Depending on how much clearing occurs Saturday afternoon, there is a
signal for areas of fog Sunday morning, especially south of I-64.
Otherwise, Sunday should bring the dry weather and mostly sunny
skies across the area as high pressure moves across the region.
After a cool start in the 30s, temperatures should warm into the
upper 50s and low-to-mid 60s Sunday afternoon. Mid- and high-level
clouds will increase from the west Sunday night, with lows falling
into the upper 30s and low 40s.

Monday through Thanksgiving...

High pressure over the region on Sunday will pass east of the
Appalachians Sunday night into Monday morning as another low
pressure system moves across the central Plains. South-southwest low-
level flow will begin to lift moisture northward into the mid-MS and
lower OH Valley during the day on Monday, increasing clouds and
promoting warm advection which should lead to milder high
temperatures Monday afternoon. There is still some timing
differences in how fast rain arrives into KY/IN, with the faster
GFS/GEM starting as early as Monday afternoon, while the slower
ECMWF holds off until Monday night. Given that models tend to be too
fast with moisture return, it would appear more likely that the
daytime hours on Monday remain dry, with rain increasing from west
to east Monday night.

The main push of rain showers is expected to cross the region late
Monday night into Tuesday morning as the upper wave and its
associated sfc low cuts across the mid-Mississippi Valley and into
the Great Lakes. The system is expected to be weakening as it passes
near our region, so it looks like the potential for strong storms
will be low and overall rainfall amounts will be modest (0.50-1").
Medium-range guidance has trended toward keeping rain showers near
the region into the first half of the day on Wednesday until the
main upper trough axis begins to push through. As a result, would
not be surprised if subsequent forecasts increase PoPs on Wednesday,
especially east of I-65.

Wednesday into Wednesday night, west-northwest winds will bring
stronger cold advection into the region, leading to a progressive
step down in temperatures as we head into Thanksgiving. While
temperatures on Wednesday should be near normal, below normal
temperatures are likely on Thanksgiving Day, with lows in the 20s
and low 30s and highs in the low-to-mid 40s. Model guidance is
fairly consistent in showing high pressure moving across the region
on Thanksgiving, so dry weather would also be expected at this time.

&&

.AVIATION /06Z TAFS THROUGH 12Z SATURDAY/...
Issued at 1234 AM EST Fri Nov 21 2025

A steady downward trend in ceilings and visibilities will continue
over the next 3-6 hours, with all sites expected to return to
IFR/LIFR conditions by 21/10-12Z. Most of the visibility reductions
over the next several hours will be due to mist and drizzle, with
the next wave of rain showers beginning to move through the region
after 09Z. Winds will be light and variable at all sites through mid-
morning. Later today, a warm front is expected to be draped from
west to east across the region. North of the front, continued
LIFR/IFR conditions are expected, with rain and mist producing
reduced visibilities. South of the front, cigs and vis should
improve to low MVFR levels. BWG and RGA have the best shot of
getting south of the warm front, with lower confidence at
SDF/LEX/HNB. Winds will also veer from E to S/SW from north to south
across the warm front. Flight categories should fall again toward
the end of the current forecast period as the sfc low tracks across
the area.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Dense Fog Advisory until 9 AM CST this morning for KYZ026-027-
     061>064-070>078-081-082.
IN...None.

&&

$$

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