461
FXUS63 KLMK 220617
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
117 AM EST Sat Nov 22 2025

.KEY MESSAGES...

* Rain showers and a few embedded storms continue this morning.

* Patchy dense fog will continue through the early morning, an SPS
  has been issued for fog through 9Z.

* Dry and mild conditions today through Monday.

* A cold front will move through on Tuesday bringing a chance for
  showers and a few storms. Severe weather is not likely with this
  system.

* Cooler shot of air will arrive for Thanksgiving Day, bringing a
  small chance for light rain/snow mix on Friday night.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 117 AM EST Sat Nov 22 2025

The shortwave trough is swinging through the Ohio Valley this
morning, which is bringing lift to present moisture over the region.
Isolated showers have increased to scattered showers. Over the
southern half of the region, there has been less rain showers and
continued overcast skies, which has prevented decoupling. Therefore,
200-300 J/kg of SBCAPE is present over southern Kentucky. However,
lapse rates are poor and hodographs are elongated and nearly
unidirectional aloft. The 35kt LLJ and mid-level jet will help to
sustain showers and storms as they pass over the area. Not expecting
severe weather from these storms, though strong storms may be
possible. Hazards include: small hail, gusty winds, lightning, and
breif heavy rainfall. Additionally, saturated low-levels, rainfall,
and light winds has allowed for patchy, dense fog development. An
SPS has been continued for dense fog and will continue through 9Z.

Low and mid level troughing and the surface cold front will not
depart the region until late this afternoon. Therefore, low clouds
will remain through most of the day today. As the front passes
through, winds will shift from the SW to the NW and CAA will allow
temperatures to cool. High temperatures today given the clouds and
CAA, will likely not depart much from the low in the upper 50s and
low 60s.

In the evening, clouds will clear out from NW to SE. Winds will be
calm to light out of the NW. These conditions, coupled with
continued CAA will allow for efficient radiational cooling and low
temperatures in the upper 30s and low 40s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 117 AM EST Sat Nov 22 2025

Sunday through Monday...

Surface high pressure and ridging aloft will result in drier
conditions. High temperatures will be in the upper 50s and low 60s.
Lows will be in the upper 30s and low 40s.

Monday Night through Friday...

On Monday, surface high pressure will shift off to the east and
southerly flow will return to the region. Aloft, a closed low
pressure originating from the desert SW will drift and open up to a
trough over the central Plains and Midwest by Monday night. This
will develop a surface low pressure system and bring a cold front
through the region late Tuesday.

Ahead of the cold front, ridging and WAA will build over the region
on Monday and Tuesday, allowing temperatures and dew points to rise.
Expecting to see high temperatures on Tuesday in the mid 60s.
Looking at NBM and LREF probabilities, there is a 40-60% chance of
exceeding 60 degree dew points over far southern Kentucky on Tuesday
afternoon.

A 45-50kt LLJ will move over the region, which will help to promote
shower development along and ahead of the cold front Monday night
through Tuesday. Ample shear over the region and weak elevated
instability will help to promote storms. Not expecting severe
weather at this time, instability looks to not be surface based and
the upper troughing is weak over the Ohio Valley.

On Wednesday, another upper low originating from SW Canada will move
SE into the upper Midwest and collide with the original upper low.
This will keep a surface low pressure over the Great Lakes through
the end of the week. Light rain showers may linger into Wednesday,
but Wednesday and Thursday should see clearing conditions and drier
weather.

On Thursday, a shortwave will meet the upper low, bringing troughing
and a shot of colder air into the region. Will likely see chilly
temps in the 20s for Friday morning. Another weak trough may swing
through along the broader troughing, which may bring some light rain
showers and lingering snow flurries Friday night.

Going into the weekend, high pressure and broad ridging will bring
quiet and slightly warmer weather.

Extended Forecast Discussion...

Moving into the extended period, earlier thinking on cold weather
arriving sometime during the Thanksgiving Holiday period into late
December is not likely to occur.  Looking at the teleconnection
pattern shows why.  The expected pattern will be in a +NAO/neutral
AO/-EPO/-PNA configuration.  The original idea for late November
cold was based on the NAO to be much more negative yielding
sufficient blocking to get colder air into the US.  A second reason
is that the MJO looks to remain in phase 6 for the remainder of
November which overall is a milder pattern.

While we will see a brief cool down near Thanksgiving, the pattern is
expected to revert back to a milder pattern for the Ohio Valley.
Given the MJO phase 6 and forecast teleconnection pattern with a
weaker NAO blocking signal, a series of lake cutter systems with
lows moving from the southern Plains into the Great Lakes will be
seen.  This will bring periods of unsettled weather to the Ohio
Valley with above normal precipitation and risks of thunderstorms
(some strong/severe).  It would appear that we`ll get a broad
baroclinic zone setting up from the Plains to the Great Lakes.  On
the north side, widespread snows will help build the winter snow
pack from the inter-mountain west into Canada and into the north-
central and northern Plains.  The overall pattern reminds me of
December 2013, at least for the first half of that month.

Models have been insistent on a stronger westerly wind burst over the
far western Pacific which should propel the MJO into Phase 7 as we
head into December.  This would favor much colder conditions on the
north side of the aforementioned baroclinic boundary.  Some south
and eastward spread of the colder airmass across the Plains may
become more evident, especially if stronger blocking can occur up
near Greenland and more significant ridging builds in Alaska.
Assuming the westerly wind burst does its job, the MJO should
continue to propagate into phase 8 which would result in a more
significant cool down as we get further into mid-December.

&&

.AVIATION /06Z TAFS THROUGH 12Z SUNDAY/...
Issued at 1221 AM EST Sat Nov 22 2025

The main impacts through the forecast will be IFR and MVFR, with
brief LIFR CIGs and VIS. We will also see a wind shift from the SW
to more north as a front works through this morning. Low VIS from
HNB-SDF-LEX will remain through the early morning with LEX/HNB
dropping below 2 mile VIS with CIGs only a couple hundred feet. Slow
improvement during the day to MVFR later in the day as we start to
slowly clear out from the west to east but it may not really happen
until late afternoon and into the evening. Once skies clear, VFR
conditions will remain through the end of the forecast period.

&&

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

&&

$$

SHORT TERM...SRW
LONG TERM...SRW
AVIATION...SRW