319
FXUS63 KLMK 111732
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1232 PM EST Tue Nov 11 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Very cold temperatures will be seen this morning with lows in the
  upper teens to lower 20s.  Wind chill values will be in the lower
  to middle teens.  Isolated slick spots will remain possible on
  bridges and overpasses.

* Warming trend begins today with breezy southwest winds developing
  this morning and continuing into the overnight hours.

* Next chance of rain comes on Friday, but a better chance
  widespread showers and possibly some thunderstorms will come late
  in the weekend and into early next week.

&&

.UPDATE...
Issued at 1142 AM EST Tue Nov 11 2025

A weak trough is moving through the Ohio Valley today and bringing a
vort lobe into the northern half of the region. This has brought a
broken mid-level cloud deck and some mid-level moisture. Though,
there is a very dry layer in the low levels, which is preventing
precipitation from reaching the surface. There are light radar
returns, however it is likely virga. Additionally, a LLJ is moving
into the region this afternoon and wind gusts will pick up in the
next few hours. The previous forecast remains on track.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 348 AM EST Tue Nov 11 2025

Current observations show mostly clear skies across southern Indiana
and central Kentucky this morning.  Temperatures are quite cold with
many locations in the lower-middle 20s.  A few of our more protected
areas are down in the upper teens.  For the remainder of the
overnight hours, no significant weather is expected.  Overnight lows
will range from the upper teens to the lower 20s.

For today, upper trough axis will continue to move off to the
northeast with the Ohio Valley remaining in a northwest flow aloft.
A weak shortwave trough axis will pass to the north of the region.
This may bring some light precipitation as far south as southern IN
and OH.  However, model soundings from across our forecast area show
a rather deep low-level dry airmass in place.  So, overall the
threat of any precipitation looks very limited.  A southwest flow
will pick up during the late morning and into the afternoon hours
resulting in breezy conditions.  Highs on the day will exhibit a
gradient of temperature with highs ranging from the lower 40s over
the Bluegrass to the mid 40s in the I-65 corridor to near 50 in the
I-165 corridor.  Wind gusts of 20-25 mph with some isolated 30 mph
gusts will be possible this afternoon.

For tonight, mostly clear skies are expected across the area.
Aforementioned upper level wave will continue to cross the region. A
rather strong 850 hPa wind maxima is forecast to push through the
region with a core of 45-50kt winds.  Model soundings show an
increasing temperature inversion associated with the warm advection
scheme.  Full momentum transfer downward will likely not occur here.
However, wind gusts of 25-30 mph will be possible into the overnight
hours.  Overnight lows will generally be in the 34-39 degree range.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 348 AM EST Tue Nov 11 2025

Wednesday through Friday Night...

For Wednesday and Thursday, dry weather is expected with a
moderation in temperatures.  An upper level ridge is forecast to
develop over the inter-mountain west with a broad trough axis
centered off the US east coast.  A northwest flow aloft will be seen
across the Ohio Valley.  Highs Wednesday will range from the upper
50s to the lower 60s with overnight lows in the low-mid 30s. Highs
Thursday will be similar to Wednesday with mainly upper 50s and
lower 60s expected.

By Thursday night, surface high pressure axis will shift east of the
region and our flow will kick around to the southwest.  A nocturnal
low-level jet is expected to develop from the Mid-MS Valley eastward
into the Ohio Valley.  A weak perturbation aloft is still forecast
to slide eastward through the region late Thursday and into Friday
which may bring some elevated convection to the region early Friday.
Otherwise, warming conditions are expected to continue with highs on
Friday rising into the lower to middle 60s over much of the area.
Some 70 degree readings are possible out in the I-165 corridor.

Saturday through Monday...

Moving into the weekend, high latitude blocking will be in place
across Canada while a shortwave ridge axis moves across the Ohio
Valley.  This will keep our weather dry for Saturday with afternoon
highs topping out in the upper 60s to the lower 70s.  A few mid 70s
are likely down across southern Kentucky.

An upper trough axis will approach the region late Saturday with a
surface cold front pushing through the area early Sunday.  There
isn`t a lot of moisture for this system to work with, but expect
some scattered showers in advance of the front.  Slightly cooler
temperatures are expected on Sunday with highs in the upper 60s.

Shortwave ridging will build over the region on Monday in advance of
a mid-level trough axis coming out of the Plains.  The overall model
trends have been slightly slower with this system, but this feature
will likely bring unsettled weather back to our region late Monday
and into Tuesday.

Extended Forecast Discussion...

Aforementioned upper level wave looks to move through the region on
Tuesday with unsettled weather.  A broad southwest flow will develop
across the southeastern US as a major upper level trough axis drops
into the four corners region.  A secondary perturbation looks to
move across the region on Wednesday bringing another round of
showers and possible storms.

High latitude blocking is expected to grow stronger across northern
Canada and into Greenland as the NAO becomes quite negative.
Aforementioned upper trough axis over the four corners will eject
into the Plains by next Thursday and amplify significantly as it
approaches the Ohio Valley/Midwest by Friday.  Signal analysis has
been highlighting the 11/21-22 time frame for the last several
weeks.  The 11/00Z Euro solution is quite impressive with a negative
tilt trough axis and deepening low pressure sliding west of the
region. If this evolution should occur, an outbreak of severe
weather will be possible from the Ohio Valley southward into the
Gulf coast states.  We`ll need to watch this period of time very
closely.

An overall active weather pattern looks to continue into late
November.  There are increasing signals that the pattern is likely
to grow increasingly colder as we move from late November and into
December.  This is due to several hemispheric conditions that may
develop. High latitude blocking is forecast to continue across
northern Canada and Greenland.  Model teleconnection forecasts show
a rather strong -AO/-NAO pattern developing with the EPO likely
going negative as well.  At the same time, the MJO which is
currently in phase 6 is forecast to migrate over into phase 7 as we
close out November and head into December.  The push into phase 7 is
likely being aided by strong stratospheric warming over the
Antarctic regions which will shove the MJO into the western
Pacific/Western hemisphere.  Not to be outdone, there is growing
forecast confidence, at least from the Euro model, that we may see
some significant stratospheric warming over Canada toward the end of
November.  To be honest, this is one of the earliest SSW events that
I`ve seen coming out of the models.  SSW events usually precede some
perturbation of the PV which can unleash colder air masses into the
US.  The Euro weeklies out through December have been showing the
development of a ridge west, trough east pattern for much of
December which is in line with historical Decembers that feature La
Nina in the Pacific.  Bottom line here is that a quick start to
winter is becoming increasingly likely and December on a whole may
be quite cold for our region.

&&

.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 1231 PM EST Tue Nov 11 2025

An upper trough and moisture has brought a mid-level cloud deck
around 10kft, where virga is present. Additionally, a 45-50kt low
level jet is building over the region this afternoon, which will
allow for gusty winds up to 28kts at the surface. Within a few hours
of sunset, a nocturnal inversion will develop and help surface winds
to relax some. With the jet present overnight, these conditions will
bring LLWS from 2-11Z over most of the region. On Wednesday morning,
surface winds will begin to veer to the west and skies will remain
clear.

&&

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

&&

$$

UPDATE...SRW
SHORT TERM...MJ
LONG TERM...MJ
AVIATION...SRW