322
FXUS63 KLMK 020546
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
146 AM EDT Mon Jun 2 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Mainly dry with warming temperatures Monday into Wednesday.

* Active weather to return Thursday and Friday with possible
  strong/severe storms and heavy rainfall.

&&

.UPDATE...
Issued at 1103 PM EDT Sun Jun 1 2025

Late afternoon convection has moved south of the region and
dissipated at this hour. The remainder of the night will feature
calm to light winds and clear skies. The southern half of the region
did the see quite as much efficient mixing as the northern half of
the region did. Therefore, patchy fog development will be possible
over the southern areas. Especially, areas that saw rain from this
afternoon. Fog will dissipate within a hour or two of sunrise in the
morning.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 302 PM EDT Sun Jun 1 2025

The big question for this afternoon and evening will be what, if
any, convection will fire along the boundary currently draped across
south central KY. Right now, the boundary appears to be situated
along a Hartford KY, to Glasgow, KY, to Lake Cumberland area line.
Dew points drop off into the low and mid 40s north of this boundary,
with low to mid 60s values south of it. Modest instability has
developed south of this boundary characterized by ML CAPE values
around 500-1000 J/KG, and the cumulus field has started to become
more agitated in this area as well. Surface moisture convergence on
the latest 18z mesoanalysis doesn`t show much at the moment, and
latest hi-res guidance doesn`t expect isolated to scattered
initiation until after 5pm. It is possible that the upper level
smoke from upstream wildfires is hurting temps/insolation just a
bit, which directly affects destabilization. For the moment, we
aren`t realizing the amount of instability that forecast soundings
would otherwise suggest. If/when showers and storms do get going,
expect isolated to widely scattered coverage. They should be in an
environment with just enough deep layer shear (25 to 30 knots) to
perhaps support some brief/loose organization. Mid level lapse rates
are better today than yesterday, so do think some hail could
accompany a gusty or isolated severe wind threat with the strongest
storms. SPC Marginal Risk looks pretty good, however the boundary
doesn`t make a whole lot of progress southward, it may need to be
lifted just a bit farther north closer to the current analyzed line
mentioned above.

Any convection dies off tonight with cool overnight lows in the
upper 40s and low 50s for most. Perhaps our SW stays more in the
upper 50s nearer the boundary. Could see some patchy fog, especially
nearer the boundary or in valleys as well.

Monday brings a quiet day with upper ridging building overhead and
likely some wildfire smoke potentially impacting the boundary layer
a bit more (rather than upper level). It seems smoke is affecting
temp ranges a bit, but will still call for warmer temps in the upper
70s and low 80s for most. Mid 80s most likely across west central KY.

&&

.LONG TERM /TONIGHT THROUGH SUNDAY/...
Issued at 302 PM EDT Sun Jun 1 2025

Monday Night - Wednesday...

An upper ridge axis and the western fringes of strong surface high
pressure anchored over the mid Atlantic Coast will continue to
dominate our pattern through mid week. This will keep us in
continued dry, and increasingly warm conditions during that stretch.
In fact, looking for above normal temps with max Ts in the 85 to 90
degree range each day. Could be a pattern to go well above guidance
on, but recent widespread rainfall, some wildfire smoke hurting
insolation, and upper sky cover all decrease confidence on going too
warm by Tue/Wed. Nevertheless, we`ll definitely have a more of a
summertime feel as we begin the month of June. Overnight lows will
also be notably milder, especially on Tuesday night as we only
bottom out in the mid 60s to around 70. There continues to be a
small chance for a shower or storm across our NW CWA by Wednesday
PM, but my gut tells me the upper ridge will mostly win out, and
this period will trend toward completely dry. Will leave some small
chances in for now.

Wednesday Night - Friday Night...

The latter half of the week looks active. The upper ridge axis from
earlier in the week will have slid east over the Atlantic Coast,
meanwhile more of a SW flow aloft ahead of broad upper troughing
over the western 2/3 CONUS will start to envelope our area. At the
surface, a trailing cold front from an eastern Canada system will
slide toward and into our region, likely stalling for at least some
time. Chances for showers and storms will steadily increase from NW
to SE starting as early as Wednesday night across our NW, but more
likely on Thursday afternoon and into Thursday night across much of
our CWA as a subtle shortwave ejects out of the southern Plains into
our area. This wave may have some strong to severe storm potential
with it as we should be fairly unstable ahead of it, and the
shortwave will provide the added deep layer shear. Something to
watch, and will continue to look for at least some signal in the
NSSL/CSU ML products. Right now, the signal remains weak, but is
there.

The front will likely stall near or over our area by Friday,
bringing added rounds of showers and storms to the area. May have to
start watching some rainfall totals by this point for some localized
nuisance or flood concerns, especially if we get some training over
the same areas.

Saturday - Sunday...

Another shortwave looks to rotate through the Great Lakes region by
Saturday, and is expected to help push the stalled frontal boundary
through our area. Models disagree on just how progressive this
evolution will be, so will have to keep some pops lingering into the
weekend. There is a chance that this weekend will be drier than
currently forecast if indeed the front makes a clean pass through
our area. For now, will keep lingering chances and slightly cooler
temps in the low to mid 80s going.

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 146 AM EDT Mon Jun 2 2025

VFR conditions likely through much of this TAF period. Some fog is
possible early this morning, mainly at RGA and HNB. Winds will
remain very light (3 kt or less) out of the E/SE through the early
morning hours. BWG will see some SCT lower clouds around 4-5 kft.

Today, a SE wind will increase to around 5 kt. Skies will be mostly
clear, albeit hazy due to the continued presence of wildfire smoke
aloft.

&&

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

&&

$$

UPDATE...SRW
SHORT TERM...BJS
LONG TERM...BJS
AVIATION...EBW