804
FXUS63 KLMK 212357
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
757 PM EDT Thu Aug 21 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Dry with near seasonal temperatures for tonight through Saturday.

* Frontal boundary to pass through the region Saturday night and
  Sunday with some showers/storms possible.

* Below normal temperatures expected for much of next week leading
  up to Labor Day.  Some overnight lows in the upper 40s will be
  possible by the middle of next week.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 312 PM EDT Thu Aug 21 2025

Partly to mostly cloudy skies were noted across the region this
afternoon.  A mix of stratus and stratocumulus has been slow to mix
out despite some afternoon heating and mixing.  A low-level
northeasterly flow with a maximum of moisture within the 900-850 hPa
layer has kept the clouds going.  The bases have lifted a good bit,
but we still have a ways to go.  Given the persistent cloud cover,
we did lower max highs a bit after lunch to lower them into the
upper 70s to the very low 80s.  For the remainder of the afternoon,
no significant weather is expected.  Partly to most cloudy skies
will continue though we should start to see that moisture eventually
mix out this evening.  Look for temps to lower back into the 70s for
much of the evening.

Into the overnight, partly cloudy skies are expected.  Ongoing
stratus and stratocumulus are expected to slowly dissipate, though
it may take much of the night to clear out due to the nocturnal
inversion strengthening.  Overnight lows look to cool into the
middle 60s in many spots, but those areas that see substantial
clearing could drop into the lower 60s.

For Friday and Friday night, upper level ridging across the plains
will continue to build eastward.  Friday looks to be a partly cloudy
day again with highs in 84-89 degree range.  Lows Friday night will
drop back into the middle 60s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 312 PM EDT Thu Aug 21 2025

Saturday through Monday Night...

Moving into Saturday, a fairly strong upper level closed low is
forecast to move through southern Canada and into the Great Lakes. A
cold front across the Midwest will drop southeastward into the Ohio
Valley Saturday afternoon.  Latest round of model data continues to
show at least some scattered showers/storms across south-central and
southeastern portions of the forecast area Saturday afternoon and
evening.  So we`ll continue to run chance PoPs through this period.
With the front holding off until the afternoon, under a southwest
flow we should see temperatures warm into the mid-upper 80s.
Temperatures Saturday night will drop back into the low-mid 60s.

Moving into Sunday, the upper closed low will continue to spin
slowly through southern Ontario and into the northern Great Lakes. A
fairly strong upper trough will then swing through the Ohio Valley
behind Saturday`s front.  Sunday continues to look dry at this point
with cooler and less humid air moving into the region.  Highs Sunday
will range from the low-mid 80s across southern Indiana and into the
northern half of Kentucky, with mid-upper 80s across far southern KY.

The much cooler air looks to arrive Sunday night with lows dropping
into the upper 50s to around 60.  Highs on Monday will be below
normal with readings in the mid-upper 70s across southern Indiana
and much of northern Kentucky, upper 70s to around 80 will be
possible across southern Kentucky.  Lows Monday night will continue
to trend cooler with overnight lows dropping into the low-mid 50s. A
few of the cooler/protected areas in southern Indiana could hit the
upper 40s.

Tuesday through Thursday...

For this period, the upper level flow will remain quite amplified
across the CONUS with a rather large ridge in the western US with a
downstream trough axis across the east.  Our area will remain in a
deep northwest flow keeping temperatures well below late August
levels.  In fact, much of Tuesday and Wednesday will feel more mid-
late September with temperatures averaging some 12-18 degrees below
normal.  Highs Tuesday will be in the mid-upper 70s with overnight
lows in lower-middle 50s, though protected valley locations could
drop into the upper 40s.  Highs on Wednesday will be similar to
Tuesday with mid-upper 70s.  Lows Wednesday night will be in the low-
mid 50s.  By Thursday, the upper trough axis will shift slightly
eastward with some building of heights aloft over our region.  This
may allow temps to warm back into the upper 70s to near 80 in a few
spots.

&&

.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 757 PM EDT Thu Aug 21 2025

Ceilings are continuing to improve. This trend is expected to
continue into the night. Light fog will be possible again tomorrow
morning at HNB, LEX, and RGA. Near LEX and RGA, there is also a
chance for some limited stratus. The rest of the period is expected
to remain VFR after any fog and/or limited status clears. Light
winds will remain out of the northeast before backing towards the
north tomorrow afternoon.

&&

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

&&

$$

SHORT TERM...MJ
LONG TERM...MJ
AVIATION...KDW