930
FXUS63 KLMK 060137
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
937 PM EDT Tue Aug 5 2025

...Forecast Update...

.KEY MESSAGES...

* Showers and storms ending. Fog possible tonight, locally dense
  in spots.

* Additional rounds of afternoon and evening showers and
  thunderstorms are expected again on Wednesday.

* Below normal temperatures through mid week, with temperatures
  warming to around normal levels by late week.

&&

.UPDATE...
Issued at 936 PM EDT Tue Aug 5 2025

Convection continues to slowly diminish this evening, although some
"chain reactions" continue to keep a few areas seeing showers and
storms. The biggest focus right now is over Grayson county where
some nearly stationary activity is ongoing. Overall, don`t expect it
to continue too much longer, but did extend measurable pops by
another hour or two to account.

Otherwise, the main focus overnight will be fog potential. T/Td
spreads are already quite low in many spots. In addition, skies are
expected to be partly to mostly clear tonight with generally light
and variable winds. The good radiational cooling conditions combined
with recent heavy rainfall in spots should make for a decent fog
setup. Guidance seems to be hitting the fog signal pretty good,
especially in our north and eastern CWA. Went a bit more aggressive
with coverage of fog, and will look for the potential for pockets or
even greater coverage of dense fog overnight. For now, it seems the
best potential for dense fog will be isolated areas where it rains
the hardest and river valleys, but will see how things go through
the late evening/overnight.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 330 PM EDT Tue Aug 5 2025

Afternoon satellite shows partly cloudy skies across much of the
region.  Surface analysis has a weak low pressure center near KFTK.
Aloft, we have a weak upper level trough axis providing synoptic
scale lift over the eastern/northeastern areas.  A concentrated area
of shower and a few thunderstorms was located along and north of the
I-64 corridor between Lexington and Louisville.  Storm motions are
not all that fast this afternoon.  While instability has been enough
to support storms, wind shear remains quite weak.  PWAT values are
in the 1.5-1.6 inch range, which fairly seasonal for late August. So
the storms are producing locally heavy rainfall, some gusty winds,
and a bit of lightning.

For the remainder of the afternoon and into the evening, current
thinking is that main convective corridor will remain along the I-64
corridor and points north.  Some additional development down along
and south of the Bluegrass Parkway may occur.  Overall, I think the
most likely corridor will be between Louisville, Frankfort, and down
toward Richmond, KY.  Basin rainfall amounts of 0.25-0.75 inches
will be possible.  However, where storms train or remain stationary,
localized amounts of 2-3, perhaps isolated 4 inch amounts could
occur in some areas.  Isolated flash flooding will be possible in
areas that see appreciable rainfall.

For this evening and into the overnight, showers and storms are
likely to diminish with the setting sun.  Partly cloudy skies are
expected overnight.  With the recent rains and light winds, some
patchy dense fog will be possible, especially in areas that see
ample rainfall this afternoon.  Lows tonight will be in the 65-70
degree range in most areas.

For Wednesday, partly cloudy skies are expected once again with
afternoon temperatures warming into the 83-88 degree range.  With
the upper trough axis remaining overhead, another round of mainly
afternoon/evening showers/storms are expected.  The highest
probability of rainfall looks to be along and east of the I-65
corridor.  Severe weather is not anticipated as wind shear values
will remain weak.  Locally heavy rainfall, gusty winds, and
lightning will be the main threats with the activity.  Look for any
storms to end by evening with overnight lows in the upper 60s to
around 70.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 330 PM EDT Tue Aug 5 2025

Thursday through Saturday Night...

Moving into the extended period upper level ridge axis over the four
corners region is forecast to expand to the northeast into the
Plains later this week.  Upper level trough axis across the Ohio
Valley is forecast to move eastward which should result in a drier
weather pattern for us locally with warming temperatures.  Still
can`t rule out some showers/storms across our far SE during the
period.

Highs Thursday will warm into the mid-upper 80s, with upper 80s to
around 90 by Friday and into Saturday.  Overnight lows will be in
the upper 60s to the lower 70s...which is seasonal for early August
around here.

Sunday through Tuesday...

Moving into the late weekend, the ridge axis looks to split a part
as a stronger trough axis moves through the northern US.  The heat
ridge dome will retract/retrograde westward back into the four
corners area while the western Atlantic ridge attempts to build
westward toward the SE US coast.  A general weakness in the 500h
ridge will likely promote a wide area of disturbed weather off the
SE coast this weekend.  This will move inland across the SE this
weekend though the bulk of it looks to remain to our southeast.
Climatological PoPs seem warranted in this pattern across our
region.  However, the aforementioned upper trough coming across the
Plains will reach the Midwest by late Monday/Tuesday which bring
additional chances for showers/storms to the region toward the end
of the period.

Highs during this period will be in the upper 80s to the very low
90s with overnight lows in the upper 60s/lower 70s.

&&

.AVIATION /00Z TAFS THROUGH 06Z THURSDAY/...
Issued at 758 PM EDT Tue Aug 5 2025

Scattered showers and storms are ongoing mainly across north central
and NE KY at this hour, with the closest impacts to the SDF/LEX/RGA
terminals. Given the sparse coverage, and expected diminishing of
storms over the next 1 to 2 hours, will stay optimistic for this
issuance, however will amend if a storm looks to directly impact a
terminal again.

Outside of that, look for a mostly quiet first part of the night
before fog chances increase after Midnight through the pre-dawn
hours. Will continue to message MVFR with some periods of IFR
possible toward dawn. Our northern TAF sites (HNB/SDF/LEX/RGA) look
to be the most vulnerable, and can`t rule out some vis even lower
than IFR around sunrise. Otherwise, look for improvement by mid to
late morning with light and variable winds and VFR returning. A few
afternoon/evening storms are again possible tomorrow, mainly east of
I-65.

&&

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

&&

$$

UPDATE...BJS
SHORT TERM...MJ
LONG TERM...MJ
AVIATION...BJS