672
FXUS63 KLMK 172312
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
712 PM EDT Mon Aug 17 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* A few showers and isolated storms are possible this afternoon,
  especially east of I-65, with a very low likelihood in strong to
  severe storms occurring.

* Daily shower and storm chances for the middle part of the week
  before a weekend of mid 80s and clear skies.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 246 PM EDT Mon Aug 17 2026

A cold front is stretching from SE Indiana down through the MO
Bootheel at this hour, and is poised to slide SE through the CWA
through late afternoon and early evening. We have gotten moderately
unstable (1500-2500 J/KG ML CAPE) along and ahead of this frontal
boundary, however the overall deep layer shear is negligible, and
not strong enough for any organized updrafts. In addition, mid level
lapse rates are struggling around 5.5 C. The resulting shower
activity triggering along the front is struggling, and expect this
to continue through the evening. Can`t rule out a few rumbles of
thunder, but overall strong storms are not expected.

Temperatures and humidity will still stay pretty muggy ahead of the
frontal passage, including temps still in the low 90s with mid 70s
dew points. Some triple digit heat indices are still possible
through afternoon and early evening down along the TN border.

Otherwise, drier air filters in tonight behind the front, and will
allow for more comfortable low temperatures in the low and mid 60s.
Some fog development may occur, however light surface winds
promoting dry air advection and some variable upper cloudiness could
be limiting factors to more widespread/dense fog concerns.


We`ll see NW flow aloft void of any shortwave activity, and high
pressure at the surface heading toward mid week. Tuesday will be dry
in the post-frontal airmass with plenty of peaks of sunshine. Highs
look to be in the low and mid 80s, which is a touch below normal for
this time of year. Dry and seasonable low are then expected again
Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 246 PM EDT Mon Aug 17 2026

*** Wednesday - Sunday ***

As the region continues in a zonal flow aloft, several shortwaves
are expected to move into the Ohio Valley. This will bring rain
chances back to the forecast for Wednesday and Thursday. A shortwave
trough will begin to move in early Thursday morning, along with a
frontal boundary pushing in from the north. A widespread area or
line of rain and storms is forecasted to push through the area early
Thursday morning. Marginal instability seems to be available
overnight ahead of the storm system, with 30-40kts of bulk shear
across western and central KY. Its still a little early to know for
sure about a severe potential, however if the forcing from the
shortwave and the frontal boundary are timed right severe weather
would not be out of the question. By Thursday evening, an upper
level trough will begin to dig into the Ohio Valley. Showers and
storms will continue to linger with a decently unstable atmosphere
and an axis of bulk shear (40-50kt) from a low level jet over the IN
and KY border.

Once the trough completely builds in over the region, a drier period
can be expected for Friday and the weekend. An area of surface high
pressure and a drier airmass is expected to build over the area.
Very pleasant weather is expected this weekend with maximum
temperatures in the mid 80s, low 60 dew points, and clear skies.

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 712 PM EDT Mon Aug 17 2026

Cold frontal boundary is pushing through the region this evening.
It has already cleared HNB/SDF and will clear LEX in the next hour.
A few showers will be possible at LEX/RGA this evening through about
18/0130Z or so.  After that, look for a period of VFR conditions
this evening and into the overnight period.  Some patchy fog
development will be possible at the terminals with the exception of
SDF.  The outlook for Tuesday calls for VFR conditions with light
north-northwesterly winds.

&&

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

&&

$$

SHORT TERM...BJS
LONG TERM....CAL
AVIATION.....MJ