738
FXUS63 KLMK 181724
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
124 PM EDT Tue Aug 18 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* Expect a dry and comfortable Tuesday across the region, with highs
  in the 80s forecast.

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

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 346 AM EDT Tue Aug 18 2026

A brief stretch of calm weather is now in store across central
Kentucky and southern Indiana as surface high pressure is building
in behind a cold front departing to our south. Looking at current
conditions across the area this morning, a mix of widely scattered
mid-level clouds and some clear skies prevail, with some very
isolated patchy fog developing in the Bluegrass. Any fog that does
develop will quickly dissipate after sunrise, with mid-level clouds
also clearing out during the day on Tuesday. With low-level
northerly flow prevailing, drier air will allow dew points to remain
in the 60s, making for really comfortable outdoor conditions.
Afternoon temperatures across the region will be a few degrees below
normal for this time of year, with highs in the low to mid 80s along
and north of the Parkways, and in the mid to upper 80s for places
south.

For Tuesday night, the area of surface high pressure over us will
shift off to the east. Winds will remain light, but switch from the
northwest to the south during the late overnight hours. Skies will
be mostly clear early, with cloud cover increasing over the western
portions of the area as our next potential round for precipitation
approaches the region. Temperatures Tuesday night will be pleasant,
with lows in the 60s forecast.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 346 AM EDT Tue Aug 18 2026

Chances for unsettled weather return Wednesday as multiple
shortwaves move towards the Ohio and Mississippi valleys. The first
wave will slowly diminish as it enters the region, resulting in low
but non-zero chances for showers and an isolated storm. Per the
latest HREF, chances of precipitation through the mid-afternoon
hours range from 10-25% over southern Indiana and north central
Kentucky. This is in part due to the combination of limited CAPE
(<500 J/kg) and wind shear (20-30 kt 0-6 km shear) at that time.
Looking broadly across the area on Wednesday, most places will
remain dry, especially for locations south of I-64 and east of I-65.
Temperatures will be slightly warmer than Tuesday, with highs in the
low to mid 80s north of the Parkways and in the upper 80s/around 90
south.

The second shortwave will move towards the region Wednesday night,
along with a weak surface frontal boundary that will slowly push
southward into Thursday. As a result, widespread showers and
thunderstorms are forecast Wednesday night through Thursday morning
(50-70% chance). Accompanying these features will be a modest low-
level jet (30-40 kt) that will help produce 30-40 kt of deep-layer
shear. Plentiful moisture will also be in place ahead of the frontal
boundary, with LREF outputting >1.8" of PW. Since this event will
occur later in the overnight, instability will be rather meager and
limit the potential for severe weather.

By late Thursday, the upper-level trough will dig into the Ohio
Valley, with the surface frontal boundary pushing off to our south.
Chances for showers and storms will linger into the late evening
hours Thursday as the front slowly moves through Kentucky. While
modest instability (~1500 J/kg of SBCAPE) will be present, a
weakening low-level jet will keep chances for stronger storms to
develop on the lower end. Once the upper trough digs over the area
by Friday, surface high pressure will fill in over the region,
allowing for a comfortable and dry end to the workweek. As the axis
of the upper trough swings over the region late Saturday into early
Sunday, another round of showers is possible. However, with fairly
dry air in place, chances will remain low (<15%). For the remainder
of the weekend and the start of the next workweek, expect dry and
pleasant, with afternoon temperatures staying in the 80s across the
area.

&&

.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 123 PM EDT Tue Aug 18 2026

VFR conditions are expected through the current forecast period,
with a lingering cu field this afternoon expected to have cloud
bases generally between 3-5k ft. Light NW winds are expected this
afternoon, with winds going light and variable after sunset this
evening. Mostly clear skies are expected overnight, with mid-level
clouds increasing from NW to SE in the early morning hours
Wednesday. A few light rain showers are possible at HNB by the end
of the current forecast period; however, due to low probabilities,
will abstain from mention in the current forecast.

&&

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

&&

$$

SHORT TERM...BEN
LONG TERM...BEN
AVIATION...CSG