302
FXUS63 KLMK 061936
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
336 PM EDT Sat Jun 6 2026

.KEY MESSAGES...

* Isolated showers and storms are possible on Sunday, though many
  will remain dry.

* Unsettled weather is expected for much of the upcoming week,
  especially for Monday and Tuesday. Daily shower and thunderstorm
  chances are expected, with heavy rainfall and localized flash
  flooding being the main threats from storms.

* Warm and muggy and conditions likely to continue throughout the
  coming week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 336 PM EDT Sat Jun 6 2026

This afternoon, mostly sunny to partly cloudy skies are present
across central KY and southern IN, with a mixture of fair weather cu
and higher level cirrus present on satellite. Temperatures have
risen into the low-to-mid 80s, with dewpoints generally in the low-
to-mid 60s as of 19Z, and we should be able to add a few more
degrees with highs expected to reach the mid-to-upper 80s later this
afternoon. While low-level moisture has increased today, a plume of
even higher moisture resides to the north and west of the area where
a cold front is in the process of stalling out over the lower Great
Lakes. While showers and storms should initiate near this boundary
later today, warmer temperatures aloft and further removal from the
best forcing should keep things mostly dry across our area.

Over the next 24 hours, the front to the north of the region is
expected to stall and eventually lift to the north as upper level
ridging builds across the Ohio Valley during the day on Sunday. At
the same time, an upper shortwave on the west side of the ridge is
expected to slowly move from the southern Plains into the mid-
Mississippi Valley, with increasing moisture and shower/storm
chances expected with this disturbance. Tonight into tomorrow, much
of central KY and southern IN will be in between these two features,
resulting in a continued low (10-20%) chance for a shower or storm.

Tonight, lows are expected to range from the mid 60s to the low 70s,
and should be generally cooler along and east of US 127. Increasing
mid- and upper-level clouds should keep fog to a minimum, though
some patchy fog can`t be ruled out in eastern and southern KY river
valleys.

For Sunday, temperatures should be relatively similar to today,
although increasing moisture and mid-level clouds could keep
temperatures down across southern KY. Most areas are expected to top
out in the mid-to-upper 80s Sunday afternoon.

If thunderstorms are able to develop on Sunday, they will have
relatively modest amounts of instability to work with, with 12Z REFS
ensemble mean SBCAPE ranging from 500-1000 J/kg during peak heating.
Storms should be relatively disorganized with less than 15 kt of
deep-layer shear, and should also be slow-moving as mean cloud-layer
winds will only be around 10 kt.

As we lose daytime heating Sunday evening, instability and
shower/storm chances should diminish initially after sunset, with
partly to mostly cloudy skies expected. Sunday night, the upper
ridge axis will move slightly to the east, allowing the upper low to
our west to move closer to the region. This should support
increasing moisture and slightly better SW flow by Monday morning.
While this runs into the end of the 12Z hi-res guidance, preliminary
progs do show showers and a few storms developing early Monday
morning west of I-65, so PoPs will begin to increase again after
midnight. The increased cloud cover and moisture should also lead to
mild temperatures, with another night of lows in the upper 60s and
low 70s expected.

&&

.LONG TERM /SUNDAY THROUGH SATURDAY/...
Issued at 336 PM EDT Sat Jun 6 2026

There is not much change in the forecast thinking for the first half
of the week. Broad upper-level ridging will continue to build across
the eastern half of North America, with the upper shortwave
mentioned in the short term discussion slowly lifting northeast
across the mid-Mississippi Valley and into the Great Lakes Monday
into Tuesday. A tropical atmosphere will also be in place with PW
values near 2" expected across the Ohio Valley for Monday into
Tuesday, which is near if not slightly above the 99th percentile of
model climatology. While rounds of showers and storms will be likely
through the first half of the week, timing of individual chances
will be difficult due to a lack of a well-defined forcing mechanism.
In general, expect rain chances to peak with daytime heating in the
afternoon and evening hours, with lower (but not low) chances for
rain during the overnight and early morning hours.

Given the abnormally high moisture levels, sounding profiles that
show deep warm cloud layers (14-15 kft), and expected slow storm
motions due to cloud layer winds of 10-15 knots, heavy rainfall and
localized flash flooding will be a threat Monday into Tuesday. The
best chances for these heavier rain swaths will be along and west of
I-65, as the richest moisture and closer proximity to the upper
shortwave should be in the western half of the CWA. Temperature
ranges for much of the week, but especially Monday and Tuesday, will
be suppressed due to the tropical atmosphere. Highs should take a
step down into the mid 80s, with lows only expected to fall into the
upper 60s and low-to-mid 70s.

From Wednesday onward, there is somewhat lower forecast confidence
due to increased ensemble spread and differing trends in guidance
over the past 24-36 hours. While the influence of the upper wave
from the first half of the week should subside by Wednesday, a
second stronger disturbance over the far northern CONUS and Canada
may be able to erode some of the ridging across the eastern CONUS
and bring a cold front close to the Ohio Valley by the end of the
upcoming week. With PW values remaining above the 90th percentile
through the week, rich moisture will continue to be available. The
main question is how quickly, and to what extent will the late week
disturbance make an impact on the Ohio Valley. The ECMWF and its
ensembles have generally been faster and more robust with this
system, bringing better chances for rain back into the area late
Thursday into Friday. The GFS and its ensembles have been generally
slower and weaker with the late week system, leading to warmer and
less stormy weather for the end of the week. The current forecast
appears to be biased toward the warmer/drier solutions, almost to
the extent of being a warm outlier, so adjustments may need to be
made to temperatures as confidence increases over coming days.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 129 PM EDT Sat Jun 6 2026

VFR conditions are expected to continue through the forecast period.
This afternoon, expect to see SW winds generally around 6-12 kt,
with a occasional 15-20 kt gusts likely during periods of less cloud
cover and deeper mixing. This evening, winds should ease and should
back toward the south for the overnight time period. Daytime heating
has led to the development of a 5k ft cu field which should
dissipate this evening, with mid- and high-level clouds continuing
overnight. Another cloud deck with ceilings between 5-10k ft is
expected to develop Sunday morning. While an isolated shower can`t
be ruled out by the end of the current forecast period, coverage
should be low enough to leave out of the forecast for now.

&&

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

&&

$$

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