Campbellsville, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

091
FXUS63 KLMK 292326
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
726 PM EDT Mon Jun 29 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* Hot and humid today with afternoon highs in the low to mid 90s
  and peak afternoon heat indices in the 100 to 115 degree
  range. An Extreme Heat Warning is now in effect through
  Thursday.

* A strong ridge of high pressure over the region will bring the
  hottest temperatures so far this year. The heat will peak
  Tuesday through Thursday, with afternoon highs in the mid 90s
  and peak index values of 100 to 115F.

* Hot and humid for the Fourth of July holiday weekend, with
  isolated to scattered storms possible in the afternoon and
  evening. Localized flash flooding and/or localized gusty winds
  will be possible each afternoon and evening with any slow moving
  storm.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 310 PM EDT Mon Jun 29 2026

The well-advertised anomalous upper ridge builds in and centers over
our region through tomorrow. Dry forecast during this time with
strong subsidence inversion showing up on area forecast soundings.
The main story will be the heat and humidity with temps expected in
the low and mid 90s combined with dew points in the 70s. Areawide
max heat indices are expected to range in the 100 to 115F range each
afternoon and evening, with little relief at night as temperatures
only into the mid and upper 70s for most. Given the prolonged nature
of the heat and humidity, a busy outdoor week leading up to the
holiday, recent flood impacts and recovery ongoing decided to
upgrade the entire area to an Extreme Heat Warning in coordination
with surrounding offices. Do think temperatures will struggle a bit
with the recent heavy rainfall, and available low level moisture
contributing to sct-bkn cu fields each afternoon/evening, however
any decrease in max Ts will likely be offset by higher dew points so
it may end up being a wash on peak afternoon heat indices. Not much
else to speak about in the short term other than perhaps some patchy
fog possible tonight.

&&

.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 310 PM EDT Mon Jun 29 2026

Wednesday Afternoon - Friday Night...

Anomalous upper ridge persists over the region, although the center
will shift slightly east to the central Appalachians. Still enough
influence to keep us hot, muggy, and mostly dry. Forecast soundings
for this time do show a weakened mid level cap/subsidence inversion,
however without any real triggering mechanism, not sure we`ll be
able to tap into the strong unstable airmass characterized by 4000-
5000 J/KG of CAPE, at least not through Wednesday. There is an
alternate scenario that could play out, however it is the less
likely outcome at this point. See more details in the "Alternate
Scenario" section below.

Oppressive heat will continue to be the story through mid to late
week. Temperatures are expected to reach solidly into the mid 90s
along with dew points well into the 70s each day. This should
continue to yield max afternoon heat indices mostly in the 100 to
110F range through at least Thursday. As we get into later Thursday
and Friday, the upper ridge does center more on the mid-Atlantic
with slightly less influence over our area. Chances for isolated to
widely scattered diurnally driven thunderstorms will increase by
this time. Forecast soundings show strong instability with little to
no vertical shear, so storm modes would certainly be pulse in
nature. Given slow storm movement, and potential for intense
rainfall rates due to the amount instability and notably high PWATs,
do think we could start running into some isolated Flash Flood
concerns for areas that have already been hit hard. Something to
watch in this pattern. Hopefully, given the lack of a strong trigger
other than diurnal heating, coverage will be sparse in nature. We`ll
also have to watch for some marginally severe hail or microburst
winds with the pulse storm modes.

Saturday - Monday...

The upper ridge steadily breaks down through the weekend with a belt
of progressive zonal westerlies starting to gain influence into our
region. Fine details are lower confidence, however there is a
general consensus of at least a shortwave or two embedded within
this flow acting as a trigger for more scattered to numerous shower
and storm coverage. The best signal is for late weekend into early
next week (Sunday or Monday) when a more pronounced shortwave may
progress through the region, along with a surface cold front. Don`t
love the look of the more active pattern through the weekend
followed by a frontal boundary passage given continued slow storm
movement thanks to weak deep layer shear. We could end up with
another weekend filled with dual threat storms capable of localized
severe winds and/or localized flash flooding. The good news is that
any tornado threats will not be realized in this type of
environment. This is definitely more of a mid to late Summer type of
setup. Another piece of good news is that this should provide some
relief from the heat, however we will still likely be at or just
above normal for temps ahead of this expected cool front.

"Alternate Scenario"

There is one scenario that we should keep in the back of our mind,
and it has been shown on two consistent runs of the GFS. In this
environment, we can be conducive to "chain reaction" type events
where a single pulse storm can cause an eventual large complex of
storms given multiple generation updrafts being triggered by the
previous pulse storm collapsing. These can become quite chaotic,
especially given the amount of available CAPE expected under the
upper ridge. Any large complex of storms caused by this chain
reaction scenario, or an upstream MCS could wreck the mid to late
week temp forecast, and it has happened before. It looks looks like
the earliest this could happen would be later Wednesday, however it
would become increasingly possible moreso on Thursday or Friday.
We`ll at least have 3 solid days of oppressive heat/humidity before
this occurs, so still felt the duration based Extreme Heat Warning
is warranted regardless of if an MCS could bust temps late week.

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 725 PM EDT Mon Jun 29 2026

VFR conditions are expected through the TAF period.  Diurnal Cu
field will mix out in the next 1-2 hours leaving skies mostly clear
for the overnight with a light southerly breeze.  Could see some
patchy low-level fog given the obscene amount of moisture in the low-
levels.  However, the light winds will likely keep the PBL too
turbulent and may ward off any large scale fog.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Extreme Heat Warning until 9 PM EDT /8 PM CDT/ Thursday for
     KYZ023>043-045>049-053>057-061>067-070>078-081-082.
IN...Extreme Heat Warning until 9 PM EDT /8 PM CDT/ Thursday for
     INZ076>079-083-084-089>092.

&&

$$

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