509
FXUS63 KLMK 300758
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
358 AM EDT Sun Aug 30 2026

.KEY MESSAGES...

* Heat and humidity continue to build for the end of the weekend
  into the start of next week. There is a 60-70% probability of
  reaching Heat Advisory criteria by the middle of the week.

* Major Heat Risk possible due to the multi-day duration of hot
  temperatures and little overnight relief. Anyone without effective
  cooling or adequate hydration will be susceptible to heat illness.

* A few shower and storm chances may return by late week, but
  current confidence is low.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 358 AM EDT Sun Aug 30 2026

Upper ridging will continue to build over central CONUS today and as
we go into the start of next week. Highs will be a little warmer
today than they were yesterday as highs approach the low 90s. Thanks
to dry air mixing towards the afternoon, dewpoints will likely lower
into mid/low 60s helping to keep heat index values into the
mid/upper 90s and could have a few gusts around 20 mph in the
afternoon. Some scattered mid-level Cu could develop in the
afternoon but expected to clear as we go into tonight. It will
remain mild as lows fall to around 70 degrees.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 358 AM EDT Sun Aug 30 2026

Monday through Thursday Night...|

The overall forecast remains on track for the strong 594 dm 500mb
ridge to continue to build and shift eastward over the Ohio Valley
by the middle of next week. This will continue to keep us dry with
daily max temperatures gradually increasing each day. While we will
see increased low-level moisture, daily afternoon dry air mix down
will result in dewpoints in the upper 60s with a few locations into
the low 70s. Latest LREF show a 60-80% probability of heat index
values over 100 for Tuesday through Thursday. Given the long
duration of 90+ degree highs, warm overnight temperatures and daily
heat index values near or slightly below the 105 Heat Advisory
criteria and after collaborating with our neighboring offices, heat
related headlines will likely be needed.

As was pointed out in the previous discussion, a few areas in our
CWA like those over the Bluegrass where there has been higher than
normal precipitation over the last 30 days, could result in lower
high temperatures due to evaporation of moisture in the ground and
vegetation. Other areas along and west of I-65 and points south have
the higher probability of seeing hotter temperatures over the next
several days.

End of the Week into Next Weekend...

Deterministic models continue to show the upper level ridge
flattening and retrograde slightly westward.  A back door frontal
boundary may try and attempt to drop south into the region and
stalls. NBM guidance continues to show widespread 30% PoP both
Friday and Saturday for isolated to scattered showers and
thunderstorms but overall confidence remains low.

&&

.AVIATION /06Z TAFS THROUGH 12Z MONDAY/...
Issued at 358 AM EDT Sun Aug 30 2026

Forecast remains unchanged as VFR flight categories remain through
the forecast period. Winds will remain light to calm through the
overnight but increase through the day as we get more mixing to
develop. We may see some mid-level Cu develop in the afternoon but
skies will clear and winds diminish as we head into tomorrow
evening.

&&

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

&&

$$

SHORT TERM...BTN
LONG TERM...BTN
AVIATION...BTN