Louisville, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

226
FXUS63 KLMK 151747
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
147 PM EDT Fri Aug 15 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Hot and humid through early next week, with highs in the 90s. Heat
  index values of 105+ are possible Sunday through Tuesday.

* A cold front will likely bring relief from the heat, along with
  increasing thunderstorm chances, by the middle of next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 348 AM EDT Fri Aug 15 2025

Conditions are dry early this morning with variable sky cover. A
patch of mid-level clouds is drifting slowly east over far southern
IN and north-central KY, while thin cirrus spreads northeast across
central KY. Fog development is noted, particularly in river valleys
in south-central and eastern KY. A diffuse frontal boundary is
draped in the vicinity of south-central KY, where KY Mesonet winds
are calm. Some expansion of the fog is likely through sunrise, and
the fog may be locally dense in some areas.

Today, a mid-level ridge will amplify as it shifts from the Plains
toward the Mississippi River Valley. Weak shortwave energy currently
over the Upper Midwest will dive southeast, around the ridge, across
Michigan and Ohio. A relatively drier column, along with increasing
mid-level subsidence, will yield partly to mostly sunny skies and
mainly dry conditions. A very isolated shower or storm does look
possible in the peak of afternoon heating/destabilization, but
coverage will be less than 10%.

Afternoon temperatures are likely to tick upward by a couple of
degrees with a modest increase in 1000-850 mb thicknesses. Highs in
the low 90s will be common, with peak afternoon heat index values in
the mid 90s to low 100s.

Tonight will be quiet and mostly clear, with calm winds and patchy
fog. Lows Saturday morning will be in the upper 60s to lower 70s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 348 AM EDT Fri Aug 15 2025

Hot and humid weather is anticipated this weekend into early next
week. Saturday through Tuesday also looks dry as well, though
forecast confidence begins to drop off by Tuesday. A strong mid-
level ridge is forecast to remain anchored near the confluence of
the Ohio and Mississippi rivers through Monday. Saturday and Sunday
will also feature high pressure at the surface. On Sunday, there is
a cold front that pushes southeast across the eastern Great Lakes,
Upper Ohio Valley, and Northeast, but it will struggle to make
headway into our area.

Saturday will be hot and mostly sunny, with afternoon highs in the
low to mid 90s. Peak afternoon heat index values touching 100+ look
more likely across most of the CWA, with the possible exception of
parts of the Bluegrass Region. Highs on Sunday will reach the mid
90s for most, with afternoon heat index values climbing to 100-105+.

Low level thicknesses continue to gradually rise into early next
week. Temperatures are currently expected to creep upward across the
board. Highs in the mid/upper 90s will be possible, with lows in the
low to mid 70s. More widespread heat index values of 105+ will be
possible, raising the concern for an elevated risk for heat
illnesses. This is in line with the experimental HeatRisk tool,
which highlights a broader area of major risk for heat-related
impacts for anyone without adequate cooling/hydration.

Heading into the middle of next week, the ridge begins to break down
and retrograde westward. Depending on how quickly this occurs, as
well as the evolution of northern stream waves, the Tuesday forecast
has some bust potential. For now, sticking with the heat with highs
in the mid/upper 90s. However, a cold front will eventually sink
south from the Great Lakes into the region sometime Tuesday into
Wednesday. This boundary will bring relief from the heat along with
increasing rain and thunderstorm chances. Highs in the 80s to low
90s look more likely for Wednesday and Thursday.

&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 146 PM EDT Fri Aug 15 2025

Other than a few isolated showers and thunderstorms forming around
LEX this afternoon flight categories are VFR and should mostly
remain that as we go through the rest of the day and into the
overnight. We will continue to hold on to primarily VFR with the
exception of tomorrow morning where we could once again have patchy
fog that would cause some VIS issues to around MVFR to isolated IFR.
As we go into the weekend we will see more VFR flight categories
with dry weather and mostly clear skies.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Air Quality Alert from 8 AM Saturday to midnight EDT Saturday
     night for KYZ029>031.
IN...Air Quality Alert from 8 AM Saturday to midnight EDT Saturday
     night for INZ091-092.

&&

$$

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