233
FXUS63 KLMK 180616
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
216 AM EDT Sat Jul 18 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* Scattered storms continue this afternoon and evening bringing
  heavy downpours, lightning, and potentially damaging wind gusts.

* Rainfall totals of 0.25-0.75" from widespread storms this
  afternoon are expected with localized 3+" possible, bringing a
  localized flash flooding threat.

* A line of storms bringing potentially damaging wind gusts
  especially across eastern-southern IN moves in Saturday evening
  around 9 PM that will slow down and weaken across central KY
  overnight into Sunday.

* There is a chance for stronger storms on Tuesday evening and into
  Tuesday night. Monitor the forecast as more details become clear.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 337 PM EDT Fri Jul 17 2026

Temperatures have peaked in the upper 80s and brushing 90s this
afternoon. With convective temperatures in the upper 80s and
towering Cu, scattered showers and storms have developed over the
region. With MLCAPE 2000-2500 J/kg and PWATS of 2-2.2 inches, storms
are robust allowing for heavy rainfall and gusty winds. HREF LPMMs
are showing localized areas of 2-3 inches of rainfall. Localized
flooding will be possible this afternoon and evening. These
conditions will continue through the remainder of the afternoon and
into the evening.

As the sun sets this evening, instability will wane and storms will
dissipate. Overnight, calm to light winds and mostly clear skies
will help temperatures to cool into the low to mid 70s. Patchy fog
will be possible in the early morning hours, especially over areas
that saw rainfall from this afternoon.

On Saturday, troughing will move through the Ohio Valley and send a
cold front south. Ahead of this cold front, temperatures will
increase into the upper 80s and brushing 90F in the afternoon. PWATs
will remain between 2 and 2.2 inches, which is in the 99th
percentile of climatology. Given these conditions, isolated to
scattered showers and storms may develop in the afternoon. These
will be pulse-like, where the main hazards will be heavy rainfall
and gusty winds.

The cold front will approach the region in the late evening and into
the Saturday night period. A line of storms is expected to accompany
the cold front. There will be a weakening shear gradient as the line
moves south through the region. Additionally, CAPE will wane
overnight. Due to these conditions, the line of storms is expected
to be weakening as it moves into and through the area. Strong winds
and brief, heavy rainfall will be possible over southern Indiana and
northern Kentucky between 9PM EDT and 3AM EDT. As the storms
approach southern Kentucky, the severe threat will be quite
limited.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 337 PM EDT Fri Jul 17 2026

The cold front is expected to stall over central/northern Kentucky
on Sunday. Continued moisture and warmth to the south of the front
will allow for another chance for showers and storms Sunday
afternoon and evening. Main hazards will be gusty winds and heavy
rainfall.

North of the cold front, we will see a reprieve from the heat with
temperatures in the mid 80s and dew points in the upper 60s.

On Monday, the front will lift northeast as a warm front. This will
allow moisture and temperatures to increase over the region.
Temperatures will return to the upper 80s and brushing 90s and dew
points in the low to mid 70s. This will put heat indices in the
upper 90s and low 100s. A few isolated showers and storms will be
possible, remaining pulse-y.

The next more impressive system will move through on Tuesday. A
strong upper low will move through the northern Great Lakes and will
send a cold front south. A strong line of storms is expected to move
through the region. EFI CAPE/Shear is showing a decent signal for
this time of year, which indicates a strong environment for severe
weather. Current timing will be Tuesday evening and into the
overnight period.

Otherwise, Tuesday will be quite warm as southerly flow continues to
pump moisture into the region. Heat indices will approach Heat
Advisory criteria around 105F.

Wednesday through the end of the week, high pressure will move into
the region and we will see drier and more mild conditions.

&&

.AVIATION /06Z TAFS THROUGH 12Z SUNDAY/...
Issued at 216 AM EDT Sat Jul 18 2026

Through the rest of the night, remaining showers are ending near
RGA. A rogue isolated shower will remain possible, but widespread
showers aren`t expected. With all the rain earlier, fog is also a
concern, but guidance currently looks optimistic with fog coverage
expected to be limited. During the day, expect another very humid
day with lots of moisture in the atmosphere. This is expected to
lead to more scattered afternoon and evening convection before a
west to east cold front drops south through southern Indiana and
central Kentucky, bringing a line of convection after 03z Sunday.

&&

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

&&

$$

SHORT TERM...SRW
LONG TERM...SRW
AVIATION...KDW