276
FXUS63 KLMK 120609
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
209 AM EDT Sat Sep 12 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* Unsettled weather pattern to continue tonight and into Saturday
  with showers and thunderstorms expected across the region.  Any
  storm will be capable of localized heavy rainfall.  Most folks can
  expect 0.5-1" of rainfall, but some very isolated amounts of 2-3"
  are possible.

* Overall drier and hotter conditions arrive early next week while
  an upper level ridge builds in.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 255 PM EDT Fri Sep 11 2026

Early morning mid-level wave axis has pushed off to the northeast.
In its wake, skies are starting to slowly clear across southern IN
and the northern half of KY.  This has led to a temperature gradient
across the region with upper 70s to around 80 across southern IN and
northern KY with mid-upper 80s down along the KY/TN border region.

For the remainder of the afternoon, we`ll see cloud cover slowly mix
out across southern IN and northern KY.  While temperatures have
been kept in the upper 70s, we should still have enough heating and
evening daylight to push temps into the lower 80s prior to sunset. A
few scattered showers/storms can`t be ruled out across southern KY
where a washed out frontal boundary resides.  However, the lack of
concentrated forcing for lift will likely keep PoP coverage at 20%
or less for the evening.  The best chances for any convection this
evening will likely be out west of the I-165 corridor.

For tonight, the next mid-level shortwave trough axis is expected to
slowly eject from the lower MS Valley.  The latest CAM solutions
show an uptick in convection across western TN and western KY by mid-
late evening spreading east-northeast into central KY overnight.
While the shortwave trough and associated height falls would be
enough support for lift, overall coverage/intensity of convection is
uncertain given that instability will be lost due to loss of daytime
heating.  However, model soundings do show a bit of elevated
instability along with plenty of low-level moisture.  So convection
that fires overnight would be capable of producing locally heavy
rainfall and lightning.  Lows tonight will be mild with upper 60s
and lower 70s expected.  Have gone closer to the HREF for low temps
tonight with this forecast issuance.

Moving on to Saturday, another in a series of shortwave troughs is
expected to move across the region.  Model soundings show plentiful
low-level moisture in place along with some instability.  Most
soundings continue to show a tall/skinny CAPE profile across the
region.  Given the expected timing of the shortwave, the highest
chances of convection look to be in areas mainly east of the I-65
corridor.  Given the instability/shear profiles, the threat of severe
weather here continues to look low.  However, slow movement of
convection given the forecast steering flow would result in locally
heavy rainfall being the main threat.  Highs for the day will likely
be limited by ongoing cloud cover and expected precipitation.  Have
gone closer to the HREF guidance here with highs in the 82-87 degree
range.

Shortwave trough axis will move northeast and away from the region
Saturday night with the threat of convection diminishing from west
to east.  Lows will be in the upper 60s to around 70.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 255 PM EDT Fri Sep 11 2026

Sunday - Thursday Night...

An upper level ridge will begin to build into the region from the
west, bringing higher surface pressure. This will bring drier and
warmer temperatures into the forecast. Maximum temperatures for
Sunday and Monday will be in the mid to upper 80s, however Tuesday
will warm into the low 90s. LREF guidance shows these temperatures
in the 90th percentile of climatology for this time of year.

PoPs are expected to stay minimal for the beginning of the week, with
slight chances of scattered showers on Wednesday. As the upper ridge
continues east, the flow aloft will shift more southwesterly
bringing some moist back into the region. Confidence is fairly low
with any developing rain due to the effect on the ridge from the
upper level trough over Canada. A draping cold front will try to
push into the Ohio Valley mid week, however some guidance is
suggesting it will become nearly stationary near the Great Lakes.
This will decrease the chances for rain as this would be the lifting
mechanism for development. Otherwise, temperatures will remain near
normal with highs in the high to mid 80s through late next week.

&&

.AVIATION /06Z TAFS THROUGH 12Z SUNDAY/...
Issued at 208 AM EDT Sat Sep 12 2026

The forecast remains on track. Earlier convection kicked off an
outflow boundary that is working north-northeast towards SDF. This
could produce south-southwest winds at SDF that could quickly gust
to around 20 knots for a short time before winds quickly ease back
down. Scattered showers will continue to work over HNB and SDF
during the rest of the night before moving towards LEX and RGA after
sunrise. Visibilities are expected to remain mostly VFR, but
ceilings are expected to drop into MVFR levels. LEX could possibly
see IFR ceilings for a short period of time with some precipitation.

&&

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

&&

$$

SHORT TERM...MJ
LONG TERM...CAL
AVIATION...KDW