686
FXUS63 KLMK 121427
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1027 AM EDT Sat Sep 12 2026

.KEY MESSAGES...

* This weekend, showers and non-severe thunderstorms expected across
  the region.

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

&&

.UPDATE...
Issued at 1026 AM EDT Sat Sep 12 2026

This morning, an area of light to moderate rain showers has
persisted across south central KY over into the Lake Cumberland
region, with more isolated light rain showers and sprinkles observed
across the Bluegrass region. Regional satellite imagery shows deeper
cloud development along the TN border at this hour, with fairly
widespread shallow stratus/stratocu elsewhere across the region.
Along and west of I-65, this stratus layer should scatter out
gradually over the next few hours, with more persistent cloud cover
expected east of I-65 through mid-afternoon.

SPC mesoanalysis features a baggy mid-level trough axis extending
from the IL/IN border down across western KY and into the lower TN
valley. This trough and associated vort max should pass east of the
region by this evening, with isolated to scattered showers and
storms developing along and ahead of the trough axis. As a result,
coverage of showers and storms should be greatest in the eastern
half of the CWA this afternoon and evening, with more sunshine and
warmer temperatures expected west of I-65. Given a fairly tall,
skinny CAPE profile and weak wind shear, expect mainly garden-
variety storms, with downpours and lightning being the main hazards.

The forecast is in good shape at this time, though we`ll continue to
monitor and make adjustments to PoPs as needed.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 411 AM EDT Sat Sep 12 2026

Currently, among zonal flow overhead we have a shortwave pushing
east, nearing the Mississippi Valley. Ahead of the wave, the Lower
Ohio Valley has southerly winds in place. This is pushing
precipitable water values to near 2 inches. In the moist environment
heavier showers and thunderstorms continue pushing north-northeast
and are now exiting our southern Indiana counties.

For the rest of the day, the shortwave will drive additional chances
for showers and thunderstorms. Through the morning hours, increasing
stratus is expected to limit warming, reducing instability. Through
the first half of the day expecting isolated to scattered showers
that will drift slowly to the east across the CWA. Into the
afternoon and evening hours, some thunderstorms will likely develop,
but with limited warming and weak mid level lapse rates, not
expecting anything strong or severe as convection struggles to grow.
Shear continues to be weak too. Highs are expected to reach into the
upper 70s to mid 80s with warmer temperatures across the west,
cooling to the east with the later precipitation.

Early tonight, any remaining showers will push off to the east and
exit the CWA. Clearing skies are expected to follow from the west.
With light winds and moisture on the ground, patchy fog is expected
to develop across the region as lows drop into the mid 60s to near
70.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 411 AM EDT Sat Sep 12 2026

Sunday, the shortwave will be east of the region, leaving zonal flow
parked mainly to our north as a cold front approaches and arrives in
southern Indiana during the evening hours. This could initiate
another round of isolated to scattered showers that would push east
over and out of the region. Overall moisture levels ahead of the
front are expected to climb back into the 1.6 to 1.8 inch PWAT
range. Convective parameters look a lot like today`s, so strong and
severe thunderstorms aren`t expected before precipitation ends
early Sunday night.

By Monday, an upper ridge with surface high pressure behind the cold
front moves in over the Lower Ohio Valley. This will bring clearing
skies and a return of WAA for Tuesday as the center of the surface
high passes. This will lift highs back into the low to mid 90s
beginning Tuesday.

Wednesday, as the upper ridge positively tilts to the east into New
England, it will leave zonal flow north of the Ohio River with upper
high pressure parked over the South. A surface high is expected to
get pushed east along the zonal flow. This is expected to push a
west to east oriented front to near the Ohio River which could set
up and become quasi-stationary, leading to low precipitation chances
through at least the end of the work week.

&&

.AVIATION /12Z TAFS THROUGH 18Z SUNDAY/...
Issued at 708 AM EDT Sat Sep 12 2026

The bulk of the precipitation has moved off to the northeast into
Ohio, but chances for light showers will remain this morning for our
eastern TAF sites, including LEX and RGA. We are expecting an MVFR
layer of stratus to impact HNB, SDF, LEX, and RGA this morning
before ceiling improve this afternoon. Later this afternoon and
evening, isolated showers and thunderstorms will once again become
possible, mainly east of Interstate 65.

&&

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

&&

$$

UPDATE...CSG
SHORT TERM...KDW
LONG TERM...KDW
AVIATION...KDW