313
FXUS63 KLMK 191214
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
814 AM EDT Wed Aug 19 2026

.KEY MESSAGES...

* Shower and storm chances (50-70%) return Wednesday night into
  early Thursday. There is a low risk for severe weather west of I-
  65 in Kentucky and localized flooding across areas west of I-75.

* Very slight (15-24%) shower and storm chances linger through
  Saturday across areas mainly east of the I-75 corridor, but most
  locations look to stay dry.

&&

.UPDATE...
Issued at 813 AM EDT Wed Aug 19 2026

A complex of showers and a few embedded thunderstorms is crossing
the Mississippi and Wabash Valleys this morning, with a few light
rain showers now observed across southwest IN. These showers and
storms are weakening as they encounter a drier, stable air mass in
the lowest 10k ft across the area, with HNB only measuring a trace
of precipitation. This complex is providing increasing coverage of a
mid-level deck of clouds which should hold temperatures down later
this morning, especially across southern IN. Father to the south and
east, dissipating cloud coverage should allow for greater warming
this morning, with temperatures expected to recover into the low-to-
mid 80s by midday.

Only made minor adjustments to the PoP/temperature forecast over the
next 3-6 hours to account for current trends in radar and satellite.
Otherwise, the forecast remains on track at this time.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 358 AM EDT Wed Aug 19 2026

Looking across the region this morning, central Kentucky and
northern Indiana continues to be under an area of surface high
pressure. The surface high is slowly drifting off to the east,
allowing relatively light winds to shift to the south. Satellite
imagery reveals mostly clear skies across the region, with very
patchy fog developing in areas near Lake CUmberland that will
dissipate by sunrise. Another feature of interest is the first of
multiple disturbances that will move over the region in the next 36
hours, currently trekking eastward over Missouri. This system will
slowly dissipate as it moves towards the Ohio Valley later this
morning, thanks in part due to very limited instability, wind shear,
and low-level moisture. There`s a slight chance for a few light
showers for places in southern Indiana and west of I-65 in Kentucky,
with very little appreciable precipitation expected. Most places
across the area will remain dry during the daytime hours on
Wednesday, with highs in the low to mid 80s forecast north of I-64,
and in the mid to upper 80s for areas south. Mid-level cloud cover
will build as the day progresses as this first disturbance moves
over the region, with the HREF suggesting some clearing will be
possible by the evening hours (~90% cloud cover by midday decreasing
to ~25%).

Chances for widespread precipitation will increase Wednesday night
as a shortwave trough begins to move over the Ohio Valley. Current
HiRes guidance has the feature entering the western counties of the
CWA around 12 AM EDT, exiting off to the south and east during the
mid-morning hours on Thursday. This features will be accompanied by
a modest LLJ (HREF mean 850 mb wind of 30-40 kt) and deep-layer
shear (35-45 kt 0-6 km shear), as well as decent PW (1.8-1.9")
ahead of the system. Three of the biggest limiting factors though
will be decreasing instability as the night progresses (>1000 J/kg
mean SBCAPE around 8 PM EDT dropping to <500 J/kg after 12 AM EDT),
weaker mid-level lapse rates, as well as limited time for low-level
moisture recovery. The Storm Prediction Center has placed a Slight
Risk for severe weather in our far southwestern CWA since
instability will be somewhat modest as it passes over that area, but
chances for strong to severe storms will decrease rapidly as the
system moves eastward. Damaging winds and isolated severe hail would
be the primary concerns west of I-65. There is a very low-end threat
for a tornado to develop, and would likely need better
thermodynamics to be realized over our region. Another concern with
this system would be heavy downpours resulting in localized flash
flooding. The most recent HREF 6 hour LPMM does show a couple swaths
of rainfall amounts greater than 2.5", so this will need to be
monitored is areas get persistent heavy rain from training
thunderstorms especially.

As the bulk of the shortwave departs to the southeast Thursday
morning, one last shortwave trough and accompanying frontal boundary
will pass over the region during the daytime hours. Chances for rain
will be slightly elevated (20-40%) for southern and eastern Kentucky
through midday, with slight chances (<35%) of isolated showers to
develop ahead of the front as it moves through. Temperatures will be
below normal for this time of year, with highs in the low to mid 80s
forecast.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 358 AM EDT Wed Aug 19 2026

Once the front departs to the south Thursday night, surface high
pressure and dry low-level air will build in over the region,
allowing for a mostly calm stretch of weather to close the workweek
and start the weekend. Temperatures will remain below normal, with
forecasted highs in the mid 80s and lows in the mid to upper 60s
Friday morning and in the low to mid 60s Saturday morning. A few
slight chances for rain are possible east of I-75, but most places
will remain dry during this stretch. The upper trough over the
eastern CONUS will dig southward on Saturday, with the trough axis
swinging over our region as well. A shortwave will accompany this
pattern chance, providing another chance for showers and isolated
storms to develop. With fairly dry low-level air in place, chances
for appreciable rainfall are fairly low (<20%).

Once the trough axis swings through late Saturday, bringing in
reinforced dry air and surface high pressure, the rest of the weekend
into the start of the following workweek looks to be dry and mild,
continuing the trend for afternoon temperatures in the 80s. The very
end of the forecast period is a little uncertain, as the sturdy
ridge over the western CONUS becomes less amplified, causing the4
upper trough over us to shift to the east. The spread in
deterministic and ensemble solutions does present some uncertainty
in precip chances after Monday, though antecedent low-level dry air
should keep probabilities low for the rest of the forecast period
(<25%).

&&

.AVIATION /12Z TAFS THROUGH 18Z THURSDAY/...
Issued at 649 AM EDT Wed Aug 19 2026

VFR conditions will prevail through the daytime hours on Wednesday,
with building mid-level cloud cover to OVC skies as the day
progresses. A few light showers are possible near HNB from 13-18z
today, with a Prob30 group included for that timeframe. Otherwise,
all other terminals will remain dry into the early evening hours. A
broad cluster of showers and storms will begin to enter the region
after 03z, impacting all terminals through at least 09z Thursday.
While ceilings should remain VFR while the showers and storms are
ongoing, heavier downpours could result in brief reductions in
visibility. Ceilings will lower behind the showers and storms
to higher MVFR levels, and was introduced in the SDF and HNB
TAFs.

&&

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

&&

$$

UPDATE...CSG
SHORT TERM...BEN
LONG TERM...BEN
AVIATION...BEN