167
FXUS61 KILN 120940
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
540 AM EDT Sat Jul 12 2025

.SYNOPSIS...
Showers and thunderstorms are possible through Sunday, particularly
in the afternoons and evenings before drier conditions briefly return
for the start of the workweek. Temperatures will be near to above
normal for the week, with warmer and more humid air gradually
building back into the Ohio Valley by midweek. Several rounds of
showers and storms will be possible midweek and beyond with a return
to a more active pattern.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Dry conditions will prevail locally early this morning, although it
will be warm and muggy. Some patchy fog will be possible in area
river valleys and the lower Scioto Valley, but widespread fog is not
expected early this morning.

We continue to keep an eye on two main concerns for today:

1) The first and primary concern is the potential for a few strong
to severe storms to develop by this afternoon into this evening. SCT
to numerous storms are expected by early afternoon amidst a very
warm/humid airmass, which will yield strong instby on the order of
SBCAPE ~2500 J/kg within a largely-uncapped environment. The approach
of a broad midlevel trof will provide just enough forcing to
initiate some SCT convection, initially near/W of I-75 in the Tri-
State and N KY by early afternoon. This initially-disorganized storm
activity will likely evolve into one or more clusters with eastward
extent by mid afternoon as initial storms near Cincy/N KY and Dayton
early afternoon move to the ENE into south-central and central OH by
late afternoon. Deep-layer shear will still be meager, so storm
organization should be relatively minimal. This being said, there
will be a very favorable deep-layer and LL thermodynamic environment
(with DCAPE >1000 J/kg) to suggest that gusty to damaging winds due
to downburst/outflow tendencies will be possible with the strongest
cores. This initial activity will push off to the E before another
(perhaps slightly more organized/linear) cluster of storms moves into
EC/SE IN and WC/SW OH and N KY during the evening. This activity
will also push E into late evening, eventually weakening with the
decrease of diurnally-enhanced instby as it gets past the I-75
corridor by 02z. This being said, some ISO activity may linger well
into the overnight with still plenty of instby to work with and some
subtly-increasing forcing due to the approach of the S/W. Will
mention the potential for a few strong to severe storms (as well as
locally heavy rain/isolated flooding due to PWs ~125% of seasonal
norms) in the HWO given the expectation for SCT to numerous storms
this afternoon through this evening. The severe threat should be
generally greater across the wrn half of the ILN FA, although a stray
strong/severe storm cannot be ruled out just about anywhere through
today.

2) With temps around 90 degrees and dewpoints in the lower 70s, heat
index values will reach into the mid to upper 90s by early afternoon
outside of areas impacted by storms. There are still enough
uncertainties regarding storms/cloud cover across the area,
particularly by mid afternoon, that there is not enough confidence
to hoist a Heat Advisory at this juncture. But certainly the
likelihood of heat index values to reach into the mid to upper 90s
will be mentioned in the HWO.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Coverage of storms should decrease late into the evening as instby
wanes a bit. This being said, a few ISO SHRA/TSRA may linger into the
overnight hours as the S/W works E through the region. Although the
sfc front will still be back to the W quite a bit, the forcing should
decrease late in the night as the midlevel S/W pivots off to the E
by the predawn hours. Warm and muggy conditions will continue tonight
as temps dip into the upper 60s and lower 70s by daybreak Sunday.

The primary system will continue to pull away from the OH Vly into
the day Sunday, with the trailing "cold" front laying out from NE to
SW across the local area by Sunday afternoon. LL convergence along
this feature should be quite weak as the boundary gradually begins
to wash out in the region. LL flow will become largely unidirectional
across the area by midday, with no substantial forcing or lifting
mechanism. This being said, do expect some ISO SHRA/TSRA to develop
once again, particularly near/S of I-70 and E of I-71 where the best
instby will reside (ahead of the front) by mid/late afternoon.
Coverage and strength of storms Sunday should be lower than will be
the case today, despite the ill-defined front draped across the
region.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Given current expectations that much of the thunderstorm activity
will develop south and east of the I-71 corridor Sunday afternoon,
confidence is high that any lingering activity likely drifts
southward into central Kentucky Sunday night. Very low PoPs remain
in the south for Sunday night and Monday due to some deeper moisture
lingering along the stalled front.

As the ridge builds over the Ohio Valley Monday night into Tuesday,
a weak shortwave begins to eject from the middle Mississippi River
Valley. Due to some timing differences in the resurgence of deeper
moisture from the southwest, low PoPs are reintroduced area wide by
Tuesday afternoon and evening. Even with the low PoPs, Tuesday is
likely to be dry for much of the area. This changes significantly
heading into midweek.

Wednesday and Thursday are expected to be quite stormy with deep
moisture arriving with the shortwave drifting into the area from the
west. This moisture persists over the region Wednesday and Thursday,
combining with the arrival of the trough and cold front Friday.
Convective activity over several days within a broad region of 1.8-
2.2" PWATs will favor periods of flash flooding in addition to the
typical summer-like downburst severe threat. The timing of the
shortwave will be key to determining the window where weather
impacts may be highest. For now, Wednesday and Wednesday night looks
to be the primary window.

Uncertainty in how quickly this wet pattern breaks down is quite
high by the end of the week and into next weekend.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will prevail area-wide through 15z. Expect a healthy
VFR Cu field to sprout by/after 15z, with SCT to numerous SHRA/TSRA
development shortly thereafter. The greatest coverage should
initially be focused across the W/SW half of the local area,
especially for KDAY/KCVG/KLUK/KILN, by 18z before clusters of
SHRA/TSRA shift off to the E toward KCMH/KLCK by 20z or so.
Additional activity is expected to move in toward/beyond 00z from the
W before waning late in the period with eastward extent. Abrupt
changes in VSBYs and wind speed/direction will be possible with any
of the SHRA/TSRA activity and will be handled with amendments as
needed.

Some MVFR CIGs are expected to overspread the area past 06z through
daybreak Sunday before lifting/scattering once again by 15z. Some
MVFR VSBYs cannot be ruled out tonight, but the expanding MVFR
stratus should inhibit widespread FG development.

Light SW winds at 5kts or less early this morning will increase to
10-15kts, with gusts close to 20kts possible, by this afternoon.
Winds will decrease following the storm activity, but should
gradually become more out of the WSW by daybreak Sunday.

OUTLOOK...Thunderstorms are possible Sunday and again on Wednesday,
with the greatest chance during the afternoon and evening on both
days. MVFR conditions are possible into early Sunday morning.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$

SYNOPSIS...KC
NEAR TERM...KC
SHORT TERM...KC
LONG TERM...McGinnis
AVIATION...KC