018
FXUS61 KILN 181814
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
214 PM EDT Fri Jul 18 2025

.SYNOPSIS...
A relative lull in thunderstorm activity is expected today before
a warm front lifts back northward overnight. This will eventually
result in scattered strong to severe thunderstorms on Saturday and
again on Sunday, with heavy rain leading to some flooding issues. A
cooldown is expected behind the cold frontal passage Sunday night,
but hot and humid air quickly builds back into the Ohio Valley by the
middle of the next work week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Weak 700mb/850mb wave ripples through Ohio today, which is helping
to initiate scattered shower activity across our CWA. Most of these
showers are not producing lightning given the weak instability
present from the thick stratus deck. Clouds are beginning to erode
near the Tristate this afternoon, with shower activity gradually
shifting eastward with time today. By the evening, majority of our
CWA should be in the clear of any rain.

Overnight, the quasi-stationary boundary draped across the Ohio River
will gradually begin to lift back northward as a warm front. However,
given the slow northward progression of the front, majority of
shower/storm development will be south of I-70 - particularly closer
to the Ohio River. Not anticipating any strong storms tonight or any
flooding concerns.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
Warm front continues to lift northward on Saturday, eventually
aligning itself across the Great Lakes region. This will place the
ILN CWA firmly in the warm sector, allowing for a hot and humid air
mass to build in. Daytime highs climb into the middle to upper 80s,
with dewpoints also rising into the lower to middle 70s, making the
air feel very muggy.

As diurnal heating ensues and we progress into the afternoon hours,
discrete showers/thunderstorms are expected to initiate. In
addition, a complex of storms that develops across the Upper Midwest
region will merge into a more organized MCS, eventually barreling
its way to our western border (likely between 5-7PM). This complex
has the best chance at providing severe storm potential to our fa.
While the wind shear values still remain poor, an isolated tornado
cannot be completely ruled out given the formation of the MCS and
potential for storm mergers and other interactions. Tornadic
probability remains low however, with damaging straight-line winds
being the primary severe threat from this MCS. The MCS is expected to
weaken as it progresses through our CWA with the loss of diurnal
heating and weak shear profiles.

Keep in mind, even with the progressive nature of this MCS, the
environment is showing PWATs in excess of 2" across our entire CWA.
This means that efficient (and even torrential) rainfall can be
expected. Locations that get hit with discrete cells earlier in the
day and again with the MCS would likely have the best chance for
hydro concerns, particularly flash flooding.

Behind this MCS, additional shower/storm activity may build back in
overnight. The Ohio Valley will remain in a location that will be
susceptible to ridge riders - additional complex`s of storms that
form and ride along with the northern periphery of the H5 ridge.
Thus, we may observe another complex of storms late Saturday night or
early Sunday given this synoptic setup. This may compound potential
flooding issues as we continue to highlight this in the HWO. Another
Flood Watch may be necessary at some point to elevate this messaging
for this weekend.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
The frontal boundary will sag slowly south across mainly southern
portions of our area Sunday into Sunday night. This will lead to
another day of widespread showers and thunderstorms, with the
highest pops across our south. With high PWs, locally heavy rainfall
will remain possible. Highs on Sunday will be in the mid to upper
80s.

The front will likely shift just off to our southwest through the
day on Monday as surface high pressure moves east across the Great
Lakes. With the potential for somewhat drier air advecting in from
the northeast, the best chances for pcpn on Monday look to be across
our southwest. Temperatures will be a bit cooler too with afternoon
highs mostly in the lower 80s.

Mid level ridging will then build into the region from the southwest
through mid week with increasing heights. This will lead to warmer
temperatures along with some lower end chances for showers and
thunderstorms. Highs on Tuesday will be in the mid to upper 80s,
increasing to highs in the lower 90s for Wednesday and Thursday.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
MVFR/IFR CIGs continue to linger today behind the weak cold frontal
passage. IFR CIGs expected to break apart later this afternoon, but
kept in a TEMPO mention at KDAY/KCMH given the latest satellite obs.
Additionally, shower activity continues to push east today with a
weak mid level wave sweeping through. Thunder is not expected, but
brief vsby reductions (and perhaps IFR CIGs) expected with the
passing showers.

VFR CIGs become more prevalent to start the night, but MVFR (and
even some IFR) CIGs build back in. Some vsby reductions at the
surface are possible with shallow moisture becoming trapped, so have
a mention of this potential for several terminals. MVFR/IFR CIGs
linger into the mid morning hours Saturday before breaking apart.

Some additional shower activity may be possible tonight and Saturday
morning, but coverage should be pretty isolated. As we progress into
Saturday afternoon, showers and storms begin to fire off in the
hot/humid air mass. Eventually, a complex of storms moves in during
the evening, eventually impacting at least the western terminals
(KDAY/KCVG/KLUK).

OUTLOOK...Thunderstorms are likely through Tuesday. MVFR ceilings are
possible Sunday night into Monday.

&&

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

&&

$$

SYNOPSIS...Clark
NEAR TERM...Clark
SHORT TERM...Clark
LONG TERM...JGL
AVIATION...Clark