536
FXUS61 KILN 181720
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
120 PM EDT Mon Aug 18 2025

.SYNOPSIS...
Surface high pressure building across the Great Lakes will offer dry
weather and near normal temperatures today. More humid and warmer
conditions arrive Tuesday and Wednesday along with an increasing
threat for showers and storms. In the wake of a cold front slightly
cooler and drier conditions are expected Thursday and Friday.
Canadian high pressure looks to offer cooler and drier air late this
weekend into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A large mid level ridge extends from the Central and Southern Plains
into the Lower Ohio Valley with a band of westerlies from the
Northern Plains thru the Great Lakes. Latest surface analysis shows a
stalled frontal boundary extending from Central KY thru IL into the
Mid MS Valley with high pressure centered just north of the Great
Lakes. In the wake of this front drier air has advected into the
region on low level northerly flow. Stratus that developed overnight
is mixed out leaving scattered to bkn cumulus clouds.

These diurnally driven cumulus clouds will dissipate with the loss
of heating early this evening with only some thin high level clouds
spilling in overnight. Some patchy fog cannot be ruled out in in
river valleys tonight.

Temperatures tonight will bottom out from the upper 50s northeast to
the upper 60s southwest.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
Mid level shortwave over the Upper MS Valley to track east thru the
Great Lakes Tuesday/Tuesday night. Expect thunderstorms to develop
to our west in a thermally more favorable environment Tuesday and
then progress eastward on the leading edge of more humid air (with
front lifting back north) - as moderate instability develops. The
highest pops will occur generally west of I-71. Highs on Tuesday will
top out in the upper 80s to near 90 degrees. Have adjusted NBM
temperatures and dewpoints down slightly (mainly across the south)
due to recent observational trends.

Weak surface low associated with the mid level shortwave tracks
across the Great Lakes with a southward attendant front pushing into
the area late Tuesday night. Shower and thunderstorm chances
overspread the entire area with the highest pops across the north -
closer to the surface low. Low temperatures Tuesday night drop to
readings ranging from the upper 60s to the lower 70s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Cold front continues to push southeast through south-central Ohio
and northeast Kentucky counties Wednesday morning, leading to light
northerly flow and advection of slightly drier air. Ensemble
guidance maintains a low chance of showers/storms due to some
uncertainty in frontal position, so have kept these PoPs until
confidence improves.

While surface dewpoints remain quite high late this week into the
early stages of the weekend, moisture depth is shallow as PWs drop
to near or just below an inch. Latest guidance offers a slight
chance of convection along a reinforcing cold front Saturday
afternoon... but this will likely be dependent on the exact timing
of the front and how much moisture return can occur ahead of it.

Behind this reinforcing cold front, high pressure will drop south
into the northern Plains to close the period. This front leads the
middle Ohio Valley into cooler temperatures and much lower dewpoints
heading into the next work week.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
Latest surface analysis shows a stalled frontal boundary south of
the Ohio River with high pressure centered just north of the Great
Lakes. In the wake of this front drier air has advected into the
region on low level northerly flow.

Stratus that developed overnight across eastern sections of the area
is continuing to mix out leaving scattered cumulus clouds. These
clouds will lift from MVFR to VFR across the entire area early this
aftn.

Diurnally driven cumulus clouds will dissipate with the loss of
heating with only some thin high level clouds spilling in overnight.
Some patchy fog cannot be ruled out - especially in in river valleys
tonight. Have MVFR visibility restrictions at KILN and KLCK with IFR
conditions at KLUK.

Fog improves quickly Tuesday with VFR conditions thru the remainder
of the morning into the afternoon. Have kept the TAFs dry thru 18Z
with a better chance for thunderstorms developing Tuesday night with
the approach of a frontal boundary. Therefore, have introduced a
pro30 at KCVG 30 hour TAF site after 21Z.

Northeast at 5 to 10 kts today become easterly at 5 kts or less
tonight and southwest at 7 to 10 kts Tuesday.

OUTLOOK...Thunderstorms are possible Tuesday night and Wednesday.

&&

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

&&

$$

SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...
AVIATION...AR