464
FXUS61 KILN 151822
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
222 PM EDT Tue Sep 15 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...
1) Warm and humid conditions develop today, with an initial chance
of storms tonight.

2) Heat and humidity continue through the week, with occasional
chances for storms through the forecast period.

&&

.DISCUSSION...
KEY MESSAGE 1)

Mid level ridge centered over the southeast expands north into the
region. Height and thickness rises will result in warmer conditions
with afternoon high temperatures peaking out from the mid 80s
northeast to the lower 90s southwest. An increase in surface dew
points will accompany the warmer temperatures with readings in the
mid 60s to 70. The combination of heat and humidity will result in
apparent temperatures topping out from near 90 northeast to near 100
southwest.

Main storm activity to remain north and northwest of ILN/s area
around the periphery of the mid level ridge during the daylight
hours. A frontal boundary encroaching into the Great Lakes will
lead to increasing precipitation chances overnight into Wednesday
morning. Storms that are expected to develop to our northwest this
evening are expected to move into west central Ohio late this
evening through the overnight hours. SPC Day 1 outlook has adjusted
the marginal risk area a little farther north. This looks very
reasonable with some of the CAM solutions showing scattered convection
moving into ILN/s northern counties. The storms are expected to be
weakening and shear and instability is not overly impressive, but
can not rule out a marginal severe threat.

KEY MESSAGE 2)

Heat and humidity will be observed through Thursday with ILN/s area
on the northern periphery of the mid level ridge. Convective chances
look most favorable across our northern counties - from the frontal
zone on the northern edge of the warm sector. Although convection
and clouds could alter the temperature forecast, at this time
Wednesday and Thursday look to be the warmest days. With surface
dewpoints getting into the lower 70s, some areas in the southern
half of the forecast area may approach heat advisory criteria (100
degree heat indices) on both days.

Looking at forecast soundings - the environment will be characterized
by marginal shear and moderate instability which suggests a lack of
an organized severe weather setup but a strong to severe storm can
not be ruled out. Heavy rain looks to be a threat with PWAT values
around 2 inches and the potential for several rounds of storms.

The ridge begins to break down on Friday and into the weekend,
offering slightly cooler temperatures. Thunderstorm chances continue
in the west- northwest flow pattern around the ridge centered over
the Lower MS Valley.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR conditions are expected today and generally continue overnight
sans the potential for river valley fog. Expect mainly high level
clouds today - which thicken up along with mid level clouds
overnight. Bulk of pcpn threat to remain north of the TAF sites and
have only a PROB30 mention of a shower late tonight into early
Wednesday for KDAY. Clouds should inhibit widespread fog development
overnight and at this time have limited the mention to MVFR vsby
restriction at KLUK.

Scattered shower and thunderstorms develop Wednesday afternoon with
the best coverage across the north after 18Z. Therefore, have omitted
the mention of thunder in the TAF/s at this time.


OUTLOOK...Thunderstorms are possible in some locations at times from
Wednesday afternoon through Friday.

&&

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

&&

$$

DISCUSSION...AR
AVIATION...AR