943
FXUS61 KILN 181817
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
217 PM EDT Sat Jul 18 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...
Key Message 1) A cold front will move southeast across the region
this afternoon into tonight. This will bring periodic thunderstorms,
and a few of the storms may become severe with damaging wind the
main threat.

Key Message 2) Another cold front will move through the region on
Tuesday. This will bring the next chance for thunderstorms and usher
in a somewhat cooler airmass for mid to late next week.

&&

.DISCUSSION...
KEY MESSAGE 1)
Prefrontal atmosphere thunderstorms supported by MLCAPE values of
2000 J/kg, though DCAPE values currently in the 500-700 J/kg range.
Enough for some storms to gust to near 40-45mph, so an afternoon
severe storm certainly is possible. Clouds are on the increase with
the afternoon convection, but where significant breaks in the clouds
and ample low level moisture/high dewpoints, heat index values are
from 95 to even 100 in some areas. With increased convection/clouds,
this should be slightly tempered as the afternoon progresses.

Main show will be with the southern Great Lakes short wave and
associated cold front pushing toward the region late this afternoon.
Shear will increase with the approaching frontal boundary, with 0-3km
values bumping up to 25-30kts, and 0-1km shear nearing 20kts in
northern reaches of central Ohio. While current convection could
diminish available instability once the organized line approaches the
region, there will still be increased low level shear. Still looking
at the main threat being damaging winds, but where ll shear is
enhanced in central Ohio a tornado is possible.

PW values of 1.9-2.1 are near the climatological max for the area, so
rapid accumulations of 1" in less than 1 hour could create isolated
flooding. The storms should be progressive in nature, though, so
flooding will be a secondary threat.


KEY MESSAGE 2)
With upper level NW flow dominating the region for Sunday and Monday,
a quiet start to the work week. For Monday night into Tuesday,
another stronger Great Lakes short wave will push into the region,
bringing a renewed chance of thunderstorms. Increasing ML CAPE and
0-6km bulk shear would bring a potential for severe storms on
Tuesday. Once this shortwave pushes through, a slightly cooler and
more stable airmass settles into the area for mid/late week.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Increasing showers and storms will occasionally bring MVFR
visibilitys this afternoon, with very heavy rain even bringing IFR
for short periods of time. Gusts from 25-35kts are possible in these
storms. A line of more widespread showers and storms will arrive in
the 22z-04z timeframe from North to South across the region. This
will bring the potential again for MFVR CIGs and VSBYS this evening,
along with another round of gusty winds. As the front sinks south of
the area after 04z, winds do slacken a bit so some visibility
restrictions are possible at the more vulnerable locations of KLUK
and KILN.


OUTLOOK...Thunderstorms possible Tuesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Air Quality Alert from midnight tonight to midnight EDT Monday
     night for OHZ042-043-051-060>062.
KY...None.
IN...Air Quality Alert from midnight tonight to midnight EDT Monday
     night for INZ050-058-059-066.

&&

$$

DISCUSSION...JDR
AVIATION...JDR