483
FXUS61 KILN 202334
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
734 PM EDT Sun Sep 20 2026

.WHAT HAS CHANGED...
Flood watch issued for tonight.

&&

.KEY MESSAGES...
1) A cold front will move through the area tonight with additional
showers and thunderstorms along and north of the front that could
impact portions of the area with heavy rain and flooding. There will
be an initial severe storm threat as well.

2) Cooler and showery weather will occur into midweek.

&&

.DISCUSSION...
KEY MESSAGE 1)

Active weather to continue this evening into the overnight with an
initial severe storm threat, then continuing with the potential for
heavy rain and flooding. A wavy surface frontal boundary is bisecting
ILN/s area. Forcing will increase late in the afternoon into this
evening as a short wave induces a wave of low pressure along the
boundary. A modest 20-25 kt low level jet will accompany this wave.

For the initial severe threat, low-level vorticity along the frontal
boundary is will combine with 25-30 kts effective shear and
1500-2000J of mixed-layer CAPE to bring the chance of a few
supercells. Threat with these storms initially will be damaging wind
gusts and large hail.

PWAT values remain anomalously high around 2 inches and the warm
cloud layer will be deep. This will lead to the potential for heavy
rain and flooding along and north of the front. HREF is showing the
potential for 1 to 3 inches stripes of rainfall overnight with LPMM
indicating that local totals in excess of 4 inches will be possible.
The exact placement of the heavy rain axis is somewhat uncertain with
the most favored location along the southern periphery of the
I-corridor. Have issued a flood watch for potential flash flooding
overnight and added a buffer of counties north and south due to the
uncertainty of exact placement.

KEY MESSAGE 2)

Cooler airmass will settle across the region. A deep mid level trough
digging southeast from the Upper MS Valley will close off as it
moves across the area midweek. At the surface, an inverted trough
will extend along the western slopes of the Appalachians. This
combination will result in showery conditions, particularly across
eastern counties. For the period Tuesday thru Friday - high
temperatures look to range from the mid/upper 60s north to the lower
70s south. These readings will be close to 10 degrees below normal.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A rainy TAF period is in store this period with showers and storms
along and behind a surface cold front. In addition to this
precipitation, a cooling near-surface layer will cause stratus to
increase behind the front. Guidance consensus is for this IFR or
low-MVFR cloud deck to persist through most, if not all of Monday.

Winds will shift to northeasterly behind the front, with a few gusts
possible initially. Showers will decrease Monday afternoon.

OUTLOOK...MVFR to IFR ceilings and visibilities possible through
Tuesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Flood Watch through Monday morning for OHZ026-034-035-042>046-
     051>056-060>065-070>074-077>082-088.
KY...None.
IN...Flood Watch through Monday morning for INZ050-058-059-066-073-074.

&&

$$

DISCUSSION...AR/04
AVIATION...04