National Weather Service Forecast for: Lancaster, OH Issued by: National Weather Service Wilmington, OH

Updated: 2:28 am EDT Sep 20, 2026

Sunday Showers And T-Storms then Chance Showers And T-Storms Monday Rain Showers Tuesday Slight Chance Rain Showers Wednesday Showers And T-Storms Likely Thursday Slight Chance Rain Showers Friday Mostly Sunny Saturday Mostly Sunny   Hi 83 °F Hi 70 °F Hi 70 °F Hi 67 °F Hi 67 °F Hi 67 °F Hi 69 °F   Overnight Showers And T-Storms Sunday Night Chance Showers And T-Storms Monday Night Chance Showers And T-Storms Tuesday Night Showers And T-Storms Likely Wednesday Night Rain Showers Likely Thursday Night Mostly Cloudy Friday Night Partly Cloudy   Lo 67 °F Lo 61 °F Lo 56 °F Lo 57 °F Lo 54 °F Lo 51 °F Lo 49 °F

Flood Watch
 

Forecast from NOAA-NWS for Lancaster, OH.

461
FXUS61 KILN 200305
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
1105 PM EDT Sat Sep 19 2026

.WHAT HAS CHANGED...
Flood watch issued for parts of southwest into south central Ohio for
overnight tonight into early Sunday morning.

&&

.KEY MESSAGES...
1) Showers and thunderstorms will develop overnight into Sunday
morning. Repeated rounds of storms could cause localized flooding.

2) Additional rounds of showers and thunderstorms will occur through
Sunday night with a potential for heavy rain.

3) Cooler and showery weather will occur for the first half of the
week.

&&

.DISCUSSION...
KEY MESSAGE 1)

A lingering instability gradient is apparent in mixed layer CAPE
graphics late this evening from southwest through south-central
Ohio. This gradient was caused by the thunderstorm complex earlier
that moved through central Ohio into southeast Ohio. Moving across
this gradient is a developing westerly low-level jet. Radar trends
show clusters of showers and storms developing in this area. With
unseasonable deep moisture in place, many of the 00Z CAMs show a
stripe of heavy rain ranging from one to three inches. Have opted to
issue a short-fuse flood watch due to flash flooding potential
overnight. Much of the guidance has these storms moving off to the
east by sunrise.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Active weather pattern on tap for the TAF period... Mid-level
disturbance moving across the Great Lakes along with the development
of a low-level jet will bring periods of showers storms overnight
into the early Sunday morning. Have amended each of the TAFs to
include this potential at least through 07Z. With the involvement of
the low-level jet and a nearly stationary instability gradient,
there is a chance one or two of the terminals could see an extended
period of storms (one to two hours). Narrowing this down to an exact
set of terminals is challenging, but the highest threat is likely
for ILN based on radar trends.

After a late morning through afternoon break, a cold front will
start to shift south during the evening. While precipitation
associated with the front and accompanying disturbance may hold off
until after 00Z, winds will shift out of the north with a few gusts
to close the 24-hour period. High-res models differ widely on
precipitation coverage and timing, so confidence is relatively low as
we get closer to 00Z.

OUTLOOK...Thunderstorms possible Monday. MVFR to IFR ceilings and
visibilities possible Sunday night through Tuesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Flood Watch through Sunday morning for OHZ063>065-071>074-080-082.
KY...None.
IN...None.

&&

$$

DISCUSSION...04
AVIATION...04

NWS ILN Office Area Forecast Discussion