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

Updated: 4:00 pm EDT Sep 20, 2026

This Afternoon Chance Showers And T-Storms Monday Showers And T-Storms Tuesday Mostly Cloudy Wednesday Rain Showers Likely Thursday Slight Chance Rain Showers then Mostly Cloudy Friday Mostly Sunny Saturday Sunny   Hi 83 °F Hi 69 °F Hi 69 °F Hi 66 °F Hi 67 °F Hi 67 °F Hi 69 °F     Tonight Chance Showers And T-Storms then Showers And T-Storms Monday Night Chance Rain Showers then Mostly Cloudy Tuesday Night Mostly Cloudy then Chance Rain Showers Wednesday Night Rain Showers Likely Thursday Night Partly Cloudy Friday Night Partly Cloudy Saturday Night Mostly Clear   Lo 60 °F Lo 56 °F Lo 56 °F Lo 54 °F Lo 51 °F Lo 49 °F Lo 49 °F

Flood Watch
 

Forecast from NOAA-NWS for Lancaster, OH.

879
FXUS61 KILN 201841
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
241 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

2) Cooler and showery weather will occur into midweek.

&&

.DISCUSSION...

KEY MESSAGE 1)

Active weather to continue overnight 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.
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.


Along with the flood threat a threat for severe weather exists into
this evening. Moderate instability combined with favorable DCAPE
values may lead to a conditional severe weather threat with some of
the initial storms late this afternoon into this evening. The main
threat is damaging winds.


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 /18Z SUNDAY THROUGH FRIDAY/...
Active weather to continue overnight with the potential for heavy
rain and flooding. A wavy surface frontal boundary will slip south of
the area this evening as a wave of low pressure ripples along it.

As the cold front moves south across the region ceilings will drop
thru MVFR to IFR. Additional showers and thunderstorms behind the
front will reduce vsbys to IFR at times. IFR ceilings will be slow
to improve to MVFR late in th e TAF period.


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

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Flood Watch from 7 PM EDT this evening through Monday morning for
     OHZ026-034-035-042>046-051>056-060>065-070>074-077>082-088.
KY...None.
IN...Flood Watch from 7 PM EDT this evening through Monday morning for
     INZ050-058-059-066-073-074.

&&

$$

DISCUSSION...AR
AVIATION...AR

NWS ILN Office Area Forecast Discussion