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

Updated: 2:16 am EDT Sep 18, 2026

Friday Chance Rain Showers then Mostly Cloudy Saturday Mostly Sunny Sunday Showers And T-Storms Monday Chance Showers And T-Storms Tuesday Showers And T-Storms Likely Wednesday Chance Rain Showers Thursday Partly Sunny   Hi 77 °F Hi 80 °F Hi 80 °F Hi 72 °F Hi 71 °F Hi 69 °F Hi 69 °F   Overnight Showers And T-Storms Likely Friday Night Partly Cloudy Saturday Night Slight Chance Showers And T-Storms then Showers And T-Storms Likely Sunday Night Showers And T-Storms then Chance Showers And T-Storms Monday Night Chance Showers And T-Storms then Showers And T-Storms Likely Tuesday Night Chance Showers And T-Storms Wednesday Night Chance Rain Showers   Lo 68 °F Lo 57 °F Lo 66 °F Lo 61 °F Lo 59 °F Lo 59 °F Lo 55 °F

Flood Watch
 

Forecast from NOAA-NWS for Lancaster, OH.

005
FXUS61 KILN 180700
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
300 AM EDT Fri Sep 18 2026

.WHAT HAS CHANGED...
No major changes.

&&

.KEY MESSAGES...
1) Showers and storms this morning may produce localized heavy rain
that could result in flooding.

2) Unsettled conditions will occur from Saturday afternoon through
the early part of next week.

&&

.DISCUSSION...
KEY MESSAGE 1)
Even as the event is unfolding, there is uncertainty how it evolves
through the morning. Showers and storms moving across the northern
part of the forecast area may be it for those locations. This
activity is pretty progressive, so any threat of flooding is quite
minimal there. Additional convection keeps developing back across
Indiana and eastern Illinois. That may blossom further as it moves
into the area. It seems that there may end up being a broken line
that extends back west like a tail from the central Ohio storms,
organizing along the west-east boundary that is sinking southwards.
This will pose a greater potential for repeated rounds of showers and
storms. The atmosphere remains very favorable for efficient rainfall
processes. The 0Z HREF and REFS continue to show the potential for
pockets of heavier rainfall, mainly focused between I-70 and the
Appalachian Highway (Route 32), through 12Z.

KEY MESSAGE 2)
There will be a brief respite tonight into Saturday morning. But the
chance of showers and storms returns Saturday afternoon. The front
moving through today will stall just south of the area. The western
end of that will lift on Saturday as an area of low pressure moves
east while the eastern end will lag. This should result in the
boundary stretching across the western part of the forecast area.
This may become a focus for diurnal convection to develop. But it is
uncertain how well defined the boundary will be at that point which
will affect the low level forcing. Some guidance is suggesting that
the old boundary will be frontolysizing while a new boundary develops
near Lake Erie.

An active jet stream across the Great Lakes will bring disturbances
through the region that will generate convective complexes. There is
the potential for an MCS to drop southeast into the region Saturday
night. Later convection may take a more easterly path, being aligned
with a boundary that will be slowly moving southward through the
weekend. The more active zone of convection near the boundary will
have the potential to produce repeated rounds of showers and storms
at any one location. Plus the return of high precipitable water and
deep warm cloud depths will lead to efficient warm rain processes
again. This mean locally heavy rain will be possible.

The front is forecast to be south of the area by Monday morning where
it will stall and then become reoriented more northeast-southwest as
waves of weak low pressure travel along it. This is in response to
the approach of a robust mid level system that will close off over
the region towards mid week. So, there will be periods of showers and
possibly some storms north of the boundary Monday into Tuesday. And
that may even linger into Wednesday across eastern counties. But it
will be cooler.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Showers and thunderstorms will move across the region during the
early part of the period. After this moves off, expect MVFR to IFR
ceilings to develop. Ceilings will then slowly lift through the day
and scatter out towards 00Z.

OUTLOOK...MVFR to IFR visibility possible in fog late tonight into
Saturday morning. Thunderstorms possible Saturday afternoon into
Sunday evening. MVFR to IFR ceilings and visibilities possible Monday
through Tuesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Flood Watch until noon EDT today for OHZ042-051-053>055-060>065-
     070>074-077>082-088.
KY...Flood Watch until noon EDT today for KYZ091>093.
IN...Flood Watch until noon EDT today for INZ050-058-059-066-073>075.

&&

$$

DISCUSSION...35
AVIATION...35

NWS ILN Office Area Forecast Discussion