940
FXUS61 KCLE 301112
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
712 AM EDT Wed Sep 30 2026

.WHAT HAS CHANGED...
Continued the trend of increasing chances for rain showers and
rainfall amounts this evening through tonight.

&&

.KEY MESSAGES...
1) Dry and pleasant weather continues most of today.

2) Light showers are likely this evening and tonight, especially
near the lakeshore, followed by a steady, soaking rain Thursday
night into Friday.

3) Much cooler this weekend into early next week with frost
potential. This period will be mainly dry with a couple of
minor rain chances.

&&

.DISCUSSION...
KEY MESSAGE 1...
Mid/upper water vapor imagery and RAP analysis show a changing
weather map this morning. Mid/upper ridging is building over the
Ohio Valley and eastern Great Lakes ahead of a northern stream
mid/upper trough starting to dig into the northern Rockies and a
southern stream closed low over the Desert Southwest. At the
surface, the high that was over the Great Lakes since the end of
last week is now centered near the Mid Atlantic coast and will
continue to drift offshore of the Carolinas through Thursday.

This is already establishing return southerly flow and resultant
warm air advection. The better pressure gradient will keep light
S winds up just enough this morning to limit fog development to
sheltered valley and lake areas of interior NE Ohio and NW PA,
and expect temperatures to rise fairly quickly after sunrise,
topping out in the mid/upper 70s this afternoon. Clouds will
increase through the day as mid-level moisture advection and
isentropic ascent ramp up ahead of a warm front, and
deterministic models, most HREF CAMS, and the RRFS have all
increased the probabilities for rain showers starting after 21Z
this evening near the lakeshore counties. Very dry low-levels at
the onset will probably limit this with mainly virga until
tonight, but increased POPS to chance/slight chance starting at
21Z.

KEY MESSAGE 2...
There will be a better chance for light rain showers tonight as
the warm front lifts across the area. Some jet support from the
right entrance of a subtle 70+ knot H3 jet streak crossing
southern Ontario associated with a mid/upper shortwave cresting
the ridge will focus moisture advection and isentropic ascent
along and north of the warm front. As mentioned above,
deterministic and hi-res guidance are coming into agreement on
light rain, so increased POPS and QPF tonight, especially across
the lakeshore counties of northern Ohio and NW PA. This could
result in a few hundredths to up to 0.10 inch of rain.

The warm sector will be mainly dry Thursday after any lingering
showers depart NW PA in the morning. Cannot rule out a few
spotty showers in the afternoon, but the main show will await
the cold front Thursday night into Friday. In terms of details,
the aforementioned northern stream mid/upper trough will dig
into the northern Plains Thursday and absorb the remnants of the
old Desert Southwest cut off low. This will lead to a weak
surface wave developing in the Mid Mississippi Valley and riding
along the cold frontal boundary. This wave and the lingering,
strong mid/upper ridge over the Southeast CONUS will cause the
front to be very slow to sag through the region Thursday night
and Friday, resulting in a prolonged band of rain showers. The
overall system looks to be weakening as it progresses through
the area since the strongest jet dynamics progress into northern
Ontario Thursday night, so this will impact how much rain falls.
Consensus remains in the range of 0.50 to 0.80 inches of
QPF between Thursday night and Friday evening given the slow
moving nature of the front and wave, with locally higher amounts
in NW Ohio and along the lakeshore possible. However, there
remains some spread in probabilistic guidance on exact totals,
with slightly more or less depending on where the steadiest
band pivots. Regardless, it will be a steady, soaking rain
Thursday night through much of Friday, but no flooding is
expected. This will be beneficial after the recent dry spell.
Gradual drying will occur from NW to SE Friday afternoon, with
all areas drying out Friday night and turning much cooler.

KEY MESSAGE 3...
The mid/upper longwave trough will establish itself across the
Great Lakes and Northeast CONUS Saturday, with a large Canadian
high at the surface building across the Great Lakes. This will
support dry and cool conditions, with highs only in the mid 60s
and lows well into the 40s away from the lake Saturday night. A
strong, reinforcing shortwave trough will drop through the
longwave trough Sunday and Sunday night, with an associated deep
surface low tracking south of Hudson Bay. This will drive
another cold front through the region, with an impressive 1030
mb Canadian high building from the Upper Midwest through the
Great Lakes early next week in the wake of the front. A few
showers are possible in eastern Ohio and western PA with the
front Sunday, and possibly lingering lake-effect showers in NW
PA Sunday night and Monday before the high builds in, but the
big story will be the cool Fall airmass. Highs in the mid/upper
60s Sunday will cool into the upper 50s to near 60 Monday and
Tuesday. Lows in the 30s look increasingly likely Monday night,
so frost headlines are possible away from the lake Monday night
into Tuesday morning.

&&

.AVIATION /12Z Wednesday THROUGH Sunday/...
VFR is expected through the TAF period with high
clouds increasing in coverage throughout the day today. Light
rain showers will move across mainly the northern portion of
the forecast area this evening into tonight. Visibility should
mainly stay above 6 SM with ceilings mostly above 5 kft.

South to southwest winds around 5 to 10 knots are expected
through the TAF period.

Outlook...Non-VFR likely with rain showers Thursday night
through Friday afternoon.

&&

.MARINE...
S winds will increase to 10-15 knots early this morning then
decrease to 5-10 knots by this afternoon, before increasing
again to 10-20 knots tonight and Thursday morning while
gradually becoming more SW behind a warm front. This will lead
to choppy conditions in the open waters. Lighter SW winds of
5-10 knots Thursday evening will become NNW at 10-20 knots by
Friday morning behind a cold front then NE at near or over
15-20 knots Friday night into early Saturday. Small Craft
headlines are possible Friday night and Saturday. Winds will
gradually flip around to S Saturday night and WNW while
increasing again late Sunday as another cold front approaches.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.

&&

$$

DISCUSSION...Garuckas
AVIATION...Saunders
MARINE...Garuckas