261
FXUS61 KCLE 211751
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
151 PM EDT Fri Aug 21 2026

.WHAT HAS CHANGED...
Added a low chance for showers/thunder in parts of Northwest OH
late this afternoon and evening. The overall forecast for the
active period Saturday into Sunday remains similar, though did
expand shower chances outside of the "snowbelt" on Sunday.

&&

.KEY MESSAGES...
1) Mainly dry weather is expected through early Saturday. A few
showers or storms are possible across parts of Northwest and
North Central Ohio late this afternoon into tonight.

2) Scattered to numerous showers and thunderstorms are expected to
move across the area Saturday afternoon and evening. There is a
Marginal Risk (level 1 of 5) for a few severe thunderstorms, with
damaging winds and hail the main risks. Locally heavy rainfall is
also possible.

3) Below average temperatures arrive for Sunday and Monday, with
periodic lake-enhanced rain showers east-southeast of Lake Erie.
A few isolated showers will remain possible across the rest of the
area on Sunday.

&&

.DISCUSSION...
KEY MESSAGE 1...
Surface high pressure begins exiting to the east-northeast
through the day today. A plume of higher theta-e air is expected
to build across western and central OH by this afternoon and
evening, allowing modest but uncapped instability to develop
through the afternoon as heating occurs. A shortwave is diving
out of the Upper Midwest early this morning and will swing
across the area this afternoon and evening with an accompanying
surface trough. Some hi-res models are depicting isolated to
widely scattered convection in response. Overall, there`s enough
there to add a 20- 30% type chance for showers/thunder across
parts of Northwest and North Central OH after 5 PM, with some
activity potentially lingering through the evening and well into
the night amid weak warm air advection. Modest forcing/
instability along with weak shear precludes a severe threat.
The rest of the area is favored to remain dry through early
Saturday. Highs will reach the upper 70s and lower 80s today,
with lows tonight ranging from the mid 50s to lower 60s.

KEY MESSAGE 2...
Active weather is expected Saturday afternoon and evening as a
seasonably deep trough digs into the Great Lakes, allowing low
pressure to gradually deepen as it tracks from Michigan into
southern Ontario and drags a strong cold front through the area.

There`s decent agreement that a pre-frontal trough will push
east across the area Saturday afternoon, with the strong cold
front itself pushing into Northwest OH late in the afternoon and
pushing southeast across and then out of the area through the
evening. Some large scale ascent begins spreading in ahead of
the digging trough by midday/early afternoon, with the greatest
support during the late afternoon and early evening as a vort
max rounds the base of the digging trough and rotates into
northern Ohio. It is likely that showers and storms will begin
developing around midday or early afternoon along both the cold
front and pre-frontal trough, along with perhaps along a lake
breeze near the lakeshore from Cleveland points northeast.
Activity should peak in coverage and intensity during the late
afternoon and early evening hours before exiting to the
southeast with the front and transitioning to lake-enhanced
showers Saturday night. Overall, much of the area should see a
shower or storm Saturday afternoon or evening with two rounds
possible across parts of the area in quick succession.

While mid-level lapse rates will remain weak at 6.0C/km or
less, some heating of a fairly moist low-level airmass (PWATs
increasing to ~1.5" ahead of the cold front) should yield
moderate instability (1000-2000 J/KG of MLCAPE) Saturday
afternoon. Along with 20-30 knots of effective deep-layer shear
and increasing forcing, this is an environment that is on the
lower end of what can support organized convection with a severe
weather threat. Activity along the pre-frontal trough becoming
more widespread earlier in the afternoon could sap some of the
thermodynamics from the atmosphere ahead of the cold front and
greater forcing that arrive during the late afternoon and early
evening. Given the lower-end environment and potential for pre-
frontal convection to muddy the picture, the current SPC Day 2
outlook maintains a Marginal Risk (level 1 of 5) for severe
weather across the entire area on Saturday. The primary threats
would be marginally severe wind gusts or hail with a few
stronger storms. A bit more heating and/or widespread convection
holding off until later in the afternoon when the cold front
and greater forcing arrive would be items that could increase
the severe threat a bit from the current outlook.

Storm motion will be from the west-southeast Saturday afternoon
and evening, fairly parallel to the advancing cold front. The
thermodynamics don`t look overwhelmingly conducive for efficient
rain rates, but given the potential for some spots to see two
rounds of storms and/or a bit of training we`ll need to monitor
for locally heavier rain Saturday afternoon/evening. Area-
average QPF of generally 0.25-0.75" is expected with this
system, but locally up to 2-3" amounts are feasible if there`s
any training or repeated rounds given the environment.

Highs on Saturday will generally be in the upper 70s or lower
80s, though it will briefly feel more muggy as dew points climb
into the mid-upper 60s for a few hours ahead of the cold front.

KEY MESSAGE 3...
As the calendar creeps towards September and a 2-3 standard
deviation 500mb trough digs over the Great Lakes, the airmass
behind Saturday evening`s cold front will feel like an early
taste of fall. In fact, over Lake Erie water temperatures that
average slightly warmer than 25C at the moment, 850mb temps
tumbling to 7-10C and with 500mb temperatures of -17 to -20C
Sunday into Monday will support lake-enhanced rain showers as
moist cyclonic flow aligns out of the west-northwest behind
departing low pressure. A bit of thunder will remain possible
with more robust activity. The coverage/intensity of any lake-
enhanced showers will be maximized with any trough passages and
lull between troughs. There is some agreement in a trough
passage in the vicinity of Sunday morning. Confidence lowers
beyond that, though there are hints that another trough or two
may cross between Sunday evening and early Monday. Lake-enhanced
showers should gradually decrease and begin shifting east-
northeast up the lake shore late Sunday night and Monday as low
pressure gradually exits and as ridging builds in, though there
remains some disagreement over how quickly that happens.

As is traditionally the case with west-northwest flow, lake-
enhanced rain will be most frequent and intense from the
Cleveland metro area points east-northeast across the higher
terrain of the "snowbelt" of Northeast OH and Northwest PA. Some
activity off the lake will be possible as far west as Sandusky
at times, especially through Sunday when moisture is deepest.
Outside of the lake-enhanced showers it will be mainly dry,
though the colder air aloft and any trough passages may
encourage a few hit/miss showers across the entire area, mainly
through Sunday evening. Building ridging should allow areas
outside of lake-enhanced showers to dry out Sunday night and
Monday.

Highs will range from the upper 60s to mid 70s Sunday and
Monday, coolest across Northeast OH and Northwest PA. Overnight
lows will dip into the 50s for much of the area, with some 40s
Monday night if we see sufficiently clear/calm conditions.

High pressure should bring at least a couple days of quieter
weather once it completely builds in early next week.

&&

.AVIATION /18Z Friday THROUGH Wednesday/...
VFR through tonight with winds less than 10kts. Cold front will
approach Saturday with building chances for showers and storms
through the day. Through 18Z Saturday, the best chances are for
FDY/TOL and will cover with -SHRA for now, but through 00Z
Sunday at CLE, chances become greater and should have convection
in the area after 20Z.

Outlook...Non-VFR expected in showers and thunderstorms on
Saturday evening. Non-VFR conditions should continue Saturday
night through early Monday in lake enhanced showers and storms
across Northeast Ohio and Northwest Pennsylvania.

&&

.MARINE...
Marine weather conditions will nice today on Lake Erie with a
light northeast to easterly winds 5 to 10 knots and waves of 1
to 2 feet. A low pressure system and cold front will approach
the eastern Great Lakes on Saturday. Winds will become southerly
to southwesterly 10 to 15 knots Saturday and waves 1 to 3 feet.
Behind the cold frontal passage, northwest winds will increase
15 to 20 knots late Saturday night into Sunday and waves will
increase 2 to 4 feet. A Small Craft Advisory may be needed for
Saturday night through Sunday. There may be some rip current
potential as well for the later half of the weekend and some
beach hazard statements may also be needed. There will also be
the potential for some waterspouts on Sunday with colder air
aloft moving over the warmer lake water. High pressure will
build in on Monday and Tuesday. Winds on Monday will be 5 to 15
knots from the west with waves 1 to 3 feet. Calmer wind and
waves are expected by Tuesday underneath the high pressure
system.

&&

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

&&

$$

DISCUSSION...Sullivan
AVIATION...26
MARINE...77