824
FXUS61 KCLE 070210
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
1010 PM EDT Fri Jun 6 2025

.SYNOPSIS...
A stationary front across central Ohio will push south into the
Ohio River Valley tonight as Canadian high pressure builds
across the Great Lakes. A warm front will begin to approach
Saturday night as weak low pressure moves out of the Mid
Mississippi Valley. The front will lift across the region Sunday
ahead of stronger low pressure moving into the Upper Midwest.
This low will progress across the Great Lakes Monday and drag a
strong cold front through the region.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
930 pm update...
With this late evening forecast update, we added patchy to areas
of fog and smoke working in the ZFP and text products through
sunrise in the morning. The haze and light smoke in the air may
linger into much of the day Saturday as well.

730 pm update...
The only minor adjustment that we made with this early evening
forecast update was to the hourly POPs for the rest of this
evening into the overnight. We lowered the POPs to slight chance
25 percent or less and that is mainly for our far eastern CWA
over in the NWPA to Youngstown to Canton areas for a a couple
more hours this evening. The rest of the overnight period will
be rain free with our attention turning to the fog potential
later tonight. We already are seeing widespread areas of 2sm to
5sm due to mainly haze and wildfire smoke drifting down from
Canada today slowly becoming more noticeable this evening.
There is some element of light fog as well with the low levels
being very moist and recent rainfall across the area. The fog
potential now through sunrise tomorrow morning is a low
confidence forecast with uncertainty as high res model guidance
is not clear cut with how things will play out. So at this time,
we will mention patchy to areas of fog, haze, and smoke will
become a little more impactful with visibility possibly lower
down to 1 to 2 miles later tonight through sunrise Saturday
morning. We will continue to monitor trends through the evening
regarding the fog and smoke and make nowcast adjustments if
needed later tonight.

Previous discussion...
Convection has blossomed across the SE portion of the CWA this
afternoon. This is where breaks in the overcast allowed for just
enough surface heating which when combined with slightly
improved mid-level lapse rates and rich low-level moisture led
to 1000-1200 J/Kg of MLCAPE. A mid/upper shortwave progressing
out of central Indiana and associated 65-70 knot H3 jet streak
is supporting a weak wave of surface low pressure that is
traversing the quasi-staionary boundary this afternoon, and that
has boosted the lift to trigger convection. The overall shear
environment is still unimpressive, but effective bulk shear has
slightly increased to around 30 knots with the approach of the
shortwave. This is supporting loosely organized multicell
clusters capable of gusty winds and small hail. An isolated
severe cell with damaging winds to 60 mph is not out of the
question, but the potential is rapidly diminishing as the
convection progresses off to the E/SE. Locally heavy rainfall is
also being monitored since soils are wet from 2 to 3 inches of
rain in some of these same locations yesterday afternoon, and
PWATs of 1.5 to 1.8 inches, deep warm cloud layers, skinny CAPE
profiles, and slow/repeated cell movement is leading to
efficient rainfall rates.

As suggested above, the convection is expected to exit E/SE of
the region late this afternoon, and it should mainly be gone by
21Z as the synoptic support begins to depart, with the frontal
boundary finally sinking southward behind it. Scattered showers
will linger near the US 30 corridor through early tonight, but
they should be done by 05Z as surface high pressure building
into the northern Great Lakes pushes the front into the Ohio
Valley and brings drier air down into the region. The main
concern overnight is fog potential. Lingering low-level moisture
and pockets of wet soil as high pressure and resulting
subsidence build in is a good set-up for radiation fog below an
inversion. The location and coverage of this fog is lower
confidence, so kept fog to patchy at this time across NE Ohio
and NW PA and along the US 30 corridor and central highlands
region. This is where potential is greater.

The high will take control Saturday allowing for quite a bit of
sunshine other than pockets of haze from lingering Canadian
wildfire smoke. Canadian high pressure and a mid/upper trough
axis progressing across the Great Lakes will support a
comfortably cool, less humid day with highs in the mid/upper
70s. The high will quickly shift east Saturday night, and a
convectively enhanced mid-level shortwave trough lifting out of
the Mid Mississippi Valley Saturday night may support a surface
wave riding along the old frontal boundary near the Ohio
Valley, with the boundary starting to creep back northward ahead
of the feature. The latest NAM and RAP significantly differ
with how this evolves due to a lot of convective feedback in the
NAM resulting in an unrealistically deep surface low. This
lowers confidence, but probabilities are increasing for showers
to at least spread into southern areas late Saturday night, so
kept chance PoPs, but slowed the northward expansion from
previous forecasts given the dry air and uncertainty. The better
potential from this wave will likely hold off until Sunday
morning. Lows Saturday night will mainly range from the upper
50s to low 60s, with some mid 50s in interior NW PA.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Surface low pressure and a shortwave aloft will move across the Ohio
Valley through Sunday evening. The shortwave will exit to the
northeast Sunday night before a broad upper trough dives southeast
towards the eastern Great Lakes region on Monday. Periods of showers
and thunderstorms are expected with both the shortwave on Sunday and
the broad upper trough through Monday. The better chance for
organized convection will be on Monday given the increased
instability and bulk layer shear ahead of a surface cold front.

High temperatures will rise into the mid 70s Sunday and Monday while
remaining humid with dew points in the lower 60s each afternoon.
Overnight lows settle in the upper 50s to lower 60s each night.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Aforementioned upper level trough will continue to gradually push
east across the local area at the start of the long term period.
Continued showers and thunderstorms are expected on Tuesday before
high pressure builds overhead from the west for Wednesday and
Thursday. The next chance for showers and thunderstorms will come on
Friday as an upper level disturbance approaches the region from
the southwest.

Gradual warming trend through the long term with highs in the
low/mid 70s on Tuesday expected to rise into the low/mid 80s by
Thursday.

&&

.AVIATION /00Z Saturday THROUGH Wednesday/...
The main aviation concern and possible weather impact that we
want to highlight with this TAF update will be the areas of
lower visibilities over northern Ohio into northwest
Pennsylvania due to mostly haze and wildfire smoke drifting down
from Canada with some element of light fog as well. The forecast
confidence is low and uncertainty exist this evening through
sunrise Saturday morning in regards to the evolution of the
fog/smoke as well as how low the visibilities may drop tonight
and potential development of very low stratus overnight for some
much of the area. The general message and expectations will be
widespread MVFR visibility for all TAF sites through the
overnight with IFR 1 to 2sm light fog/smoke for most of the TAF
sites developing after 06z through 12z along with possibly low
stratus forming between 500 and 1000 feet overnight. After
sunrise, we should see some quick improvement with visibility
around 5sm through mid to late morning and the low stratus will
break up between 12z and 15z. By late morning we should have
mostly VFR conditions with high level ceilings but the smoke
haze may continue through the rest of the afternoon and evening
on Saturday with 5sm to 6sm, could be a little lower in spots
during the daytime on Saturday. Winds will be mainly from the
north or northeast 5 to 10 knots, lighter tonight and closer to
10 knots during the day Saturday.


Outlook...Non-VFR is likely with scattered showers and
thunderstorms Sunday through Monday, possibly lingering into
Tuesday for areas closer to the lakeshore.

&&

.MARINE...
Generally onshore flow between 8 and 12 knots, occasionally 15
knots, will continue through Saturday night. Flow becomes
northeasterly to easterly at 10-15 knots by Sunday morning as a warm
front approaches the lake. Low pressure will pass in the vicinity
of Lake Erie during the day Sunday with winds turning southwesterly
by Sunday night. Southwesterly to southerly flow 10-15 knots is
expected to persist through the middle of next week. Winds and waves
should remain below small craft criteria. Winds and waves may be
higher in thunderstorms over the lake Sunday through Tuesday.

&&

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

&&

$$

SYNOPSIS...Garuckas
NEAR TERM...Garuckas/77
SHORT TERM...13
LONG TERM...13
AVIATION...77
MARINE...13