645
FXUS61 KCLE 091159
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
759 AM EDT Wed Jul 9 2025

.SYNOPSIS...
A warm front will slowly lift north to the south shore of Lake
Erie this morning. Low pressure crossing the central and eastern
Great Lakes this afternoon through tonight will drag a cold
front across the region by Thursday morning. This front will
stall in the vicinity of the southern Great Lakes through the
end of the week before lifting back north Saturday ahead of a
stronger low moving into the Great Lakes.

&&

.NEAR TERM /THROUGH THURSDAY/...
Active weather will return to northern Ohio and Northwest PA
today after a brief respite as a fairly strong shortwave trough
crosses the Great Lakes. Early morning infrared satellite and
water vapor loops show this mid/upper shortwave dropping towards
the northern Great Lakes. A lead, weaker shortwave is currently
crossing the thumb region of Lower Michigan where the right
entrance region of an associated 65-75 knot H3 jet streak is
helping to generate convection over southern Lower Michigan and
extreme NW Ohio. The sub 20 knot southwesterly low-level jet and
best theta-e advection associated with this shortwave should
mainly pass NW of the region through sunrise, so kept PoPs at
slight chance confined to NW Ohio.

The better chance for showers and thunderstorms will come late
this morning through the afternoon as the main mid/upper
shortwave drops into the central Great Lakes. An associated weak
surface low over Lower Michigan will lift a warm front slowly
northward to the south shore of Lake Erie by midday. This will
allow the higher dew points and pool of instability to spread
back into the region this morning, and as the southern edge of a
50-60 knot mid-level jet rounding the base of the shortwave
impinges on the region, new convection will develop. The main
limiting factor for widespread thunderstorm coverage today is
cloud cover. Mid-level clouds streaming into the region this
morning will slow surface heating, and RAP forecast soundings
only suggest 500-1000 joules of MLCAPE by mid afternoon, which
is also not helped by weak mid-level lapse rates of only 5.5 to
6 C/Km. This makes convective coverage uncertain, and all of the
HREF members offer different solutions for the locations and
coverage of showers and thunderstorms from late morning through
the afternoon. Nevertheless, the increasing synoptic forcing
from the shortwave passing just to our north will allow
scattered showers/storms to develop, but mainly capped NBM PoPs
at high chance given the uncertainty on coverage. Any
thunderstorm could produce strong winds as forecast soundings
suggest modest deep layer bulk shear increasing to 25-30 knots
this afternoon, supporting loosely organized multicell clusters.
Additionally, PWATs increasing to 1.50 to 1.65 inches, deepening
warm cloud layers, and fairly tall, skinny CAPE will also lead
to locally heavy rainfall with any thunderstorm. The latest
SWODY1 from SPC maintains a Marginal Risk for NW and north
central Ohio to cover the wind potential, and a Marginal Risk
for excessive rainfall also remains from WPC for the locally
heavy rainfall rates.

As the mid/upper shortwave trough progresses toward the eastern
Great Lakes tonight, the trailing cold front will gradually
move southeastward through the region, with chances for showers
and thunderstorms diminishing with the loss of both daytime
heating and forcing. Surface ridging will attempt to build south
into the region Thursday, but the cold front becoming quasi-
stationary between central Ohio and U.S. 30 will keep chances
for convection in place with daytime heating, especially over
the central and southern counties. Slightly tweaked NBM PoPs for
Thursday. Any thunderstorm could once again produce locally
heavy rainfall and gusty winds, and while there is again
uncertainty on the amount of coverage Thursday afternoon, the
coverage should be less than Wednesday since the only real
forcing is the lingering frontal boundary.

It will be warm and humid through the period, with highs in the
low/mid 80s today and Thursday and lows tonight in the low to
mid 60s.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
The mid/upper trough axis will linger over the eastern Great
Lakes and Northeast U.S. Thursday night into Friday while
surface ridging continues over the northern and central Great
Lakes. This ridging may be strong enough to push the quasi-
stationary boundary slightly farther south, so have lower PoPs
for diurnal convection Friday. By Friday night and Saturday,
quasi-zonal mid/upper flow will return to much of the CONUS as a
strong shortwave trough progresses into the northern Plains.
This combined with weakening surface ridging over the Great
Lakes will cause the front to slowly drift back northward across
the region. The synoptic support will remain well to the west
through Saturday, but chances for convection will slowly
increase as the front lifts north and brings the pool of
instability back into the region. Better chances for showers and
thunderstorms may come Saturday night and Sunday as the
aforementioned shortwave progresses through the Great Lakes,
with an associated surface low dragging a cold front through the
region. Uncertainty continues on the amplification of the
shortwave trough and timing of the frontal passage, which
affects how widespread and organized the convection will be, but
overall, Saturday night/Sunday looks like the best opportunity
for more of an organized round of showers/storms.

Highs in the mid/upper 80s Friday will warm into the low 90s
Saturday, and could see heat indices approach 100 in parts of
the area Saturday given dew points climbing into the 70s. Lows
in the low/mid 60s Thursday night will warm into the upper
60s/low 70s Friday and Saturday nights.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
Above normal temperatures and daily chances for convection will
be the theme through early next week. Any cooling behind the
cold front will be brief Sunday as the mid/upper trough over the
Great Lakes gives way to a broad building central and eastern
CONUS mid/upper ridge by Monday and Tuesday. This is in response
to a deepening mid/upper trough in the northern Rockies and NW
Plains. The front will likely lift back north as a warm front
late Sunday and Monday, and with additional shortwave energy on
the northern periphery of the building ridge interacting with
the front combined with increasing instability, chances for
scattered convection will continue. Temperatures in the mid 80s
Sunday will warm back to near 90 Monday and Tuesday.

&&

.AVIATION /12Z Wednesday THROUGH Sunday/...
Weak low pressure is over Lower Michigan at 12Z with a moisture
axis extending southwest across Indiana. Light echos can be seen
moving into western Ohio but these may not reach the ground or
will be light as they approach the I-75 corridor. The
challenge today will be timing scattered showers and
thunderstorms that develop this afternoon into early evening
with generally light forcing. Thunderstorms have the best
chance of occurring at TOL between 18-23Z then a little later
at CLE/FDY/MFD. Have included a prob30 at CAK/YNG after 22Z but
confidence is lower on coverage reaching those areas. Wind gusts
of at least 20-25 knots are possible with thunderstorms but may
need to amend to add higher wind gusts of 40+ knots if a strong
thunderstorm develops, mainly in NW Ohio. MVFR and brief IFR
visibilities are possible with thunderstorms. Precipitation is
expected to diminish after sunset with mainly mid-level cloud.

Winds will be southwesterly today, generally ahead of
thunderstorms. The trough moves southeast later today and may
result in a wind shift to the north at northern terminals or
downwind of Lake Erie while winds will tend to be light and
variable again tonight.

Outlook...Non-VFR will be possible with scattered showers and
thunderstorms Thursday through Sunday with the best chance
during the afternoon each day.

&&

.MARINE...
Winds on Lake Erie are generally expected to be 10 knots or less
through Friday except when thunderstorms occur. Winds will be light
this morning with lake breezes and onshore flow this afternoon. A
weak trough will cross the lake Thursday morning with winds veering
from southerly to northerly. Southerly winds start to increase on
Saturday ahead of a trough moving into the Central Great Lakes. A
wind shift to the west/northwest is likely behind this trough late
Saturday night into Sunday with slightly higher winds and
waves.

Scattered thunderstorms are expected on Lake Erie today and may
impact marine conditions. A low chance remains on Thursday with
chances of thunderstorms returning again over the weekend.

&&

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

&&

$$

SYNOPSIS...Garuckas
NEAR TERM...Garuckas
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...10
MARINE...10