524
FXUS61 KCLE 271041
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
641 AM EDT Thu Jun 27 2024

.SYNOPSIS...
High pressure will persist over the area through Friday before
moving off the Northeast Coast Friday evening. A low pressure
system will impact the Great Lakes region on Saturday and
Saturday night before high pressure returns on Sunday.

&&

.NEAR TERM /THROUGH FRIDAY/...
630 AM Update...
Low stratus/fog had begun to diminish this morning as
temperatures rise a bit faster than previously forecast and
winds increasing closer to 10 mph. This will be the continued
trend over the next couple hours and diminishing by mid-morning.
Aside from adjusting temperatures to reflect current
observations, no other changes were needed with this update.

Previous Discussion...
High pressure has begun to build east across the area this
morning, which is expected to persist through this period. This
morning, light and variable winds coupled with very moist low
levels has resulted in areas of fog/low stratus, primarily for
areas along and east of I71. Areas west of I71 may see patchy
fog develop, although widespread fog is not expected given the
drier low level moisture/larger dewpoint depression. These foggy
conditions will likely impact the morning commute, so motorists
should use caution and give more time as visibilities may
quickly be reduced. Once the sun rises, increased surface
heating will result in these conditions mixing out completely by
late morning. High pressure will keep things dry across the
area and with a predominantly north flow, high temperatures will
only climb into the low to mid 70s today, making for a pleasant
June day. Tonight, low temperatures will fall into the low to
mid 50s and the potential for patchy fog returns across far NE
OH and NW PA. Any fog that does develop should dissipate mid-
morning on Friday, making way for mostly sunny skies and highs
in the low to mid 80s.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
A high pressure ridge at the surface and aloft exits E`ward Friday
night through Saturday morning as a trough at the surface and aloft
overspreads our CWA from the north-central United States and
vicinity. Simultaneously, a surface warm front is forecast to drift
N`ward through our region as a surface low moves from near northern
MN to central ON, south of James Bay. The warm front will usher-in a
much warmer and more humid air mass originating over the Gulf of
Mexico. Moist isentropic ascent along the upper-reaches of the warm
front and low-level convergence/moist ascent along the surface warm
front are expected to release weak to moderate instability,
including elevated CAPE, and trigger periodic/scattered showers and
thunderstorms Friday night into Saturday morning, especially after
midnight. Moderate to strong deep layer bulk shear will allow
showers and thunderstorms to be organized. However, some boundary
layer stabilization via nocturnal cooling and melting levels higher
than 10.5k feet AGL should curb severe thunderstorm potential Friday
night into Saturday morning. Overnight lows should reach the lower
60`s to lower 70`s around daybreak Saturday.

A trough at the surface and aloft continues to affect our CWA
Saturday afternoon through Saturday night as embedded shortwave
troughs move from near the north-central United States and vicinity
toward the Upper Great Lakes and vicinity. Simultaneously, the
aforementioned surface low moves NE`ward toward Labrador and allows
the trailing cold front to sweep E`ward across our CWA Saturday
evening through about daybreak Sunday morning. Behind the front, a
low-level ridge begins to build from the north-central United States
and vicinity as troughing farther aloft lingers over the eastern
Great Lakes and Upper OH Valley. Highs are forecast to reach the mid
70`s to lower 80`s in NW PA and mainly the 80`s in northern OH late
Saturday afternoon amidst low-level warm/moist air advection and
peeks of sunshine. Lows should reach the 60`s around daybreak Sunday
due, in part to low-level CAA behind the cold front.

Additional scattered showers/thunderstorms are expected Saturday
afternoon through Saturday night due to the release of weak to
moderate CAPE, including elevated CAPE, via the low-level return
flow of warm/very humid air from the Gulf of Mexico undergoing
isentropic ascent and low-level convergence/moist ascent along the
cold front. Moderate to strong deep layer bulk shear will allow
convection to remain organized. Severe thunderstorms in the form of
multicells and supercells are possible Saturday afternoon through
early evening given the projected thermodynamic/kinematic
environment. Any severe hail will probably be marginal and generated
by the relatively-strong rotating updraft of any supercell because
melting levels are expected to remain above 10.5k feet AGL. Damaging
convective gusts are possible given the potential for enhanced low-
level flow and diurnal convective mixing of the boundary layer
yielding steep low-level lapse rates and sizable DCAPE. A tornado or
two is possible given the expectation of significant veering and
strengthening of winds with height in the 0 to 1 km AGL layer amidst
favorably-low mixed layer LCL`s. Fair weather is expected region-
wide by daybreak Sunday morning as stabilizing subsidence
accompanies the building low-level ridge behind the cold front.

Odds favor fair weather on Sunday through Sunday night as the low-
level ridge continues to build from the north-central United States
and vicinity, yet farther aloft flow remains W`erly to NW`erly and
embedded shortwave disturbances impact our area. At this time, low-
level cold/dry air advection and stabilizing subsidence accompanying
the ridge are expected to prevent shower/storm initiation. Late
afternoon highs are expected to reach the 70`s to 80F on Sunday and
be followed by overnight lows in the 50`s to lower 60`s around
daybreak Monday.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
Fair weather is expected Monday through Tuesday as ridging at the
surface and aloft builds and eventually crests E`ward over/near our
CWA. In addition, a warm front should sweep N`ward through our area
on Tuesday and usher-in a much warmer/more humid air mass
originating over the Gulf of Mexico. Monday`s highs should reach the
70`s to 80F in the late afternoon and be followed by lows mainly in
the 50`s to lower 60`s around daybreak Tuesday. Tuesday is expected
to be warmer with highs mainly in the 80`s.

Periodic showers and thunderstorms are expected Tuesday night
through Wednesday night as cyclonic W`erly flow aloft and embedded
shortwave disturbances affect our region, net surface troughing
becomes established across northern OH/NW PA, and a cool front
eventually sweeps E`ward across our CWA Wednesday night. Moderate to
strong deep layer bulk shear will allow convection to be organized.
Strong to severe storms are possible, especially Wednesday afternoon
through early evening given the expectation of a typical diurnal
cycle in boundary layer temperatures/instability within the
warm/moist sector. Overnight lows should reach the 60`s to lower
70`s Tuesday night and Wednesday night. Daytime highs on Wednesday
should reach the 80`s to lower 90`s.

Odds favor fair weather on Thursday, July 4th when a shortwave ridge
and attendant surface ridge are forecast to build E`ward over/near
our CWA and be accompanied by stabilizing subsidence. Daytime
heating and the presence of only a slightly-cooler air mass are
expected to allow late afternoon highs to reach the 80`s.

&&

.AVIATION /12Z Thursday THROUGH Monday/...
A mix bag of conditions linger across the area as patchy low
stratus/fog continue to impact terminals. Conditions should
steadily improve over the next few hours, rebounding to
widespread VFR by mid-morning and persisting for the remainder
of this TAF period. There is a non-zero chance of additional
fog/low stratus development over far NE OH and NW PA tonight
which may possibly impact KYNG and KERI. Confidence in this is
low as high clouds moving into the area should slow cooling so
opted to not mention in this TAF. Light and variable winds this
morning will become northerly at 5-10 knots for today. After
sunset, winds will again return to light and variable.

Outlook...Non-VFR possible in showers and thunderstorms on
Saturday.

&&

.MARINE...
Waves are expected to trend 3 feet or less in U.S. waters through
Saturday night. NW`erly to NE`erly winds around 5 to 15 knots are
expected today and then these winds are expected to veer toward
SE`erly tonight as a ridge affects Lake Erie and the parent high
pressure center moves from the Upper Midwest to northern NY. Winds
remain around 5 to 15 knots on Friday and vary between SE`erly and
NE`erly as the ridge continues to influence Lake Erie and the parent
high pressure center moves to Atlantic waters near Nantucket.
Friday`s winds are expected to trend onshore (i.e. NE`erly) during
the late morning through early evening courtesy of lake breeze
development. NE`erly to SE`erly winds around 5 to 15 knots veer to
S`erly Friday night through Saturday morning as the ridge exits
E`ward and a warm front sweeps N`ward across Lake Erie. S`erly winds
around 10 to 15 knots veer to SW`erly Saturday afternoon as a cold
front approaches from the west. These winds then veer to WNW`erly
Saturday evening through Sunday morning as the cold front sweeps
E`ward across Lake Erie. Waves primarily remain 3 feet or less, but
occasional 4 footers are expected in central Lake Erie by Sunday
morning.

Behind the cold front, a stronger ridge builds from the north-
central U.S. and western Great Lakes. In response, primarily NW`erly
to N`erly winds around 10 to 20 knots are expected Sunday afternoon
through Sunday night. Waves as large as 3 to 5 feet are expected.
The waves will trend largest in the central basin due to greater
fetch and a Small Craft Advisory will probably be needed. N`erly
winds are forecast to veer toward NE`erly or E`erly on Monday and
ease to 5 to 15 knots as the ridge continues to build from the west.
Waves subside to 3 feet or less.

&&

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

&&

$$

SYNOPSIS...Campbell
NEAR TERM...Campbell
SHORT TERM...Jaszka
LONG TERM...Jaszka
AVIATION...Campbell
MARINE...Jaszka