-- Discussion containing changed information from previous version are highlighted. --
925
FXUS61 KCLE 100731
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
331 AM EDT Fri May 10 2024

.SYNOPSIS...
A surface trough over the region today will drift to the eastern
Great Lakes by tonight. Low pressure moves across Ontario into
New York State on Saturday as a cold front crosses the region
from west to east. High pressure briefly builds over Ohio on
Sunday before the next weakening cold front moves southward over
the region by Monday night.

&&

.NEAR TERM /THROUGH SATURDAY/...
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Surface low pressure has moved east of the region but we still
have an upper level trough that needs to pass overhead through
the day. So expect some weak lift to persist across the region
through the morning with light rain/sprinkles expected. The
rain ends from west to east late this morning into the afternoon
with it persisting the longest across NW PA. It then looks to
be dry tonight with cloud cover decreasing.

It will remain cool today with highs ranging from the mid 50`s
across the east to the mid 60`s across NW OH. The decrease in
the cloud cover and light winds tonight should allow
temperatures to range from the upper 30`s to upper 40`s. We will
need to monitor for some patchy frost across inland NE OH into
inland NW PA. At this point it does not look widespread enough
to issue a frost advisory.

After a brief period of high pressure over the region Friday
night it looks like we will get another fast moving storm system
to impact the area. This storm system will be moving through the
northwesterly flow with its cold pool of air moving overhead.
This should lead to the development of a few thunderstorms along
and ahead of a cold front that sweeps west to east across the
CWA through Saturday evening. The cold air aloft may end up
contributing to hail to develop within the best updrafts. It
does NOT appear there will be enough instability in the atmosphere
to grow this hail to severe levels. Highs Saturday should range
from the mid 50`s across NW PA to the lower 60`s across NW OH.
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&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
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By Saturday night, the aforementioned low pressure system will shift
to be centered over the eastern Great Lakes region. This low will
continue to drift east overnight as a progressive upper level trough
over the Great Lakes brings additional synoptic support to the area.
This synoptic support coupled with a relatively cool 850-mb flow of
2-4C across Lake Erie should allow for continued rain showers over
far NE OH and NW PA through Sunday morning. All showers should end
by late Sunday morning as a nose of high pressure pushes north of
the area. Late Sunday into Monday, a boundary will become near
stationary north of the area which will act as a focus for
additional shower development, keeping much of the area dry into
Monday morning. In the meantime, the area will linger in the warm
sector of the system, allowing for southwest winds to usher in
warmer and more moist air over the area. Showers are expected to
become more widespread Monday afternoon as stalled boundary begins
to move towards the area as a cold front. Initial forcing will be
primarily diurnal instability, but as the front moves east late
Monday into Tuesday, frontogenesis coupled with upper level support
from a jet stream will result in widespread shower development. With
the better forcing, cannot rule out thunder late Monday into early
Tuesday. General QPF for late Monday through the overnight hours
should remain below 0.2", but higher totals are expected in the
long term period.

Saturday night lows will remain quite chilly with temperatures
dropping into the low to mid 40s. By Sunday night, temperatures will
be a mid more mild only dropping into the upper 40s to mid 50s as
WAA becomes established across the area. High temperatures will
follow a similar trend with highs on Sunday reaching into the mid
60s to low 70s, but will then warm on Monday to reach into the low
to mid 70s.
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&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
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The long term period looks to remain fairly active as another system
is expected to move east across the Ohio River Valley through
Wednesday night. Models diverge in the exact placement of this low,
so opted to maintain slight chance PoPs for much of the area, but
any northerly shift in the track will likely result in more
widespread showers with greater QPF associated with it. These
showers will primarily be supported by an upper level shortwave
trough, although models do suggest areas of frontogenetic and
isentropic lift. By Thursday, all long range models, including the
GFS and ECMWF, have a high pressure system building over the Great
Lakes region as an upper level ridge pushes east. Opted to decrease
PoPs for the end of the period given the consistency in models, but
any shift in timing of the low pressure midweek may result in
showers continuing through the end of the period. Highs throughout
the period will gradually warm from being in the upper 60s on
Tuesday to being in the mid 70s by Thursday. Overnight lows will
generally linger in the mid 50s through the period.
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&&

.AVIATION /06Z Friday THROUGH Tuesday/...
A few area of light rain or sprinkles remain across the region
as we wait for an upper level trough to cross the region
through the day. VFR cloud covers the entire region but do think
there could be some patchy MVFR ceilings where the light
rain/sprinkles are most persistent. Otherwise drier air will
spread across the region from west to east through the afternoon
with ceilings gradually dissipating.

Northerly winds of 5-10 knots may become gusty for a few hours
through early afternoon. Gusty may reach 20 knots. The winds
then decrease by evening as the winds shift to the northwest and
eventually to the southwest overnight.

Outlook...Non-VFR possible in showers and thunderstorms Saturday
into Saturday night. Non-VFR possible on Tuesday in rain showers.

&&

.MARINE...
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High pressure has gradually begun to push south over the area as a
low pressure system gradually departs off the Mid-Atlantic Coast
today. This has allowed winds to become north-northeasterly across
Lake Erie and weaken to 5-10 knots. As a result, the Small Craft
Advisory has been cancelled this morning. Winds will remain light
into Saturday before shifting to be southwesterly at 15-20 knots as
another low pressure system tracks across the Lake Erie Basin. As
the center of the low pushes east, winds will become northwesterly,
remaining at 15-20 knots for the central and western basins, but
diminishing to 10-15 knots for the eastern basin through much of
Saturday night. This will be the next period to keep an eye for the
potential of additional marine headlines. High pressure returns on
Sunday and allows all winds to weaken from the northwest at 5-10
knots. As another system moves into the area, winds will again
become established from the south-southwest, increasing to 10-15
knots late Sunday into Monday.
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&&

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

$$

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