821
FXUS61 KCLE 110504
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
104 AM EDT Thu Jul 11 2024

.SYNOPSIS...
The remnants of Beryl will lift across northeast Ohio this
afternoon, dragging a cold front across the region this evening.
A trough will cross Lake Erie tonight into Thursday morning
before high pressure finally builds in Thursday afternoon.
Another trough will cross the Great Lakes Friday into Saturday.

&&

.NEAR TERM /THROUGH TODAY/...
12:30 AM Update...

Updated to higher PoPs over NE Ohio and NW PA overnight where
wraparound moisture, a surface trough, and some lake instability
are generating widespread light rain and drizzle. New forecast
package will be out by 4 AM.

9:50 PM EDT Update...

Most of the forecast remains valid per latest trends in obs and
model guidance. However, based on those trends, updated our
surface wind and gust forecast through about midday tomorrow to
better reflect the E`ward progression of the cold front in our
CWA and surface ridge building behind the front. Please see
discussion below for additional info.

8:08 PM EDT Update...

Most of the forecast remains valid. However, updated POP`s and
QPF through early tomorrow afternoon given latest trends in obs
and model guidance. Aloft, a shortwave trough lifts NE`ward from
the central and eastern Great Lakes to QC and vicinity through
early tomorrow afternoon as a ridge builds from the Mid MS
Valley region. At the surface, Beryl`s remnant low moves from
the eastern Great Lakes toward the Canada/northern New England
border. This will allow the trailing cold to drift E`ward, away
from near the I-77 corridor early this evening, and exit the
rest of our CWA by about daybreak tomorrow morning. Behind the
front, a congealing ridge builds from northern ON and the Mid MS
Valley.

Scattered showers associated with Beryl`s warm conveyor belt
undergoing most isentropic ascent aloft and releasing weak
potential instability will exit our CWA generally from west to
east through about the wee hours of Thursday morning. In
addition, a sufficiently cold/moist atmospheric column and the
seeder-feeder process over/downwind of ~23C Lake Erie will
allow steadier lake-enhanced rain showers to impact areas
generally southeast of Lake Erie, amidst NW`erly mean low-level
flow behind the cold front. However, these lake-enhanced showers
are expected to end early Thursday morning as considerable
drying aloft causes the seeder-feeder process to end. However,
upslope flow-forced showers, enhanced by added moisture from
Lake Erie, are expected to continue generally southeast of Lake
Erie, in/near the snowbelt, before ending by around midday
Thursday as drier low-level air enters from the west, as does
stabilizing subsidence accompanying the aforementioned ridge.

Previous Discussion...

As of 3 pm, our severe weather threat has end across NW PA as
winds have veered southwest as well as all of northern Ohio this
afternoon. The center of the low pressure system and remnant of
Beryl is currently over the central basin of Lake Erie this
afternoon. This system will continue to track northeast
overnight. Scattered rain showers on the backside of this
exiting system will continue through the evening into the
overnight with a gradual decrease in POPs from west to east late
tonight and early Thursday morning. Gusty winds from the
southwest will be up to 40 mph possible through early evening.
Winds will become northwesterly late this evening and overnight
with gusts up to 25 mph possible.

A few lingering showers will be possible across NW PA early
Thursday morning. Clouds will be decreasing from west to east
during the morning Thursday. Weak high pressure will build in on
Thursday along with clearing skies. Temperatures will be cooler
in the middle 70s over NW PA and NE OH to the lower 80s over
NWOH. High pressure and clear skies Thursday night will allow
temperatures to fall into the upper 50s to lower 60s across the
area.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
Multiple periods of showers and thunderstorms are possible
throughout the short term period as multiple short wave troughs move
through the region. On Friday, a weak surface ridge will push over
the area allowing for primarily dry conditions throughout the day.
There is a non-zero chance of light showers with an isolated
thunderstorm sneaking into the far NW OH counties during the
afternoon hours as an upper level shortwave progresses northeast
across the western Great Lakes region. By Friday night, a less
diurnally favorable environment coupled with the departing shortwave
should leave the area with primarily dry conditions through
Saturday. The best chance for widespread precipitation will arrive
Saturday night as moisture increases across the area with a warm
front beginning to push north across the area. This moisture will be
enhanced by another shortwave and isolated thunder is possible, but
given the diurnally unfavorable environment. High temperatures on
Friday will climb into the low to mid 80s before increasing into the
mid to upper 80s for Saturday`s high. Overnight lows will follow a
similar trend with Friday night temperatures falling into the low to
mid 60s, but only dipping into the mid to upper 60s Saturday night.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Much of the long term forecast will be dominated by a warm pattern
courtesy of a surface high pressure  allowing for strong WAA to
become established. Although hot, the long term period may mark
another period of unsettled weather as a parent low over Ontario
meanders to the east, moving multiple shortwaves across the Great
Lakes region. With dewpoints expected to increase into the upper 60s
to low 70s, increased instability in the afternoons will likely lead
to multiple rounds of convection across the area through the period.
On Tuesday, models suggest an associated cold front approaches from
the north before stalling near the lakeshore of Lake Erie then
progressing south on Wednesday. There is quite a bit of model
divergence in handling this system, so opted to blanket it with 20-
30% PoPs through much of the period. Sunday through Tuesday will be
days to keep an eye on the forecast and monitor for severe weather,
which will be better discerned in upcoming forecasts. High
temperatures through the period will climb into the upper 80s to low
90s with heat indices expected to be in the 90s. Overnight lows will
drop into the upper 60s to low 70s. The next potential cool off will
come on Wednesday, but is highly dependent on the progression of the
aforementioned low pressure and associated fronts.

&&

.AVIATION /00Z Thursday THROUGH Monday/...
Aloft, W`erly to SW`erly flow resides over our region as a
disturbance lifts NE`ward from the eastern Great Lakes region
and vicinity through 00Z/Fri, a ridge builds from the Mid MS
Valley region, and a separate disturbance approaches from the
Upper MS Valley. At the surface, Beryl`s remnant low moves from
the eastern Great Lakes toward the Canada/northern New England
border through 00Z/Fri. The trailing cold front continues
sweeping E`ward away from the I-77 corridor in NE OH and should
exit the rest of our region by ~10Z/Thurs. Behind the front, a
congealing ridge builds from northern ON and the Mid MS Valley.

Regional surface winds around 10 to 15 knots veer from SW`erly
to W`erly with the passage of the cold front. Farther behind the
front, winds veer to NW`erly and ease gradually to around 5 to
10 knots as the aforementioned ridge builds and is accompanied
by a relaxing MSLP gradient. Our regional surface winds will
gust up to 20 to 25 knots at times through early Thurs
afternoon, especially east of KTOL and KFDY.

Outlook...Isolated showers/thunderstorms with non-VFR possible
during the afternoon through early evening hours of Friday.
Periodic showers/thunderstorms with non-VFR also possible this
Saturday night through Monday.

&&

.MARINE...
As the remnants of Beryl continue to move northeast through the
region, winds have begun to gradually shift to the northwest and
increase. Strongest winds observed currently are over the western
basin where sustained winds are 15-25 knots with waves still less
than 1 foot, but expected to climb to 3-4 feet over the next couple
hours. These hazardous marine conditions will gradually spread east
across Lake Erie this evening, with sustained winds of 15-25 knots,
waves 3-6 feet, and rip currents all likely. As a result, a Small
Craft Advisory has been issued for the western basin until Thursday
morning and for the remaining basins through Thursday evening. A
Beach Hazards Statement has also been issued for Bay View OH to
Vermilion for tonight and then Vermilion to Ripley NY from tonight
through Thursday evening.

By Thursday evening, high pressure will push east across the area,
allowing for winds to weaken to 5-10 knots and waves to diminish to
2 feet or less. These fairly calm marine conditions will persist
through Tuesday with the wind becoming sustained from the southwest
on Sunday through Tuesday at 10-15 knots. Although there is quite a
bit of divergence in model agreement on handling the next system, a
cold front may stall somewhere near the lake on Tuesday before
progressing south on Wednesday. With a warm and moist airmass in
place, expect afternoon thunderstorms with locally gusty winds,
especially on Monday and Tuesday. Aside from the next 24-36 hours,
no additional marine headlines are anticipated at this time.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Beach Hazards Statement until 8 AM EDT this morning for OHZ009.
     Beach Hazards Statement through this evening for OHZ010>012-
     089.
PA...Beach Hazards Statement through this evening for PAZ001.
NY...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for
     LEZ142>144.
     Small Craft Advisory until 8 PM EDT this evening for
     LEZ145>149.

&&

$$

SYNOPSIS...Griffin
NEAR TERM...Garuckas/Griffin/Jaszka
SHORT TERM...Campbell
LONG TERM...Campbell
AVIATION...Jaszka
MARINE...Campbell