390
FXUS61 KCLE 230132
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
932 PM EDT Sat Jun 22 2024

.SYNOPSIS...
Low pressure glides across the Great Lakes on Sunday while
dragging a cold front east through the region. High pressure
builds overhead behind the front for Monday and Tuesday.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
930 PM Update...
No changes needed with this update. Temperatures are currently
in the 80s with heat indices still in the mid to upper 80s.
Expect one last night of very warm overnight temperatures in the
70s.

Previous Discussion...
The heat and humidity come to an end as low pressure centered
over the Upper Midwest will glide east toward the Great Lakes
region tonight. As the low moves into the region it will drag a
cold front east across Northern Ohio and Northwest Pennsylvania
tomorrow. Expect showers and storms to develop along the cold
front to enter western zones early Sunday morning. Hi-res
guidance continues to indicate increasing instability and shear,
roughly 1500-2000 J/kg MUCAPE and 30-35 knots of 0-6 km shear,
by Sunday afternoon and evening along and east of I-71. This
moderately unstable and sheared environment has prompted a
Marginal Risk (Level 1/5) from the Storm Prediction Center with
a primary hazard of damaging wind gusts and large hail. Extreme
eastern portions of our forecast area were clipped with a Slight
Risk (Level 2/5) for severe weather where the best instability
and shear exist. Best potential for strong to severe storms
looks to be between 1 and 9 PM tomorrow afternoon and evening
based on the current timing of the frontal passage. Lingering
moisture and northwesterly flow will keep PoPs in the forecast
along the lakeshore in NE OH and NW PA through Sunday night.

Strong southwesterly flow tonight and increased cloud cover will
allow for one final night of warm overnight lows in the mid to upper
70s. Broad northwesterly flow behind the cold front will usher in
cooler, more seasonable air. Near normal high temperatures tomorrow
in the upper 70s to lower 80s with overnight lows settling in the
low to mid 60s Sunday night.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Monday will finally bring relief from the prolonged hot and humid
pattern as the mid/upper trough axis digs through the eastern Great
Lakes as the associated surface low tracks across New England. This
will allow the cold front to sweep east of the area quickly Monday
morning, but the surface low becoming vertically stacked beneath the
mid-level low will lead to wraparound moisture during the morning.
The latest NAM suggests scattered showers associated with this in
far NE Ohio and NW PA, so added slight chance to chance PoPs there.
Any showers will gradually exit Monday afternoon as surface ridging
builds in from the west, before settling overhead Monday night.
Highs Monday will be much cooler with 75 to 80 expected in NE Ohio
and NW PA and low to mid 80s in north central and NW Ohio. Lows
Monday night will drop into the upper 50s to low 60s, so a good
night to finally open the windows.

The heat will remain close by due to broad/flat mid/upper ridging
across the Rockies and Plains, and this will allow hot/humid
conditions to quickly surge back into the region ahead of another
northern stream mid/upper shortwave diving from the Upper Midwest
into the Great Lakes Tuesday and Tuesday night. An associated
surface low tracking into the central Great Lakes Tuesday will pull
a warm front through the region leading to strong warm air advection
before the trailing cold front approaches Tuesday night. This will
cause high temperatures Tuesday to warm into the upper 80s to low
90s with dew points once again rising through the 60s, followed by
overnight lows in the 70s Tuesday night. In terms of convection, a
few isolated thunderstorms cannot be ruled out Tuesday as the warm
front lifts through on the nose of stronger theta e advection, but
the better chance will come with the approaching cold front Tuesday
night, so have PoPs gradually spreading east late Tuesday and
especially Tuesday night. Due to overnight timing and the best
forcing staying to the north until Wednesday, coverage of showers
and storms will probably not be very widespread Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Deterministic and ensemble guidance is coming into better agreement
on the cold front crossing the region Wednesday as the mid/upper
trough axis deepens across the Great Lakes in response to the
shortwave moving east. However, timing of when the front will cross
on Wednesday remains uncertain. This makes it impossible to say at
this point what degree of severe weather threat there will be, but
given seasonably strong jet dynamics and the warm, humid, unstable
airmass, at least somewhat organized strong to severe thunderstorms
are possible Wednesday. Surface high pressure building in and
mid/upper troughing overhead will bring dry and much cooler, less
humid conditions Wednesday night and Thursday. This will not last
long though as confidence is increasing that elongated mid/upper
ridging will quickly flex back northward across the Midwest and
southern Great Lakes Friday through Saturday in response to a strong
mid/upper trough progressing from the northern Rockies through the
northern Plains. This will pull heat and humidity back into the
region for the end of the week into next weekend, along with
increasing chances for thunderstorms as a baroclinic zone/theta e
gradient will be nearby on the northern periphery of the thermal
ridging (heat dome).

Highs in the mid/upper 80s Wednesday will cool into the upper
70s/low 80s Thursday before quickly warming back into the mid 80s to
low 90s Friday and solid low 90s Saturday.

&&

.AVIATION /00Z Sunday THROUGH Thursday/...
VFR conditions will continue through most of tonight before
weakening showers and thunderstorms move into the area early
Sunday morning. Have showers at KTOL/KFDY starting at 09-10Z,
reaching KYNG/KERI by 14Z. There`s still some uncertainty in how
showers and thunderstorms shake out Sunday; the weakening
morning convection may produce a few rumbles of thunder at
KTOL/KFDY but they should weaken to light showers before
possibly redeveloping into thunderstorms east of a line from
KCLE to KCAK later in the morning. Additional scattered showers
and thunderstorms are possible as a cold front moves east into
the area Sunday afternoon, best chance from KCLE to KMFD east
where there will be more time for diurnal destabilization. Any
showers/thunderstorms that move directly over terminals could
produce non-VFR visibilities, but generally expect VFR
conditions outside of thunderstorms. With that being said, KTOL
and KFDY will likely remain pretty cloudy with a period of MVFR
ceilings likely Sunday morning into the afternoon.

Winds will be out of the southwest at 6 to 12 knots this
evening, but expect winds to ramp up to 12 to 17 knots with
gusts to 25 knots ahead of the cold front Sunday morning and
afternoon. Isolated gustier winds are possible with any
stronger storms that develop. Winds become west/northwesterly
behind the cold front towards the end of the period.

Outlook...Non-VFR possible in scattered showers and
thunderstorms across Northeast Ohio and Northwest Pennsylvania
Sunday night into Monday. Additional non-VFR possible in showers
and thunderstorms Tuesday evening through Wednesday.

&&

.MARINE...
Southwest winds are expected to increase to 15-25 knots quickly
Sunday morning ahead of a cold front. This will be a short duration
of 4 hours or so Sunday morning into early afternoon in the western
basin, but will last into Sunday evening in the central basin and
especially the eastern basin. With this in mind, issued Small Craft
Advisories for the western basin from 12 to 18Z, but ran the central
and eastern basins from 17 to 00Z. The longer fetch will build 2 to
5 foot waves in the central and eastern basins in the afternoon and
evening, so issued Beach Hazard Statements from the lakeshore of
Cuyahoga County to Erie PA for a high risk of rip currents. Winds
will quickly turn NW behind the front Sunday evening and decrease to
10-15 knots Sunday night and Monday. Light winds are then expected
until Tuesday afternoon when SSW winds increase to 10-15 knots
behind a warm front, becoming WSW at 10-20 knots Tuesday night and
Wednesday as a cold front crosses the region. Winds then turn N and
decrease Wednesday night and Thursday as high pressure returns.

&&

.CLIMATE...
The records for Saturday, June 22 are listed below for our official
climate sites.

Date   Toledo     Mansfield   Cleveland   Akron     Youngstown   Erie
06-22  99(1988)   95(1988)    98(1988)   97(1988)   97(1933)    94(1988)

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Beach Hazards Statement from Sunday afternoon through Sunday
     evening for OHZ011-012-089.
PA...Beach Hazards Statement from Sunday afternoon through Sunday
     evening for PAZ001.
NY...None.
MARINE...Small Craft Advisory from 8 AM to 2 PM EDT Sunday for
     LEZ143>145.
     Small Craft Advisory from 1 PM to 8 PM EDT Sunday for
     LEZ146>149.

&&

$$

SYNOPSIS...Iverson
NEAR TERM...Iverson/Maines
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...Maines
MARINE...Garuckas
CLIMATE...