-- Discussion containing changed information from previous version are highlighted. --
846
FXUS61 KCLE 240124
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
924 PM EDT Sun Jun 23 2024

.SYNOPSIS...
High pressure will build overhead for Monday and Tuesday. Low
pressure over Ontario will drag another cold front east across
the area on Wednesday before high pressure returns for the end
of the work week.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
-- Changed Discussion --
920 PM Update...
Scattered light lake-enhanced rain showers over Lake Erie are
approaching NE OH and NW PA, so maintained low rain chances
through tonight. No changes needed with this update.

Previous Discussion...
Low pressure over Quebec will continue to drag a cold front east
across northern Ohio through this evening. Showers and
thunderstorms have developed ahead of the cold front this
afternoon under a fairly moist and increasingly unstable
environment. Dew points in the upper 60s to lower 70s and
substantial clearing support a corridor of 1500-2000 J/kg of
surface based CAPE over north central and northeast Ohio. Expect
current storm clusters to become more organized as they push
eastward into eastern Ohio and western Pennsylvania later this
afternoon and early evening. The best potential for severe
storms will likely occur just east of the local area, but can`t
rule out any stronger storms approaching severe limits as they
exit the CWA in the next few hours. Primary threat in any strong
to severe storm will be damaging wind gusts.

Strong to severe storm threat will diminish this evening as the
front exits to the east. Wrap around moisture and broad scale
northwest flow behind the front will support some lingering lake
enhanced rain showers across Northeast Ohio and Northwest
Pennsylvania through Monday morning. High pressure builds overhead
behind the cold front and will bring dry weather to the region to
begin the work week.

Near normal temperatures return through the near term with overnight
lows settling in the low 60s each night with high temperatures
on Monday rising into the upper 70s to lower 80s. Slightly
cooler across Northwest Pennsylvania on Monday night as lows
drop into the low to mid 50s.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
The heat and humidity will quickly surge back into the region
Tuesday as broad mid/upper ridging flexes back northeastward from
the southern Plains and Mississippi Valley in response to a
mid/upper shortwave trough approaching the northern Great Lakes. The
surface high will shift east to the Mid Atlantic coast by Tuesday
morning allowing a warm front to lift into northern Ohio with
accompanying warm air advection as 850 mb thermal ridging of 21 C
noses in from the southwest. The latest operational NAM, GFS,
Canadian, and ECMWF runs suggest a weak, convectively enhanced
shortwave dropping southeastward through the southern Great Lakes on
the northeast periphery of the ridge Tuesday morning. This could
support a decaying MCS riding along the warm frontal boundary/theta
e gradient where warm/moist theta e advection will be maximized on
the nose of a roughly 30 knot low-level jet. Pattern recognition
supports an MCS, but a fairly stable airmass will be in place
northeast of the warm front, so the complex should either be
weakening as stated above or elevated. This should generally prevent
any severe weather unless stronger elevated convection can produce
some hail. The main impact will be to the temperature and cloud
forecast. Morning clouds and showers associated with the complex
could hang around into the afternoon and hold temperatures down a
few degrees, so went a bit cooler in NE Ohio and NW PA (mid/upper
80s). Highs in the 90s are still a solid bet in NW Ohio though, and
have upper 80s to low 90s from north central Ohio through NW Ohio.
The humidity will be on the rise through the day as dew points
return to the 60s.

Moving into Tuesday night and Wednesday, the mid/upper shortwave
trough will progress through the central Great Lakes leading to a
deepening longwave trough over the Great Lakes and NE U.S. The
associated surface low will pass well to the north across northern
Ontario and Quebec, but the trailing cold front will sink across the
region Wednesday as the troughing aloft deepens. This front and the
dynamics associated with the digging mid/upper trough will generate
additional showers and thunderstorms late Tuesday night and
Wednesday, so have elevated PoPs both periods. Timing of the front
seems to be trending faster, with a Wednesday morning to midday
frontal passage. This combined with widespread clouds and showers
Wednesday may limit the severe potential, but given the dynamics, it
could still be a fairly active day Wednesday since the boundary will
be slowly sagging through a juicy airmass with PWATs nearing 2
inches. The strength of the thermodynamics will be determined by how
much heating can occur as well as timing of the front. Much cooler
and drier air will filter in Wednesday night as surface high
pressure starts to build in from the northern Great Lakes.

Highs will range from the low to mid 80s Wednesday with muggy
conditions. Lows Tuesday night will stay in the upper 60s to low
70s, cooling into the upper 50s to low 60s Wednesday night.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Mid/upper troughing will remain across the Great Lakes and NE U.S.
Thursday with surface ridging centered over the Great Lakes and Ohio
Valley. This will support mostly sunny skies and pleasantly cool
conditions with highs in the mid/upper 70s Thursday and lows in the
mid/upper 50s Thursday night. Low 50s will even occur in NW PA
Thursday night!

The active pattern will quickly return for the end of the week into
next weekend as a strong northern stream mid/upper trough progresses
from the northern Rockies into the northern Plains Friday before
deepening across the Great Lakes by Sunday. In response, mid/upper
ridging will rapidly flex back north and eastward Friday and
Saturday as the surface high repositions along the Mid Atlantic
coast. This will lead to a warm front lifting across the region
Friday, opening the door to strong warm air advection and hot, humid
conditions once again. Timing of showers and thunderstorms is very
uncertain this far out, but have gradually increasing PoPs Friday
night and Saturday in the hot and likely unstable airmass. The best
chance will likely hold off until the cold frontal passage Saturday
night or Sunday, which will be the next potential for strong to
severe storms.

Highs will warm into the mid/upper 80s Friday with upper 80s/low 90s
Saturday before cooling into the upper 70s to mid 80s Sunday.

&&

.AVIATION /00Z Monday THROUGH Friday/...
Convection has exited the area and dry weather will prevail
outside of a small chance of light lake-enhanced showers across
NE OH and NW PA tonight. Rain chances are relatively low so did
not include in the TAFs at this time, but there should not be
any impacts to ceilings or visibility even if a shower happened
to move over a TAF site. Expect VFR through the period with
scattered mid-level clouds (broken in NW PA and extreme NE OH)
through tonight, but skies should clear significantly on Monday.

Winds will be out of the northwest at 6 to 12 knots through the
TAF period with a few gusts to 20 knots this evening. Winds
start to diminish towards the very end of the forecast period.

Outlook...Non-VFR possible in showers and thunderstorms Tuesday
evening through Wednesday.

&&

.MARINE...
Winds and waves will be at their peak on Lake Erie this afternoon
and early evening when W to WSW winds of 15-25 knots are expected
with occasionally higher gusts. This will generate 2 to 5 foot
waves, with the highest being in the central and eastern basins.
This will elevate rip current risks. The winds will gradually
subside this evening and tonight behind the cold front, shifting to
NNW at 15-20 knots. It still looks reasonable for the Small Craft
Advisory to end on the western basin at 00Z, but higher waves will
keep the need for Small Craft headlines and Beach Hazards statements
through at least 09Z in the central and eastern basins since it will
take longer for the waves to drop below 4 feet. It`s possible that
the Small Craft Advisory and Beach Hazards Statement will need to be
extended farther into Monday morning from Conneaut to Ripley, but
confidence is too low at this point.

Quieter conditions are then expected on the lake the rest of the
week outside of thunderstorms. Winds will become W and decrease to 5-
10 knots late Monday before becoming SW at 10-20 knots late Monday
night through early Wednesday. Winds then turn W to NW late
Wednesday and NNW Wednesday night behind a cold front while decrease
to 10-15 knots. Light E to NE winds are then expected Thursday and
Friday as Canadian high pressure drifts from the Great Lakes into
New England.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
OH...Beach Hazards Statement until 8 AM EDT Monday for OHZ010>012.
     Beach Hazards Statement through Monday afternoon for OHZ089.
PA...Beach Hazards Statement through Monday afternoon for PAZ001.
NY...None.
MARINE...Small Craft Advisory until 8 AM EDT Monday for LEZ145>147.
     Small Craft Advisory until 2 PM EDT Monday for LEZ148-149.
-- End Changed Discussion --

&&

$$

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