426
FXUS61 KCLE 230349
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
942 PM EST Fri Nov 22 2024

.SYNOPSIS...
A surface trough will linger over the area through Saturday
before high pressure builds north for Saturday night through
Sunday. Another low pressure system will impact the region on
Monday into Tuesday before high pressure returns in the middle
of the week.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...

9:42 PM EST Update...

Most of the forecast remains valid per latest trends in obs and
model guidance. However, did increase POP`s slightly in roughly the
western-quarter of our CWA. Light and scattered lake-effect rain
showers originating over Lake Michigan are expected to stream
generally SE`ward across the aforementioned area through most of the
predawn hours of Saturday morning based on latest trends in radar
data and the 18Z/Fri run of the RGEM, which has had the best handle
on recent observed trends in lake-effect precip. Weakening mean low-
level flow associated with a ridge building very slowly from the
Upper Midwest and vicinity should reduce the inland extent of the
Lake Michigan lake-effect showers by daybreak Saturday. Please see
discussion below for further details.

Previous Discussion...

A large scale trough over the East Coast with an associated
surface low pressure center will gradually meander eastward
through the near term period, leaving the CWA on the back edge
of the trough. This will result in a continued northerly to
northwesterly mean low-level flow with 850mb temperatures of 0C
to -2C advecting across a relatively warm Lake Erie. Thus,
persistent lake-effect rain showers are expected through
Saturday morning. The heaviest lake-effect rain showers
associated with an upstream moisture connection to Lake Huron
will target the distant east side of metro Cleveland south-
southeastward to eastern Stark County and vicinity this evening.
The heaviest rain associated with the aforementioned upstream
moisture connection will begin to shift gradually eastward
during the wee hours of Saturday morning and reach northwest PA
by midday Saturday as mean low-level flow backs from primarily
northerly to northwesterly. By Saturday afternoon, lake-effect
rain showers should become more focused across the primary
snowbelt as the best forcing shifts along with the steering flow
gaining more of a westerly component. Late Saturday, high
pressure and a drier airmass is expected to begin to push north,
resulting in the gradual decrease in lake effect precipitation
and the return of drier conditions. Although dreary and wet, the
good news is that all showers should remain as rain with
temperatures tonight expected to remain in the upper 30s to low
40s and highs on Saturday climbing into the mid to upper 40s.
Overnight lows Saturday night will be a bit cooler, dropping
into the mid 30s.

Aside from the precipitation potential, it is worth noting the
potential for gusty winds through this evening. A strong LLJ of
40-50 knots will push southeast across the area will
periodically mix down to the surface. This will result in
sustained winds of 15-20 mph, gusting up to 30-35 mph through
late this evening. As the trough departs further east, the
gradient will weaken, allowing winds to become 10-15 mph,
gusting up 20 mph, especially along the lakeshore. By Saturday
evening, winds will shift to westerly and weak to 5-10 mph with
no gusts. Overall impacts should remain minimal with these gusty
winds.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Upper level ridge axis will be located from the Mid-South to
Minnesota Sunday morning. At the same, the surface high will be
located over Tennessee Valley creating a southwest flow over the
forecast area on Sunday. Upper level ridge will slide east on Sunday
increasing heights and yielding a slight warming trend on Sunday.
This feature will maintain the slight warming trend Sunday through
Monday. A storm system is expected to track across the Rockies
Sunday night and move east across the Central Plains on Monday. The
associated wave will become neutral Monday afternoon and negatively
tilted from Minnesota to Indiana Monday night. Low level flow ahead
of this system will advect in lower and mid layer moisture.
Precipitable water values will increase from 0.5 inch early Sunday
to one inch by Monday night. At this time, rain chances will be
introduced late Sunday night and increased to likely pops Monday
afternoon and evening. a cold frontal passage is expected Monday
night with strong cold air advection with boundary layer winds
approaching 30 knots across land and 40 knots on Lake Erie. Under
rain showers and warm air advection before the cold front, Monday
will be our warmest day in the forecast with high temperatures in
the 50 to 60 degree range. This will be a very dynamic system with
very marginal instability. A clap a thunder is possible along the
front Monday night but not worth mentioning with right now.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A dramatic change will occur on Tuesday with strong cold advection
on Tuesday. The main trough will continue to lift northeast and
leave zonal flow over the forecast area through Wednesday. However,
northwest flow at 850mb will yield brief periods of lake enhanced
precipitation on Wednesday. A wave over south central Canada will
dive southeast and combine and another system over the Rockies to
bring in the next system later in the week. A developing low
pressure system moving west to east from the southern plains into
the Appalachians. Northern portion of the precipitation may reside
across central Ohio, the south half of the forecast area Thursday.
At this time, there is a great deal of uncertainty on the track and
will need to watch this system for changing precipitation types as
well. A trough is expected to over eastern Canada and east half of
Conus next weekend and give a good chance cold Canadian air coming
down south.

&&

.AVIATION /00Z Saturday THROUGH Wednesday/...
At the surface, a trough lingers over and near Lake Erie,
northern OH, and NW PA through 18Z/Sat. Thereafter, the trough
begins to exit slowly E`ward as a ridge builds from the Upper
Midwest and vicinity through 00Z/Sun. Our regional surface winds
are expected to vary between W`erly and NNW`erly around 10 to
20 knots. Gusts up to 20 to 30 knots are expected at times. The
most-persistent gusts are expected immediately downwind of Lake
Erie, including at KERI.

Widespread low-level clouds with primarily MVFR to IFR ceilings
are expected through 00Z/Sun. However, these low-level ceilings
should rise to the VFR range at/near KTOL and KFDY after
17Z/Sat. Widespread lake-enhanced/effect rain showers will
continue to stream generally S`ward from Lake Erie through
06Z/Sat. Thereafter, scattered to widespread lake-enhanced/effect
rain showers will stream generally SE`ward from the lake as mean
low-level flow backs from N`erly to NW`erly. Visibility is
expected to vary between VFR and IFR in precip.

Outlook...Additional lake-effect rain showers with non-VFR
possible in and near the primary snowbelt of NE OH and NW PA
Saturday evening through Sunday afternoon. Scattered and
periodic rain and/or snow showers with non-VFR expected this
Monday through Wednesday.

&&

.MARINE...
Will maintain high end Small Craft Advisory through this evening
with winds up to 30kts sustained this evening and wave heights
pushing 10 feet. A slow decrease in winds will occur with pressure
gradient slowly relaxing through Saturday. Therefore, winds will
subside to 15-20 knots on Saturday with wave heights gradually
decreasing before becoming southwesterly Sunday 10-15kts into
Monday. Strong cold front tracks across the lake late Monday into
Monday night. Strong west winds of 20 to 30 knots are possible after
the frontal passage Monday night into Tuesday.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 10 AM EST Saturday for LEZ142.
     Small Craft Advisory until 7 PM EST Saturday for LEZ143.
     Small Craft Advisory until 7 AM EST Sunday for LEZ144>147.
     Small Craft Advisory until 10 AM EST Sunday for LEZ148-149.

&&

$$

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