000
FXUS61 KCLE 290531
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
1231 AM EST Tue Nov 29 2022

.SYNOPSIS...
High pressure will persist into Tuesday. By Tuesday night into
Wednesday, a strong low pressure system will track through Upper
Midwest into the Upper Great Lakes with a cold front pushing east
across the area. High pressure will return across the region
for Thursday and Friday.

&&

.NEAR TERM /THROUGH TODAY/...
There was a small patch of drizzle reported in Cleveland and it
continues to move northeast over the lake. Otherwise, just some
cloud cover extending across the local area at this time and
expect this trend to continue overnight. Current forecast pretty
much on track so no major changes.

Previous Discussion...

A weak area of high pressure is currently moving in from the
west across Ohio. A stratus deck of clouds have been stubborn to
break up this afternoon. There are few breaks in the clouds
this late afternoon but will fill back in this evening. There
also has been a persistent band of scattered light rain showers
and patches of drizzle coming off Lake Erie across the Cleveland
metro area into portion of northeast Ohio. These scattered rain
showers are showing signs of slowly decreasing and will continue
to fade away into the early evening hours.

By early tomorrow morning, the weak area of high pressure will
move off towards the East Coast. We will see a light return of
southerly winds tonight. The extensive stratus deck of clouds
over the Ohio Valley will "slosh" back northward across our
region tonight into tomorrow morning. A strong area of low
pressure will deepen tomorrow across the Upper Midwest as it
tracks through the Great Lakes region late tomorrow night. We
will see southerly winds increase 10 to 20 mph by Tuesday
afternoon. High temperatures on Tuesday will range from the
upper 40s out east to the upper 50s out west.

Widespread rain showers will move in from west to east Tuesday
evening and through the night ahead of a strong cold front
advancing through the Midwest and Ohio Valley regions. Southerly
winds will continue to slowly ramp up through the night 15 to 25
mph. Warm air advection along with the southerly winds will keep
temperatures from falling too much during the night or actually
may hold somewhat steady through the night. The strong cold
front will be knocking on our western areas by 12z Wednesday
morning. We will have rain chances near 100 percent and can`t
rule out a few isolated thunderstorms as well. Right now, it
does not appear we will have any organized convection with this
front but it will be windy.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
A fairly deep mid/upper trough will swing through the central and
eastern Great Lakes Wednesday while becoming negatively tilted. This
will result in a dynamic late Fall storm system lifting northward
into Hudson Bay characterized by a surface low rapidly deepening to
978 mb. As this deepening low tracks into Hudson Bay, the trailing
cold front will plow eastward through northern Ohio and NW PA
Wednesday morning. Guidance is coming into agreement on a 12-15Z
frontal passage, so high temperatures will occur in the morning as a
50-60 knot low-level jet encourages strong warm/moist advection.
This moisture advection and strong frontogenetic forcing from a 130+
knot H3 jet will lead to a band of steady rain progressing west to
east along and ahead of the cold front, so kept categorical PoPs
Wednesday morning decreasing from west to east. Most areas should
see 0.30 to 0.60 inches of rain, but higher amounts of 0.50 to 0.80
inches are likely east of I-77 in eastern Ohio and western PA. The
synoptic rain will end as a light rain/snow mix from west to east as
temperatures rapidly crash behind the cold front.

A typical dry slot behind the cold front will allow most areas to
see a dry afternoon on Wednesday, but strong cold air advection
through the afternoon with H85 temps falling to -11 to -12 C over
Lake Erie by 21Z and well aligned westerly flow will lead to the
development of lake-effect snow showers, so expect the primary
snowbelt east of Cleveland and NW PA to start getting snow showers
by late afternoon, especially along I-90 from Lake County to Erie,
PA continuing through Thursday morning (more on that below). A tight
pressure gradient between the departing low and strong 1030 mb
surface high pressure building into the Midwest combined with strong
cold air advection, good mixing, and strong pressure rises behind
the front will lead to gusty winds Wednesday afternoon and evening.
Sustained westerly winds of 15-25 knots with gusts over 30 knots are
a good bet, especially along and west of I-71, so wind chill values
will drop into the upper teens/low 20s by late Wednesday afternoon
making it feel much worse after the warm morning start. Speaking of
the temperatures, morning highs on Wednesday will reach the low/mid
50s before falling into the low 30s Wednesday afternoon.

Confidence is increasing for a quick hitting but decent lake-effect
snow event Wednesday night into Thursday morning. Continued cold air
advection and well aligned westerly flow will support snow showers
over the primary snowbelt of far NE Ohio and NW PA. The window is
short before strong surface ridging quickly builds in from the south
on Thursday, crashing the inversion and backing the flow, but
between 00 and 12Z Thursday, conditions look quite favorable.
Equilibrium levels rise to 7-8 thousand feet with conditional
instability as -12C 850 mb temps over an average 47F lake leads to
400-450 joules of lake induced CAPE. Moisture is thin though with
much of it being a little below the DGZ, so snowfall will not be
very efficient. A 260-270 boundary layer flow will likely keep most
of the snow showers near the lakeshore from Lake County to Erie, PA
the first half of the night before a subtle trough veers the flow a
bit in the 06-12Z timeframe which could push snow showers into more
of Lake, northern Geauga, and NE Cuyahoga Counties, as well as
inland Ashtabula and Crawford Counties. Typically the long westerly
fetch leads to a single west-east band, but NAM BUFKIT profiles show
some shear, so it is possible that a solid, dominant band fails to
materialize. At this time, trended snowfall amounts upward slightly
but no higher than 2 to 4 inches in the primary snowbelt of NE Ohio
and 3 to 6 inches in NW PA (highest in northern Erie County).
Lingering snow showers will fairly quickly exit toward western New
York late Thursday morning into the afternoon as the flow backs and
high pressure builds in, so most areas should see sunshine Thursday
afternoon. Strong radiational cooling is expected Thursday night as
the high slides overhead.

Highs Thursday will only reach the low/mid 30s with lows Wednesday
night and Thursday night dipping into the low/mid 20s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A very active pattern will continue through early next week with
only short breaks between systems, so we are definitely entering
Winter. The broad surface high quickly departs to the east coast
Friday morning ahead of the next mid/upper shortwave trough and
associated surface low swinging into the Upper Midwest by Friday
evening. Mid/upper shortwave ridging building into the Ohio Valley
ahead of the aforementioned trough will allow most of Friday to be
dry with warm air advection pumping high temperatures back into the
upper 40s/low 50s, but a few showers could move into NW and north
central Ohio Friday evening as isentropic ascent increases. As the
mid/upper trough axis swings through the Great Lakes Friday night
and Saturday, deepening surface low pressure will track north of the
region and pull a strong cold front through the area. This will
bring another round of rain showers and gusty winds as the system
looks very dynamic, but models are in disagreement on the timing.
At this time, have chance PoPs Friday night and Saturday for rain
showers ending as a little rain/snow mix, but the exact timing will
likely change. The airmass behind this system is mainly Pacific
based, so not expecting much snow or drastically colder temps behind
it. Surface ridging will briefly return Saturday night into Sunday
supporting dry conditions, but the next upstream trough and
associated surface low will already be approaching from the middle
of the country late Sunday into Monday, so expect another round of
rain showers at that time.

Highs Friday will be in the upper 40s/low 50s with generally low 50s
Saturday before cooling into the low 40s Sunday. Warming will start
again Monday with highs in the upper 40s to near 50, so big
temperature swings will be taking place in the extended.

&&

.AVIATION /06Z Tuesday THROUGH Saturday/...
Mixed-bag of MVFR and VFR across the TAF sites early this
morning, although anticipating widespread drops to MVFR ceilings
through much of the morning.Improvement back to VFR will occur
by late morning into the early afternoon.

Winds are generally out of the south early this morning, around
5 knots. South to southeasterly winds will quickly ramp up by
later this evening and overnight, with sustained winds
increasing to 15 to 20 knots and gusts of 20 to 25 knots. The
highest gusts up to 35 knots will found at ERI towards the end
of the TAF period. Have gone ahead and included LLWS at
TOL/FDY/CLE for this package, given the arrival of southerly
winds of 50 to 55 knots at 2,000 feet later this evening and
overnight.


Outlook...Non-VFR possible in rain showers areawide late tonight
into Wednesday. Lingering, non-vfr possible in lake effect snow
showers across the snowbelt Wednesday night into Thursday.
Additionally, westerly wind gusts up to 35 knots are possible
Wednesday afternoon and evening.

&&

.MARINE...
The lake will remain quiet tonight and Tuesday with high pressure in
control, but that all changes Tuesday night and Wednesday as a
strong low pressure system lifts north of the region and pulls a
strong cold front across Lake Erie Wednesday morning. Ahead of the
front, S winds will increase Tuesday night to 15-25 knots before
turning westerly by late Wednesday morning and increasing to 25-35
knots, with gusts over 40 knots at times. Issued a Gale Watch
starting at 15Z Wednesday, and expect impressive waves of 8-13 feet
in the central and eastern basin. W winds of 25-30 knots will
continue Wednesday night gradually decreasing to 10-15 knots by
Thursday evening, so 7-10 foot waves will continue on the central
and eastern basins through midday. Besides the winds, water levels
on the western basin will likely fall below the critical mark of 0
inches Wednesday afternoon and remain below into Thursday morning.

High pressure will support lighter winds Thursday night and Friday
before S winds increase to 15-25 knots late Friday and Friday night
ahead of the next system, becoming W at 20-30 knots Saturday. Winds
this far out are always conservative, so another round of Gale
headlines is possible Saturday.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Gale Watch from Wednesday morning through Wednesday evening
     for LEZ142>144-162>164.
     Gale Watch from Wednesday morning through late Wednesday night
     for LEZ145>147-165>167.
     Gale Watch from Wednesday morning through Thursday morning for
     LEZ148-149-168-169.

&&

$$
SYNOPSIS...Griffin
NEAR TERM...Griffin/Lombardy
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...Kahn
MARINE...Garuckas

NWS CLE Office Area Forecast Discussion