663
FXUS61 KCLE 130831
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
331 AM EST Mon Jan 13 2025

.SYNOPSIS...
A cold front will track across the region this morning,
ushering in colder air through the middle of this week. An
upper level trough reinforces the cold air Tuesday. High
pressure mid week.

&&

.NEAR TERM /THROUGH TUESDAY/...
The near term forecast will include another shot of Arctic air
and more lake effect snow for the primary snowbelt. A strong cold
front is pushing through the area this morning, currently
located east of the I-77 corridor. Today`s daily max
temperatures have already occurred ahead of this cold front.
Temperatures will slowly fall through the 20s during the rest
of today.

An upper level trough will dig across the Great Lakes region
over the next couple of days. The low level flow will be mainly
from the west-southwest today with cold air advection. Winds
will gusts up to 30 mph today. Most of the area will remain free
of precip but can`t rule out a few isolated snow flurries
passing through. The 850 mb temperatures will fall to around
-18C by this evening. Lake effect snow showers and squalls will
start to develop and organized by tonight. The low level flow
will favor the lake effect to hug near the lakeshore of NEOH
and NWPA, with some LES into inland Erie County PA.

The main axis of the trough will pivot across on Tuesday. The
low level flow will become more westerly on Tuesday which will
shift the lake effect snow bands further into the primary
Snowbelt of NEOH and NWPA. Elsewhere, scattered flurries or
light snow showers will be possible across much of northern Ohio
with little or no accumulations expected. The main show and
impactful weather will be over the snowbelt of NEOH and NWPA for
accumulating snowfall on Tuesday. We have upgraded all of Erie
County PA to a Lake Effect Snow warning. The lakeshore zone of
Ashtabula County will remain as a watch due to some uncertainty
on snowfall totals at this time. See the WSWCLE product or
winter weather headlines for the latest snowfall and impact
expectations.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A positively tilted trough is forecast to extend southwest across
much of the contiguous United States to begin the short term period
with an associated surface low centered near Nova Scotia. This set
up will allow for a surface trough to linger across the area Tuesday
night and Wednesday, maintaining a northwest flow across Lake Erie.
850mb temperatures are expected to slowly warm as a ridge builds
across the western Great Lakes region, but during this period models
suggest 850mb temperatures lingering in the -16 to -18C range.
Although Lake Erie continues to cool with temperatures hovering near
0C, these upper air cold temperatures and lingering low level
moisture are expected to allow lake effect snow to persist across
the primary snowbelt. Local enhancement in NWPA is possible with the
potential of a Lake Huron connection developing. In addition, models
suggest a surface convergent boundary and omega lift persisting along
the lakeshore counties. In addition, with the persisting cold, snow
ratios for the lake effect is expected to be closer to 20:1.
Overall, snowfall totals from Tuesday night through Wednesday
evening are looking to range 3-6 inches across the primary snowbelt,
with Erie County PA expected to 4-8 inches with highest totals
across the far northeastern portion of the county.

By Wednesday afternoon, a brief shortwave ridge will build over the
entire CWA, which will bring a drier airmass and will keep any
additional lake effect snow showers isolated nearest the lakeshore
in far NE OH and NW PA. Late Wednesday night/early Thursday morning,
another upper level shortwave trough pushes southeast across the
area with another surface trough returning. This will lead to a
period of synoptic driven snow showers for areas along and east of
I77. Overall snow totals are expected to be less than an inch as
this will be a very quick moving trough. By Thursday night, all snow
showers should end and the area will be dry as another ridge builds
over the area and mark a transition to a WAA regime.

Highs on Wednesday will remain chilly, only climbing into the upper
teens to low 20s, but on Thursday temperatures will warm into the
upper 20s to low 30s. Overnight lows Tuesday night will drop into
the single digits across the southwest portion of the CWA, dropping
into the low to mid teens elsewhere. Widespread single digits are
expected Wednesday night, before milder lows in the low 20s returns
on Thursday night. On Tuesday and Wednesday nights, wind chill
values will drop into the negative values, with the coldest wind
chill temperatures expected on Wednesday night.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
The long term period will remain in an active pattern as a deepening
upper level trough begins to impact much of the contiguous US.
Initially on Friday, dry conditions are expected to persist and
milder temperatures return as a ridging pattern over the area marks
the transition to a WAA regime. A warm front associated with a low
over the north central US is expected to move north sometime on
Friday afternoon. As this moves north, rain showers are expected to
push north across the area and persist into Saturday. There is a
chance of a rain/snow mix in portions of the area Friday night, but
the bulk of precipitation should remain as rainfall. The associated
cold front is expected to push east late Saturday into Sunday, which
will mark the transition back to very cold temperatures and the
potential for lake effect snow to return to areas across the
snowbelt.

There remains uncertainty in the timing of the onset of
showers and the spatial extent, but models are pretty consistent in
an amplifying trough pushing south across much of the US, moving a
very cold airmass south. This threat of much cooler temperatures
returning is reflect as well in the 8-14 Day Temperature Outlook
from CPC that has much of the eastern portion of the country at a 70-
80% chance of being below normal for temperatures. This cold threat
is primarily after this period, but found it worth noting.

Highs on Friday and Saturday will climb into the mid to upper 30s,
before beginning to cool on Sunday with highs back in the low to mid
20s. Overnight lows will follow a similar trend with lows Friday
night dropping into the upper 20s to low 30s before cooling into the
upper teens for Saturday night.


&&

.AVIATION /06Z Monday THROUGH Friday/...
MVFR to low end MVFR ceilings are expected for much of the area
through this TAF period. Any precip will be confined to the
lakeshore areas of the primary Snowbelt like around ERI. Lake
effect snow showers are expected to develop and impact ERI later
today through tonight with 2sm to 5sm reduction in
visibilites and MVFR to low end MVFR. Gusty winds will be
another impact at all TAF sites today from the southwest 12 to
18 knots with gusts over 25 knots at times. Most of the gusts
will relax by 00z this evening but remain from the southwest 10
to 13 knots.

Outlook...Non-VFR in lake effect snow will continue through
Wednesday across NE OH and NW PA. Non-VFR possible in ceilings
and system snow across the area on Thursday.

&&

.MARINE...
This morning, a cold front will continue to move east across Lake
Erie with winds persisting from the southwest at 15-25 knots into
Tuesday. Winds will gain more of a northwesterly component on
Tuesday, remaining 15-25 knots but shifting to an onshore flow. This
will result in waves across the central and eastern basin to build
to 5-8 feet. As a result, a Small Craft Advisory remains in effect
for Vermilion to Avon Point until 7AM Wednesday and for Avon Point
to Ripley NY until 7PM Wednesday. Depending how long the
aforementioned surface trough lingers over the eastern basin, this
Small Craft may need to be locally extended in coming updates.

In addition to the hazardous small craft conditions, the sustained
strong winds out of the southwest has resulted in water levels
falling at Toledo. As of 2:55 AM EST, the water level at Toledo was
7.1 inches above low water datum, or 4.1 inches above the critical
mark for safe navigation. Although forecast guidance is not yet
catching up to the ongoing conditions, there is medium confidence
that the water levels will drop below the 3" critical mark today
into Tuesday. As a result, a Low Water Advisory has been issued for
the western basin until 1 PM Tuesday.

A brief period of high pressure on Wednesday will briefly weaken
winds to 10-15 knots from the west-northwest which may be a period
where no hazards exist on Lake Erie. However, if the northwest
aspect persists a bit longer, waves 4 feet or greater may persist
and require continued Small Craft headlines. On Thursday, winds will
increase to 15-25 knots from the southwest as a short wave trough
impacts the area. These winds may again weaken on Friday briefly
before the next system impacts the region this weekend.


&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Winter Storm Watch from late tonight through late Wednesday
     night for OHZ089.
PA...Lake Effect Snow Warning from 1 AM Tuesday to 1 AM EST
     Thursday for PAZ001-002.
MARINE...Low Water Advisory until 1 PM EST Tuesday for LEZ142>144-
     162>164.
     Small Craft Advisory until 7 AM EST Wednesday for LEZ145.
     Small Craft Advisory until 7 PM EST Wednesday for LEZ146>149.

&&

$$

SYNOPSIS...Griffin
NEAR TERM...Griffin
SHORT TERM...Campbell
LONG TERM...Campbell
AVIATION...Griffin
MARINE...Campbell