313 
FXUS61 KCLE 201948
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
348 PM EDT Mon Oct 20 2025

.SYNOPSIS...
Low pressure moves into the Great Lakes tonight into Tuesday, with
this low pressure only slowly drifting east and northeast into Canada
through Thursday. A cold front attached to this low will move through
the local area on Tuesday, with a re-enforcing cold front expected
early Thursday. High pressure builds in to end the week. 

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
The narrow ridge axis that is sliding east across the area today will
exit to the east tonight. It will be dry and mostly clear through a 
majority of the night tonight with winds briefly going light and 
variable this evening, then picking up from west to east out of a 
southerly direction through the overnight. Lows will range from the 
mid 30s in valleys east of I-79 in Northwest PA to the low to mid 40s 
elsewhere. Northwest Ohio will be a bit milder owing to a quicker 
onset of southerly breezes, keeping them in the mid-upper 40s. Some 
patchy frost is possible across some deeper valleys in east of I-79 in
Northwest PA where winds will stay light/variable the longest...these
areas have already had one or two freezes, and with little concern 
for frost anywhere else will forgo frost headlines for tonight. 

Unsettled weather quickly returns late tonight or early Tuesday. A 
deep closed low will move east into the Great Lakes tonight into 
Tuesday. A warm front will move east across the area late tonight and
early Tuesday, followed quickly by a cold front Tuesday morning 
through early afternoon from west to east. There will be a brief 
period of rather focused and strong forcing for ascent along the cold 
front, along with perhaps a bit of elevated instability and decent 
mid-level moisture. Models are in decent agreement in a band or 
broken band of showers moving east across the area very late tonight 
through about midday Tuesday just ahead of the cold front. QPF will 
generally be 0.10" or less with these early Tuesday showers, though 
most areas will see a bit of rain, warranting a 70-80% POP in a narrow
band moving east across the area. There will be a period of mainly 
dry and even sunnier weather behind the morning band of showers, with
a potent shortwave rotating around the larger closed low and re- 
enforcing surface trough moving west to east across the area Tuesday 
evening. The combination of forcing ahead of the shortwave, weak 
surface-based instability beneath cold air aloft, and convergence 
along the surface trough leads to high confidence in another band or 
broken band of showers/isolated thunder (with potential for pea sized
hail and brief gusty winds) moving east across the area late Tuesday 
afternoon/evening. We should see a mainly dry overnight period Tuesday
night behind this feature (just some isolated lingering showers
beneath the broad cold pool aloft), with a robust band of lake effect
rain taking shape over the lake amid colder west-southwest flow. This
lake effect may clip the lakeshore from Lake County points northeast.

Highs on Tuesday will reach the low-mid 60s, with some upper 50s
across the higher terrain of PA. Lows Tuesday night will generally
range from the upper 30s to mid 40s. West-southwest winds will be
gusty on Tuesday, with gusts of 25-35 MPH. 

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
This would be a high-stakes lake effect snow forecast in about a 
month..as it is, a period of chilly, breezy, and somewhat showery 
weather is expected as broad troughing aloft and cool/moist low-level
cyclonic flow only slowly drifts east-northeast from the Great Lakes 
towards Quebec and New England the second half of the week. Robust 
lake effect will be ongoing offshore Wednesday, swinging onshore 
behind a cold front Wednesday night into Thursday as winds shift more 
west-northwesterly.

The combination of the warmer than average lake and chilliest airmass
of the fall thus far will lead to strong and deep instability over the
lake through the duration of the short term forecast. Fairly deep and
abundant synoptic moisture is expected beneath the large trough/closed
low. 500mb temperatures falling to -25 to -27C over lake water 
temperatures of around 18C suggests enough instability for 
thunder/lightning within more organized and robust lake effect bands, 
with forecast soundings also showing sufficiently deep and strong 
instability for charge separation (needed for lightning) over and just
downwind of the lake. Some small hail or graupel will probably occur
at times within deeper convective cores within the lake effect,
especially over the lake and within about 10 miles of it. Flow aloft
will be fairly well-aligned outside of some windows when vort maxes
rotate through, supporting an organized single band when winds are
parallel to the long axis of the lake through Wednesday night. 

A single band is expected to push east-northeast up the lake towards 
Buffalo on Wednesday, perhaps grazing the lakeshore from Lake County 
points northeast at times. This intense single band is expected to 
slowly push onshore Wednesday night into the primary snowbelt, as the 
mean flow shifts more west-northwest behind a cold frontal passage. 
The heavier lake effect may get as far southwest as about a CLE-YNG 
line Thursday, though the very warm lake will lead to a strong lake- 
aggregate trough, which could make it hard for the band to push quite 
that far south. Because the lake effect will be quite convective and 
intense, rainfall totals along the lakeshore between Lake County OH 
and Erie County PA will need to be monitored Wednesday night into 
early Thursday if the band is particularly stationary across parts of 
that corridor...however, we can still take some rain and the band may
be just transient enough to keep rainfall totals from getting out of 
control. Lake effect will ebb and flow some Thursday and Thursday 
night as any additional troughs rotate around the closed low and 
through the region, with activity likely breaking into less organized
multi-bands at times when the flow over the lake veers more northwest. 
Ridging will start to nose in from the southwest Thursday night, 
beginning the process of focusing the lake effect back up the eastern 
lakeshore and slowly losing intensity. The updated QPF forecast has 
2-3" of rain clipping the lakeshore between Lake County OH and Erie 
County PA through Thursday...as long as this is spread out over a 
24-36 hour period it will be manageable, though will need to monitor 
for locally higher amounts if the band hangs up more than expected.

Outside of the lake effect chilly, partly to mostly cloudy, and 
breezy conditions are expected for Wednesday and Thursday. Shower 
chances will be largely tied to the passage of any shortwaves and 
associated surface fronts/troughs outside of the snowbelt. Some lake 
effect showers from Lake Michigan will likely get into Northwest OH at
times Wednesday night and Thursday. Outside of the eastern Lake Erie 
shoreline, QPF amounts will be light. Winds may gust up to 40 MPH 
Wednesday afternoon ahead of the approaching cold front. Highs will be
stuck well into the 50s both Wednesday and Thursday, with the higher 
terrain of the primary snowbelt (especially in PA) probably staying in
the 40s. Overnight lows will be in the 30s and 40s (warmest near the 
lake and into the snowbelt, coldest well south and southwest of the 
lake). Beneath the upper trough and amid low-level cyclonic flow, it 
will be hard to see good radiational cooling (needed for frost) 
Wednesday night. Conditions may be a bit more conducive Thursday night
away from the snowbelt and Lake Erie. 

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
High pressure slides through the Ohio Valley Friday into early
Saturday. This will lead to quieter weather to end the week and start
the weekend, outside of the potential for some (less significant) lake
effect to linger across far Northeast OH and Northwest PA. A 
weakening system in the sub-tropical jet will attempt to spread into 
the Ohio Valley late Saturday or Sunday, with a weak shortwave 
potentially dropping from the northwest into the Great Lakes at the 
same time. Given this, some low POPs return to the forecast at times 
by Sunday and Monday, though impactful weather is unlikely with 
confidence in seeing rain currently on the lower side. Temperatures
gradually moderate towards normal by Monday. 

&&

.AVIATION /18Z Monday THROUGH Saturday/...
Mainly VFR across the TAF sites this afternoon with
deterioration to MVFR/IFR likely in a line of rain showers 
Tuesday morning. Have this line of rain showers timed out with 
prevailing MVFR vsbys accompanied by brief IFR tempo groups as 
it moves from west to east through Tuesday morning. MVFR 
ceilings may linger immediately behind the line of showers, 
though improvement to VFR will eventually arrive by mid to late 
afternoon. 

Winds are generally out of the west to southwest this afternoon,
10 to 15 knots with periodic gusts of 18 to 22 knots. Winds will
diminish to 5 knots or less following sunset, favoring a
southerly direction. A brief window of LLWS is possible across
the central and western TAF sites overnight into Tuesday morning
as a belt of 40 to 45 knots of southwest flow resides at around
2kft. Behind the line of showers in the late morning to early
afternoon, winds will become southwest and increase to 10 to 15
knots with periodic gusts of 22 to 25 knots possible.

Outlook...Non-VFR possible in rain showers along a cold front
Tuesday afternoon and evening. Non-VFR becomes more likely on 
Wednesday into Friday in widespread lower ceilings and rain 
showers, particularly across Northeast Ohio and Northwest
Pennsylvania. Brief VFR conditions may arrive late Friday ahead
of another round of non-VFR chances in scattered rain showers 
on Saturday.

&&

.MARINE...
Rough marine conditions are anticipated this week as a strong low 
pressure system moves east through the Great Lakes on Wednesday. The 
potential for a brief window of Gale-Force winds is increasing 
Wednesday afternoon and evening with this package, particularly 
across the central and eastern basin of Lake Erie. 

Otherwise, a brief lull in the winds is expected this evening before 
southwest winds of 15 to 25 knots return late tonight into Tuesday. 
Southwest winds will further increase into the 25 to 30 knot range 
Tuesday night into Wednesday behind a cold front, with winds perhaps 
briefly touching 35 knots at times as they begin to favor a westerly 
direction Wednesday evening. Elevated west winds of 20 to 25 knots 
will then likely persist through Thursday night before diminishing 
to near 15 knots by Friday afternoon. In terms of headlines, went 
ahead and issued a Small Craft for much of the western and central 
basin of Lake Erie through 12Z Wednesday. Additional Small Craft 
Advisories will be needed across the eastern basin once the existing 
headlines expire later this evening. 

Will likely need a Low Water Advisory on Wednesday as southwest 
winds begin to peak in excess of 25 knots across the western basin 
of Lake Erie. At this point, there is a medium chance for water 
levels to drop below the critical mark of -1 inch. Given the cooler 
air mass in the wake of the cold front and convergent flow across 
Lake Erie at times, the potential for waterspouts will also 
increase, particularly Tuesday night into Thursday morning across 
the central and eastern basin of Lake Erie. 

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for 
     LEZ144>146.
     Small Craft Advisory until 11 PM EDT this evening for 
     LEZ147>149.

&&

$$

SYNOPSIS...Sullivan
NEAR TERM...Sullivan
SHORT TERM...Sullivan
LONG TERM...Sullivan
AVIATION...Kahn
MARINE...Kahn