733
FXUS61 KCLE 090156
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
956 PM EDT Tue Oct 8 2024

.SYNOPSIS...
A weak low pressure trough lingers over and near Lake Erie
through Wednesday as a high pressure ridge builds from the Upper
Mississippi Valley and western Great Lakes. The ridge is then
expected to advance eastward through our region on Thursday and
begin to exit toward New England and the Mid-Atlantic states on
Friday. A warm front is expected to sweep northeastward through
our region on Friday and be followed by the southeastward passage
of a cold front Friday night into Saturday as a low tracks from
northern Ontario toward northern Quebec.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
930 PM EDT Update...
Lake effect/enhanced showers remain possible across NW PA and
possibly far NE OH tonight into early Wednesday. As of now, it
appears that southwest winds over land have nudged the majority
of the shower activity into western New York, but will need to
see if a boundary dropping south across Lake Erie will provide
convergence and an increase in shower coverage across the
northeastern part of the CWA over the next few hours. Maintained
chance PoPs across NW PA, but lowered PoPs to slight chance
(less than 25 percent) for northeastern Ohio.

Can`t rule out some patchy frost in low-lying areas that manage
to dip into the lower 30s tonight, but temperatures will once
again be marginal so opted to omit from the forecast at this
time.

Previous Discussion...
Cyclonic NW`erly flow aloft persists through Wednesday. One
shortwave disturbance embedded in this flow will advance SE`ward
across our CWA tonight and another is expected to move SE`ward
across eastern Lake Erie and NW PA Wednesday afternoon through
early evening. At the surface, a trough lingers over/near Lake
Erie as a ridge builds from the Upper MS Valley and the western
Great Lakes. Primarily fair weather is expected through
Wednesday as stabilizing subsidence accompanies the
aforementioned ridge. However, isolated lake- effect/enhanced
rain showers may stream generally E`ward and then SE`ward from
Lake Erie late this evening through the wee hours of Wednesday
morning as a surface trough, attendant to the first shortwave
trough, sweeps SE`ward across ~20C Lake Erie and encounters
moderate lake-induced CAPE amidst a sufficiently- cold/moist
W`erly to NW`erly mean low-level flow. A few rain showers are
also possible Wednesday afternoon through early evening over
eastern Lake Erie and NW PA, courtesy of moist isentropic ascent
aloft preceding the axis of the second aforementioned shortwave
trough. Overnight lows are expected to reach mainly the upper
30`s to upper 40`s around daybreak Wednesday. Late afternoon
highs on Wednesday are forecast to reach the mid 50`s to lower
60`s in NW PA, the lower to mid 60`s in NE OH, and the 60`s to
70F farther west.

Fair weather is expected region-wide Wednesday night as the
ridge at the surface and aloft builds from the north-central
United States and the western Great Lakes, and is accompanied by
stabilizing subsidence. Mainly clear sky, weak or calm surface
winds, and limited humidity at/near the surface are expected to
promote efficient nocturnal cooling Wednesday evening through
daybreak Thursday morning. In NW PA, lows are expected to range
from the mid 30`s to near 40F in interior valleys to the lower
to mid 40`s along/near the Lake Erie shore in Erie County. In
northern OH, lows are expected to reach the upper 30`s to lower
40`s in interior areas to mainly the mid to upper 40`s along and
near the Lake Erie shore.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
High pressure will be the main player for the weather in the short
term. The surface high will build in from the north and drift
southward into the Tennessee Valley throughout the day on Friday. The
conditions will be fairly short lived as a weak cold front will move
across the region late Friday night. There is little moisture
support with the front so, likely PoPs have been confined to the
most northeastern counties in OH and northwestern PA with a higher
chance PoPs along the shoreline.

Sky conditions will clear out and winds will be minimal, especially
across the eastern half of the CWA, as much of the region will be
situated underneath the high pressure. Lows Friday morning will be
in the low 40s for the western half of the CWA and the mid to high
30s for the eastern half. Given the factors mentioned above, there
will be a good frost potential across counties east of I-71 and an
advisory maybe needed. Areas closer to the lake should stay a fair
bit milder with lows in the mid 40s. Highs for Thursday will be in
the mid 60s for those out west and in the high 50s further east. On
Friday, as the high pressure builds to the south, southerly flow
will return and temperatures will climb into the mid 70s for much of
OH and high 60s for PA. Lows Friday night will follow the same trend
and be about 10-15 degrees warmer than the previous night with most
of the CWA being in the low 50s, upper 40s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
The weak cold front from Friday night will continue to pass through
the area Saturday. A more potent upper level trough will move in
from the upper Midwest and cross through the region Saturday into
Sunday. A surface low pressure will develop ahead of the upper level
trough and move through the area on Sunday. Timing and intensity of
the cold front are still not in agreement, though precipitation
potential will be in the area from Sunday through the end of the
period, especially for northeastern OH and northwestern PA. After
the front moves through Sunday, PoPs will be driven by the
northwesterly flow across the lake for the areas previously
mentioned. Temperature wise, Saturday and Sunday will be fairly mild
before the front moves through with highs in the mid to upper 60s.
Saturday lows will be in the low 50s and Sunday night lows will drop
down into low 40s. For the rest of the period, temperatures will be
seasonly cool with highs in the low to mid 50s and lows in the low
40s, upper 30s.

&&

.AVIATION /00Z Wednesday THROUGH Sunday/...
Lake-enhanced/effect showers are possible at KERI tonight into
early Wednesday morning which could result in brief/periodic
MVFR conditions. Otherwise, expect VFR through the TAF period.
Winds will be out of the west/northwest and under 10 knots
through most of Wednesday morning before becoming predominantly
northwesterly and increasing to 10 to 15 knots with gusts to 20
knots likely after 15Z. Gusts at KERI may reach 25 knots during
the afternoon. Expect winds to diminish and become more
northerly during the last couple of hours of the TAF period.

Outlook...Scattered rain showers with non-VFR possible Friday
night through upcoming weekend.

&&

.MARINE...
There is a small window for the potential of waterspouts
tonight into Wednesday morning with some lake effect showers
from Lorain County eastward. Generally, winds will keep the
northwestern orientation through Wednesday before veering to the
north Thursday morning. There will be brief period of stronger
winds Wednesday into Wednesday night in the eastern basin as a
surface trough axis moves through the region. This will cause
waves to build more in that area and as a result, a Small Craft
Advisory has been issued for nearshore zones east of Willowick
Wednesday morning through late Wednesday night.

High pressure will take control on Thursday and winds will be
fairly light across the lake and then shift out of the south as
the high moves south. On Friday, winds will then increase to
10-20 knots out of the southwest ahead of a surface cold front.
This may require a need for another Small Craft Advisory for
areas east of Cuyahoga Friday night into Saturday. Winds should
be light across the lake on Saturday behind the cold front but
will become unsettled again on Sunday ahead of another cold
front with winds increasing to 15-20 knots out of the northwest.
There will be the potential for a small craft headlines during
that time period once details becoming clearer later in the
week.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory from 8 AM Wednesday to 4 AM EDT Thursday
     for LEZ147>149.

&&

$$

SYNOPSIS...Jaszka/Maines
NEAR TERM...Jaszka
SHORT TERM...Kennedy
LONG TERM...Kennedy
AVIATION...Maines
MARINE...Kennedy/Saunders