Portage, Ohio Weather Forecast Discussion

496
FXUS61 KCLE 051142
AFDCLE
Area Forecast Discussion
National Weather Service Cleveland OH
742 AM EDT Fri Sep 5 2025
.SYNOPSIS...
A high pressure ridge continues to exit eastward toward the coast
of the northeast United States before a cold front sweeps
eastward across our region early this afternoon through early
evening. Behind the front, a trough lingers over and near Lake
Erie through this weekend as a ridge attempts to build from the
northern and central Great Plains and eventually the Upper to Mid
Mississippi Valley.
&&
.NEAR TERM /THROUGH SATURDAY/...
A ridge at the surface and aloft continues to exit toward the
northeast United States coast and farther east through Saturday
as a trough at the surface and aloft begins to overspread our
region from the Upper Midwest and vicinity. Accordingly, W`erly
to SW`erly cyclonic flow aloft becomes established over our
region, embedded shortwave disturbances traverse our area, and
an attendant surface cold front should sweep E`ward through our
region during this early afternoon through early evening.
Intervals of sunshine and net low-level WAA ahead of the cold
front and along the backside of the exiting ridge should allow
our highs to reach the mid 70`s to lower 80`s late this
afternoon. Net low- level CAA behind the cold front should allow
our lows to reach mainly the upper 40`s to upper 50`s around
daybreak Saturday. Despite peeks of sunshine, continued net low-
level CAA should contribute to below-normal highs in the mid
60`s to near 70F late Saturday afternoon.
Note: patchy dense river valley steam fog and radiation fog are
expected to impact north-central OH and especially NE OH and NW
PA through daybreak this morning. Some of the fog will also
result from nocturnal cooling allowing stratus to expand
downward to the surface amidst sizable low-level moisture, weak
winds at/near the surface, and sufficient nocturnal cooling.
After daybreak this morning, the onset of diurnal convective
mixing of the boundary layer should allow fog to dissipate
between roughly 8 AM and 10 AM EDT.
The NBM continues to suggest today`s surface cold front passage
will be dry. This seems plausible since model soundings suggest
a stout subsidence inversion or isothermal layer between about
5kft and 10kft MSL, associated with subsidence accompanying the
exiting ridge, will result in large CIN for parcels rooted
at/near the surface in the warm/moist sector. However, from
about sunset this evening through Saturday afternoon, moist
isentropic ascent along the upper-reaches of the E`ward-moving
front should release weak potential instability and trigger
primarily light and isolated to scattered rain showers,
especially roughly along and east of I-71. Note: 850 mb
temperatures cooling to near 6C over/downwind of ~22C Lake Erie,
a WSW`erly mean low-level flow of sufficiently-cold/moist air
over/downwind of the lake, and the development of sizable lake-
induced CAPE should allow a band of lake-effect rain showers,
heavy at times, to form and stream ENE`ward over much of Lake
Erie and across portions of western NY late Saturday morning
through sunset Saturday evening.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
Aloft, cyclonic SW`erly to NW`erly flow and embedded shortwave
disturbances should affect the Lake Erie region and Upper OH
Valley Saturday night through Sunday night as the longwave
trough axis moves from the Upper Midwest toward northeast United
States. On Monday, flow aloft should become W`erly to NW`erly
and slightly anticyclonic as a subtle shortwave ridge builds
from the Upper Midwest and vicinity. At the surface, a trough
lingers over and near Lake Erie, including our CWA through
Sunday night, and a ridge attempts to build from the northern
and central Great Plains and eventually the Upper to Mid MS
Valley through Sunday night. On Monday, the surface ridge
should build in earnest from the Mid MS Valley and eventually
the Lower to Mid OH Valley. The projected weather pattern
evolution at the surface and aloft should maintain net low-level
CAA across our area. Daily lows should reach mainly the lower
40`s to mid 50`s around daybreak Sunday and Monday,
respectively. The coldest lows should be reached farther to the
south and west in our CWA, where clearer sky and greater
nocturnal cooling are expected. Despite intervals of sunshine,
late afternoon highs should reach only the 60`s to near 70F on
Sunday and Monday, respectively.
Mean low-level flow of sufficiently-cold/moist air over/downwind
of ~22C Lake Erie is expected to maintain lake-effect rain
showers over/downwind of the lake Saturday night through Sunday
night as lake-induced CAPE remains sizable. During Saturday
night, the mean low-level flow should veer from WSW`erly to
W`erly and allow the lake-effect rain, heavy at times, to shift
S`ward into the primary snowbelt and vicinity in our CWA. On
Sunday through Sunday night, the mean low-level flow should veer
gradually from W`erly to NW`erly and allow scattered lake-
effect rain showers, heavy at times, to eventually impact the
entire snowbelt and vicinity in our CWA. A few lake-effect
thunderstorms are possible on Sunday, when greater low-level
moisture should contribute to greater lake-induced CAPE,
including within the primary electrical charge separation zone
(i.e. the portion of the LICAPE profile that spans the lake-effect
cumuliform cloud temperature range from 0C to -20C). The
intensity of lake-effect rain showers should decrease Sunday
night, as lake-induced CAPE begins to wane via a lowering
subsidence inversion and low-level dry air advection
accompanying the aforementioned surface ridge. On Monday,
lingering and light lake-effect rain showers streaming SE`ward
over/downwind of Lake Erie should end by early afternoon as
lake-induced CAPE wanes further for the same reasons mentioned
above. Current odds favor fair weather outside the lake-effect
rain due, in part to stabilizing subsidence accompanying the
aforementioned ridge.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
The above-mentioned ridge at the surface and aloft should exit
gradually E`ward on Monday night through Wednesday, but
continue to impact our region. Current odds favor fair weather
as stabilizing subsidence accompanies the ridge. Mainly clear
sky, light surface winds, and low humidity at/near the surface
will promote efficient nocturnal cooling, which should allow
lows to settle into the 40`s or 50`s around daybreak Tuesday and
Wednesday, respectively. Warmer late afternoon highs in the
70`s on Tuesday and the mid 70`s to lower 80`s on Wednesday are
expected as daytime heating is complemented by net low-level WAA
on the backside of the aforementioned ridge.
A shortwave trough axis aloft and attendant surface cold front
should sweep generally SE`ward through our region Wednesday
night. At this time, it appears rather dry air at/near the
surface should prevent measurable rainfall from accompanying the
passage of the cold front and shortwave trough axis. Overnight
lows should settle into mainly the upper 40`s to upper 50`s
around daybreak Thursday as net low-level CAA follows the cold
front. On Thursday, another ridge at the surface and aloft
should build from the north-central United States, western Great
Lakes, and vicinity and maintain net low-level CAA across the
Lake Erie region and Upper OH Valley. Late afternoon highs
should reach the upper 60`s to upper 70`s. Stabilizing
subsidence and resulting fair weather are expected with the
ridge.
&&
.AVIATION /12Z Friday THROUGH Tuesday/...
Some fog and low stratus over NE OH and NW PA will continue to
diminish over the next hour or two this morning. The only
terminal that will be impacted will be KYNG but conditions are
expected to improve to VFR. With a warm front north of the area,
expecting mid-level clouds to enter through day in the warm
sector of a low pressure system. Winds are expected to mix down
effectively during the daytime hours and southwest winds with
gusts to 20 to 30 kts will be expected. A cold front will cross
the area during the afternoon and evening hours and winds will
shift to the west then northwest. Some precipitation could
develop ahead of the front after 00z. However, while confidence
in coverage is high, an impact at a terminal remains low but
will keep some vicinity shower at KCAK and KYNG.
Outlook...Non-VFR possible with rain and ceilings into Saturday.
Non-VFR also possible with lake effect clouds and rain in NE
OH/NW PA on Saturday night into Sunday.
&&
.MARINE...
There is a brief reprieve in stronger winds on Lake Erie early
this morning, as a surface ridge is over the region and has
allowed for weaker southerly flow on the lake. This morning, a
warm front will move through the region and winds will increase
in the warm sector of the feature this afternoon as the pressure
gradient increases and a strong low level jet moves over the
lake. Strong southwest flow is still expected with winds in the
20 to 30 kt range and gale force gusts possible over the central
basin of the lake. The current Small Craft Advisories and Beach
Hazards Statements for today into tonight remain valid. With the
strong southwest flow today, low water levels for western Lake
Erie remain a possibility. If winds overperform this afternoon,
then a Low Water Advisory may need to be issued, as any
overperformance could lead to water levels reaching the critical
mark for safe navigation.
Behind the front for Saturday and Sunday, a trough will remain
in the region and elevated west to southwest flow will remain on
the lake and there may be a need for a new round of Small Craft
Advisories and Beach Hazards Statements for the eastern half of
the lake with waves building to around 4 ft. This can be
evaluated over the next forecast cycle. High pressure will enter
for Monday and Tuesday and lighter flow on the lake will allow
for more favorable marine conditions, especially Tuesday when
offshore flow will return.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Beach Hazards Statement through late tonight for OHZ010>012-
     089.
PA...Beach Hazards Statement through late tonight for PAZ001.
MARINE...Small Craft Advisory until 10 PM EDT this evening for
     LEZ142>144.
     Small Craft Advisory until 4 AM EDT Saturday for LEZ145>149.
&&
$$
SYNOPSIS...Jaszka
NEAR TERM...Jaszka
SHORT TERM...Jaszka
LONG TERM...Jaszka
AVIATION...Sefcovic
MARINE...Sefcovic

NWS CLE Office Area Forecast Discussion