709
fxus61 kcle 181121
afdcle
area forecast discussion
national weather service cleveland oh
721 am edt thu sep 18 2025
.synopsis...
high pressure briefly weakens tonight and friday, allowing a
backdoor cold front to move southwest across the area during the day
friday. high pressure builds back into the northeast for saturday. a
warm front lifts across the area saturday night and sunday.
&&
.near term /through tonight/...
warm and quiet persists today as high pressure weakens a bit but
remains in control. as of 2:00 am a small area of dense fog has
developed near the oh/pa border between ashtabula and erie/crawford
counties. expect some expansion of fog through sunrise, particularly
across low-lying portions of northeast oh and northwest pa, though
a bit of patchy fog could fill in across the typical lower-lying/
rural locations and river valleys farther west too. will monitor the
potential need for a special wx statement or (less likely) a dense
fog advisory over the coming hours across parts of northeast oh and
northwest pa if dense fog starts getting more widespread. once fog
lifts by 9 or 10 am this morning, mostly sunny skies are expected
sans some afternoon cumulus. highs will range from the upper 70s in
extreme northeast oh and northwest pa to the mid to upper 80s
towards the i-75 corridor and marion. minimum rh values will fall to
25-35% well-inland from lake erie this afternoon, though with
fairly light north to northwest winds of 50-10 mph. minimum rh
values will stay 40-50% near and east of the lake.
high pressure will break down briefly tonight as a backdoor cold
front drops in from the north, before pushing south-southwest across
the area through friday. some showers/storms will likely develop
well to our north/northwest across northern lower michigan this
afternoon along the front and drop southeast towards northeast
oh/northwest pa the first half of tonight. the expectation is that
the dry and stable airmass locally will lead to this activity
falling apart before it can make it in, precluding a mentionable pop
for showers in the forecast. however, can not totally rule out some
dying sprinkles making it in late this evening from the northwest.
the front itself will reach the southern lake erie shoreline in the
cleveland area around dawn friday. there will likely be some
increase in clouds with the front, but continue to expect a dry
frontal passage overall. lows tonight will stay up a few more
degrees than recent nights, ranging from the mid 50s to lower 60s.
some patchy fog is possible tonight, though it should be limited.
&&
.short term /friday through saturday night/...
a backdoor cold front will be pushing onshore from the north-
northeast friday morning, and will push south-southwest across the
area through the afternoon. there will be an increase in clouds
along and behind the front as some modest moist isentropic lift
occurs in the low-mid levels atop the shallow front. some models
suggest a few sprinkles or showers may try developing due to this
isentropic lift in the afternoon across our southern or western
counties closer to the front. continue to run with a dry forecast
for friday given fairly limited amounts of moisture and lift, though
it will be cloudier, somewhat breezier and slightly cooler than
recent days...and can not entirely rule out needing to throw in a
sprinkle mention or slight chance (20%) shower mention if model
agreement improves. either way, nothing impactful/beneficial. highs
on friday will get dialed back a bit due to the increased clouds and
modest push of cold air advection, expected to range from the low-
mid 70s in far northeast oh and northwest pa to the mid 80s towards
findlay and marion. minimum rh values will dip to 30-40% towards
findlay-marion-mt. vernon friday afternoon, but will be higher
elsewhere. winds will turn north-northeast at 7-15 mph.
the backdoor front is expected to stall across western/southern ohio
friday night and saturday before lifting back northeast as a warm
front saturday night into early sunday. dry, mostly clear, and
cooler conditions are expected for friday night as high pressure
builds southeast out of canada and into new england. fog should be
limited to deeper river valleys friday night/early saturday. lows
will dip well into the 40s from interior portions of far northeast
oh into northwest pa. values will trend milder farther west, with
the i-75 corridor struggling to cool past the upper 50s. dry and
warm conditions are forecast for saturday with highs bouncing back
a bit, ranging from the mid 70s in erie to the upper 70s to mid 80s
elsewhere...warmest towards findlay-mt. vernon. minimum rh values
will again dip to 30-40% inland from the lake saturday. will need to
monitor for an isolated shower or storm saturday afternoon or
evening across our southwest counties in closer proximity to the
front, as modest instability combined with lift from a weak
approaching shortwave may interact with the front to allow for some
limited convection to pop. the current forecast is dry as most
models suggest that high pressure anchored to our northeast and dry
air will dominate, but it`s something to monitor. otherwise, dry
weather will persist through saturday night with lows trending
milder as the warm front brings an airmass change and more
clouds...lows are expected to range form the mid 50s to lower 60s.
&&
.long term /sunday through wednesday/...
more unsettled weather is expected for the long term with
occasional shower/thunder chances returning to the forecast, though
any dents in the developing drought appear more more cosmetic in
nature than anything else.
we will break into the warm sector on sunday as the warm front exits
to the northeast. sunday will be warm and mainly dry, though with
dew points creeping up several degrees towards 60. the grids have a
slight chance (20%) for showers/thunder across most of the area on
sunday, though slight chances are "silent" in forecast products that
far in the future so you won`t see it in the text. the combination
of modest instability, any mesoscale boundaries (such as the lake
breeze), and very weak large scale ascent (evident via subtle 500mb
height falls after 18z) could be enough for a few showers or (non-
severe) storms to pop during the afternoon and early evening. any
activity that develops sunday to our west (closer to the front and
better forcing) may drift in before completely falling apart sunday
night, for which the forecast a 20-40% pop (highest northwest).
the broad pattern for monday and tuesday will feature ridging
persisting across the southeast as troughing digs into the plains
states, with a weak shortwave working across the great lakes ahead
of the larger trough diving into the plains. we are expected to
remain in the open warm sector for monday and most of tuesday given
ridging holding strong over the southeast. the trough over the
plains is expected to close off and begin drifting east-southeast by
wednesday. this will likely erode the ridging enough from the west
for a cold front to approach late tuesday or wednesday, though
models and ensembles do not agree on the specifics...common for a
pattern featuring a closed-off low nearly a week out...leading to
lower confidence in the pop and temperature forecast that far out.
pops have increased a bit for monday afternoon and evening, into the
40-60% range (highest across western and northern counties). while
no frontal passages are expected, there is increasing agreement in a
belt of large-scale lift working across the area monday or monday
night as a weak shortwave works through the great lakes. this could
combine with a modestly humid and unstable airmass to allow for
better coverage of showers/thunder. the forecast maintains fairly
general chance pops (20-30% at night, 30-50% each day) tuesday and
wednesday given the prospect of an approaching cold front but low
confidence in the details. temperatures should remain above average
for at least monday and tuesday, though may trend a bit cooler by
wednesday depending on timing of the cold front. in terms of
potential rain coverage and amounts, the prospects for at least
some rain potential a few days in a row starting as early as sunday
(potentially peaking monday-tuesday) is encouraging. however,
forcing may remain modest for most of this period with rain largely
driven by convection, which is inherently hit or miss (and quite
often the heavier rain amounts with convection are the exception
rather than the rule). for perspective on this, nbm ensemble 10th
percentile qpf amounts through wednesday morning (10% chance of less
per the ensemble) range from 0.00 to 0.10" across the area, meaning
some solutions still lead to very little rainfall across parts of
the area. however, the 90th percentile (10% chance of more)
generally ranges from 1.25-1.75", suggesting parts of the area may
see beneficial rain...likely tied to any more organized convection.
&&
.aviation /12z thursday through monday/...
patchy fog has developed across parts of the area and is
expected to last through ~13z. kyng is the primary taf site to
experience visibility restrictions down to 1/4 sm, though kfdy
and ktol may see brief mvfr visibilities.
once fog dissipates, should see vfr conditions with sunny skies.
a cold front moves in from the north late tonight, with mvfr/ifr
possibly accompanying the front. for now, only included mvfr
ceilings at keri where confidence was highest.
winds will generally be light and variable, though an afternoon
lake breeze will produce slightly stronger northwest winds of
5-10 knots in northeast ohio and northwest pennsylvania,
including keri, kcle, kyng, and kcak.
outlook...non-vfr will be possible with patchy fog and low
ceilings early friday morning. non-vfr with scattered showers
and thunderstorms will be possible sunday afternoon through at
least tuesday.
&&
.marine...
light and variable winds are expected through tonight, though
there may be a few hours this afternoon of around 10 knots
onshore flow with a lake breeze. a cold front crosses the lake
very late tonight into friday morning, with winds becoming
east-northeast behind it. these winds should generally be around
10 knots, though lake breeze enhancement will increase these
winds to 15 knots during the afternoon. this east-northeast flow
continues through saturday and saturday night, with speeds of
around 15-20 knots expected. it`s possible we may need a small
craft advisory and beach hazard statement for at least part of
lake erie on saturday. should see winds become south to
southwest on sunday as high pressure moves off to the east
coast, with these conditions persisting through at least
tuesday.
&&
.cle watches/warnings/advisories...
oh...none.
pa...none.
marine...none.
&&
$$
synopsis...sullivan
near term...sullivan
short term...sullivan
long term...sullivan
aviation...saunders
marine...saunders