CLE issues Area Forecast Discussion (AFD) at Oct 18, 3:40 PM EDT313
FXUS61 KCLE 181940
AFDCLE
Area Forecast Discussion
National Weather Service Cleveland OH
340 PM EDT Sat Oct 18 2025
.SYNOPSIS...
Low pressure will lift through Michigan and into Ontario on Sunday,
dragging a strong cold front across the area. High pressure quickly
slides east through the region on Monday. The next low pressure
quickly moves into the Great Lakes on Tuesday pushing another cold
front east through northern Ohio and northwestern Pennsylvania.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
Aside from some minor changes, guidance remains consistent in low
pressure lifting from the mid-Mississippi Valley into Michigan tonight
while deepening, with the low lifting out of Michigan and into Ontario
on Sunday while beginning to slowly fill. This will drag a strong cold
front east across the area on Sunday. Secondary low pressure begins
taking shape over the upper Ohio Valley by Sunday evening, before
exiting towards the Northeast Sunday night. Widespread beneficial
rains and gusty winds are expected late tonight through at least the
first half of Sunday night...though outside of wind gusts approaching
advisory-criteria (46-57 MPH) Sunday morning/early afternoon across
parts of the area, the risk of hazardous weather is minimal.
Rain Timing & Amounts:
Scattered showers/thunderstorms have developed to our west-southwest
along a pre-frontal trough this afternoon, and will try lifting into
Northwest Ohio through this evening. The greatest potential may be
activity pushing into Central Indiana as of 3:30 PM, as that would
lift into Northwest Ohio after 8 PM if it holds together. Otherwise,
it will be mainly dry across the area to start the night. A few
showers may spread in late tonight into Sunday morning well ahead of
the approaching cold front on the nose of a strong low-level jet.
Otherwise, rain chances will ramp up from west to east pre-dawn Sunday
through early Sunday afternoon along and just ahead of the cold
front. This may include some strongly-forced, low-topped convective
filaments along the front itself, with a slight chance of thunder.
There will be a relative lull in rain behind the cold front, before
the trough aloft closes off and allows a new surface low to begin
deepening over the upper Ohio Valley Sunday afternoon and evening
before exiting northeast overnight. The closing off of the trough
aloft and developing secondary surface low will cause wrap-around
rain (perhaps with a bit of banding and some embedded weak convection,
especially Sunday evening across our southern and eastern counties)
to spread back in late Sunday afternoon and evening, with this wrap-
around rain gradually ending from west to east Sunday night.
QPF has trended down a bit across most of our area with this system,
largely due to stronger convection staying just west of us tonight
and slightly slower development of the secondary low, taking greater
QPF with that a bit off to our east and southeast later Sunday/Sunday
night. Still, much of the area is forecast to see 0.40 to 1.00" of
rain, with locally higher amounts of up to 1.50" still in play (mainly
across our extreme west, or across our south/southeast) IF organized
convection can play out. No flooding concerns given the drought.
Synoptic Gusty Winds:
We are still looking at two windows of stronger winds...one very late
tonight through early Sunday afternoon, lifting east-northeast across
the area along and just ahead of the cold front beneath a strong low-
level jet. After a relative lull for a few hours behind the cold front
into Sunday afternoon, the gradient tightens as cold air advection
increases late Sunday into Sunday night from west to east,
particularly across the southern portions of the area. We currently do
not have sufficient confidence in advisory-level (46-57 MPH) gusts
occurring on any sort of widespread basis in either window.
The strongest winds aloft will occur in the low-level jet just ahead
of the cold front...across the western half of the area, 850mb winds
are expected to increase to 55-65kt with 925mb winds of 40-50kt for a
few hours ahead of the cold front very late tonight into Sunday
morning. The low-level jet does gradually weaken while working east
across our area, with winds aloft of 45-55kt at 850mb and 35-40kt at
925mb expected across the eastern half Sunday morning/early afternoon.
These southerly low-level jets never fully mix down, though with a
warmer than normal airmass winds will turn gusty beneath the jet, with
potential for a brief window of better downward momentum transfer on
the leading edge of rain pushing in Sunday morning. The forecast
maintains 35-45 MPH wind gusts area-wide just ahead of the cold front
Sunday morning (into the early afternoon towards and into PA), with
some potential for some sporadic 50 MPH gusts west of the I-77
corridor on the leading edge of the rain pushing in. There will be
some downslope enhancement near the eastern Lake Erie shoreline,
though with winds veering slightly and mixing heights increasing
quickly Sunday morning, this is not a classic downslope setup, which
lowers confidence in stronger gusts in those favored areas (such as
the Erie PA lakeshore). After a brief lull, the low-level jet
increases to 30-40kt late Sunday into Sunday night behind the
developing secondary low to our east. In a cold advection regime
these winds will mix down better, though with notably weaker winds
aloft a period of 30-40 MPH gusts is in the forecast for a few hours.
This is the first good blow of the season after a quiet summer, with
trees still largely foliaged. Some branches/limbs may start coming
down even with sub-advisory gusts, leading to potential for isolated
power outages. Will monitor forecast trends closely for potential
advisory issuance if the forecast gust increases at all, and may put
out a Special Wx Statement to raise awareness.
Convective / Severe Potential:
Any convection that pushes into Northwest OH this evening should be
weakening and sub-severe, with spotty gusty winds possible given
lingering low-level inverted-v soundings. Will need to monitor any
convective filaments that push into Northwest OH for locally enhanced
(perhaps close to severe-level) winds early Sunday given the very
strong low-level jet. Otherwise, the SPC has removed the Day 2
Marginal Risk for severe weather from our forecast area. Any
convective filaments that play out along the front farther east can
help bring briefly stronger gusts down...however, weakening low-level
wind fields with time, minimal instability, and signs of some rain
occurring immediately ahead of the cold front and weakening the low-
level lapse rates all argue against severe-level gusts making it to
the surface with any convection along the cold front as it works east
across our area Sunday. The Marginal Risk remains in place to our
southeast, so activity may try perking up slightly before exiting.
Temperatures:
After record warmth in Toledo this afternoon (and well above average
warmth elsewhere) lows will be very mild tonight, mainly in the 60s.
It will stay in the 60s (lower 70s east) ahead of the front on
Sunday, gradually cooling behind the front through Sunday afternoon.
Stronger cold advection Sunday night pushes lows well into the 40s.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Any lingering wrap-around/lake-enhanced showers across far Northeast
OH and Northwest PA will exit to the east-northeast on Monday, with a
ridge axis high quickly sliding east into and across the area. Skies
will trend sunnier from west to east through the day, with highs
ranging from the mid-upper 50s in Northwest PA to the low-mid 60s
across Northwest and Central Ohio. Most of Monday night will remain
tranquil ahead of the next fast-approaching system, with southerly
breezes struggling to decouple outside of deeper valleys and lows
generally settling into the 40s.
A large, closed upper low will swing into the Great Lakes Monday night
into Tuesday. An embedded shortwave and cold front are likely to cross
Tuesday morning, bringing shower potential and a wind shift. The
greatest potential for rain will be over and east of Lake Erie into
the primary snowbelt of far Northeast OH and Northwest PA, with any
showers more scattered with light QPF elsewhere. We should see a
relative decrease in rain chances Tuesday night as the flow backs
southwesterly ahead of the next shortwave and re-enforcing cold front,
though the forecast retains low POPs across parts of the area for now
(with higher POPs towards the Northwest PA lakeshore) given the
generally troughy and unsettled pattern. Highs Tuesday will generally
reach the low to mid 60s, with lows Tuesday night mainly in the 40s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Troughing aloft and chilly, cyclonic low-level flow will remain over
the Great Lakes for Wednesday and Wednesday night. This troughing
gradually lifts out Thursday into Friday as high pressure builds in. A
system may move in from the west next weekend, though confidence in
that is low.
Chilly, somewhat breezy, and somewhat showery weather is expected for
Wednesday and Wednesday night, particularly east-southeast of Lake
Erie. Shower chances gradually diminish Thursday into Friday, though
guidance has trended slower in terms of lifting out the large trough
over the Great Lakes/southeast Canada/New England in recent runs, so
some lake effect showers may persist into the end of the week. Outside
of the lake effect, there is greater confidence in a drier trend for
Thursday and Friday. We'd be looking quite an intriguing lake effect
snow setup if it were the right time of year. The long term will be on
the cooler side of average. Some potential for frost/freeze exists
given the airmass mid-late week if we can get a night that's mainly
clear and calm across parts of the area, but confidence is low. Rain
chances may return by Saturday, though confidence is very low.
&&
.AVIATION /18Z Saturday THROUGH Thursday/...
Widespread VFR conditions are being observed across the area this
afternoon as the area sits within the warm sector of an approaching
low pressure system. As a warm front continue to lift north of
the area, atmospheric mixing will result in southerly winds of
10-15 knots, gusting up to 25 knots until the sun sets and
conditions begin to stabilize around 00Z. Ongoing convection
upstream in Illinois/Indiana will gradually push northeast
towards the area, presenting the potential for showers and
possible a few rumbles of thunder near that 00Z timing for
western terminals. Both FDY and TOL are the only terminals opted
to put a mention of -TSRA in the TAF given that the instability
may still be enough to promote lingering convection.
As the night progresses, a strong LLJ will kick north across the
areas with 850mb winds around 45-50 knots enhancing the wind
field across the area. Winds will gradually increase from 06Z
Sunday onward, peaking with gusts up to 30-35 knots by mid-
morning for most terminals. These strong winds are expected to
occur within a WAA regime ahead of an approaching cold front.
Opted to primarily handle the strong winds with gusts, with the
exception of FDY and TOL where LLWS of 50 knots was include
given the timing and likely stable environment that early in the
morning. This cold front is expected to move east Sunday
morning, bringing widespread showers to the area and gradually
diminishing conditions from VFR to MVFR. In heaviest showers,
cannot rule out periods of IFR but confidence was too low to
include with this update. As the cold front moves east, winds
will back and weaken behind the boundary.
Outlook...Periods of non-VFR in showers and thunderstorms are
expected Sunday. Gusty winds are anticipated on Sunday with the
highest wind gusts of 30-40 knots anticipated Sunday afternoon.
Non-VFR will be possible in showers Tuesday through Wednesday.
&&
.MARINE...
A relatively quiet Lake Erie this afternoon will quickly become
hazardous tonight as a low pressure system tracks northeast through
Michigan. This low pressure is expected to tighten the gradient
across Lake Erie, quickly increasing southerly winds after 08Z
Sunday as a strong LLJ of 45-50 knots surges north ahead of an
approaching cold front. This increase in low level winds will result
in surface winds of 20-25 knots from the south across Lake Erie by
12Z Sunday. As the gradient continues to tighten, winds will max out
near gale force late morning through the afternoon on Sunday. As a
result, a Gale Watch has been issued for all basin in Lake Erie with
up to 35 knot southerly winds possible. These strong winds will also
elevate the offshore waves to be 6-8 feet, possibly higher.
Confidence was not fully there to go ahead or not with a Gale
Warning so opted to let one more run of winds come in with models
before deciding on Gale Warning vs. Small Craft Advisory. Either way
the lake will be very hazardous on Sunday. In addition, will have to
keep an eye on water levels across the western basin through the day
on Sunday, but current forecasts keep levels about the critical mark
which is likely due to the more prevalent southerly versus
southwesterly winds.
As the cold front moves east Sunday, winds behind the boundary will
begin to back and become west-northwesterly by 00Z Monday, remaining
15-30 knots. This will allow waves to build along the southern shore
to 4-6 feet, possibly approaching 8 feet in some locations. Winds
Sunday night will likely not be strong enough to maintain any Gale
headline if one is issued, but expected a Small Craft Advisory to
persist through Monday.
There may be a brief lull in strong winds as the area transitions
between one system to another low pressure system moving into the
region late Monday into Tuesday. Winds will once again increase from
the southwest at 20-25 knots across Lake Erie, building waves up to
4-6 feet along the shore with waves up to 10 feet in the open
waters. As a cold front moves east Tuesday, winds will gradually
back but remain elevated through Thursday. This period will need
additional marine headlines. A brief period of high pressure builds
over the area on Friday and will finally allow marine conditions to
become calmer into early next weekend.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Gale Watch from Sunday morning through late Sunday night for
LEZ144>148-164>168.
Gale Watch from Sunday afternoon through late Sunday night for
LEZ149-169.
&&
$$
SYNOPSIS...Sullivan
NEAR TERM...Sullivan
SHORT TERM...Sullivan
LONG TERM...Sullivan
AVIATION...04
MARINE...04
Source:
CLE issues Area Forecast Discussion (AFD) at Oct 18, 3:40 PM EDT---------------
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