731
FXUS61 KCLE 251737
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
137 PM EDT Wed Sep 25 2024

.SYNOPSIS...
A weak cold front will slowly move through the area today. High
pressure will build from the northwest for Thursday. The remnant
low pressure of Helene will enter the Ohio Valley for Friday and
Saturday.

&&

.NEAR TERM /THROUGH THURSDAY/...
1230 PM Update...
Another line of showers has begun to develop just ahead of the
cold front near the I71 corridor. Locally heavy rainfall is
possible with this line along with a couple rumbles of thunder,
but no severe weather is expected due to limited mesoscale
support. These showers will slowly move east through the
evening, allowing for conditions to dry out behind the front.
Except cloudy conditions to persist with few breaks of sunshine
possible across western counties.

930 AM Update...
This morning, showers and a few rumbles of thunder have worked
their way into the far southeastern tier of counties, extending
from Knox to Mahoning Counties with additional showers in
Crawford County PA. This will be the primary focus of shower
activity today, although cannot rule out some showers a bit
further north. Given the marginal mesoscale environment, not
expecting anything severe today, but will monitor radar trends
for anything rogue. With this update, the only change really
needed was adjustments to temperatures as current observations
suggest a bit warmer start to the day than previously forecast.
No other changes were needed with this update.

630 AM Update...
Some shower activity has been in and out of NE OH and NW PA
this morning and will continue through today ahead of a cold
front. Have added PoPs a touch further west than the previous
forecast with the front remaining sluggish in NW Ohio.

Previous Discussion...
A cold front across Northwest Ohio this morning will slowly move
east across the forecast area today. Ahead of the front,
additional showers and some embedded thunder will be possible
with help of the main trough entering the Great Lakes region,
decent moisture in the region, and even a touch of instability.
With the energy of the upper trough splitting between a trough
to the northeast and a cut off upper low over the lower Ohio
Valley, the surface front may not reach the eastern portion of
the forecast area until tonight and have PoPs for much of the
day to reflect that any shower chances are possible until the
front passes to east. High pressure will build from the
northwest for Thursday and this feature will allow for dry
conditions to return to the area. Temperatures through the
period will run close to normal.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
The remnants of Helene will drift inland and effectively be
absorbed into an upper low over the Ohio/Tennessee valleys late
this week into the early part of the weekend. High pressure will
likely maintain control over the local area through Thursday night,
but PoPs begin to increase as early as Friday morning as moisture
begins to stream north into the Ohio Valley as the surface low moves
northwest into the the vicinity of the Illinois/Missouri/Kentucky
borders. From there, the low will churn to the southwest of the
local area throughout the weekend and periodic showers with low-end
chances of thunderstorms are possible Friday afternoon through
Saturday night. There`s still quite a bit to iron out with the
progression of Helene as it prepares to make landfall and moves
inland in the upcoming days, so opted to maintain consistency and
cap PoPs at slight chance to chance. Will continue to refine PoPs as
the scenario becomes a bit more clear. If a rainier forecast does
pan out, dry air may wrap into the area so it may not be a washout.
Precip coverage will probably be highest during peak diurnal heating.

The pressure gradient will tighten considerably Friday as the high
struggles to maintain control over the region, resulting in breezy
northeast winds to 25 to 35 mph downwind from Lake Erie.

Highs will generally be in the 70s throughout the short term period
but a few spots may touch 80 degrees in southern zones Saturday.
With that being said, the temperature forecast will likely change
with the precipitation forecast; increased cloud cover and rain
chances may result in cooler highs. Expect overnight lows in the
upper 50s to lower 60s each night.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
The aforementioned upper low will finally begin to gradually
progress east across the Ohio Valley during the start of the long
term period and periodic showers and thunderstorms remain possible
through the remainder of the weekend. There`s still some uncertainty
in how quickly the low exits and whether or not a ridge builds over
the region so maintained PoPs for the time being. By Tuesday
afternoon, an upper trough and surface cold front may approach from
the northeast, resulting in additional chances of showers and
thunderstorms.

Temperatures will be a few degrees above normal Sunday and Monday,
but a cooler weather pattern may begin to unfold as temperatures
fall to near normal values Tuesday.

&&

.AVIATION /18Z Wednesday THROUGH Monday/...
Quiet a mix bag of conditions across the area this afternoon as
a cold front slowly meanders east. Behind the boundary/west of
I71, ceilings continue to bounce between high end MVFR/low end
VFR with winds from the west-northwest at 5-10 knots. These
conditions will likely continue over the next couple hours. By
evening, most western terminals, including KTOL, KFDY, and KMFD
should rebound to VFR through the first half of tonight. For
areas along and east of I71, conditions continue to range from
IFR to VFR due to a variety of reasons. First off, there are
generally lower ceilings ahead of the cold front, generally
ranging from 800-1500 ft, but with some scattering in the cloud
deck. The second reason is due to ongoing precipitation just
ahead of the boundary extending from eastern Cuyahoga County,
southwest to Knox County. Terminals that are impacted by this
line will likely have visibilities reduced to MVFR/IFR
visibilities. In addition, winds will persist from the southwest
at 5-10 knots through this evening. In general, this group of
terminals are not likely to rebound to VFR until tomorrow.

By tonight, winds will become light and variable across the
area. For far western terminals, conditions should remain VFR.
Elsewhere, especially in areas where it rains today, there is a
potential for fog develop that will reduce conditions to MVFR
and IFR in spots. The highest confidence in conditions being
reduced to IFR visibilities is at KCAK and KYNG where
visibilities could drop below 2SM with ceilings lowering below
1kft. KCLE, KMFD, and KERI may see some patchy fog, but with
lower confidence opted to only drop them to MVFR with this
update. By the end of this period, winds will begin to increase
to 5-10 knots from the northeast.

Outlook...Strong northeast winds are expected across the region
on Friday. Non-VFR may return in showers and thunderstorms this
weekend.

&&

.MARINE...
A Small Craft Advisory remains in effect from Conneaut OH to Ripley
NY until 12Z/8 AM this morning, but southeasterly winds are already
beginning to diminish. Winds will diminish to 15 knots or less and
shift to the west/northwest as a cold front crosses the lake this
afternoon through tonight. By Thursday morning, flow will become
northeasterly as high pressure builds over Lake Erie with winds
strengthening to 10 to 20 knots as the remnants of Helene move
inland on Thursday night. Winds will peak at 20 to 25 knots Friday
afternoon into Friday evening, although some guidance members are
hinting at potential for winds reaching as high as 30 knots. Small
Craft Advisories will most likely be issued for Friday morning
through late Friday night or Saturday morning. Northeast winds
diminish to to 10 to 15 knots with winds near 20 knots likely in the
open waters of the central basin so it will probably remain choppy
even after headlines end. East/northeast winds 10 to 15 knots will
persist through Sunday.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.

&&

$$

SYNOPSIS...Sefcovic
NEAR TERM...Campbell/Sefcovic
SHORT TERM...Maines
LONG TERM...Maines
AVIATION...Campbell
MARINE...Maines