620
FXUS61 KCLE 261748
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
148 PM EDT Thu Sep 26 2024

.SYNOPSIS...
A weak cold front will gradually move east today as high
pressure briefly builds into the Great Lakes region this
afternoon. The tropical remnant low of Helene enters the Ohio
Valley on Friday night, where it will remain through the weekend
as it rapidly weakens.

&&

.NEAR TERM /THROUGH FRIDAY/...
9:40 AM Update:
Just some minor tweaks needed to the POP and sky grids through
this afternoon. A few showers are ongoing from near Wooster to
Akron with dry weather elsewhere. Adjusted POPs a bit to
increase them in that corridor this morning.

Previous Discussion:
A weak cold front continues to progress eastward this morning,
with modest 850-925mb moisture and frontogenesis leading to some
scattered rain showers generally south of a KMFD-KCLE-KERI
line. Should see these showers dissipate as the front departs
to the southeast and high pressure builds into the Great Lakes
region, skirting the northern part of the forecast area this
afternoon into tonight. After making landfall later this
evening, Helene will work its way northward, rapidly dissipating
as it does so. Even so, the northernmost rain bands will move
in from the south during the day Friday, with rain chances
increasing compared to previous forecasts, with KFDY-KMFD-KCAK
and areas south increasing to 60-70% PoPs. Because of how
quickly Helene dissipate as it approaches the Ohio Valley, there
will be a minimal to no flood risk for our forecast area, though
there could be a modest chance for a beneficial 0.25-0.50" QPE
for some parts of central Ohio.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
The remnants of Helene will settle over the Ohio Valley with the
upper low beginning to creep north or east into the area during the
short term period. Moisture will continue to stream north into the
area over the weekend with periodic showers and perhaps isolated
thunderstorms possible. Showers will be hit and miss and generally
light so do not anticipate a complete washout or a drought-
buster. Coverage will be highest during peak diurnal heating
Saturday and Sunday with the best rain chances in the southwestern
part of the CWA, which will be closer to the surface low.

High temperatures will be in the 70s each day with lows in the upper
50s to lower 60s anticipated each night.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
Upper low will finally drift east into the Mid-Atlantic Monday and
off the East Coast Tuesday. However, an upper trough may linger
somewhere in the eastern vicinity of the CWA through as late as
Tuesday morning as a ridge attempts to build over the Lower Great
Lakes. If the trough remains to the east of the area, a drier
forecast may pan out, but any residual troughing over the local area
could result in continued scattered shower chances. Maintained
slight chance to chance PoPs for the time being, but it`s possible
that the forecast improves in the upcoming days. An upper trough and
surface cold front will move east/southeast across the Upper Great
Lakes and across the region at some point Tuesday and possibly into
Wednesday, but there`s quite a bit of uncertainty in the
timing/strength of the upper trough. Regardless, this feature will
bring additional precipitation chances to the local area towards the
end of the long term period.

Temperatures will generally be near to a couple degrees above normal
early next week, but cold air advection behind the aforementioned
cold front may usher slightly below normal temperatures into the
region Wednesday.

&&

.AVIATION /18Z Thursday THROUGH Tuesday/...
MVFR to locally IFR ceilings persist near a slow-moving frontal
boundary across eastern Ohio and northwestern PA, including at
MFD, YNG, and ERI. The front will continue to gradually push
south and weaken into this evening which should allow VFR to
return. Otherwise, we remain beneath expansive VFR clouds
streaming northward from Hurricane Helene. As the system makes
landfall and begins pushing inland tonight into Friday,
interaction with an upper-level disturbance will help draw
deeper moisture northward. This will allow for cloud bases to
gradually lower from south to north on Friday with some light
rain potentially getting into MFD before 18z. All terminals,
except for ERI and perhaps YNG, have a decent chance to see some
rain after 18z with a period of MVFR visibility possible. Except
MVFR cloud bases to overspread most sites (except for ERI) from
south to north through the day Friday. The initial timing of
MVFR is somewhat uncertain at CLE due to some downslope flow.

Winds will be out of the east-northeast through the TAF period.
Speeds will remain modest and 12 knots or less through early
Friday. Speeds and gusts will increase into Friday afternoon.
Sustained winds of 20-25 knots and gusts to 35 knots are looking
increasingly likely at TOL, FDY and MFD, especially between 18z
Friday and 0z Saturday. Speeds will gradually diminish to the
east/northeast, though gusts up to 30 knots will be possible at
CLE and CAK, with gusts 20-25 knots towards YNG and ERI.

Outlook...Periods of non-VFR are possible with scattered rain
showers and low ceilings Friday afternoon through Monday.

&&

.MARINE...
Light and variable winds this morning will shift to the northeast
and increase to 10 to 15 knots this afternoon. Flow will
continue to increase over Lake Erie as Helene moves inland late
tonight into Friday with winds peaking at 25 to 30 knots with gusts
to 35 knots Friday afternoon into Friday evening. The highest winds
and waves will be in the western and central basins of the lake.
Winds diminish to 10 to 20 knots Saturday into Sunday. Small
Craft Advisories will be needed Friday and Saturday and may continue
from roughly The Islands to Avon Point through Sunday. Expect winds
to shift to the east/southeast and diminish further Monday.

&&

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

&&

$$

SYNOPSIS...Saunders
NEAR TERM...Saunders/Sullivan
SHORT TERM...Maines
LONG TERM...Maines
AVIATION...Sullivan
MARINE...Maines