-- Discussion containing changed information from previous version are highlighted. --
393
FXUS61 KCLE 242341
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
741 PM EDT Tue Sep 24 2024

.SYNOPSIS...
Low pressure moves northeast across the Great Lakes region
through Thursday and will drag a weak cold front across the area
late Wednesday into early Thursday. High pressure enters from
the northwest on Thursday.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Surface warm front continues lift across the region as the
parent low pressure moves northeastward across Lower
Michigan this evening. Shower and thunderstorm coverage has
decreased for the time being, however, we`re beginning to see
some redevelopment of showers and storms across Northern
Indiana. Can`t rule out strong to severe thunderstorms,
especially across the I-75 corridor, as current mesoanalysis
indicates a favorable environment with MLCAPE values of 1000+
J/kg coupled with bulk shear magnitudes of 30-35 kts. As such,
portions of Northwest Ohio remain under a Marginal Risk (Level
1/5) for Severe Weather through this evening. Showers and
thunderstorms will diminish in coverage and intensity later this
evening as the surface low continues to lift north. Low
stratus/patchy fog will move overhead tonight given recent
rainfall/lingering low level moisture and calm winds. Upper
level trough will continue to dig eastward through Wednesday
with lingering shower and thunderstorm chances east of I-71
through Wednesday night.

Overnight lows tonight will generally settle in the low 60s.
Slightly warmer Wednesday afternoon with highs in the mid 70s.
Cold front will begin to cross the region Wednesday night into
Thursday morning which will allow for lows to dip into the upper
50s in NW Ohio and lower 60s elsewhere.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
There will be some lingering post-frontal showers Thursday morning
in NE OH and NW PA but will be ending by mid-day. During the day
Thursday, high pressure will build in ushering in dry weather for
the next 24-36 hours. On Friday, an upper level low will interact
with Tropical Storm Helene as it moves inland from the Gulf Coast.
This will bring moisture northward from as the storm wraps around
the upper level low. There is uncertainty of how far north the
moisture will be as the system will stall out in the Tennessee/Ohio
River Valleys. With that, PoPs will be similar to previous forecasts
with 40 percent in the southwestern counties and around 30 percent
for the northeast counties for Friday evening.

Highs will generally be in the high 70s for Thursday and Friday and
lows in the upper 50s, low 60s each night. The high temperatures may
be limited depending on if there are any showers in the southern
counties for Friday.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Going into Saturday the upper level low across the mid-Mississippi
River Valley will start to meander northeastward into the Ohio River
Valley region. There is still uncertainty on the location and
strength of the system as it will be slow moving, but will continue
to influence the weather for the region through the weekend. As a
result, expect dreary weather into the beginning of next week with
overcast skies, low-end chance of PoPs, and a few thunderstorms.

Temperatures will trend towards normal for the area, with highs in
the mid to upper 70s on Saturday and low 70s by Tuesday. Lows will
follow a similar pattern, being in the low 60s, upper 50s on
Saturday and by Tuesday everyone will be in the mid 50s.

&&

.AVIATION /00Z Wednesday THROUGH Sunday/...
-- Changed Discussion --
Convection to continue for the next few hours and needed to use
some TEMPO TSRA for the first 2 hours or so of the forecast for
a few of the terminals given the ongoing thunderstorm activity.
Once the convection wanes for the night, expecting low stratus
to form and go to IFR after 08Z tonight, with these low ceilings
continuing through around 15-18Z Wednesday before mixing out
and lifting/dissolving out. Thunderstorms contain wind and hail
threat this evening with some rotation possible.

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

&&

.MARINE...
A Small Craft Advisory will be in effect from 21Z Tuesday to 12Z
Wednesday morning due to downsloping winds in the eastern basin of
Lake Erie. Winds will be out of the southeast at 15 to 25 knots
overnight before subsiding Wednesday morning as winds shift to be
more southwesterly at 10 to 15 knots. A cold front will move across
the lake Wednesday afternoon and the winds with veer to be out of
the northwest, but with a weaker pressure gradient, will only be 5
to 10 knots. Through the day on Thursday, the winds will shift out
of the northeast as high pressure builds into the region. The
pressure gradient will then tighten as Tropical Storm Helene moves
northward from the Gulf Coast during the day on Friday. Winds will
be east-northeasterly and increase to 15 to 25 knots for most of the
central and western basins of Lake Erie and therefore, a strong
chance for a Small Craft Advisory to be needed for Friday into
Saturday.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 8 AM EDT Wednesday for LEZ148-149.

&&

$$

SYNOPSIS...Iverson
NEAR TERM...Iverson
SHORT TERM...Kennedy
LONG TERM...Kennedy
AVIATION...26
MARINE...Kennedy