974
FXUS61 KCLE 011958
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
358 PM EDT Sat Jun 1 2024

.SYNOPSIS...
Weak low pressure will move northeast across the Central Great
Lakes region late tonight and Sunday. High pressure briefly
returns Sunday night and Monday before a warm front lifts north
Monday night. Low pressure will cross the Upper Great Lakes on
Wednesday with a cold front moving east across the area
Wednesday night.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
The dry airmass that was in place across the region today will be
replaced by increasing moisture and showers late tonight into
Sunday. Moisture arrives ahead of a weak trough crossing the region
overnight through Sunday. Dewpoints are starting off in the mid 40s
to lower 50s this afternoon. A nearly vertically stacked trough is
located over eastern Illinois this afternoon with a swath of light
showers extending from Lake Michigan southeast across Indiana.
Although some virga is likely at first, leading showers are likely
to reach the I-75 corridor between 9-11 PM with a slow eastward
progression overnight. A 40 knot low level jet will be focused
across NW Ohio which will enhance coverage in the west tonight. The
eastward progression is perhaps a touch slower still, reaching
Cleveland/Akron between 3-7 AM. Lows tonight will be 5-10 degrees
warmer than last night given the increasing coverage of clouds and
showers. Sunday will feel markedly different as dewpoints increase
to near 60 degrees with cloudy skies and showers to start the day.
The steadier rain driven by isentropic ascent will decrease in
coverage by early afternoon. Low levels will remain quite moist and
some weak instability does try to develop across mainly NW and North
Central Ohio as the surface low slowly pivots eastward. There is a
window during the afternoon where scattered showers and possibly a
few thunderstorms could re-develop before mid-levels start to warm
and chances decreases. Precipitation amounts will tend to range
from 0.10-0.50 inch through Sunday evening. Highs on Sunday
will occur late in the day and range from near 70 in the east to
upper 70s in the west.

Boundary layer moisture is forecast to remain high into Sunday
night. As breaks start to develop in the clouds, some fog may
develop, especially in NE Ohio where weak convergence will be
located.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A ridge will continue to build east Monday with return flow
developing throughout the day as the ridge axis pushes east of the
local area. Both temperatures and humidity will increase in response
to the southerly flow and expect highs in the upper 70s to lower 80s
with dew points in the lower 60s. Monday night`s lows will be in the
low to mid 60s.

An upper level shortwave will approach from the west Monday evening
into Tuesday, but generally expect the best forcing to remain to the
west of the area through at least Tuesday afternoon or evening. The
best of shower and thunderstorm activity will be located where there
is a bit more lift, however there is enough instability to warrant
chances of showers and thunderstorms primarily west of I-71 Tuesday
afternoon and early evening. It`s quite possible that most locations
remain dry on Tuesday due to lack of forcing. By Tuesday night, the
shortwave energy will begin to move east into the area as a cold
front advances east across the Mississippi Valley and anticipate an
uptick in rain chances towards the end of the short term period.
Instability will be lower due to the loss of diurnal heating, so the
thunder chances will be lower (but not zero) Tuesday night.
Persistent southerly flow/warm air advection will allow temps to
increase both Tuesday and Tuesday night; highs will be in the mid
80s with lows in the mid to upper 60s. Dew points will climb into
the low to mid 60s which will make it feel quite muggy but apparent
temperatures should stay close to the actual temperature due to
breezy southerly winds.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Shower and thunderstorm chances increase further on Wednesday as the
aforementioned cold front and a negatively tilted trough aloft
continue to approach from the west. Instability will depend on the
location of a warm front which should be to the north of Lake Erie
Wednesday; the farther north the warm front is, the farther north
the more widespread instability reaches. If the warm front is
farther south than expected, the highest instability and best chance
of convection may be suppressed to southern zones or to the south of
the CWA. As stated in the previous discussion, there`s still quite a
bit to iron out in regards to the upper trough and the timing of the
best forcing/shear. If shear/forcing manage to align with the best
instability, there could be potential for organized (and
perhaps stronger) convection Wednesday.

A broad upper low will settle somewhere over the Great Lakes
Thursday through the start of the weekend. The cyclonic flow and
cold air advection will most likely result in below normal
temperatures and scattered/periodic showers with a chance of
afternoon thunderstorms.

&&

.AVIATION /18Z Saturday THROUGH Thursday/...
VFR conditions will continue through at least 00Z and later for
terminals in NE Ohio and NW Pennsylvania. Clouds will thicken
and lower from west to east this evening as a trough approaches.
Rain is likely to begin at TOL/FDY around 02-03Z while not
beginning at CLE until 07-09Z. After rain begins ceilings will
tend to lower to MVFR. There is some discrepancy among guidance
options about IFR conditions late tonight into Sunday morning.
Did bring a window of IFR into TOL but very dry low levels
preceding the rain today and arrival time later in the morning
made confidence somewhat lower at terminals farther east.
Included a tempo for IFR conditions and will re-evaluate with
the next forecast cycle for ceilings on Sunday. The rain will
tend to be light in general although perhaps more moderate at
TOL. MVFR visibilities are possible in rain, especially in the
morning hours on Sunday. The steadier rain will tend to end at
TOL/FDY by 13Z and CLE towards 16Z although a few showers may
linger behind. At this time not expecting thunderstorms.

South to southeast winds of 7-12 knots expected this afternoon
with a few gusts to 20 knots possible. The exception to this is
at ERI where a lake breeze has already developed and NE winds
are forecast to continue this afternoon. Winds will remain out
of the south tonight and eventually veer to southwest or west
as low pressure passes overhead on Sunday.

Outlook...Thunderstorms and associated non-VFR possible at
times Tuesday through Thursday.

&&

.MARINE...
Southeast flow will develop over the lake this evening with winds
increasing to 10 to 15 knots for a few hours tonight. There will
likely be a brief period of south winds to 15 to 20 knots in the
western basin before daybreak Sunday, but expect southwesterly winds
to diminish below 15 knots by mid to late morning. Otherwise, expect
quiet marine conditions through at least Tuesday morning. Warm air
advection will allow southerly winds to gradually increase to around
15 knots Tuesday into Wednesday which could result in some chop. The
next chance for a Small Craft Advisory/Beach Hazards Statement will
occur late Wednesday into Thursday as southwest winds increase to
about 20 knots as a cold front crosses the region.

&&

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

&&

$$

SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...Maines
LONG TERM...Maines
AVIATION...KEC
MARINE...Maines