737
FXUS61 KCLE 020603
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
203 AM EDT Sun Jun 2 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 TONIGHT/...
900 pm update...
There were no impactful changes made to the ongoing near term
forecast at this time.

Previous discussion...
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 /06Z Sunday THROUGH Thursday/...
Rain showers ahead of a weak area of low pressure are spreading
across the area from west to east early this morning. VFR ahead
of the rain. Brief MVFR vsby is possible with more moderate rain
showers through this morning though expect VFR vsby to be most
common overall. This more widespread batch of light to briefly
moderate showers will exit east by late morning or early
afternoon. Isolated pop up showers are expected this afternoon,
especially across Northwest and North Central Ohio. The risk
for thunder is very low overall with just a slight chance for
an isolated storm from CLE and CAK points west this afternoon.

More widespread restrictions will come from ceilings. Widespread
IFR to low MVFR ceilings are in place upstream and have already
reached TOL. Expect lower ceilings to gradually spread east
through this morning, though a drier low-level air mass in
place ahead of the rain to the east and a downsloping south-
southeast flow makes IFR potential more uncertain the farther
east one goes. Maintained a period of IFR for at least a few
hours this morning at TOL, FDY and MFD. Can`t rule it out at
CAK, YNG, and perhaps CLE, though confidence is lower and
ultimately kept them MVFR with this cycle. Ceilings should rise
slightly this afternoon with a bit of heating, though we may
hang on to MVFR at most sites. While we try to scatter out the
stratus this evening fog/mist may quickly replace it tonight.

Winds will be out of the south at 6 to 14 knots through Sunday,
becoming light and variable Sunday night.

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/Griffin
SHORT TERM...Maines
LONG TERM...Maines
AVIATION...Sullivan
MARINE...Maines