460
FXUS61 KCLE 011905
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
305 PM EDT Wed May 1 2024

.SYNOPSIS...
A weak cold front will move east through the area tonight and
stall across the Lower Ohio Valley. This front will lift back
north as a warm front on Thursday, followed by a cold front on
Friday into Saturday. Another weak cold front may cross the area
on Sunday.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
A scattered cu-field has developed ahead of a weakening cold
front across portions of eastern MI and Northwest OH this
afternoon, although NUCAPS sounding indicate an abundance of
mid-level dry air so not really anticipating any precipitation
associated with the front apart from perhaps a brief isolated
shower or two this afternoon/evening.

Otherwise, attention then turns towards Thursday as this weak
cold front will lift back north as a warm front. There may be
enhanced convergence with the interaction of the lifting warm
front and developing lake breeze Thursday afternoon and evening,
particularly across north-central and Northwest Ohio. Started
with a slight chance of thunderstorms at this point for Thursday
afternoon/evening, but think that further adjustments may be
necessary if trends continue.

Above-average temperatures in the upper 70s to lower 80s will
persist through the near term period.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Friday will be the start of an unsettled weather pattern that will
carry on into next week. A mid/upper shortwave trough over the
northern Plains in the morning will deamplify and lift into the
vicinity of James Bay by Saturday, with a weakening surface low
taking a similar track as the closed and occluding system tries to
become vertically stacked. This will result in a weakening cold
front slowly pivoting into the area late Friday, with the front
further slowing as it attempts to cross the region Friday night into
Saturday, likely stalling and washing out in far eastern Ohio,
western PA, and the Appalachians by Saturday night. Deepening
warm/moist advection and the approaching front will start to bring
scattered showers and thunderstorms into the area Friday as boundary
layer heating of increasingly moist low-levels results in MLCAPE of
1000-1500 J/Kg, with slightly more SBCAPE. However, there is not
much of a trigger for convection until the front moves in, and poor
mid-level lapse rates of only around 5 to 5.5 C/Km will prevent any
higher instability. This will limit the coverage of the
showers/storms during the day Friday, with most not arriving until
Friday night, and it will also greatly limit any severe weather
potential, with generally garden variety thunderstorms expected.
Once the front starts to slowly cross the region Friday night, the
showers/storms will become more widespread. Still not expecting
anything severe since the instability will be waning overnight and
the main jet dynamics lift well to the NW, but lift from the
pivoting frontal boundary will allow it to rain in most areas Friday
night.

As mentioned above, the front will start to stall and wash out over
eastern/southeastern areas Saturday and Saturday night. This is due
to mid/upper ridging holding strong over the eastern CONUS and the
dynamics becoming displaced well to the NW. This will keep fairly
widespread showers/storms over the area through Saturday, especially
east of I-77. Cannot rule out locally gusty winds with any
thunderstorms, but the main impact will be locally heavy rainfall
from slow moving and training storms Friday night and Saturday. The
stalling boundary, weak shear profiles, and deep layer flow aligned
parallel to the boundary all support slow moving, training
convection, and with seasonably high PWATs averaging 1.50 inches,
this could lead to localized flooding. Eastern Ohio and western PA
have had drier weather the past 2 weeks, so they can take some rain,
and that is where the risk for training will be, so will leave any
flood mention out of the HWO for now. Coverage of precip will
gradually decrease Saturday night as the front washes out.

Highs Friday will reach the low/mid 80s with sticky dew points in
the low 60s. Highs Saturday will cool into the upper 60s/mid 70s.
Lows Friday night will drop into the upper 50s/low 60s, with ranges
of about 55-60 Saturday night.


&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A few showers and thunderstorms will continue Sunday as moisture
tied to the old washing out front remains in the area, but coverage
should be far less than Saturday leading to a nice overall day.
Attention then turns to what could potentially be a very wet and
stormy pattern next week as a deep mid/upper trough develops over
the Rockies and slowly moves through the Plains through midweek,
forcing height rises and a broad SW flow to develop from the Lower
Mississippi Valley through the Ohio Valley and Great Lakes. Several
lead shortwaves ejecting out of the main trough will likely traverse
an active baroclinic zone oriented SW to NE, and this combined with
broad warm/moist advection will support waves of convection.
Guidance is in poor agreement on where the boundary will set up and
the timing of shortwave energy, as is expected this many days out,
so stayed with NBM PoPs Monday through Wednesday which has a gradual
increase to likely/categorical by Tuesday and Wednesday. It will
definitely not rain all the time, but the windows of drier weather
will be pinpointed as we get closer. The location of the boundary
will also determine the extent of any severe weather or flooding
threats. What is certain is that it will turn very warm and humid
again. Highs in the low/mid 70s Sunday and Monday with reach the
upper 70s/low 80s by Tuesday and Wednesday.


&&

.AVIATION /18Z Wednesday THROUGH Monday/...
VFR across the TAF sites early this afternoon with VFR to
persist through the TAF period. Can`t rule out a brief isolated
shower/storm somewhere across the area later this afternoon
ahead of a weak cold front, but chances appear too limited to
include in TAFs so have gone ahead and removed vcsh mention from
CLE.

Winds are generally out of the southwest ahead of the
approaching cold front, 10 to 15 knots with gusts of 20 to 25
knots. Winds will shift towards the west immediately behind the
cold front later this afternoon and evening, decreasing to 10
knots or less after sunset. Winds may become light and variable
overnight before favoring a slight east to northeast direction
by Thursday morning. A lake breeze may develop at CLE/ERI late
Thursday morning/early afternoon.

Outlook...Non-VFR likely in showers and thunderstorms Friday
afternoon through Saturday. Non-VFR may persist in additional
isolated to scattered showers and thunderstorms on Sunday and
Monday.

&&

.MARINE...
Quiet marine weather will continue through the weekend outside
of locally higher winds and waves from thunderstorms since
pressure gradients will remain weak. Winds will turn light and
variable tonight followed by ENE at 5-15 knots Thursday as high
pressure builds into the eastern Great Lakes. Winds will then
oscillate between ENE and ESE at 5-15 knots Thursday night
through Friday night until turning more SE at 10-15 knots late
Saturday and finally S to SW Sunday while decreasing to 5-10
knots. ENE winds of 10-15 knots will then redevelop by Monday.


&&

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

&&

$$

SYNOPSIS...Kahn
NEAR TERM...Kahn
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...Kahn
MARINE...Garuckas