173
FXUS61 KCLE 131313
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
913 AM EDT Mon May 13 2024

.SYNOPSIS...
High pressure will linger over the area before a cold front
moves east late tonight into early Tuesday. This front will slow
as it moves southeast of the area as another low pressure system
tracks east across the Ohio River Valley Tuesday into
Wednesday. High pressure returns on Thursday.

&&

.NEAR TERM /THROUGH TUESDAY/...
9:30 AM Update...

Forecast remains on track today with no changes. Showers over NW
PA have exited the area setting up a mainly dry and very warm
day.

630 AM Update...
Weak reflectivities over NW PA have resulted in scattered light
showers this morning, but with a dry low level with dew points
in the low 40s the bulk of the precipitation is evaporating
before reaching the surface. These showers will push east of the
area this morning allowing for the whole area to remain dry
today. No changes were needed with this forecast update.

Previous Discussion...
Low pressure centered near James Bay is currently moving a warm
front east just north of the area. The forcing along the front
coupled with a weak LLJ has allowed showers to persist across
Lake Erie, although they are weakening as they move east. Some
of these scattered showers may clip far NE OH and NW PA over the
next couple hours before the warm front moves east and the
entire CWA is placed within the warm sector of the low. The
biggest change with this forecast update is the timing of the
associated cold front moving east. Models have slowed the onset
of precipitation which will allow for today and the first part
of tonight to remain dry. In addition, due to the delay in the
frontal passage, clouds will take longer to build east which
will allow diurnal heating and WAA to result in highs today
reaching into the upper 70s to low 80s.

As the cold front slowly meanders towards the CWA tonight, an
upper level trough will continue to support the development of a
surface low near southern Missouri and Illinois. Once this
trough becomes more progressive on Tuesday, the associated low
will begin to track east across the Ohio River Valley and also
allow the aforementioned cold front to finally move east.
Overnight lows will remain mild, only falling into the upper 50s
to low 60s. This system is quite tricky when it comes to
precipitation timing as much of the synoptic support for showers
does not move into the area until near the end of the period,
but with moisture increasing across the area there is a
potential for diurnal showers/thunderstorms to develop on
Tuesday ahead of that forcing. Due to this, opted to maintain
chance PoPs through Tuesday morning and then gradually increased
PoPs to likely Tuesday afternoon with chance thunder. Will need
to continue to monitor this system especially with the dramatic
slow down in recent model runs. Tuesday highs will be cooler
only climbing into the mid to upper 60s.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
Low pressure tracks across southern OH Tuesday night into with much
of its energy being transfered to off the Middle Atlantic Coast. The
best chances of showers should be Tuesday evening then we watch them
move decease in coverage and decrease from west to east through
Wednesday afternoon. At this point rainfall amounts should be
between a tenth to a third of an inch. This all assuming that most
of the thunderstorms remain south of the CWA. High pressure briefly
reaches over the region Thursday but the next storm system may impact
the region by late Thursday night as a warm front lifts
northeastward across the CWA. Temperatures through the short term
period are expected to be near to slightly above seasonal
averages.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
Models are struggling with the timing of storm systems moving
through a progressive upper level flow. This makes the long term
period difficult to create a forecast that will be consistent.
Current models bring a storm system across the region on Friday with
showers and thunderstorms possible. The uncertainty is how quick
these clear out in its wake Saturday into Sunday. These days could
end up being dry but will carry low POP`s in the forecast right now
with the uncertatiny. Another storm system may arrive for Monday
afternoon with another round of showers and thunderstorms possible.
The one thing that looks certain is that temperatures will be above
seasonal averages through the long term.

&&

.AVIATION /12Z Monday THROUGH Friday/...
VFR conditions will persist for much of this period as the area
is positioned in the warm sector of a low centered near James
Bay. Tonight, a cold front will begin to push east across the
area and will be accompanied by showers. The timing and extent
of showers across the area remains a bit uncertain due to the
interaction expected between the boundary and another low
pressure moving east into the Ohio River Valley. With the
highest confidence in shower development closer to the center of
the low over the Midwest, opted to introduce showers overnight
for KFDY, KMFD, KCAK, and KCLE at the very end of this period
while maintaining VCSH for the remaining terminals. Not
expecting the initial onset of precipitation to result in
reduction of visibilities, but models do suggest lower MVFR
ceilings building in across the southern tier of counties. As a
result, opted to diminish conditions to MVFR for KFDY and KMFD.

In terms of winds, southwest winds of 5-10 knots will increase
this afternoon to 10-12 knots, locally up to 15 knots for
western terminals. Gusts up to 20 knots are possible along and
west of I71 this afternoon, but will calm as winds weaken to
5-10 knots and shift to become southerly through the end of the
period.

Outlook...Non-VFR possible in showers and thunderstorms late
tonight through Wednesday.

&&

.MARINE...
Southerly offshore flow is expected through Tuesday morning ahead of
a cold front that crosses the lake by Tuesday afternoon. North to
northeast winds are then expected into Wednesday.The strongest
winds likely occur Tuesday night into Wednesday with 10 to 20 knots
anticipated. Waves likely build to 2 to 4 feet near and west of
Geneva on the lake. Winds becoming lighter Wednesday night into
Thursday with light and variable conditions. Winds increase from the
south once again Thursday night into Friday.

&&

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

&&

$$

SYNOPSIS...Campbell
NEAR TERM...Campbell/Garuckas
SHORT TERM...MM
LONG TERM...MM
AVIATION...Campbell
MARINE...MM