270
FXUS61 KCLE 220621
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
221 AM EDT Wed May 22 2024

.SYNOPSIS...
A strong low pressure system moving into northern Ontario
will push a cold front into the region Wednesday morning and
moving through later in the day Wednesday, stalling out along
the Ohio River Valley Wednesday night and Thursday. High
pressure Thursday. Another cold front stalls over northern Ohio
Thursday night into Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
930 PM Update...
Made slight adjustments to temperatures as current temperatures
are a few degrees warmer than previously forecast. Ultimately
raised the overnight a degree or two across the area, but the
remainder of the forecast is unchanged.

630 PM Update...
The lake breeze has begun to weaken and any shower/thunderstorm
development along it has diminished. This should leave the area
dry until late tonight when the cold front approaches the area
from the west bringing with it the potential of some
showers/storms. There were minor adjustments to the wind
forecast to reflect the decaying lake breeze, but aside from
that there were no other changes needed.

Previous Discussion...
Plenty of surface based instability with heating today with low
level lapse rates over 7C/km, but there is clear evidence of mid
level drying occurring as seen on the mid level water vapor
satellite imagery. While a couple of isolated showers have formed
along the lakeshore east of Cleveland and near Erie, PA, the
thinking is that this drying will largely inhibit any large scale
convection today. However, a few more isolated cells during the
remainder of peaking heating cannot be completely ruled out along
the lake breeze boundary.

Meanwhile, a low pressure system moving into the Mississippi Valley
will continue an eastward track through the overnight hours.
Expecting a linear complex of storms to approach the western CWA
after 09Z tonight, but the thought is that moving into northwest
Ohio, these storms will likely be in a decaying phase. Cold front
enters the CWA after 12Z. Depending on the morning convective debris
moving eastward and how fast is dissolves out/moves out expecting
quick destabilization in the late morning hours with convective
initiation again after 15Z. Multiple forcing mechanisms possible here
with the cold front, old outflow boundaries, and possible
differential heating boundaries despite synoptic scale winds near
the lakeshore. Track of the low pressure system will turn northward
into the Thunder Bay region of northern Ontario and will be
occluding. Will get a noticeable decrease in the low level jet
strength Wednesday as a result with a lowering of the 0-6km shear.
Still have a wind threat with dry air above around 600mb that could
enhance gusts where the dynamics in the column may not be as strong.
The best threat for severe is roughly east of the I-71 corridor, and
still carry a slight risk from SPC for Wednesday. Some directional
shear could produce some rotating storms as well. Cold front will
ultimately be slow to exit the southeast zones into Wednesday night
with the front well out ahead of the aforementioned occluding
low.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The overall 500 mb mid level steering flow aloft will be west-
southwesterly towards the end of the week. A slow moving and weak
frontal boundary will be near central Ohio on Thursday. Afternoon
heating will allow for scattered showers and thunderstorms to once
again develop along and near this weak frontal boundary. The higher
POPs will be closer to central Ohio and lesser values near the
lakeshore areas. Thursday`s high temperatures will be a little
cooler than previous days but still in the middle 70s to lower 80s.

A shortwave trough will move across the Upper Midwest into the
western Great Lakes region on Friday. This shortwave trough will
help the stalled frontal boundary over central or southern Ohio lift
back as a warm front on Friday. Scattered showers and thunderstorms
will develop again with the warm front lifting through Friday
afternoon and evening. High temps will be warmer in the lower to
middle 80s on Friday.

A weak area of low pressure will track eastward across the Upper
Great Lakes region late Friday night into Saturday. A trailing cold
front will advance across the Great Lakes and Ohio Valley region
late Friday night. Showers and thunderstorms will be likely ahead
and along this frontal boundary late Friday night. It appears that
this system will be coming through during the weakest thermodynamics
and organized convection is not anticipated at this time.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A cold front will be pushing through during the first half of the
day on Saturday. Showers and isolated thunderstorms will be possible
early in the day before drier air moves in from the west. High
pressure will build in over the area late Saturday into Saturday
night. Temperatures will be cooler this weekend with highs in the
70s and overnight lows in the 50s. Another shortwave trough will
track across the Ohio Valley late Sunday into early Monday with
another round of showers and storms. Temperatures will remain
slightly above average through the weekend.

&&

.AVIATION /06Z Wednesday THROUGH Sunday/...
VFR with clear conditions will start off the TAF period this
morning. Winds early this morning will slowly increase ahead of
a system that will allow for shower and storm chances today.
Toward daybreak, some showers and storms will approach the KTOL
and KFDY corridor but will be on a weakening trend, if they even
arrive. Have a VCTS mention for now, but this could be overdone
still and have all other conditions as VFR. The boundary of
these storms that will enter will progress east today and likely
be a trigger to new storm development this afternoon. The main
area would be KCLE to KMFD and east, although confidence in a TS
at a terminal is limited to just KCAK, KYNG, and KERI, and have
a TEMPO window when the best chance for a TS at those terminals
would be this afternoon. Additional TS is unlikely after a brief
window this afternoon and clouds will be present across the
region until a final cold frontal passage. Behind the front,
skies will trend to clear and winds will favor a generally
westerly flow.

Outlook...Scattered showers and storms on Friday and Saturday
could also bring brief non-VFR conditions.

&&

.MARINE...
A lake breeze has developed again near the lakeshore this afternoon.
This weak lake breeze will fizzle out closer to sunset this evening.
Winds should shift from the southeast under 10 knots this evening. A
southwest flow of 10 to 15 knots will develop late tonight in
response to an approaching cold front by Wednesday morning. Winds
will diminish to 5 to 10 knots behind the front late Wednesday and
briefly become westerly Wednesday night. Winds will shift from the
south or southwest around 10 knots Thursday through early Friday.
East to southeast winds 10 to 15 knots are expected Friday night
through Saturday. No marine headlines for the lake are anticipated
at this time through the weekend.

&&

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

&&

$$

SYNOPSIS...26
NEAR TERM...Campbell/26
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Sefcovic
MARINE...Griffin