362
FXUS61 KCLE 040604
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
204 AM EDT Thu Jul 4 2024

.SYNOPSIS...
A cold front will cross the lake tonight and stall near the Ohio
River on Thursday. Low pressure will then develop west of the
Great Lakes on Friday and will lift the stalled front north as a
warm front. The low will extend a weak cold front across the lake
on Saturday afternoon, followed by high pressure by Sunday into
Monday.

&&

.NEAR TERM /THROUGH TODAY/...
1:30 AM Update...

Dropped PoPs overnight as the weak front pushes south,
otherwise, the forecast remains on track.

900 pm update...
We decreased POPs again between 15 and 30 percent for the rest
of the evening.

710 pm update...
We have decreased the hourly POPs from now through the rest of
the overnight. We knocked them down from likely to chance POPs
or 20 to 40 percent for the rest of the evening. We are
expecting mostly a quiet evening with a few additional showers
and isolated storms that could redevelop but most locations will
remain dry.

Previous discussion...
Main concern of the near term period will be over the next
several hours as a line of pre-frontal showers and thunderstorms
roughly along and east of the I-71 corridor continues to move
east. For the most part, this line remains sub-severe with the
exception of a more-dominant cell moving east across portions of
Summit/Portage counties. Damaging wind gusts will be the
primary threat with this cell. Otherwise, the most recent WOFS
runs suggest that strong winds will remain possible along and
east of the I-77 corridor through the rest of the afternoon
associated with this line, albeit remaining sub- severe,
generally 50 mph or less.

Given the unfavorable mid-levels and widespread cloud debris
behind this initial line of storms, not anticipating much
redevelopment along and ahead of the actual cold front,
currently located on a SW to NW axis just east of Chicago. This
should result in a relative lull in precipitation for much of
the area this evening and overnight as the weak cold front sags
east to southeast through the area and stalls just south of the
US-30 corridor.

For Thursday (July 4), we`ll be monitoring another decaying
convective complex across portions of IL/IN for any
redevelopment of showers and storms across our area in the
afternoon and evening hours. There remains a disparity between
hires models on precipitation placement for the 4th, and will be
dependent on where the cold front eventually settles/stalls
this evening and overnight. Confidence remains low on the cold
front placement on Thursday, though it appears precipitation
chances are more likely along and south of the US-30 corridor.
Temperatures on the 4th are expected to be seasonable, in the
mid-80s.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
Low pressure system will be occluding as it tracks into the Great
Lakes Friday bringing the highest chances of showers and storms
through the day 2-7 forecast. Dewpoints into the lower 70s and
temperatures into the mid 80s will increase the SBCAPE to around
1500J/kg, combining with an increase in the low level winds ahead of
the cold front for a thunderstorm threat for the CWA. Also noting
significant drying above around 600mb with inverted V soundings
introduces a wind threat with the storms. Will be watching to see
how this unfolds in the upcoming forecasts and whether it all comes
together, or conversely, factors that could hinder the threat for
the day. Behind the cold front, cooler and drier airmass filters in,
knocking the dewpoints and temperatures down 5-10 degrees for
Saturday. Not much in the way of POPs for Saturday across the CWA,
but may need to add some in for the cold pool convective chances
with some lingering CAPE sandwiched above the boundary layer and
below around 750mb. Question will be if there is enough layer
humidity to produce precipitation.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
High pressure will be decaying as it moves through the Ohio Valley
region, but will keep the CWA dry through Monday. Flow aloft turns
southwesterly ahead of an upper level trough and an accompanying
surface low pressure system/cold front that will move in Tuesday.
This will become the next chances for showers and storms for the
region, and with winds turning southerly, temperatures will be
increasing through the long term forecast period.

&&

.AVIATION /06Z Thursday THROUGH Monday/...
A diffuse frontal boundary will sink to near the Ohio River
this morning allowing for mainly dry conditions and VFR skies
today. Patchy fog and mist is possible early this morning at
KMFD, KCAK, and KYNG, but went less widespread with this TAF
issuance since rainfall was pretty sporadic yesterday. The front
will begin to lift back northward as a warm front tonight, and
this will spread showers and thunderstorms back into the region
from SW to NE. Feel that the activity will still be scattered,
so kept the mentions to VCSH and VCTS, but brief MVFR is
possible in any heavier downpours.

Light S to SW winds early this morning will turn more W to NW
later this morning and this afternoon and increase to 5-10 knots
before becoming E to SE tonight as the front lifts northward.



Outlook...Non-VFR possible in showers and thunderstorms on
Friday.

&&

.MARINE...
Southwest winds tonight become light and variable Thursday, then
southeasterly Thursday night with wave heights less than a foot
after tonight. Winds southerly Friday 10-15kts ahead of a cold
front capable of producing thunderstorms moving through west to
east, becoming southwesterly 15-20kts Friday night. Wave heights
increase to 1-3ft in the nearshore waters east of Cleveland, and 1-
3ft away from the immediate shoreline west through the islands to
Toledo. by Saturday morning. Winds ease out of the northwest Sunday
with waves 1-2ft.

&&

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

&&

$$

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