-- Discussion containing changed information from previous version are highlighted. --
629
FXUS61 KCLE 041107
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
707 AM EDT Sat May 4 2024

.SYNOPSIS...
An active pattern continues as a warm front lifts back north into
the area today. Low pressure will move west to east through the
Central Great Lakes late tonight into Sunday pulling a weak cold
front east across the area. This frontal boundary will stall across
southern Ohio on Monday as high pressure builds over the Great Lakes
Region.

&&

.NEAR TERM /THROUGH SUNDAY/...
-- Changed Discussion --
The forecast remains on track this morning with a few light
showers around. Expect coverage to be limited through the
morning with expanding coverage of showers and a few
thunderstorms this afternoon.

Previous discussion...A moist airmass remains in place across
the region with PW values of around 1.30 inches. The local area
resides between an upper level trough approaching the Midwest
and a ridge anchored along the East Coast. At the surface, winds
veer around to the southeast lifting a warm front back north
into the area. This will be the driving feature for scattered
showers and a few thunderstorms to develop and move north
through the afternoon. Instability will be a little higher
towards the I-75 corridor with 500-1000 J/kg of surface based
CAPE. Shortwave energy will move out of the Tennessee Valley
today across Northeast Ohio and Northwest Pennsylvania. This
will help focus showers by this evening across eastern portions
of the forecast areas. The flow through the column remains weak
so any thunderstorms that develop will be slow moving. Despite
cloud cover and expanding showers, temperatures are forecast to
reach the 70s. Raised highs at Erie Pennsylvania a few degrees
as southeasterly downsloping winds become breezy this afternoon
and evening.

The more convectively driven showers in the west should wane this
evening while rain continues across the east fueled by the
shortwave energy. Mild and humid conditions will continue tonight.

Upper level trough over the Midwest lifts northeast towards James
Bay through Sunday morning. The trailing cold front moves west to
east across the forecast area on Sunday. Modest instability of
500-1000 J/kg of surface based CAPE is forecast to develop in
the warm sector ahead of the front. In addition we will have a
little better forcing provided by the front and shortwave energy
passing north of Lake Erie. Coverage of showers and
thunderstorms will develop along a line from near Geauga County
west to the Central Highlands. Temperatures will be in the 70s
with dewpoints in the lower 60s. It looks like a few
thunderstorms may develop west of I-71 but coverage should
increase as storms reach Northeast Ohio. Bulk shear values are
on the order of 25-30 knots. The should provide a little better
organization so the Storm Predication Center has placed eastern
portions of the forecast area into a Marginal Risk for severe
weather on Sunday afternoon and evening which seems reasonable.
-- End Changed Discussion --

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
Sunday night into Monday should be the best chance of the short term
period to have no shower/storm chances for the CWA and primarily go
with a dry forecast prior to 18Z Monday. This begins in a post
frontal environment with high pressure building over the Great Lakes
and pushing the cold front further to south away from the southern
zones. Upper level trough will track into the region from the
southwest, bringing the POPs northward then back into the southern
zones later Monday into Monday evening before exiting, and the
surface high pressure regaining control of the area. Frontal
boundary that stalled south of the CWA will push back northeastward
Tuesday in response to an intermountain west upper low driving a mid
latitude system eastward into the Mississippi Valley. Higher POPs
return late Tuesday as a result. Not much instability to work with
until Tuesday when SBCAPE returns in the warm sector and low/mid
levels flows increase. Monday will be one of the cooler days in the
forecast, but rebounding, again, in the warm sector Tuesday back
into the 70s to near 80F for the area.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
Cold front Tuesday night followed by weak surface high pressure into
Wednesday, but operational models then develop another surface low
moving in from the southwest as the progressive nature of this
Spring pattern continues. As this surface low passes through the CWA
Thursday, another cold front pushes through in its wake Thursday
night. Along with POPs making yet another comeback in this time
frame, a cooler airmass will follow for the end of the long term
behind the cold front. 70s give way to 60s for Friday and Saturday
in this cooler regime.

&&

.AVIATION /12Z Saturday THROUGH Wednesday/...
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A few pockets of light showers are ongoing at the start of the
period. Coverage will be limited this morning then will increase
with diurnal heating, especially after 20Z. Scattered showers
with a few thunderstorms will originate across Central Ohio and
spread north through the afternoon. Included tempos for showers
with mainly MVFR conditions but may need to add thunder if we
get sufficient daytime heating and confidence is high enough.
Otherwise ceilings are primarily VFR but will lower to MVFR as
the warm front lifts back north this morning. By tonight,
coverage will be focused more towards Northeast Ohio and
Northwest Pennsylvania. Otherwise ceilings will tend to be MVFR
for much of the day with reduced visibilities in showers and
IFR possible in thunderstorms. Ceilings are expected to lower on
Saturday night as a slow moving trough approaches from the
west. Several sites are expected to drop to IFR.

Winds will tend to be 10 knots or less through the period. Light
and variable winds through 14Z will become south to
southeasterly for most inland terminals. Lakeshore areas will
hold onto an east or northeast wind for longer, but also
eventually expected to shift around to the south/southeast. Erie
is the one site that may see gusts to around 20-25 knots
tomorrow afternoon/evening.

Outlook...Non-VFR likely with periodic showers and thunderstorms
on Tuesday and Wednesday.
-- End Changed Discussion --

&&

.MARINE...
Easterly winds today become offshore tonight, but the quick changing
surface weather systems moving through the region will be
characteristic of varying wind directions through the forecast
period. Winds largely less than 15kts as well during this time, and
expect wave heights in the nearshore and open waters to remain below
2ft except for Monday. Waves could briefly be over 2ft in northerly
winds behind a cold front at that time in the central and western
basin, and again towards the end of next week.

&&

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

&&

$$

SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...26
LONG TERM...26
AVIATION...KEC
MARINE...26