-- Discussion containing changed information from previous version are highlighted. --
311
FXUS61 KCLE 261820
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
220 PM EDT Sun May 26 2024

.SYNOPSIS...
Low pressure will track northeast from the Mississippi Valley
toward the central Great Lakes today and tonight, lifting a warm
front into the area today followed by a cold front on Monday. A
few disturbances will cross the area Tuesday into Wednesday
before high pressure returns Thursday.

&&

.NEAR TERM /THROUGH MONDAY/...
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A line of showers and thunderstorms extends from east of Chicago
along the I-65 corridor through Indiana and into southwest Ohio.
Storms are beginning to enter a more favorable environment for
stronger convection with temperatures across Ohio reaching the
lower 80s, prompting SBCAPE values above 3000 J/kg and DCAPE
values of 1000 J/kg or higher. Therefore, a Severe Thunderstorm
Watch has been issued for a portion of the forecast area through
8 PM, as the leading line of thunderstorms will enter Hancock to
Knox County at around 4 PM and move northeast toward Lake Erie.
The most concerning portion of the line will be the leading edge
entering Southwest Ohio with bowing segments allowing for some
stronger winds to make it to the surface. There is some
potential for a QLCS tornado with this line but the 0-3 km wind
shear values are presently decreasing through northern Ohio so
the tornado window could be brief as the line enters the
forecast area. However, the main threat will be the damaging
wind threat.

All indications that this line will continue northeast through
the forecast area and exit the far NW PA counties by Midnight.
So far, there has been rather robust clearing behind the main
line with a dominant cold pool and there should be a distinct
multi-hour break in rain and thunderstorms for the area
tonight. However, another round of more scattered convection
will generate and move into the region, once there is some
recovery. There will be better support further south and
southwest, where there will be a larger recovery window, and
storm coverage will be better outside of the forecast area.
However, there will be some synoptic lifting mechanisms with the
low to the northwest, cold front to the west, and the main
upper trough aloft that should allow for some more thunderstorms
to develop into the forecast area. Severe trends with these
storms will be substantially lower than this afternoon/evening.
Showers and storms will be possible through the first half of
Monday until the cold front passes through the forecast area.
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&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Shortwave troughs will continue to move along the parent upper level
trough for much of the short term period, resulting in additional
potential for showers and thunderstorms on Tuesday and Wednesday.
Initially on Monday night, a few lingering showers are possible
across the eastern counties as a surface cold front moves east of
the area, but any dry period will be shortly lived as another
shortwave advects energy across the area Tuesday morning. The best
chance of showers and thunderstorms on Tuesday should be downwind of
a northwest flow across Lake Erie, but with diurnally instability
and enough moisture elsewhere, cannot rule out additional showers
and thunderstorms over the remainder of the area through Tuesday
night. On Wednesday, another weak cold front will move southeast
across the area, marking the transition to a dry period for the end
of the week. By Wednesday night, high pressure and an associated
upper level ridge will finally be pushing east and drying out the
area.

High temperatures on Tuesday will climb into the upper 60s to low
70s for much of the area before cooling behind the departing cold
front to only reach into the 60s on Wednesday. Overnight lows will
also gradually cool from the mid to upper 50s on Monday night to the
mid 40s by Wednesday night.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
A dominant upper level ridge and associated surface high pressure
over the central portion of the US will act as the primary moderator
of weather through the long term period. This will allow for at
least a couple dry days, but will also result in temperatures again
climbing to above normal for this time of year with highs reaching
into the upper 70s to low 80s by Saturday. There is a bit of
difference in the timing of the progression of the ridge, but either
way it looks to remain over the area.

&&

.AVIATION /18Z Sunday THROUGH Friday/...
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Main concern for the TAF period is a line of thunderstorms
stretching from east of Chicago southeast to Cincinnati that is
moving northeast toward the airspace. Thunderstorms have a
history of strong winds with wind gusts to 50 kt possible and
non-VFR conditions, mostly to low MVFR and IFR, in the heaviest
rainfall. The line is moving in a general south-southwest to
north-northeast orientation and will take some time still to
reach the southwest terminals. Have timed in TS chances with a
broader VCTS window and a narrower TEMPO group to highlight the
best period for the strongest wind gusts and lowest prevailing
flight conditions. Behind the main line of storms there could be
some residual convection, however, there has been a fair amount
of clearing behind the line so far. Unfortunately, low pressure
sweeping through the region will allow for another round of
showers and storms to develop later tonight and may impact
terminals to a lesser extent overnight. Confidence in this
second round is a bit lower as coverage will be down a bit from
this main line this afternoon and evening. Ceilings will start
to fill in overnight to a prevailing MVFR and there will be
trends to some IFR for many locations of interior northern Ohio.
There will be a potential for showers and storms ahead of a
final cold front on Monday and this may be limited to NE OH and
NW PA through the end of the TAF period. Winds will start east
to southeast and veer to the south after tonight`s convection
and then to the southwest with the cold frontal passage on
Monday.

Outlook...Non-VFR expected with low ceilings and any residual
showers and thunderstorms through Monday night. Periodic Non-
VFR conditions may persist in scattered showers and
thunderstorms on Tuesday and Wednesday.
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&&

.MARINE...
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A Small Craft Advisory and Beach Hazards Statement have been
issued for western Lake Erie through 8 PM this evening with the
increased easterly flow this afternoon.

Previous Discussion...
Low pressure over the Plains will move northeast towards the region
today, extending a warm front north of Lake Erie this afternoon.
This will result in east winds of 5-10 knots transitioning to south-
southwest winds at 10-15 knots which will persist into Monday. On
Monday, a cold front will move east, again shifting the winds to
gain a more westerly component and increasing to 15-20 knots for the
nearshore waters and up to 25 knots for the open waters. With an
established onshore component, waves will build to 3-5 feet
throughout the day on Monday, additionally creating hazardous
swimming conditions with an increased risk of rip currents. One or
two additional weak cold front will move east across the area on
Tuesday and Wednesday, keeping winds from west-northwest, but
gradually weakening them to 10-15 knots by Wednesday morning. This
period will likely need a Small Craft Advisory, but held off for one
more forecast period to get a better handle on timing.

Late Wednesday into Thursday, high pressure will build across the
region, allowing for winds on Lake Erie to persist on Thursday from
the north-northwest at 10-15 knots before weakening to below 10
knots through the end of the week.
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&&

.CLE WATCHES/WARNINGS/ADVISORIES...
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OH...Beach Hazards Statement until 8 PM EDT this evening for OHZ003-
     007.
PA...None.
NY...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for LEZ142-
     143.
-- End Changed Discussion --

&&

$$

SYNOPSIS...Maines
NEAR TERM...Sefcovic
SHORT TERM...Campbell
LONG TERM...Campbell
AVIATION...Sefcovic
MARINE...Campbell/Iverson