751
FXUS61 KCLE 210015
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
815 PM EDT Thu Jun 20 2024

.SYNOPSIS...
Upper level ridge builds west through the rest of this week. Low
pressure develops over the Upper Midwest Saturday before moving
into the Great Lakes region. This low will drag a cold front
southeast across the region on Sunday.

&&

.NEAR TERM /THROUGH FRIDAY NIGHT/...
8:15 PM Update:
Scattered convection continues across Northwest OH. Stronger
cores have produced sub-severe hail along with localized wind
damage due to microbursts. Storms have been slow-moving with
locally heavy rain as well. We should see activity begin to
weaken over the next 1-2 hours, ending the threat. Made minor
tweaks to POPs to reflect trends.

Previous Discussion:
Pop-up thunderstorms mainly along the I-75 corridor and the
Lake Erie lakeshore will continue for the next few hours under
an unseasonably warm and unstable airmass. Strong to severe
limits are possible with any storm with a primary threat of
damaging wind gusts. Moist atmosphere with above average PWATs
will continue the threat for heavy rainfall and instances of
flooding in any persistent and slow moving storms.

Cold front stalls just south of the lakeshore overnight tonight
before becoming stationary and draped across Lake Erie through
Friday. We`ll remain warm and unstable once again tomorrow so
there remains the potential for scattered showers and
thunderstorms to develop across inland sites tomorrow
afternoon along this boundary. Warm overnight lows tonight and
tomorrow night settle in the upper 60s to lower 70s. Another hot
day tomorrow with highs in the upper 80s to mid 90s and heat
indices approaching 100.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Expect zonal flow to develop aloft Saturday with a warm front to the
north of Lake Erie as low pressure lifting northeast across the
Upper Midwest begins to push a cold front towards the CWA. Similar
to previous days, there could be some scattered showers primarily
across NE OH and NW PA where there will be convergence/forcing due
to a lake breeze boundary during the afternoon. There will still be
a decent amount of moisture/buoyancy, so any thunderstorms that
develop could produce stronger downbursts.

The weather pattern begins to shift Sunday as the aforementioned
cold front approaches from the west and crosses the CWA at some
point during the day. This will provide a chance of more widespread
and organized convection and there may be potential for stronger
storms due to enhanced wind shear ahead of the front. Still looking
like damaging wind gusts as the main threat with perhaps large hail,
but there could be enough helicity in place for a low-end tornado
risk.

Hot weather will continue through the weekend, but should start
seeing signs of a cooling trend by Sunday. Saturday`s highs will be
in the 90s with heat indices as high as the upper 90s to around 100
degrees. As with previous days, any convection will result in cooler
temperatures and lower heat indices. Saturday night`s lows will be
in the 70s; spots west of I-71 in addition to urban areas such as
Cleveland and Erie will likely remain in the upper 70s. Sunday`s
highs will be in the mid to upper 80s with lower 90s more likely in
NW OH. Sunday`s heat indices will be in the upper 80s to lower 90s.
By Sunday night, lows will be in the mid 60s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
High pressure will build into the area behind the cold front Monday
and expect a brief break from heat with highs in the 80s. NW PA and
the higher elevations of NE OH and NW PA will be several degrees
cooler in the upper 70s. Temperatures will climb back into the upper
80s to lower 90s Tuesday as a ridge builds back into the region, but
do not anticipate oppressive heat since dew points will remain in
the lower 60s. Still quite a bit of uncertainty in the synoptic
setup for the remainder of the long term period, but shower and
thunderstorm chances may increase as early as Tuesday night and
continue through Wednesday as a cold front approaches the area. High
pressure should quickly follow the front, so expect dry weather for
Thursday. Highs will be in the 80s (possibly 90s near the I-75
corridor) Wednesday and post-frontal temps Thursday afternoon will
be in the upper 70s to lower 80s.

&&

.AVIATION /00Z Friday THROUGH Tuesday/...
Scattered thunderstorms ongoing across Northwest and North
Central OH are capable of producing frequent lightning and
locally strong wind gusts to 40 knots. Activity will gradually
subside through the evening. TOL most likely to be impacted, but
FDY and perhaps MFD will need monitored as well. Otherwise,
could see a bit of fog/mist again very early Friday morning.
Like this morning, impacts to TAF sites should generally limited
but did include some 4-6SM mist at a few sites for a brief
window to highlight the potential. Future forecasts may be able
to better pin down where (or if) lower vsby may be possible.
Another day with isolated to scattered convection on Friday,
though the focus will likely be across Northwest OH and then
across interior eastern OH, with cooler northerly winds keeping
activity from roughly MFD-CAK-YNG-GKJ points south. Used some
VCSH and VCTS mentions to indicate the window where convection
appears most likely near our western and southern sites.
Confidence in storms directly impacting TAF sites is low, less
than 50% at all, but is relatively higher (20-40%) at TOL, FDY,
MFD, CAK and YNG. Lowest risk (<15%) is at CLE and ERI.

Winds become light and variable overnight tonight. Can`t rule
out patchy fog developing again tonight across eastern
terminals. On Friday winds turn northwesterly while remaining
below 10 knots.

Outlook...More organized thunderstorms with non-VFR conditions
possible Sunday afternoon.

&&

.MARINE...
Outside of locally higher winds/waves in any afternoon/evening
thunderstorms, quiet marine conditions are anticipated through the
daytime hours Saturday. By Saturday night into Sunday, southwest
winds will likely ramp up as a cold front approaches from the west
and wind speeds will reach 15 to 20 knots. May need Small Craft
Advisories if winds continue to trend higher. Winds should diminish
to 15 knots or less and become west/northwest Sunday evening into
Sunday night with variable winds 10 knots or less likely Monday. On
Tuesday, winds may increase to 10 to 15 knots as another cold front
approaches from the west.&&

.CLIMATE...
A prolonged stretch of hot weather is expected this week.
Temperatures are forecast to approach or exceed record highs on
several days. The records for Thursday, June 20 to Sunday, June
23 are listed below for our official climate sites.

Date   Toledo     Mansfield   Cleveland   Akron     Youngstown   Erie
06-20  98(1953)    94(1988)   96(1988)    95(1933)   95(1933)    92(2016)
06-21  100(2022)   96(1988)   95(2022)    97(1933)   98(1933)    95(1933)
06-22  99(1988)    95(1988)   98(1988)    97(1988)   97(1933)    94(1988)
06-23  96(1911)    91(1964)   94(1948)    94(1923)   94(1943)    92(1964)

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Heat Advisory until 8 PM EDT Saturday for OHZ003-006>014-
     017>023-027>033-036>038-047-089.
PA...Heat Advisory until 8 PM EDT Saturday for PAZ001>003.
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...Iverson
NEAR TERM...Iverson/Sullivan
SHORT TERM...Maines
LONG TERM...Maines
AVIATION...Sullivan
MARINE...Maines
CLIMATE...