-- Discussion containing changed information from previous version are highlighted. --
532
FXUS61 KCLE 170140
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
940 PM EDT Sun Jun 16 2024

.SYNOPSIS...
An upper ridge will remain in place over the region through this
week, resulting in near-record temperatures across the area.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
-- Changed Discussion --
A line of showers and storms extends across Southwest Lower
Michigan into North Central Indiana. The main trajectory of this
line appears to be close to due east and should miss most of the
forecast area to the north toward the Detroit metro. Some
residual convection on the south end may scrape the Toledo metro
toward daybreak and have some PoPs mentioned for the end of the
tonight period. Temperatures continue to be on track for
overnight lows.

7 PM Update...
Minor changes to the forecast at this time. A lake breeze has
pushed up to 30 miles inland from Lake Erie and temperatures are
considerably cooler north of the boundary. The boundary will
wash out over the next couple of hours before conditions cool
with the diurnal cycle. Lows remain on target to the mid 60s to
lower 70s.

Previous Discussion...
Upper ridge will continue to build over the region through the
near term period, resulting in the beginning of a prolonged
heatwave. Temperatures will be noticeably warmer tonight;
instead of lows in the 50s like Saturday night, tonight`s lows
will be in the mid 60s to lower 70s. A shortwave and MCV will
ripple across lower Michigan overnight and weakening
showers/thunderstorms may clip NW OH early Monday morning, but
still quite a bit of spread in guidance in regards to the
evolution of the convection and the southward placement by the
time it nears the CWA. Convection may develop along any residual
boundaries from this feature or a lake breeze boundary Monday
afternoon, but otherwise there won`t be much in the way of
convergence so overall precipitation chances will be relatively
low (~20-30%) late Monday morning into Monday afternoon. With
that being said, the atmosphere will be quite juicy so any
showers/storms that develop could produce locally heavy
rainfall.

While rain chances are low, any clouds/precipitation could throw
a wrench into the heat index forecast and result in sub-100
degree apparent temperatures Monday. There`s a decent chance
that heat indices will touch 100 degrees in at least a few spots
Monday afternoon, but would like to have a better idea of the
cloud/precipitation forecast before making a decision on
locations that will (likely marginally) meet Heat Advisory
criteria Monday. Opted to maintain the Excessive Heat Watch for
now due to the lower confidence in precipitation
chances/placement. In the event of a dry forecast with less
cloud cover, heat indices may be a touch higher. Monday`s highs
will climb into the 90s with locations near the I-75 corridor
possibly creeping into the upper 90s and expect dew points to
increase throughout the day, reaching at least the upper 60s by
Monday afternoon. Even if a Heat Advisory isn`t needed for
Monday, heat indices will climb well into the 90s areawide.

The aforementioned shortwave should lift away from the area by
Monday evening and overnight lows will only manage to fall into
the low to mid 70s with slightly warmer temps possible in urban
areas. Can`t rule out a stray shower, but generally expect dry
(albeit muggy) weather Monday night with clouds increasing from
the southwest as the next shortwave climbs the ridge.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
A dominant upper level ridge will be in place over the eastern US
during the short term period. The associated surface high on Tuesday
will be centered near the East Coast, putting the forecast area on
the backside of the high. This positioning should allow of a period
of increased low level moisture to sneak in through Tuesday
afternoon. With plenty of instability and isentropic lift,
especially across eastern counties, opted to maintain chance PoPs
through Tuesday afternoon with thunderstorms possible. Primary
concern with any thunderstorms will be heavy rainfall and localized
wind, but not anticipating anything severe or widespread at this
point. High temperatures on Tuesday will climb into the 90s across
the area with apparent temperatures values in the upper 90s,
possibly touching 100 in some locations including the urban heat
islands. The potential caveat to the temperature forecast is that in
areas where showers develop, temperatures will locally cool a bit,
although humidity values will increase. By Tuesday night, the
aforementioned high pressure retrogrades a bit, drying out the low
levels again and marking the return to dry conditions. Overnight
lows will only drop into the low to mid 70s, not providing much
relief from the hot day. As discussed throughout the last week, a
heat wave will be well established across the area by midweek with
temperatures on Wednesday climbing into the 90s and heat index
values possibly exceeding 100 for areas along and west of I71.
Overnight lows will continue to only drop into the 70s on Wednesday
night.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The long term forecast is not going to look much different than the
rest of the week with the dominant ridging pattern continuing to
influence the weather across the area. Have opted to introduce a
slight chance of PoPs on Friday as a weak boundary approaching the
southern shores of Lake Erie from the north, however models suggest
it becoming stalled before lifting north as a warm front Saturday.
Due to this, opted to only include the immediate lakeshore in the
precipitation potential, but will continue to monitor in the coming
updates to see if models maintain this boundary. At the far end of
the long term period late Saturday into Sunday, long range models
suggest a low pressure finally tracking into the region and bringing
the potential for showers and cooler temperatures. Exact timing of
this low diverges amongst models, but they all suggest this dominant
high finally beginning to move east. With that in mind, maintained
well above average temperatures in the 90s through Saturday with
slightly cooler temperatures on Sunday.

&&

.AVIATION /00Z Monday THROUGH Friday/...
Primarily VFR conditions are expected through the period. Clear
skies will persist through the overnight hours. A lake breeze
boundary has pushed inland, passing south of KCLE and KERI.
North winds will continue over the next hour or two before the
boundary washes out and southerly flow returns to these
terminals. Mid level clouds from remnant convection this evening
and some diurnal cumulus will enter for Monday. There is some
potential for clouds to become some isolated showers and storms
but confidence in coverage and timing is very low at this time
to put into TAF. South to southwest flow will be favored through
the end of the TAF period, outside of any slight variation due
to showers or storms.

Outlook...Primarily VFR expected through Thursday. Isolated
thunderstorms are possible Tuesday afternoon, but confidence is
low.

&&

.MARINE...
East-northeast winds of 5-10 knots today will shift to become south-
southwest on Monday and will persist through this week as high
pressure remains dominant over the region. Waves today will linger
at 1-2 feet along the lakeshore, but should generally be 1 foot or
less for the remainder of the week. There is a chance of scattered
showers and thunderstorms Monday and Tuesday afternoon, but nothing
widespread is expected.

&&

.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 Monday, June 17 to Friday, June
21 are listed below for our official climate sites.


Date   Toledo     Mansfield   Cleveland   Akron     Youngstown   Erie
06-17  97(1994)    94(1936)   94(2018)    94(2018)   95(1994)    90(2018)
06-18  98(1994)    93(1994)   96(1944)    96(1944)   95(1994)    92(2018)
06-19  98(1995)    94(1994)   92(1995)    94(1994)   94(1994)    92(1931)
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)

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Excessive Heat Watch from Monday morning through Friday
     evening for OHZ003-006>014-017>023-027>033-036>038-047-
     089.
     Air Quality Alert until midnight EDT tonight for OHZ010>014-
     020>022-089.
PA...Excessive Heat Watch from Monday morning through Friday
     evening for PAZ001>003.
NY...None.
MARINE...None.

&&

$$

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