307
FXUS61 KCLE 212017
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
417 PM EDT Fri Jun 21 2024

.SYNOPSIS...
An upper level ridge slides southwest through Saturday as low
pressure develops over the Upper Midwest. The low will move
toward the Great Lakes on Sunday while extending a cold front
across the area. High pressure will build across the region for
Monday.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
Afternoon convection has developed along a lake breeze across
Northern Ohio and Northwest Pennsylvania. Slightly lower
temperatures and dew points this afternoon have kept MLCAPE
values generally around 1000-1500 J/kg and storms fairly
isolated. As with the past week, any convection will diminish
with sunset as we lose daytime heating. Overnight lows tonight
settle into the upper 60s to lower 70s with patchy fog possible
once again tonight in areas that receive storms this afternoon
and evening.

Surface boundary lifts north over Lake Erie tonight as upper level
ridging builds southwest ahead of low pressure currently centered
over the Upper Midwest. As we become sandwiched between these two
systems, southwest flow will increase while also transporting warmer
air into the region. Much warmer and unpleasant tomorrow with high
temperatures in the mid to upper 90s and heat indices
approaching 100 degrees. Made no changes to our heat headlines
with a Heat Advisory still in effect areawide through 8 PM
tomorrow. We should remain fairly dry for much of the day
tomorrow before the aforementioned low pressure drags a cold
front toward western zones late Saturday night. Most of the
impacts along and ahead of the front will occur on Sunday. More
information can be found in the short term discussion below...

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Low pressure tracks across Upper Michigan towards southern Quebec on
Sunday. A ribbon of high theta-e air will slide northeast ahead of
the cold front which is likely to produce expanding coverage of
showers through the morning and into the afternoon. PW values will
be near 2 inches and expect to see an uptick in thunderstorm
activity as the front pushes south into higher instability air
during the afternoon, especially south of a line from Findlay to
Mansfield to Youngstown. The Storm Prediction Center does have a
marginal risk for severe thunderstorms across much of the forecast
area and expect heavy rain to also be a concern, especially if any
training of storms occurs with uni-directional southwesterly flow
ahead of the front. Much drier air does arrives from west to east
through the afternoon and should bring an end to precipitation.
Sunday will be another hot and muggy day although with high
temperatures peaking in the 80s. Heat index values are still likely
to surpass 90 degrees generally along and west of I-77.

A much welcomed break from the humidity will come on Monday as high
pressure builds over the Great Lakes Region and dewpoints drop back
into the upper 50s/near 60. High temperatures will be within a few
degrees of normal seasonal values but the lower humidity will be
noticeable. Overnight low temperatures will also range from 55-65
which will be more pleasant.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
The upper trough quickly moves east on Tuesday with a broad but
somewhat flat ridge across the Plains and retrograding westward
towards the Intermountain West region. This results in some
uncertainty as we transition to more of a northwest flow pattern
by late next week. Temperatures warm again on Tuesday but
dewpoints remain low enough that we are only expecting a chance
of showers and thunderstorms in NW Ohio. Heat index values could
surpass 95 degrees again in portions of Northwest Ohio. By
Wednesday with see better moisture return ahead of a stronger
cold front with higher chances of showers and thunderstorms
across the whole area. This front is expected to bring cooler
temperatures by Thursday, especially from north central Ohio to
Northwest Pennsylvania where some area may have a day with high
temperatures in the 70s.

&&

.AVIATION /18Z Friday THROUGH Wednesday/...
Scattered thunderstorms are developing along the lake breeze
boundary this afternoon. The chance for thunderstorms to impact
terminals will be highest along the edges of our local area at
KTOL and KYNG. As with the past week, these thunderstorms will
diminish as we lose daytime heating this evening.

Northwest flow with north flow along the lakeshore less than 10
knots will turn light and variable overnight tonight. Higher
wind gusts possible in any thunderstorm that moves over a
terminal this evening. Wind speeds out of the southwest will
increase tomorrow morning to 8-12 knots.

Outlook...Thunderstorms will increase in coverage Sunday
afternoon with non-VFR conditions possible.

&&

.MARINE...
Good marine conditions continue on Saturday on Lake Erie with lake
breezes on the eastern half of the lake during the afternoon.
Southwest winds increase Saturday night into Sunday to 15 to 20
knots as a cold front approaches from Michigan. Winds will veer to
westerly and eventually northwesterly behind the front Sunday into
Sunday night. Some models are starting to indicate a little stronger
winds behind the front but consensus is not very strong yet.
Conditions look to approach Small Craft criteria but appear to
remain just below for now.  Shower and thunderstorms may also impact
Lake Erie through early afternoon before the front pushes south.

High pressure builds over the Great Lakes on Monday with northwest
winds decreasing. Another cold front is forecast to cross Lake Erie
on Wednesday.

&&

.CLIMATE...
The records for Friday, June 21 through Sunday, June 23 are listed
below for our official climate sites.

Date   Toledo     Mansfield   Cleveland   Akron     Youngstown   Erie
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
SHORT TERM...KEC
LONG TERM...KEC
AVIATION...Iverson
MARINE...KEC
CLIMATE...