148
FXUS61 KCLE 180759
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
359 AM EDT Tue Jun 18 2024

.SYNOPSIS...
An upper level ridge will persist over the region through this
week, resulting in widespread near-record temperatures across
the area with isolated to scattered thunderstorms possible each
day. The next system won`t arrive until the end of the weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
Going to use some degree of a persistence forecast here on the
periphery of the dominant upper level ridge that has provided the
first day of heat in what will be a week of above normal
temperatures. The more recent forecasts have seen either an increase
in the low/mid level moisture supporting convective cloud growth, or
that the models are finally resolving what was always going to be
there much better. Satellite imagery is showing a solid connection
to a tropical moisture feed from the Gulf of Mexico/Bay of Campeche
providing the moisture for the convection. Plenty of SBCAPE from
high dewpoints and air temperatures in this environment to get
scattered thunderstorm activity for the entire region, again, in a
south to north type flow. With relatively freely rising parcels in
surface to 700mb lapse rates eclipsing 8C/km, some drier air aloft
and inverted V soundings will lend to another day with wind gust
threats despite a relative lack of shear. Pockets of low level f-gen
help with initiation as will a couple of weak waves aloft.
Temperatures on the high side again and will leave the Heat Advisory
in place, but precipitation cooling and cloud cover will keep some
locations in check in terms of temperatures. Some locations not
affected by this could still get into the mid to upper 90s once
again.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
The heat wave and headlines will continue through the short term
period with daily afternoon heat indices in the upper 90s to lower
100s. Not much relief is expected at night either with low
temperatures in the 70s.

Only real change to the forecast is an increased risk for afternoon
isolated strong thunderstorms on Thursday and Friday as moderate to
strong instability will pool across the southern and eastern Great
Lakes. Weak shear less than 20 knots is expected, so anticipate any
thunderstorms that do develop will be poorly organized and generally
short-lived. These storms will primarily carry a damaging wind risk
given steep low-level lapse rates and large theta-e differences.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
One last surge of extreme heat may arrive on Saturday ahead of an
approaching upper-level low across the Upper Great Lakes. The
current headlines may need to be extended a day further through
Saturday as heat indices reach the upper 90s to lower 100s in the
afternoon. Moderate to strong instability across the Lower Great
Lakes may result in isolated strong thunderstorms on Saturday,
though anticipate any storms that develop to be poorly organized and
generally short-lived given the weak shear in place.

The better potential for more organized strong thunderstorms will
arrive on Sunday as a well-defined upper-level low moves east across
the Upper Great Lakes, extending a surface cold front through the
area. Moderate to strong instability appears to remain in place
combined with 30 to 35 knots of southwesterly mid-level flow.

Behind the front, more cooler and more seasonable weather will
arrive, with temperatures in the low to mid-80s on Monday.
Anticipate dry weather conditions as a surface high briefly builds
in across the Great Lakes.

&&

.AVIATION /06Z Tuesday THROUGH Saturday/...
Went with a lesser used route of PROB30 groups in the TAFs for
expected isolated to scattered thunderstorm activity that will
peak with heating Tuesday. Some of this is a persistence
forecast, based on the amount of storms that occurred Monday,
but still, terminals themselves not guaranteed to get affected
directly. This may be switched to TEMPOs or VCTS/CB in upcoming
issuances, but feel the this setup is ideal for the PROB30
usage. Otherwise, mainly southerly wind components 5-10kts away
from storms and cumulus clouds developing with heating after
15Z.

Outlook...Primarily VFR expected through Friday. Isolated
thunderstorms are possible Wednesday afternoon.

&&

.MARINE...
A generally quiet marine forecast is in store for Lake Erie as a
large upper-level ridge remains across the Eastern CONUS, resulting
in limited surface flow. Only concern will be in the afternoon and
early evening hours this week as daily isolated to scattered
thunderstorms could bring strong wind gusts and small hail.

&&

.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 Tuesday, June 18 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...Heat Advisory until 8 PM EDT Friday for OHZ003-006>014-017>023-
     027>033-036>038-047-089.
PA...Heat Advisory until 8 PM EDT Friday for PAZ001>003.
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...26
NEAR TERM...26
SHORT TERM...Kahn
LONG TERM...Kahn
AVIATION...26
MARINE...Kahn
CLIMATE...