Area Forecast Discussion
Issued by NWS Cleveland, OH
Issued by NWS Cleveland, OH
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
230
FXUS61 KCLE 211133
AFDCLE
Area Forecast Discussion
National Weather Service Cleveland OH
733 AM EDT Tue Jul 21 2026
.WHAT HAS CHANGED...
Confidence is increasing for a line of showers and thunderstorms
to develop and move east across the area late this morning and
early afternoon. If storms become severe, damaging wind gusts
are the most likely hazard. Concern is also increasing for a few
rotating storms to develop later this afternoon and evening
across NE OH/NW PA.
&&
.KEY MESSAGES...
1) Showers and storms will develop and move east across the area
late this morning and early afternoon. The most likely window
for severe weather is between 11 AM and 2 PM along and east of
the I-71 corridor with damaging wind gusts being the primary
hazard.
2) Anomalously-cool air mass arrives on Wednesday with lake-
enhanced showers possible.
3) Temperatures return near or slightly above normal by the end
of the week and weekend. Shower and thunderstorm chances
increase by early next week.
&&
.DISCUSSION...
KEY MESSAGE 1...
The latest water vapor imagery (~3 AM ET) depicts a potent
shortwave across southern Wisconsin/Lake Michigan early this
morning, with scattered showers and storms beginning to develop
across northern Illinois. This area of showers and storms will
be the main area to watch this morning and early afternoon as
the shortwave continues to quickly move east through the Lower
Great Lakes, providing plenty in the way of environmental shear
to support organized convection. There remains some uncertainty
on the amount of destabilization ahead of the line, mainly west
of the I-71 corridor, where probabilities of >1000 J/kg of CAPE
are lower. Further east, along and east of the I-71 corridor,
severe weather chances appear to be increasing with a longer
period of daytime heating ahead of the line. Given the
anticipated line storm mode, damaging wind gusts up to 70 mph
are the primary concern with a most likely time window between
11 AM and 2 PM, particularly along and east of the I-71
corridor.
Attention then turns to later this afternoon and evening across
portions of Northeast Ohio and Northwest Pennsylvania where a
second area of pre-frontal showers and thunderstorms may
develop. Concern is increasing for a few rotating storms with
this round as the low-level hodograph profile becomes more
favorable, potentially resulting in a localized tornado risk,
evident by the slight westward expansion of the 5% tornado
probabilities in the latest SPC SWODY1 outlook. These storms
appear to be driven by mesoscale processes mainly below 700 mb,
evident by an abundance of dry air aloft, and thus, anticipating
this second round of convection to be fairly shallow, similar
to the type of storms seen across Wisconsin yesterday (7/20).
Confidence on this second round remains on the lower side,
especially with regards to intensity and coverage.
KEY MESSAGE 2...
A strong cold front will move across the area tonight, ushering
in a chilly air mass into the region, characterized by 850 mb
temperatures falling as low as 6C on Wednesday. Lake-enhanced
rain showers will be possible throughout Wednesday across
portions of Northeast Ohio and Northwest Pennsylvania in
addition to ample cloud cover, especially Wednesday morning and
early afternoon. As a result, high temperatures may struggle to
get out of the 60s in some spots.
KEY MESSAGE 3...
A large upper-level ridge across the Western and Central CONUS
will gradually expand further east into the Great Lakes by
Friday into the weekend, resulting in temperatures to return
near or slightly above normal in the 80s. However, a series of
upper-level troughs across Hudson Bay appear poised to block the
eastward progression of the ridge. This pattern would appear to
favor increasing shower and thunderstorm chances across the area
by early next week if trends continue.
&&
.AVIATION /12Z Tuesday THROUGH Saturday/...
First round of showers and thunderstorms is moving east into
the western part of the area early this morning. This round of
storms will continue to move east across the area this morning
with additional redevelopment likely on the western edge of
storms as better forcing moves into the region. Amendments will
likely be needed as confidence in convection coverage into this
afternoon increases. Regardless, any storms will be capable of
producing non-VFR conditions and erratic wind gusts to at least
35 knots. Locally higher thunderstorm gusts to 50 knots are
possible primarily at southeastern terminals late this morning
into this afternoon. Another round of showers/storms is possible
ahead of a cold front this evening, but would like to see how
the atmosphere recovers this afternoon before getting too
aggressive with shower/thunderstorms. Lake effect showers/clouds
will likely develop behind the cold front tonight which could
produce MVFR ceilings and perhaps some light showers at
KERI/KYNG/KCLE in the later part of the TAF period.
Southwest winds will increase to 10 to 15 knots with gusts to
20 to 25 knots this morning. As mentioned above, wind gusts will
likely be stronger in thunderstorms. Winds will shift to the
northwest and diminish to about 10 knots with periodic gusts to
20 knots behind a cold front tonight.
Outlook...Residual non-VFR possible on Wednesday in lake effect
rain showers and clouds across the eastern half of the area.
&&
.MARINE...
Southwest winds will increase to 15 to 25 knots this morning,
resulting in waves of 3 to 5 feet in the nearshore zones from
roughly Vermilion to Ripley NY. Winds may briefly diminish as a
cold front crosses the area this afternoon/evening, but strong
cold air advection will cause winds to shift to the northwest
and increase to about 20 knots overnight, which will produce
continued elevated waves into Wednesday. The Small Craft Advisory
from Maumee Bay to the Islands has been adjusted to start early
this morning and end at 4 AM Wednesday morning to account for
the enhanced northwest flow behind the cold front. Meanwhile,
the Small Craft Advisory remains in effect from the Islands to
Ripley NY from 8 AM this morning until 10 PM Wednesday evening.
Thunderstorms are likely this morning and afternoon which will
result in higher winds/waves.
Winds will diminish below 10 knots by early Thursday morning and
expect light (10 knots or less) and variable flow through at
least the first half of the weekend.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Beach Hazards Statement through Wednesday evening for
OHZ010>012-089.
PA...Beach Hazards Statement through Wednesday evening for PAZ001.
MARINE...Small Craft Advisory until 4 AM EDT Wednesday for LEZ142-143.
Small Craft Advisory until 10 PM EDT Wednesday for LEZ144>149.
&&
$$
DISCUSSION...Kahn
AVIATION...15
MARINE...15