932
FXUS61 KCLE 171948
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
348 PM EDT Tue Jun 17 2025

.SYNOPSIS...
Our region remains along the northwestern flank of the Bermuda-
Azores subtropical high pressure ridge until a cold front moves
southeastward across northern Ohio and northwest Pennsylvania
Wednesday night through early Thursday afternoon. Behind the
front, a ridge builds from the Upper Mississippi Valley through
Thursday night before our area becomes located along the
northwestern flank of the ridge this Friday through upcoming
weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Cyclonic SW`erly flow aloft and embedded/subtle shortwave
disturbances affect our region through daybreak Thursday as a
stronger and consolidating shortwave trough approaches from the
northern Great Plains and eventually the western Great Lakes. At
the surface, our CWA remains along the northwestern flank of the
Bermuda-Azores subtropical ridge and within a warm/humid air
mass originating over the Gulf for the time being. Unusually-
high PWAT`s within this air mass will contribute to
showers/storms capable of producing heavy rainfall (more details
farther below). A cold front should begin moving SE`ward
through our area overnight Wednesday night and usher-in a
slightly cooler and less humid air mass. This front should near
I-71 in our CWA by daybreak Thursday. Behind the front, a ridge
begins to build from the Upper MS Valley. Overnight lows are
expected to reach the mid 60`s to lower 70`s around daybreak
Wednesday. Peeks of sunshine and daytime heating complemented by
low-level warm/moist air advection from the Gulf should allow
daytime highs to top-out near 80F in northwest PA and the lower
to upper 80`s in northern OH late Wednesday afternoon. Overnight
lows should reach the 60`s around daybreak Thursday.

Low-level convergence/moist ascent along an ongoing Lake Erie
lake breeze front extending from the northeast side of the city
of Cleveland through northern Erie County, PA, downshear outflow
boundaries, and surface trough axes accompanying the
aforementioned shortwave troughs are continuing to release weak
to moderate boundary layer instability amidst modest effective
bulk shear as of 3 PM EDT. Localized flash flooding remains a
concern, especially where multiple rounds of showers/thunderstorms
manage to impact the same areas. The greatest potential for
flooding exists along the aforementioned lake breeze front
through this early evening. WSW`erly mean mid-level flow of
about 20 to 30 knots is expected to exhibit a large component
parallel to the mesoscale front, which will promote
training and slow-moving convection.

Shower/thunderstorm coverage is expected to decrease around and
especially after sunset this evening, in response to nocturnal
cooling-related stabilization of the boundary layer. However,
isolated showers and thunderstorms remain possible the rest of
this evening through Wednesday afternoon due to the following:
moist isentropic ascent preceding shortwave trough axes and
releasing at least weak, elevated CAPE; low-level
convergence/moist ascent along surface trough axes eventually
releasing moderate to perhaps strong boundary layer CAPE
Wednesday afternoon as the warm/moist sector boundary layer
destabilizes via daytime heating and continued low-level moist
air advection from the Gulf, and the effective inflow layer
eventually becomes surface-based. During the afternoon, isolated
straight-line convective wind damage may become a concern as
low-level lapse rates steepen and DCAPE grows to moderate
magnitudes via diurnal convective mixing of the boundary layer,
and effective bulk shear remains moderate.

Based on latest trends in NWP model guidance, expect a QLCS to
develop upstream of our CWA Wednesday afternoon, outpace the
aforementioned cold front, and persist E`ward across our CWA
Wednesday evening through the first few predawn hours of
Thursday morning as effective bulk shear remains moderate within
the warm/moist sector. Straight-line convective wind damage is
the main concern with this QLCS, especially roughly along and
west of the longitude of Cleveland, since moderate to strong
boundary layer CAPE, steep low-level lapse rates, and moderate
DCAPE should linger well into the evening. A few mesovortex-
related tornadoes are possible, especially during the early
evening, as surface-based ESRH increases and mixed layer LCL`s
lower/become more-favorable amidst SSW`erly nocturnal LLJ
development. This LLJ will allow low-level winds to
increase/strengthen with height to a greater extent and increase
low-level moisture advection from the Gulf. Overnight Wednesday
night and farther east in our CWA, the severe thunderstorm
potential should diminish as the warm/moist sector boundary
layer stabilizes somewhat via nocturnal cooling. However,
showers and thunderstorms should remain a concern as the likely
weakening QLCS persists farther E`ward and the synoptic cold
front potentially triggers additional, albeit isolated
showers/thunderstorms amidst the release of weaker, yet
sufficient instability. Additional periods of torrential
rainfall are expected tonight through Wednesday night as PWAT`s
remain unusually-high in the warm/moist sector.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Aloft, the stronger shortwave trough axis should move generally
E`ward across our region on Thursday. At the surface, the
attendant cold front is expected to sweep E`ward across the rest
of our CWA through the early afternoon. Behind the front and
shortwave trough, a ridge at the surface and aloft will continue
to build from the western Great Lakes and vicinity. Isolated to
scattered showers/thunderstorms are possible along and ahead of
the front, within a warm/moist sector with at least weak
instability belonging to parcels rooted in the low-level
atmosphere and at least modest effective bulk shear. Fair
weather is expected behind the front as stabilizing subsidence
accompanies the ridge. Despite intervals of sunshine, weak low-
level CAA behind the cold front will contribute to late
afternoon highs reaching the 70`s to near 80F.

Current odds favor fair weather Thursday night through Friday
night as the aforementioned ridge at the surface and aloft
continues to affect our region. Farther aloft, the ridge axis
should remain west of our area, but the low-level ridge axis is
expected to eventually become located east of our region later
Friday through Friday night. This will allow low-level
warm/moist air advection from the Gulf and southern Gulf Stream
to become reestablished in northern OH and NW PA. Daytime
heating should contribute to late afternoon highs reaching the
upper 70`s to mid 80`s on Friday. Overnight lows should reach
the 60`s to lower 70`s around daybreak Saturday.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
At this point, hot, humid, yet fair weather is expected in our
region this Saturday through Monday night as our region remains
located along the western flank of the aforementioned low-level
ridge, while the ridge axis farther aloft drifts from near the
western Great Lakes and Lower OH Valley toward the Lake Ontario
region and Carolinas. Low-level warm/moist air advection from
the Gulf and southern Gulf Stream will continue to impact our
region. This factor combined with daytime heating will likely
allow late afternoon highs to reach the 80`s to lower 90`s on
Saturday and then mainly the upper 80`s to mid 90`s on Sunday
and Monday, respectively. Balmy overnight lows in the upper 60`s
to mid 70`s are expected around daybreak Sunday through Tuesday.

On Tuesday, our region should remain within the low-level
warm/moist air advection regime from the Gulf and southern Gulf
Stream as we remain along the western flank of the high pressure
ridge at the surface and aloft. A few showers/thunderstorms are
possible, especially during the PM hours, as shortwave troughs
embedded in SW`erly flow aloft and attendant surface trough axes
sweep through our region and the warm/moist sector boundary
layer destabilizes via daytime heating. Late afternoon highs
mainly in the upper 80`s to mid 90`s are expected once again.

Note: Daily maximum heat indices in the 90`s to 100F or so are
expected this Sunday through Tuesday. Heat Advisories may
eventually be needed for portions of our CWA. Stay tuned to
future forecast updates.

&&

.AVIATION /18Z Tuesday THROUGH Sunday/...
Mix bag of conditions are being observed across the area this
afternoon as showers and thunderstorms have begun to develop.
Within these storms, heavy rain remains the primary concern and
showers have had a history of reducing visibilities to as low as
3/4SM. Initial impacts to terminals will be KMFD, KFDY, and KCLE
before portions of the east CWA fill in as well. Given the
scattered nature of these storms, opted to handle the reduced
visibilities and weather aspect as TEMPOs through around 00Z
this evening.

After sunset, reduction in instability will allow for the bulk
of showers to dissipate and most terminals to rebound to VFR
into the early morning hours on Wednesday. There is a potential
for patchy fog/low stratus to develop for inland terminals, so
opted to reduce those terminals to MVFR/IFR around 08Z to
daybreak for the impacted terminals. The terminals along the
lakeshore may briefly have reduced ceilings, but confidence is
low there so opted to not include it with this update. By mid to
late Wednesday morning, showers and thunderstorms will once
again develop across the area and pose the potential for reduced
conditions to MVFR and IFR across the area. Opted to handle the
bulk of this potential with PROB30. The more notable impact to
terminals is expected to occur Wednesday evening as a decaying
QLCS pushes across the area.

Winds will remain from the southwest through the duration of
this TAF period. Winds this afternoon will be 5-12 knots with
the strongest winds and localized gusts up to 20 knots at
terminals receiving showers. Overnight winds will weaken to
around 5 knots before again increasing from the southwest in the
afternoon.

Outlook...Non-VFR likely with scattered to periodic showers and
thunderstorms Wednesday through Thursday. The best chance of
thunderstorms will be Wednesday evening into early Thursday
morning. There is a small chance of isolated thunderstorms
Friday afternoon and Saturday afternoon over far northeast Ohio
and northwest Pennsylvania.

&&

.MARINE...
Low pressure moving east from Ontario to Quebec has lifted a
warm front north of the lake, allowing for southwest winds of 10
to 15 knots to become established. These winds will persist into
Wednesday evening before increasing from the southwest to 15-20
knots Wednesday evening into the overnight hours ahead of an
approaching cold front. This increase in winds may need a short
duration Small Craft Advisory Wednesday into Thursday, but will
continue to monitor trends in the winds for better detail on
that potential. Behind the cold front Thursday night, winds will
weaken from the west-southwest at 5-10 knots through Saturday
morning. Another warm front will lift north on Saturday, briefly
increasing winds from the southwest to 10-15 knots Saturday
afternoon. After that, winds will return to 5-10 knots but
persist from the southwest. Given the prolonged southwest flow,
waves along the southern lakeshore should remain 2 feet or less
with the exception of when the cold front pushes east. During
that time, waves may increase to 3-5 feet across central and
eastern basins.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.

&&

$$

SYNOPSIS...Jaszka
NEAR TERM...Jaszka
SHORT TERM...Jaszka
LONG TERM...Jaszka
AVIATION...04
MARINE...04