347
FXUS61 KCLE 181947
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
347 PM EDT Fri Apr 18 2025

.SYNOPSIS...
Low pressure moves across the western Great Lakes this evening
before dragging a cold front southeast across the local area on
Saturday. The cold front will stall across the Ohio River Valley
as high pressure briefly builds overhead from the north. The
cold front will lift back north as a warm front on Monday as
another system approaches from the Great Plains.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
Mid to upper level ridge and associated dry air will continue to
exit eastward as an upper level trough pushes west. Surface low
pressure is expected to track northeast across Lower Michigan
through tonight while swinging a cold front east overnight tonight.
The timing of the frontal passage continues to slow with most
precipitation associated with the front occurring after midnight.
Given the unfavorable timing of the frontal passage, the severe
weather threat continues to dwindle. However, can`t rule out
isolated instances of strong to marginally severe storms across
Northwest Ohio late tonight given a few hundred Joules of MLCAPE and
roughly 40 knots of deep layer shear. As such, the northwest corner
of our CWA has been clipped with a SWODY1 Marginal Risk (Level 1/5).
Any strong to severe storm that does materialize may produce
damaging wind gusts.

The aforementioned cold front will remain stalled across the Ohio
River Valley on Saturday, allowing for periods of rain showers and
thunderstorms to continue through Saturday. There is the potential
for some pockets of stronger storms mainly south of US-30 on
Saturday along a narrow band of weak instability. Similar to Friday
night`s threat, damaging wind gusts will be the primary hazard.

Warm overnight lows expected ahead of the cold front as they settle
in the low to mid 60s. Temperatures will gradually cool during the
day on Saturday with highs in the 60s likely achieved just after
sunrise. Cooler behind the cold front Saturday night with lows in
the low 40s with mid 30s possible across Northwest Pennsylvania.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The weather for the later half of this weekend will be drier than
the first half. An area of high pressure will build down from
southern Ontario into the Eastern Great Lakes on Sunday bringing
fair weather conditions. Temperatures will be cooler on Sunday as a
Canadian airmass will advect into the region on northerly winds.
High temps Sunday afternoon will be slightly below average ranging
from the mid 50s near the lakeshore and low 60s towards central
Ohio.  The low level flow will eventually become easterly late
Sunday and wind speeds will increase slightly Sunday night as a
pressure gradient develops over the region.  The next storm system
that will bring another round of April showers and possible
thunderstorms will track from the Midwest into the Great Lakes and
Ohio Valley late Sunday night into Monday. A surface low pressure
system and trialing cold front will track from the Cornbelt Region
and through the Upper Great Lakes during the day Monday. We will
bring back slight to chance POPs late Sunday night and increase the
rain chances to very likely by Monday afternoon. Ahead of the
approaching cold front Monday, temperatures will warm back into the
70s. There is some potential for a couple strong to isolated severe
storms possible with the cold front later on Monday. Timing and over
thermodynamics for organized, severe convection is somewhat
uncertain and appears to limited at this time.  Temperatures will be
cooler again behind the front Monday night down into the 40s.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A small area of high pressure will move across the Ohio Valley on
Tuesday with brief cool down and a break from rain chances. High
temperatures will be knocked back down to seasonable averages for
late April Tuesday in the low to mid 60s and the weather will be dry
as well. The overall weather pattern will become more zonal or
westerly flow in the middle and upper levels. The main storm track
or Jet Stream will favor along the northern CONUS near the border
with Canada. This pattern setup usually favors milder to warmer
temperatures for the extended forecast with highs in the 70s during
the middle and end of next week. With the storm track close to the
Great Lakes region, there may be a couple weak, fast moving storm
system that could bring some scattered rain chances later next week
but timing and POPs are somewhat uncertain this far out in the
forecast.

&&

.AVIATION /18Z Friday THROUGH Wednesday/...
Some light rain showers with embedded thunder will continue to
push east along the eastern lakeshore over the next hour with a
brief VCTS mention at CLE and ERI. The main rain/thunderstorm
threat will come later tonight ahead of a cold front pushing
southeast across terminals. Have initial round of rain entering
western terminals around 04Z and reaching eastern terminals
around 06Z. More widespread rain showers with embedded
thunderstorms will move overhead early Saturday morning and
continue through the afternoon as the cold front stalls south of
the local area. Generally anticipate VFR cigs/vis to drop to
MVFR with the more widespread rain showers by Saturday.

Breezy southerly winds will continue for the next 6 hours or so
with peak gusts between 30 and 35 knots. Winds gradually shift
southwesterly while decreasing slightly to 15-20 knots sustained
with gusts to 25+ knots. Behind the cold front, winds turn
westerly and decrease below 15 knots.

Outlook...Periodic rain showers with non-VFR expected Saturday
through this Monday night. Isolated to scattered thunderstorms
are possible at times on Saturday and Monday.

&&

.MARINE...
We will allow the eastern Lake Erie zones of the Small Craft
Advisory to expire at 4 pm. The western zones of the SCA will
continue until 8 pm this evening. The main marine concerns  this
afternoon into this evening for any early season boaters or
fisherman will be the gusty southwest winds 15 to 25 knots. Waves
conditions will be lower closest to the lakeshore and up to 4 feet
further away with this offshore wind flow through tonight.  A cold
front will move across Lake Erie Saturday morning or midday. The
flow will become westerly to northwest behind the front later
Saturday 10 to 15 knots. Additional SCA may be needed if the winds
become slightly higher with that onshore flow.  High pressure will
build down over the Great Lakes Saturday night into Sunday. The
wind flow will be northerly by Sunday morning and gradually become
easterly late Sunday into SUnday night 10 to 15 knots. Easterly
winds will increase up to 15 to 20 knots by Sunday night into Monday
morning. Another cold front will approach the lake by Monday
afternoon. The flow will be southerly 15 to 20 knots ahead the cold
front Monday. High pressure will build over the lake Monday night
and Tuesday with a westerly flow 10 to 20 knots.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
     LEZ142>146.
     Small Craft Advisory until 4 PM EDT this afternoon for
     LEZ147>149.

&&

$$

SYNOPSIS...13
NEAR TERM...13
SHORT TERM...77
LONG TERM...77
AVIATION...13
MARINE...77