635
FXUS61 KCLE 190519
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
119 AM EDT Fri Jul 19 2024

.SYNOPSIS...
A ridge continues to affect northern Ohio and northwest
Pennsylvania through Friday as the parent high pressure center
moves from the Upper Mississippi Valley to the Lake Erie region.
The high pressure center is then expected to move little this
weekend and allow the ridge to continue to affect our region.

&&

.NEAR TERM /THROUGH TODAY/...
900 PM Update...
Clouds have diminished and expect mostly clear to clear skies
for the rest of the night. Can`t rule out patchy valley and/or
radiational fog in southeastern zones early Friday morning. No
changes were needed with this update outside of small
adjustments to hourly temperatures and dew points based on
latest observations and forecast trends.

Previous Discussion...
Cyclonic flow aloft, varying between SW`erly and NW`erly, and
embedded shortwave disturbances affect our region through Friday
night. At the surface, a ridge associated with an unusually-
cool and less-humid air mass continues to affect our region as
the center of the ridge drifts from the Upper MS Valley toward
Lake Erie and weakens. Fair weather is expected to persist as a
stabilizing subsidence inversion accompanies the low-level
ridge. Overnight lows are expected to reach mainly the 50`s to
lower 60`s around daybreak Friday morning and Saturday morning,
respectively, as mainly clear to partly cloudy sky, weak or calm
surface winds, and surface dew points mainly near 50F to 55F
promote efficient radiational cooling during evening hours
through daybreak. The warmest lows are expected over/very near
~76F Lake Erie. Localized river valley steam fog is expected and
patchy radiation fog is possible around daybreak both mornings,
especially in interior NW PA and NE OH. Any fog will dissipate
soon after daybreak via the onset of diurnal heating/convective
mixing of the boundary layer tapping into drier air aloft.

On Friday, late afternoon highs are expected to reach the mid 70`s
to 80F as diurnal convective mixing of the boundary layer occurs
amidst 850 mb temperatures near 11C to 12C. Despite a very marginal
temperature contrast between relatively-warm surface air over
surrounding land and Lake Erie, a very weak synoptic MSLP gradient
and the anticyclonic circulation of the synoptic surface high
pressure center settling over the lake are still expected to allow a
lake breeze to occur Friday afternoon through early evening. The
N`erly synoptic MSLP gradient in most of our CWA will allow the lake
breeze to have significant inland extent, especially from roughly
the longitude of the Lake Erie Islands and points farther east. This
has been a consistent signal in the last few runs of the HRRR and
other mesoscale NWP models. The coolest highs on Friday are expected
over/within a couple miles of Lake Erie.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
The weekend forecast appears quiet for the local area. A weak upper
low to the west over Minnesota and Iowa will block an upper trough
moving through eastern Canada from overtaking the Great Lakes
region. This will actually allow for some upper ridging to form over
the local area and keep high pressure in place across the region.
With that, will keep the forecast dry with relatively seasonable
temperatures with 80s for highs. Lows on Saturday night could
continue to be a bit cool with mid 50s under clear conditions. Lows
should recover somewhat for Sunday into the 60s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
After a weekend reprieve of weather, the forecast for next week
returns to conditional shower/storm chances before a bonafide
weather system will approach the area for the middle of the week.
For Monday, the weak upper low over the Midwest will open up and the
energy will push east toward the Great Lakes region. A warmer air
mass with temperatures in the mid to upper 80s should be in place to
generate some instability to help diurnally force convection.
However, moisture in the region will be fairly limited and will be
the main factor to prevent much from happening. With the western low
gone, a larger upper trough will swing into the Great Lakes region
on Tuesday and Wednesday. This system will bring a more formal low
pressure system with a cold front through the area, which should
force more widespread shower and storm chances and have PoPs to
likely levels. A stronger upper wave of the trough will move through
on Thursday and allow even better support for showers and storms on
Thursday. However, several rounds of rain and lingering clouds could
make Thursday more conditional thermodynamically, but will keep some
likely PoPs in the forecast for now. Overall, Tuesday through
Thursday will be a period to watch for shower and storm chances and
potential summer weather hazards.

&&

.AVIATION /06Z Friday THROUGH Tuesday/...
VFR. High pressure. Winds light and variable/light northerly
less than 10kts.

Outlook...VFR expected through Monday morning. Isolated
showers/thunderstorms with non-VFR possible Monday afternoon
and evening with better chances for showers and thunderstorms
Tuesday.

&&

.MARINE...
One final push of a surface trough across the lake tonight will
allow for a window of enhanced northerly winds, especially for the
central basin of Lake Erie. Waves will marginally respond to 3 ft,
but should stay controlled enough to not need a Small Craft
Advisory. High pressure will be in control of the Great Lakes region
for Friday through Sunday and marine weather should be quiet. Winds
will be light, less than 10 kt, and variable through the period, as
there will be directional changes with lake and land breezes. Waves
will respond by staying 2 ft or less through the period and likely
just flat through Sunday. High pressure will move out starting on
Monday and a warm front will approach the lake. Winds will shift
from the northeast to east during the day and then southeast at
night, all at 10 kt or less.

&&

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

&&

$$

SYNOPSIS...Jaszka
NEAR TERM...Jaszka/Maines
SHORT TERM...Sefcovic
LONG TERM...Sefcovic
AVIATION...26
MARINE...Sefcovic