584
FXUS61 KCLE 011021
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
621 AM EDT Mon Jul 1 2024

.SYNOPSIS...
A ridge affects our region through Tuesday as the parent high
pressure center moves from the western Great Lakes to southern New
England. This ridge exits eastward Tuesday night as a warm front
sweeps northward through northern Ohio and northwest Pennsylvania. A
weak cold front is still poised to sweep southeastward through our
region Wednesday night and be followed by a weak ridge building from
the western Great Lakes through Thursday.

&&

.NEAR TERM /THROUGH TUESDAY/...

6:20 AM EDT Update...
Forecast remains valid per latest trends in obs and model
guidance. No changes appeared necessary.

Previous Discussion...
A ridge aloft continues to build from the Great Plains and then
begins to crest E`ward over our CWA on Tuesday. Simultaneously,
the surface portion of this ridge continues to affect northern
OH and NW PA as its parent high pressure center moves from the
western Great Lakes to southern New England. Stabilizing
subsidence accompanying the ridge will allow fair weather to
persist. Despite CAA continuing at the surface, daytime heating
combined with a lowering and strengthening subsidence inversion
will allow high temperatures to reach mainly the lower to mid
70`s late this afternoon. These readings are about 10F below-
average for July 1st. Mainly clear sky and weak winds/low
humidity at the surface will promote efficient radiational
cooling this evening through daybreak Tuesday morning, when lows
are expected to reach mainly the 50`s. However, lows are
forecast to reach the upper 40`s in the interior valleys of NW
PA, while the Lake Erie Islands will have lows reach the 60`s
courtesy of a weak onshore surface flow from ~72F Lake Erie
reducing nocturnal cooling. A weak synoptic MSLP gradient and
sufficient daytime heating of surrounding land will allow a Lake
Erie lake breeze to occur during the late morning through early
evening hours of Tuesday. The lake breeze is expected to
penetrate up to two miles or so inland since slight strengthening
of the synoptic MSLP gradient is forecast through the day as
the aforementioned surface ridge interacts with a
developing/deepening surface low in vicinity of the CO plains.
Late afternoon highs are expected to reach the upper 70`s to
lower 80`s in NW PA and mainly the lower to mid 80`s in northern
OH as daytime heating is complemented by developing/strengthening
synoptic WAA along the western flank of the low-level ridge.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
Unfortunately, the midweek weather forecast, including the
Independence Day holiday, appears active with likely shower and
thunderstorm chances on Wednesday and Thursday. Storms could have
both severe and flooding potential and will need to be monitored
going forward. Tuesday night will be dry, but temperatures will
remain elevated with warm advective return flow across the region.
This flow will allow for dew points to return into the 60s in time
for Wednesday, when a cold front will approach and cross the region.
The timing of the front will be problematic, approaching the area
during peak heating and as the entrance region of a jet streak
passes to the north. There should be plenty of instability and lift
to allow for widespread showers and storms across the region and
have likely PoPs. The instability will also allow for storms to
reach strong to severe levels and the entire area is highlighted in
a Day 3 Marginal Risk for severe weather and portions of our central
Ohio counties are in a higher level Slight Risk for Wednesday
afternoon/evening. The front will push south Wednesday night but
stall somewhere across Ohio. The trends are that the front will
remain closer to the Ohio River, but any northern trend will allow
for possible repeated rain chances into Thursday. For now, will
blend with the front well south that will just allow for scattered
shower and storm chances on Thursday. Some instability in the region
will allow for some conditional strong to severe storm chances, but
lower confidence than Wednesday at this point. Repeated rounds of
rain on Wednesday and Thursday will pose a flooding threat for some
of the area. Temperatures will be warm ahead of the cold front on
Wednesday, likely into the upper 80s and lower 90s. Temperatures
will be more seasonable on Thursday in the 80s.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
An unsettled weather pattern will continue into Friday and probably
Saturday as well. The front from mid-week over the Ohio Valley will
get lifted back north across the area on Friday, as a low pressure
system moves through the Great Lakes region. Have a mix of chance to
likely PoPs on Friday to account for this synoptic setup. The low
will trail a cold front across the region on Saturday, which could
generate some scattered showers and storms during the afternoon and
have some lower PoPs in the 20-30% range. Some form of high pressure
will enter the region for Sunday and will likely end up allowing for
a dry day in the forecast. There is some disagreement on the arrival
of the next system early next week, which will prevent a dry
forecast for now, but believe that Sunday will trend to dry.
Temperatures appear seasonable in the mid 80s for the weekend.

&&

.AVIATION /12Z Monday THROUGH Friday/...
VFR and fair weather expected through 12Z/Tues as a ridge aloft
continues to build from the Great Plains. Simultaneously, the
surface portion of this ridge continues affecting our region as
the core of the surface ridge moves from the western Great Lakes
toward central NY. Accordingly, our regional surface winds
remain around 5 to 10 knots and veer gradually from N`erly to
NE`erly to SE`erly. Few to scattered lake-effect stratocumuli
continue to stream generally SSW`ward from Lake Erie before
dissipating by 15Z/Mon due, in part to continued low-level dry
air advection.

Outlook...Non-VFR expected in periodic showers and thunderstorms
this Wednesday through Friday.

&&

.MARINE...
Locally enhanced north to northeast flow over the central basin of
Lake Erie will allow for 4 ft waves to continue over the next couple
of hours and have the Small Craft Advisory and Beach Hazards
Statement continuing through 8 AM. Northeast flow will diminish
through the day today as high pressure settles into the region and
marine weather conditions will improve through evening. High
pressure will move east for Tuesday and southeast return flow will
start to overtake Lake Erie. A warm front will approach the lake
during the daytime hours and likely hang around the southern shore
by afternoon, allowing for more easterly flow over the water and
southeast flow on land for a brief period. The front will clear the
lake on Tuesday night and southerly flow will be favored, increasing
on Wednesday as a cold front approaches. There could be a need for a
brief Small Craft Advisory on Wednesday with the stronger offshore
flow. The cold front will cross the lake by Wednesday night and
light westerly flow will become favored across the basin. The front
will stall over the Ohio Valley for Thursday and light generally
offshore flow will be favored. This front will get lifted back north
toward and across the lake on Friday and southerly flow will be
enhanced a bit. There will be shower and storm chances for Wednesday
through Saturday with an unsettled weather pattern in place. Some
storms may need a short fused marine warning headline, especially on
Wednesday.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Beach Hazards Statement until 8 AM EDT this morning for
     OHZ009>012-089.
PA...Beach Hazards Statement until 8 AM EDT this morning for PAZ001.
NY...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for
     LEZ144>149.

&&

$$

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