175
FXUS61 KBUF 032042
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
442 PM EDT Mon Jun 3 2024

.SYNOPSIS...
Fair dry weather will be found throughout the vast majority of the
region through at least Tuesday night...as weak high pressure Lake
Ontario will move to the New England coast. It will then become
quite unsettled later Wednesday through Thursday. Meanwhile...the
warm humid weather will give way to noticeably cooler conditions for
the latter portion of the week.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
While weak surface-based high pressure will support partly to mostly
sunny skies late this afternoon...a brief isolated shower cannot be
ruled out inland from the lakes.

A well amplified upper level ridge will be parked over the Lower
Great Lakes tonight through Tuesday night...while the associated
area of sfc high pressure will move to the New England coast. This
scenario will keep general subsidence over the region with only a
slight chance for a shower Tuesday afternoon away from the lakes.

Temperatures will be above normal...particularly Tuesday into mid
week when the mercury will be solidly 10 degrees above early June
standards.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Wednesday will mark the start of unsettled weather that will last
into the weekend. The next upper level trough will pivot east across
the Great Lakes Wednesday, allowing for a shortwave trough with
multiple areas of vorticity to pass across the region through
Wednesday night. As such a warm front will advect in deeper moisture
from the Gulf States causing precipitable water values to peak
towards 1.75 inches. Due to the multiple waves of vorticity, expect
multiple rounds of showers and thunderstorms, first with the passing
of the warm front and then an additional line of storms late
Wednesday.

Expect mainly thunder chances through Wednesday and Wednesday night
as MUCAPE values will average between 1000 and 1500 J/kg. Preventing
these storms from becoming severe are the limited 0-6 km bulk shear
values of 25-30 knots, however these values are also supporting
storms to keep on moving through and therefore don`t expect flash
flooding to be an issue.

By Thursday, another round of showers and thunderstorms will be
possible with the passage of the cold front. While the environment
will be bountiful with moisture the severe parameters will be to the
east of the area. Overall expect heavy downpours to be the main
concern and don`t expect these storms to become severe.

In the wake of the front, a closing upper level low will rotate
south towards the eastern Great Lakes. With the moist cyclonic flow
overhead the renewed chances for showers will continue Thursday
night, through with the deeper axis of moisture now outside of the
region, showers will be on the lighter side.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Our weather will be dominated by a cool/moist cyclonic flow aloft
through the entire period. This will come in the form of a large
upper trough that will dominate the eastern third of the CONUS and
far western Atlantic basin. Within this large upper trough an upper
low is expected to close off and wobble about somewhere within the
bounds this trough. As is typical, long range model guidance
continues to struggle with a consensus on evolution and placement of
said feature, although at this point appears that it will most
likely be oscillating somewhere over the Northeast or Mid Atlantic
region.

In terms of sensible weather, not only will this keep daytime highs
at least a bit on the cooler side of average, but will also keep our
weather unsettled overall. Peak of any daily shower/storm activity
will reside during the afternoon/early evening hours when strong
surface heating and the persistent cool/moist cyclonic flow combine
to maximize instability. Highest concentration for showers/storms
will be along and inland of diurnally/mechanically driven lake
breeze circulations. Add to this the presence of smaller scale
embedded areas of shortwave energy consistently rotating about the
periphery of the upper low that will only enhance precipitation
chances, timing and placement of these features in relation to the
positioning of the upper low will be critical to the forecast. All
this said, in between these smaller scale features there will be dry
time built in, especially off peak heating hours. Stay tuned.

As alluded to above, daytime highs will likely remain at least a bit
below normal through the period overall. This will translate to
highs averaging in the upper 60s to low 70s. Being that we are now
well into June, if more insolation is seen over some portions of the
region during the afternoon hours, temperatures locally could easily
exceed expectations.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
Late this afternoon and early this evening...expanding lake shadows
will bring mainly clear skies near the lakeshores. Inland from
these...a SCT-BKN cumulus field of 3500-5000 feet will gradually
thin out with diminishing heating...though some localized 2500-3000
ft ceilings will be possible for a few more hours along a lake
breeze convergence zone situated in between KBUF and KIAG.

While fog is expected to redevelop over parts of the region
tonight...resulting in localized MVFR to IFR weather...the bulk of
the region will maintain VFR conditions.

Fair VFR conditions are then fully anticipated for Tuesday.

Outlook...

Wednesday...Mainly VFR with some showers and thunderstorms,
especially over the far western counties during the afternoon.
Wednesday night and Thursday...Areas of MVFR with showers and
thunderstorms likely.
Friday and Saturday...VFR/MVFR with showers and thunderstorms likely.

&&

.MARINE...
A weak pressure gradient will continue to maintain light to
modest winds and minimal waves into midweek.

A cold front will cross the eastern Great Lakes Wednesday night and
Thursday with a few rounds of thunderstorms likely. West to
southwest winds will increase on the lakes behind the cold front
Thursday through Friday with choppy conditions developing.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...RSH
NEAR TERM...JJR/RSH
SHORT TERM...EAJ
LONG TERM...JM
AVIATION...JJR/RSH
MARINE...AR/Apffel/JJR