227
FXUS61 KBUF 031033
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
633 AM EDT Mon Jun 3 2024

.SYNOPSIS...
Weak high pressure will build across the region, resulting in
mainly dry weather through Tuesday, although an isolated shower
or thunderstorm can`t be ruled out during the afternoon hours.
Above average temperatures will prevail the first half of the
work week before a cold front brings showers and thunderstorms
later Wednesday through Thursday. The front will also usher in
cooler temperatures by late in the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Weak low pressure will exit off the New England coast, but it
will leave a lot of boundary layer moisture in its wake. This
will result in lots of cloud cover this morning. Patchy fog
across the Western Southern Tier early this morning will
dissipate later this morning. Otherwise, a partial clearing and
mainly dry weather today as weak mid-level ridging builds into
the region. That said, an isolated shower or thunderstorm will
still be possible during peak heating where low level convergence
is enhanced by differential heating, terrain, and lake breeze
boundaries. Highs will range from the mid 70s to low 80s.

Any showers will taper off by this evening, with rain-free
weather under weak ridging at the surface and aloft.
Considerable breaks in the cloud cover should allow radiation
fog to develop at some locations tonight. This could be locally
dense in the Southern Tier river valleys.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
Tuesday an upper level ridge axis will remain over our region. While
there will be a fair amount of instability, MUCAPE values over 1,000
J/KG, there is not much of a lifting mechanism (front, convergent
boundary, shortwave trough aloft) and subsidence from this upper
level ridge, along with some drier air aloft, will keep any
afternoon convection isolated. Greatest area for any showers or
thunderstorms will be the Genesee Valley and Finger Lakes region,
closest to the area of highest instability. Evening convection, that
will now include east of Lake Ontario region, will wane with lower
instability overnight.

Of note will be the temperatures Tuesday. Aloft, 850 hPa
temperatures +14 to +16C will aid in afternoon highs well into the
80s. Comfort levels will begin to lower with the humidity also
building through the afternoon. Some stickiness will become apparent
by the evening as temperatures cool some, wind flow relaxes and
boundary layer moisture increases.

Wednesday through Thursday will be a much different story. A warm
front will usher in deeper moisture from the Southeast, with PWAT
values reaching 1.75 inches. In addition to the remaining warmth in
the 80s, dewpoints will rise into the mid 60s with a humid day for
our region. Aloft a shortwave trough with multiple convective vort
maxes will pass over our region Wednesday and Wednesday night. This
will bring multiple rounds of showers and thunderstorms, first with
the warm front, then an additional line of storms within a muggy
Wednesday night as a cold front crosses the region. MUCAPE values of
1,000 to 1,500 J/Kg will maintain thunder chances, but 0-6 km bulk
shear values of 25 to 30 knots will keep severe potential low. There
will be the threat for heavy downpours within this moisture rich
airmass, with potential for training storms ahead of the cold front
Wednesday night. The 25 to 35 knots of flow aloft should keep storms
moving, with any flooding concerns arising from training clusters of
storms.

By Thursday the focus for storms will be to the east, ahead of the
cold front and still within a moisture rich environment. There is
still lacking much wind shear, thus the severe threat will be
low...with again moderate to heavy downpours being the bigger focus.
Behind the cold front an closing upper level low will rotate down
towards our region. Moist, cyclonic flow aloft will bring renewed
chance for showers, albeit much lighter now that we are behind the
axis of deeper moisture.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A closed upper level low will drop across our region this period,
with cooler but unsettled conditions. Multiple shortwave rotating
around this upper level low, combined with steepening lapse rates
will maintain showers and thunderstorm chances each day right
through this period.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
For the most part, the stratus cloud deck prevented fog from
forming last night. The exception is the Western Southern Tier
(including KJHW) where fog did develop last night. This fog will
dissipate this morning, and the stratus will gradually lift and
scatter out through this afternoon. Ridging at the surface and
aloft will support mainly rain free weather outside of isolated
showers or storms this afternoon which will be driven by diurnal
instability.

There`s risk for more localized (but possibly dense) fog
tonight. With light winds this will depend on breaks in the
mid-level clouds with the greatest risk for fog in the Western
Tier Valleys (again including KJHW).

Outlook...

Tuesday...VFR.
Wednesday...Mainly VFR with a chance for showers and thunderstorms,
especially in the afternoon.
Wednesday night and Thursday...Areas of MVFR with showers and
thunderstorms likely.
Friday...VFR/MVFR with a chance of showers. Chance of a few spotty
thunderstorms Friday afternoon and evening.

&&

.MARINE...
A weak pressure gradient will continue to maintain light winds and
minimal waves into mid-week.

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...AR/Apffel
NEAR TERM...AR/Apffel
SHORT TERM...Thomas
LONG TERM...Thomas
AVIATION...Apffel
MARINE...AR/Apffel