049
FXUS61 KBUF 151834
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
234 PM EDT Sun Jun 15 2025

.SYNOPSIS...
Outside of a few spotty showers at times, Canadian high pressure
will keep mostly dry and comfortable weather in place through
Monday. A series of low pressure systems will then lift a stalled
boundary to our south back northwards as a warm front Tuesday,
bringing warmer and increasingly unsettled conditions through
midweek.

&&

.NEAR TERM /THROUGH MONDAY/...
Sprawling sfc high pressure will gradually shift east across
southern Ontario and Quebec provinces through tonight as a stalled
frontal boundary remains well to our south across the Ohio Valley
and Mid-Atlantic states. A weak inverted trough draped between these
two features will linger across Western and North Central NY, with
some remnant low-level moisture mainly south of the lakes. This will
result in just patchy stratus and strato-cu mostly across the
interior areas, which could manifest as some patchy fog overnight.
Outside of a spot shower or two however, mainly dry weather will
prevail through tonight.

While the boundary and moisture to our south won`t budge much, the
high will loosen its grip over our region Monday as it further
shrinks into the northwestern Atlantic. With less of a stabilizing
influence, diurnal heating and perhaps some weak lake breeze
convergence could allow for bit more in the way of nuisance shower
activity across the forecast area in the afternoon. Confidence
remains relatively low in overall coverage though chances look
greatest across the Niagara Frontier and around the Tug Hill/Western
Dacks.

&&

.SHORT TERM /MONDAY NIGHT THROUGH THURSDAY/...
On Tuesday the next shortwave trough will move east across the Ohio
Valley and Lower Great Lakes...and as it does so will encourage the
stalled-out frontal boundary to our south to start to slowly make
its way back north as a warm front. Weak to modest warm advection/
isentropic upglide out ahead of this feature will spread increasing
moisture and lift across our area during Tuesday...which in turn
will result in a general southwest-northeast increase in shower
potential as we push through the day. This will particularly be the
case during the afternoon hours...when destabilization from diurnal
heating will come into play and could also lead to a few thunder-
storms across far western New York. At this point pcpn coverage
continues to generally look on the scattered side...save for across
the Southern Tier and interior Finger Lakes...which will lie closer
to the warm front and where convection may thus be a bit more
numerous.

As we move into Tuesday night the shortwave trough will slide off to
our east. Coupled with nocturnal stabilization...this should lead to
a general decrease in convective coverage Tuesday evening. This
said...with the aforementioned warm front temporarily stalling out a
little to our south in the wake of this wave and a second...
northern stream shortwave trough over northern Ontario/Quebec trying
to push a weakening cool front into our area from the northwest...a
few more showers/isolated storms will remain possible through the
night.

What will also be rather noticeable Tuesday and Tuesday night will
be the arrival of notably more humid air across our region...with
surface dewpoints rising into the mid to upper 60s during the day
Tuesday...then remaining in this general vicinity Tuesday night. As
such...Tuesday will have a much more muggy and summerlike feel than
Monday in spite of similar high temperatures...with the more humid
airmass then keeping lows from falling much below the mid to upper
60s Tuesday night.

Then as we push into the midweek period...a phasing shortwave
pattern will carve out a deeper longwave trough across the Great
Lakes Wednesday through Thursday...with a strengthening wave of
surface low pressure and piece of shortwave energy ahead of this
trough tracking northeastward from the upper Midwest to Quebec. This
will help to finally lift the warm front through our area sometime
between Wednesday afternoon and Wednesday night...with a downright
soupy midsummer airmass (surface dewpoints of near 70F and 850 mb
temps in the mid to upper teens) overspreading our area in its wake.
Coupled with daytime heating and the arrival of a southwesterly low
level jet...the approach and passage of the warm front will bring a
renewed potential for showers and thunderstorms Wednesday and
Wednesday night...with additional convection likely on Thursday
attendant to the system`s trailing pre-frontal trough and cold
front. While the exact details and timing of all this remains murky
at this range...the general setup may be supportive of heavy
rainfall and more robust convection should all parameters come into
favorable alignment. Needless to say...this is a time frame that
will need to be closely watched over the coming days.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
As we move into the long term portion of the forecast...convection
should tend to quickly wane in the wake of the cold front Thursday
night...though a few showers/isolated storms could linger into
Friday in association with the passage of the supporting upper level
trough axis. Otherwise it will briefly turn cooler and much less
humid to end the work week...before burgeoning upper level ridging
amplifies across the central/eastern CONUS next weekend into the
beginning of the following week. This would bring increasing heat
and humidity back into our region over the weekend (especially for
Sunday)...along with at least a low potential for some MCS-type
shower and thunderstorm activity as the upper level ridge axis
amplifies across the western/central Great Lakes.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
High pressure will gradually shift across southeastern Canada into
Monday as a stalled boundary remains well to the south over the Ohio
Valley. Mainly VFR weather should prevail at the TAF sites through
this evening as the former exerts its stabilizing influence over the
region, though moisture circulating northward from the latter will
result in stubborn patchy stratus and strato-cu. Cigs will be a mix
of MVFR to low VFR across the higher terrain areas of the Southern
Tier through early evening, with IFR or lower with patchy fog
possible later tonight. Low confidence in impacts to cigs/vsbys at
KJHW. VFR will prevail further north with limited clearing.

While some improvement to cigs/vsbys is expected Monday morning, the
weakening influence of the high to the northeast will likely allow
for more low VFR diurnal cu and scattered to isolated shower
activity across the Niagara Frontier, mainly after 18z.

Outlook...

Monday night...Mainly VFR. Chance of showers with lowering cigs
across the Southern Tier late.

Tuesday...Mainly VFR with a chance of showers and thunderstorms,
especially southern portions of the area.

Wednesday and Thursday...VFR/MVFR with showers and thunderstorms
likely.

Friday...Mainly VFR. A chance of showers and thunderstorms,
mainly east of KROC.

&&

.MARINE...
Canadian high pressure will shift across Quebec to the northwestern
Atlantic through Monday as several weak waves of low pressure ripple
along a stalled frontal boundary across the Ohio Valley. This will
result in light to modest northeasterly breezes across the lakes and
minimal wave action across the nearshore waters.

The high will move further out to sea as a more potent low pressure
system tracks from the Upper Great Lakes Monday night to southern
James Bay by Tuesday evening. This will cause winds to initially
shift southeasterly before turning south/southwesterly through
Wednesday, though SCA conditons are not expected. Choppier
conditions will likely form Thursday as a more potent system and
associated cold front move across the lakes.

&&

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

&&

$$

SYNOPSIS...PP
NEAR TERM...PP
SHORT TERM...JM/JJR
LONG TERM...JM/JJR
AVIATION...PP
MARINE...PP