259
FXUS61 KBUF 311013
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
613 AM EDT Mon Aug 31 2026

.WHAT HAS CHANGED...
Minor changes to the forecast with this forecast update.

&&

.KEY MESSAGES...
1) Unsettled weather will continue through much of the week with
occasional rounds of showers and thunderstorms, including some
potential for severe thunderstorms Tuesday and Wednesday.

2) Warm and very humid Tuesday through Wednesday.

&&

.DISCUSSION...
KEY MESSAGE 1...Unsettled weather will continue through much of the
week with occasional rounds of showers and thunderstorms, including
some potential for severe thunderstorms Tuesday and Wednesday.

A persistent northwest to southeast oriented frontal zone over the
Great Lakes will continue to bring an extended period of active
weather through midweek. A multitude of low amplitude mid level
shortwaves will traverse the northern periphery of a strong ridge
over the central US, with each one bringing a period of enhanced
ascent to the Great Lakes. The shortwaves will also modulate the
frontal position, as will the influence of composite outflow and
cold pools from passing rounds of showers and thunderstorms.

The elevated frontal zone will remain stalled just upstream through
this morning, with associated isentropic ascent and moisture
transport supporting occasional showers across Western NY and into
the Genesee Valley and western Finger Lakes at times. Instability
will remain very limited through midday, with just a small chance of
some isolated thunder. Patchy fog will continue through mid morning
in some areas before dissipating.

This afternoon through tonight, the frontal zone will move gradually
northeast across the area, carrying the most widespread showers
eastward with time. The most widespread rain this afternoon will be
found from Western NY into the Finger Lakes, gradually drifting into
Central NY and the North Country late today and tonight. Instability
will remain limited today through tonight given extensive cloud
cover and showers, but just enough tall/skinny CAPE may develop this
afternoon through tonight to support a few isolated to widely
scattered thunderstorms.

Tuesday through Tuesday night, northwest flow aloft will continue
across the Great Lakes, with the frontal zone draped from the Nickel
Belt of Ontario to central or eastern NY. Greater instability will
develop Tuesday than recent days as surface temperatures climb into
the 80s and rich boundary layer moisture arrives. Isolated to widely
scattered showers and storms may develop Tuesday along lake breeze
and other local boundaries with daytime heating and continue through
at least Tuesday evening. That said, a lack of synoptic scale
forcing and warm mid level temperatures may keep convective coverage
limited. While SPC has maintained a slight risk of severe for
Tuesday through Tuesday night from Western NY into the Finger Lakes,
this risk may end up being quite isolated and conditional on
sufficient forcing.

The most active day of the period still appears to be Wednesday. A
stronger shortwave will move east across Ontario and Quebec, forcing
a belt of stronger mid level flow to develop across the Great Lakes.
Height falls and DPVA will spread southeast across the Great Lakes
Wednesday afternoon through Wednesday night, with increasing large
scale ascent. An EML plume is forecast to advect ENE through the
Ohio Valley, with the northeastern tail of the EML possibly
extending into the eastern Great Lakes Wednesday.

Strong instability developing beneath EML induced capping will
advect towards the eastern Great Lakes and help set the stage for
potential severe weather Wednesday afternoon and evening once large
scale forcing arrives and helps to overcome the EML induced cap.
Forecast soundings show an impressive juxtaposition of moderate to
strong shear and strong instability by Wednesday afternoon, which
may support a notable severe weather risk. This potential is still a
few days away however, and the finer mesoscale details and timing of
prominent forcing will ultimately drive the evolution of convection
and potential for severe storms. Stay tuned.

The mid level trough will deepen across Quebec Thursday through
Friday, pushing the frontal zone south and west with time. There may
still be a few scattered showers and thunderstorms Thursday as the
front moves south across the area, followed by a return to mainly
dry weather Friday as a more stable and drier airmass arrives from
Canada.

KEY MESSAGE 2...Warm and very humid Tuesday through Wednesday.

Humidity will begin to creep upward today, with dewpoints rising
into the upper 60s to near 70 across Western NY this afternoon.
Extensive clouds and showers will keep temperatures in the 70s
however.

Dewpoints will climb even higher Tuesday through Wednesday, reaching
the low to mid 70s on the lake plains resulting in an oppressive
feeling airmass. Temperatures will also climb into the 80s both
days, with a heat index possibly reaching the lower 90s at times.
The frontal zone will settle south again later in the week and help
to remove the oppressive humidity, with dewpoints dropping back to
more reasonable values Thursday and especially Friday.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
A stalled frontal zone just upstream will continue to produce
occasional showers through this morning across Western NY and into
the Genesee Valley and western Finger Lakes, with mainly dry weather
east of the Genesee Valley. The chance of thunder will remain low
through the morning hours, although an isolated weak thunderstorm or
two cannot be ruled out across the western Southern Tier. Areas of
low stratus and patchy fog will persist through the morning hours
with areas of MVFR/IFR conditions.

This afternoon through tonight, the stalled frontal zone will move
gradually eastward across the region as a warm front. Associated
forcing and moisture convergence will carry numerous rounds of
showers and a few isolated thunderstorms eastward with time. The
most persistent showers from Western NY to the Finger Lakes this
afternoon will trend eastward into Central NY and the North Country
tonight. Widespread MVFR CIGS will continue along and east of the
frontal zone this afternoon through tonight, with some IFR at times
tonight across Central NY and higher terrain.

Outlook...

Tuesday through Thursday...VFR/MVFR with occasional rounds of
showers and thunderstorms. Storms and heavier showers will produce
brief/local IFR.

Friday...Mainly VFR with a slight chance of a shower.

&&

.MARINE...
A northwest to southwest orientated frontal zone will remain draped
across the Great Lakes much of the week. The frontal position will
oscillate back and forth several times across the lower Great Lakes,
flipping the wind direction at times. Winds will occasionally
increase into the 10-15 knot range producing choppy conditions on
both lakes, but winds and waves are expected to remain below Small
Craft Advisory criteria through the week.

There will be a chance of thunderstorms at times, especially Tuesday
through Wednesday. A few storms may contain locally higher winds and
waves.

&&

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

&&

$$

DISCUSSION...Hitchcock
AVIATION...Hitchcock
MARINE...Hitchcock