Severe Thunderstorm Warning 97, NWS Buffalo, NY

514 
WWUS51 KBUF 012121
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
521 PM EDT Tue Sep 1 2026

NYC003-012130-
/O.EXP.KBUF.SV.W.0097.000000T0000Z-260901T2130Z/
Allegany NY-
521 PM EDT Tue Sep 1 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ALLEGANY COUNTY
WILL EXPIRE AT 530 PM EDT...

The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

&&

LAT...LON 4202 7800 4213 7775 4200 7775 4200 7798
TIME...MOT...LOC 2120Z 326DEG 28KT 4191 7770 

$$

HSK

Area Forecast Discussion
National Weather Service Buffalo NY
317 PM EDT Tue Sep 1 2026

.WHAT HAS CHANGED...
The forecast remains on track per latest trends in obs and model
guidance. No major changes with this update.

&&

.KEY MESSAGES...
1) Periodic showers and thunderstorms are expected through
Thursday. Some storms may be severe through this early evening
and especially on Wednesday into Wednesday night.

2) Quieter weather, overall, expected Thursday night into Friday.

&&

.DISCUSSION...
KEY MESSAGE 1...Periodic showers and thunderstorms are expected through
Thursday. Some storms may be severe through this early evening
and especially on Wednesday into Wednesday night.

Aloft, W'erly to WNW'erly 500 mb flow near 40 to 50 knots and
embedded mid/upper-level shortwave troughs affect Western and
Central NY through Thursday. At the surface, a synoptic front,
augmented by Lake Erie and Lake Ontario lake breezes, will
remain nearly-stationary between the southern shore of Lake
Ontario and the northern shore of Lake Erie in/near our forecast
area through this early evening. The front is then expected to
drift N'ward and across Lake Ontario later this evening through
early Wednesday afternoon as a low wobbles E'ward across
northern ON to near James Bay. An especially-humid air mass
originating over the Gulf will reside in the warm sector,
generally south of the front. Our entire CWA is then expected to
reside in the warm and very humid sector the rest of Wednesday
before a cold front sweeps SE'ward through our region during the
daylight hours of Thursday as the aforementioned low wobbles
farther E'ward across northern QC. Note: Note: periods of heavy
rainfall are possible ahead of the cold front, amidst unusually-
high PWAT values, through Thursday (see details farther below).

Daytime highs should reach mainly the mid 70's to mid 80's today
and Wednesday, and mainly the lower 70's to lower 80's on
Thursday as a cooler air mass overspreads our region behind the
cold front. The aforementioned high humidity ahead of and
especially behind the first above-mentioned front will
contribute to limited nocturnal cooling tonight and Wednesday
night. Lows are expected to reach mainly the 60's to near 70F
around daybreak Wednesday and Thursday, respectively.

Mainly fair weather is expected for the time being. Isolated
showers and thunderstorms remain possible through this early
evening along the synoptic front in vicinity of I-90 in Western
and Central NY. Rather dry mid-level air/resulting detrimental
entrainment of unsaturated ambient air and stabilizing
subsidence in the wake of a recent shortwave trough axis passage
will limit the potential for this convection to initiate. If
showers and storms do develop, a few severe storms with
damaging straight-line wind gusts are possible amidst moderate
boundary layer CAPE, moderate to strong deep-layer bulk shear,
and steep low-level lapse rates/moderate DCAPE. Any showers/storms
are expected to dissipate by mid-evening, in response to
boundary layer stabilization via nocturnal cooling.

After midnight tonight and through daybreak Wednesday, isolated
to scattered showers and thunderstorms are possible as far east
as roughly the Genesee Valley in our CWA, in response to moist
isentropic ascent ahead of a shortwave trough axis and low-level
convergence/moist ascent along an attendant surface trough axis
releasing weak to moderate CAPE, including elevated CAPE, amidst
moderate to strong effective bulk shear. Can't totally rule-out
a severe storm with damaging straight-line wind gusts since
modest nocturnal cooling should allow DCAPE to remain sizable
and prevent DCIN from being excessive. Additional rounds of
organized showers and thunderstorms are expected the rest of
Wednesday morning through Thursday, as deep-layer bulk shear
remains moderate to strong and at least weak to moderate CAPE,
including elevated CAPE, is released by the following: moist
isentropic ascent ahead of shortwave trough axes; low-level
convergence/moist ascent along surface trough axes attendant to
the shortwave troughs and along the warm and cold fronts;
downshear outflow boundaries interacting favorably with ambient
low-level vertical wind shear. The greatest coverage of showers
and thunderstorms is expected Wednesday afternoon through early
evening, when daytime heating in the warm/moist sector should
yield moderate to strong boundary layer CAPE. This is when
severe storms in the form of multicells, including bow echoes,
and supercells, appear most-likely. Damaging straight-line wind
gusts and damaging hail up to golf ball-size are expected to be
the main severe convective WX hazards due to the expectation of
steep low-level lapse rates/large DCAPE and mid-level lapse
rates near 7C/km contributing to sizable MUCAPE in the hail
growth zone. A tornado or two is possible since low-level winds
may veer and strengthen significantly with height, resulting in
sizable surface-based ESRH amidst favorably-low mixed layer
LCL's. Localized flash flooding is possible where showers and
storms manage to train, which should be the case along the warm
front and any outflow boundaries oriented roughly west-to-east,
which will be largely parallel to W'erly to WNW'erly mean mid-
level flow.

KEY MESSAGE 2...Quieter weather, overall, expected Thursday
night into Friday.

Mainly fair weather is expected Thursday night through Friday as
a surface high pressure ridge builds from northern ON and
vicinity, behind the cold front. However, NW'erly flow aloft and
embedded shortwave troughs will impact our region. Moist
isentropic ascent ahead of the shortwave trough axes and low-
level convergence/moist ascent along surface trough axes
attendant to the shortwaves may release weak, yet sufficient
instability, including elevated CAPE, to generate isolated
showers and thunderstorms, especially Thursday night. Lows
should reach mainly the mid 50's to lower 60's around daybreak
Friday. Highs should reach the 70's late Friday afternoon.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Stationary boundary remains, and will remain draped across the
western and north-central NY through the TAF period, allowing the
warm/humid airmass to persist across the region. The stalled
boundary currently bisects the area, stretching from eastern Lake
Ontario southeast into the eastern Finger Lakes/central NY. To the
west of front (KBUF/KIAG/KJHW/KROC) Mainly lower-end VFR cu decks
dominate, while to the east and northeast (KART) of said front, more
in the way of solid OVC marginal MVFR/lower-end VFR decks are in
place. Expect areas of marginal MVFR CIGS to continue across
portions of Central NY and the North Country, with mainly SCT-BKN
lower-end VFR across Western NY, the Genesee Valley, and western
Finger Lakes. A few isolated to widely scattered showers and
thunderstorms may develop this afternoon and evening, but most of
the time will be rain free. The best chance of a few spotty showers
and storms will be across the higher terrain of Central NY and the
North Country. A lake breeze driven convergence zone may also
support a few isolated thunderstorms from the Niagara Frontier east
across the Genesee Valley and western Finger Lakes from mid
afternoon through early evening.

Tonight, any isolated showers and storms will dissipate this evening
with the loss of daytime heating, with mainly dry weather prevailing
most of the night. A few showers and scattered thunderstorms may
arrive very late tonight or early Wednesday morning across western
NY from weakening convection upstream associated with a weak
shortwave trough. Plentiful low level moisture will again support
the development of fog and some low stratus during the second half
of tonight. Mainly light fog (possible MVFR VSBY) is expected across
the lower elevations, while thicker fog (or stratus intersecting the
hilltops) may develop across the higher terrain with IFR/LIFR flight
conditions possible.

Any fog should dissipate by mid morning or so, leaving mainly VFR
conditions through early afternoon on Wednesday, although low
stratus may take longer to erode across the higher terrain. Area of
showers/isolated storms associated with the aforementioned weak
shortwave trough located over western NY to start the day, will then
make there way from across the region through the first half of
Wednesday.

Outlook...

Wednesday afternoon through Wednesday night...Occasional showers and
thunderstorms, especially late Wednesday through Wednesday night.
Some storms may be strong with locally gusty winds, hail, and
torrential downpours. VFR/MVFR, with local IFR in storms.

Thursday...VFR/MVFR with a chance of showers and thunderstorms,
mainly across the Southern Tier and Finger Lakes.

Friday and Sunday...Mainly VFR. River valley fog with local IFR each
late night and early morning across the Southern Tier.

&&

.MARINE...
A frontal zone will remain draped across our region through
Wednesday night. Southwest winds up to 10 to 15 knots are
expected on Lake Erie through Wednesday, producing a light to
moderate chop. Winds will be lighter and more variable on Lake
Ontario due to the wavering frontal zone. The front will move
southeastward through the region Thursday and will be followed
by a high pressure ridge building from northern Ontario and
vicinity through Friday. West to northwest winds and a light
chop are expected behind the front. Winds, mainly northwest to
northeast, and waves will remain below Small Craft Advisory
criteria through the upcoming holiday weekend as the
aforementioned high pressure ridge continues to build.

There will be a chance of thunderstorms at times through midweek.
Thunderstorm chances will peak late Wednesday afternoon through the
first half of Wednesday night. Some of these storms may produce
strong winds, hail, and locally higher waves.

&&

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

&&

DISCUSSION...Jaszka
AVIATION...JM
MARINE...Hitchcock/Jaszka

Hazardous Weather Outlook
National Weather Service Buffalo NY
200 PM EDT Tue Sep 1 2026

NYZ001>005-010>014-019>021-085-022000-
Niagara-Orleans-Monroe-Wayne-Northern Cayuga-Northern Erie-Genesee-
Wyoming-Livingston-Ontario-Chautauqua-Cattaraugus-Allegany-
Southern Erie-
200 PM EDT Tue Sep 1 2026

This Hazardous Weather Outlook is for portions of western and north
central New York.

.DAY ONE...This afternoon and tonight.

Isolated severe thunderstorms are possible through this early
evening. Damaging wind gusts appear to be the main hazard with any
severe storm.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Several rounds of showers and thunderstorms with periods of heavy
rainfall are expected Wednesday through Wednesday night. Some storms
may be severe with damaging wind gusts and hail, respectively. A
tornado or two and localized flash flooding are possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

NYZ006>008-022000-
Oswego-Jefferson-Lewis-
200 PM EDT Tue Sep 1 2026

This Hazardous Weather Outlook is for portions of central New York.

.DAY ONE...This afternoon and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Several rounds of showers and thunderstorms with periods of heavy
rainfall are expected Wednesday through Wednesday night. Some storms
may be severe with damaging wind gusts and hail, respectively. Localized
flash flooding are possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

LEZ040-041-LOZ042>045-062>065-022000-
Lake Erie nearshore waters from Ripley to Dunkirk-
Lake Erie nearshore waters from Dunkirk to Buffalo-
Lake Ontario nearshore waters from the Niagara River to Hamlin Beach-
Lake Ontario nearshore waters from Hamlin Beach to Sodus Bay-
Lake Ontario nearshore waters from Sodus Bay to Mexico Bay-
Lake Ontario nearshore waters from Mexico Bay to the Saint Lawrence
River-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
Lake Ontario open waters from Hamlin Beach to Sodus Bay-
Lake Ontario open waters from Sodus Bay to Mexico Bay-
Lake Ontario open waters from Mexico Bay to the Saint Lawrence River-
200 PM EDT Tue Sep 1 2026

This Hazardous Weather Outlook is for portions of Lake Erie and Lake
Ontario.

.DAY ONE...This afternoon and tonight.

Isolated severe thunderstorms are possible through this early
evening. Damaging wind gusts appear to be the main hazard with any
severe storm.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Several rounds of showers and thunderstorms with periods of heavy
rainfall are expected Wednesday through Wednesday night. Some storms
may be severe with damaging wind gusts and hail, respectively.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

SLZ022-024-022000-
Saint Lawrence River from Cape Vincent to Ogdensburg-
Saint Lawrence River from Ogdensburg to Saint Regis-
200 PM EDT Tue Sep 1 2026

This Hazardous Weather Outlook is for the New York waters of the
Saint Lawrence River.

.DAY ONE...This afternoon and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Several rounds of showers and thunderstorms with periods of heavy
rainfall are expected Wednesday through Wednesday night. Some storms
may be severe with damaging wind gusts and hail, respectively.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

LEZ020-LOZ030-022000-
Upper Niagara River and Buffalo Harbor-Lower Niagara River-
200 PM EDT Tue Sep 1 2026

This Hazardous Weather Outlook is for portions of Lake Erie and Lake
Ontario.

.DAY ONE...This afternoon and tonight.

Isolated severe thunderstorms are possible through this early
evening. Damaging wind gusts appear to be the main hazard with any
severe storm.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Several rounds of showers and thunderstorms with periods of heavy
rainfall are expected Wednesday through Wednesday night. Some storms
may be severe with damaging wind gusts and hail, respectively.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf