Special Marine Warning 113, NWS Buffalo, NY

Area Forecast Discussion
National Weather Service Buffalo NY
314 PM EDT Wed Sep 2 2026

.WHAT HAS CHANGED...
The SPC now has our entire forecast area in a slight to
enhanced risk of severe thunderstorms this afternoon into
tonight. The greatest risk for severe thunderstorms exists in
Western NY and the Finger Lakes. The likeliest window for severe
storms appears to be from 4 PM to 11 PM EDT this evening.
Please see discussion below for further details.

&&

.KEY MESSAGES...
1) Periodic showers and thunderstorms are expected through Thursday.
Some storms will be severe later this afternoon and evening.

2) Quieter weather, overall, expected Thursday night through
Saturday.

&&

.DISCUSSION...
KEY MESSAGE 1...Periodic showers and thunderstorms are expected through
Thursday. Some storms will be severe later this afternoon and evening.

W'erly to WNW'erly mid/upper-level flow near 40 to 60 knots and
embedded shortwave disturbances affect our region through
Thursday. At the surface, our CWA resides within a warm and very
humid sector originating over the Gulf before a cold front
sweeps E'ward through Western and Central NY between about 2 AM
and 9 AM EDT Thursday morning. This warm and very humid air mass
will contribute to periods of heavy rainfall with showers and
storms (more details below). Behind the cold front, an extensive
high pressure ridge associated with a cooler and drier air mass
begins to build from northern ON and vicinity. High temperatures
are expected to reach mainly the mid 70's to mid 80's this
afternoon and be followed by overnight lows in the 60's around
daybreak Thursday. Highs should reach the 70's to 80F late
Thursday afternoon.

As of 2:50 PM EDT, a broken line of showers and thunderstorms,
including supercells, had already developed over southern ON,
along a pre-front surface trough axis. Periodic and organized
showers and thunderstorms amidst moderate to strong deep-layer
bulk shear are expected today through Thursday as 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 cold
front; downshear outflow boundaries interacting favorably with
ambient low-level vertical wind shear. Of greatest concern is
the aforementioned storms that have developed over southern ON.
These storms are expected to grow upscale into a QLCS consisting
of multicells, including bowing segments, and supercells as the
storms persist generally ESE'ward and impact our CWA late this
afternoon, and especially this evening, and encounter a pre-
storm environment that includes moderate to strong boundary
layer CAPE. Strong to damaging straight-line wind gusts are
expected as the storms encounter steep low-level lapse rates and
moderate to strong DCAPE stemming from diurnal convective
mixing of the boundary layer through this late afternoon and
then limited nocturnal cooling in the warm/moist sector boundary
layer this evening into tonight. Sporadic severe hail is
possible due to mid-level lapse rates near 7C/km contributing to
large MUCAPE in the hail growth zone, but rich low-level
moisture contributing to unfavorably-high ambient atmospheric
melting levels near 11kft AGL should curb the severe hail
threat, at least somewhat. A few tornadoes are possible with
mesocyclones and mesovortices, and a strong tornado cannot be
ruled out since low-level winds veering and strengthening
significantly with height should yield surface-based ESRH near
150-300 m2/s2 amidst favorably-low mixed layer LCL's. Localized
flash flooding is possible through tonight, especially where
showers and storms manage to train along any outflow boundaries
that manage to become oriented largely parallel to the W'erly to
WNW'erly mean mid-level flow.

KEY MESSAGE 2...Quieter weather, overall, expected Thursday night
through Saturday.

The surface high pressure ridge continues to build from
northern ON, and vicinity and humidity at the surface and aloft
continues to decrease gradually, Thursday night through
Saturday. However, northwesterly flow aloft and embedded
shortwave troughs will continue to impact our region through
Friday before the ridge aloft begins to build from the west
Friday night through Saturday. 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 Thursday
night through Friday. Current odds favor fair weather Friday
night through Saturday due to stabilizing subsidence
accompanying the ridge at the surface and aloft. Lows should
reach the mid 50's to mid 60's around daybreak Friday and mainly
the upper 40's to near 60F around daybreak Saturday as the
cooler air mass associated with the ridge continues to
overspread Western and Central NY. Late afternoon highs should
reach the 70's on Friday and the mid 60's to mid 70's on
Saturday. Note: partial clearing, the cooler air mass, lingering
low-level moisture, and weak surface winds should yield steam
fog in the river and lake valleys east of Lake Ontario, in the
Finger Lakes, and in the Western Southern Tier around daybreak
Friday and Saturday, respectively.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Stubborn stationary boundary will remain draped across western and
north-central NY through the first half of tonight, before a cold
front moves into the region late tonight through Thursday morning,
finally shoving the stalled boundary south and east of the area.
Otherwise, convection from earlier in the day has moved south and
east, leaving mainly VFR conditions with just a few spotty light
showers over the Finger Lakes region currently.

Next round of showers and storms can already be seen forming off to
the west and will get in here later this afternoon and evening. Some
storms may become severe, with the main threats being severe level
wind gusts and isolated strong tornadoes, with the main window being
from around 19Z this afternoon through 03Z this evening. Large hail
is a lesser threat, but will also be possible. Expect IFR to VLIFR
flight conditions within any stronger storms through late this
evening, with mainly VFR expected outside of convection.

Though most, if not all of the severe threat will diminish by around
midnight, showers and scattered storms are expected to continue into
the second half of tonight ahead of the approaching cold front.
Showers and storms will start to taper off from north to south late
tonight through Thursday morning as the cold front presses slowly
south across the region. Otherwise, near-saturated low levels will
promote the development of fog and low stratus again tonight, with
MVFR to LIFR conditions expected. The worst conditions are expected
to be across the higher terrain.

Most of the fog and low stratus will slowly dissipate through
Thursday morning, with the majority of the area expected to see a
return to drier weather and VFR by late Thursday morning/midday,
although a few showers and storms and MVFR may linger across the
Southern Tier into the afternoon hours.

Outlook...

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

&&

.MARINE...
S'erly to SW'erly winds up to 10 to 15 knots are expected on
Lakes Erie and Ontario before a cold front sweeps E'ward across
the lakes overnight tonight through about mid-morning on
Thursday. The front will be followed by a high pressure ridge
building from northern Ontario and vicinity. Behind the front,
W'erly to NW'erly winds around 10 to 15 knots and waves of 3
feet or less are expected through Friday. Light and variable
winds and waves remaining 3 feet or less are expected this
Friday night through Monday as the aforementioned ridge
continues to build into our region.

There will be a chance of thunderstorms at times through
Thursday. 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...Jaszka

Hazardous Weather Outlook
National Weather Service Buffalo NY
443 PM EDT Wed Sep 2 2026

NYZ001>008-010>014-019>021-085-032045-
Niagara-Orleans-Monroe-Wayne-Northern Cayuga-Oswego-Jefferson-Lewis-
Northern Erie-Genesee-Wyoming-Livingston-Ontario-Chautauqua-
Cattaraugus-Allegany-Southern Erie-
443 PM EDT Wed Sep 2 2026

...TORNADO WATCH 645 IN EFFECT UNTIL 11 PM EDT THIS EVENING...

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

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Tornado Watch.

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

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Hazardous weather is not expected at this time.

.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

LEZ020-040-041-LOZ030-042>045-062>065-032045-
Upper Niagara River and Buffalo Harbor-
Lake Erie nearshore waters from Ripley to Dunkirk-
Lake Erie nearshore waters from Dunkirk to Buffalo-
Lower Niagara River-
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-
443 PM EDT Wed Sep 2 2026

...TORNADO WATCH 645 IN EFFECT UNTIL 11 PM EDT THIS EVENING...

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

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Tornado Watch.

Several rounds of showers and thunderstorms with periods of heavy
rainfall are expected today through tonight. Some storms may be
severe with damaging wind gusts and hail, respectively. A waterspout
or two are possible.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Hazardous weather is not expected at this time.

.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

SLZ022-024-032045-
Saint Lawrence River from Cape Vincent to Ogdensburg-
Saint Lawrence River from Ogdensburg to Saint Regis-
443 PM EDT Wed Sep 2 2026

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

.DAY ONE...Tonight.

Several rounds of showers and thunderstorms with periods of heavy
rainfall are expected today through tonight. Some storms may be
severe with damaging wind gusts and hail, respectively. A waterspout
or two are possible.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Hazardous weather is not expected at this time.

.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

Preliminary Local Storm Report
National Weather Service Buffalo NY
136 PM EDT Wed Sep 2 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0825 AM     Tstm Wnd Dmg     Batavia                 43.00N 78.18W
09/02/2026                   Genesee            NY   Utility Company

            Several hundred power outages in and around
            Batavia caused by tree limbs and/or damage
            to electrical lines.

&&

SGK

Preliminary Local Storm Report
National Weather Service Buffalo NY
624 PM EDT Wed Sep 2 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0619 PM     Tstm Wnd Dmg     2 SSW Castile           42.61N 78.07W
09/02/2026                   Wyoming            NY   911 Call Center

            Tree down across 19A.

&&

Preliminary Local Storm Report
National Weather Service Buffalo NY
625 PM EDT Wed Sep 2 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0620 PM     Tstm Wnd Dmg     2 NW Portageville       42.60N 78.07W
09/02/2026                   Wyoming            NY   911 Call Center

            Tree and wires down on 19A.

&&

Preliminary Local Storm Report
National Weather Service Buffalo NY
630 PM EDT Wed Sep 2 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0621 PM     Tstm Wnd Dmg     1 WNW Portageville      42.58N 78.06W
09/02/2026                   Wyoming            NY   911 Call Center

            Tree and wires down on 19A/ Route 436.

&&

Preliminary Local Storm Report
National Weather Service Buffalo NY
644 PM EDT Wed Sep 2 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0625 PM     Tstm Wnd Dmg     Portageville            42.58N 78.04W
09/02/2026                   Livingston         NY   911 Call Center

            Tree down on Portageville Road.

&&