Alert archive / New York / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 92, NWS Buffalo, NY

August 12, 2026Ontario County, New York

NWS Buffalo, NY issued this severe thunderstorm warning at Aug 12, 2026, 6:17 PM EDT for Ontario County, New York. It was in force for 58 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 12, 2026, 6:17 PM EDT (22:17 UTC)
Expired
Aug 12, 2026, 7:15 PM EDT
In force
58 min
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Ontario County, NY

The radar

The Buffalo radar (KBUF), 107 km from the middle of the area, began a volume at 22:19 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 12, 6:25 PM EDTTSTM WND DMG2 W Bristol, NYTree down across entire Silvernail Road.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 8 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 10.3 hours before the alert went out and 104 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Buffalo Intl Airport, NY at 12:00Z on 2026-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 590 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 12:00Z on 2026-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
590 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
739 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7

Open this sounding in Storm Lab

The text

As transmitted.

825 
WUUS51 KBUF 122217
SVRBUF
NYC069-122315-
/O.NEW.KBUF.SV.W.0092.260812T2217Z-260812T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
617 PM EDT Wed Aug 12 2026

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  Central Ontario County in western New York...

* Until 715 PM EDT.

* At 616 PM EDT, a severe thunderstorm was located near Bloomfield,
  or 11 miles west of Canandaigua, moving east at 25 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Geneva, Canandaigua, Bristol, Bloomfield, Rushville, Honeoye,
  Gorham, East Bloomfield, West Bloomfield, and Holcomb.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

If on or near Canandaigua Lake, get away from the water and move 
indoors or inside a vehicle. Remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4280 7759 4284 7759 4285 7758 4286 7755
      4289 7756 4294 7752 4294 7748 4295 7748
      4287 7698 4276 7697 4276 7731 4272 7735
TIME...MOT...LOC 2216Z 289DEG 22KT 4287 7750 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HSK
4 follow-up statements
209 
WWUS51 KBUF 122234
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
634 PM EDT Wed Aug 12 2026

NYC069-122315-
/O.CON.KBUF.SV.W.0092.000000T0000Z-260812T2315Z/
Ontario NY-
634 PM EDT Wed Aug 12 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR CENTRAL ONTARIO COUNTY...

At 634 PM EDT, a severe thunderstorm was located near Bristol, or
near Canandaigua, moving southeast at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Geneva, Canandaigua, Bristol, Bloomfield, Rushville, Gorham, Seneca
Castle, Cheshire, Cottage City, and Bristol Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

If on or near Canandaigua Lake, get away from the water and move 
indoors or inside a vehicle. Remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4277 7750 4294 7740 4287 7698 4276 7697
      4276 7731 4272 7735
TIME...MOT...LOC 2234Z 301DEG 23KT 4282 7736 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HSK
209 
WWUS51 KBUF 122246
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
646 PM EDT Wed Aug 12 2026

NYC069-122315-
/O.CON.KBUF.SV.W.0092.000000T0000Z-260812T2315Z/
Ontario NY-
646 PM EDT Wed Aug 12 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR EAST CENTRAL ONTARIO COUNTY...

At 646 PM EDT, a severe thunderstorm was located near Rushville, or 8
miles south of Canandaigua, moving east at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Geneva, Canandaigua, Rushville, Gorham, Seneca Castle, Cheshire,
Cottage City, Bristol Mountain, and Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

If on or near Canandaigua Lake, get away from the water and move 
indoors or inside a vehicle. Remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4274 7741 4292 7729 4287 7698 4276 7697
      4276 7731 4272 7735
TIME...MOT...LOC 2246Z 286DEG 13KT 4277 7730 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HSK
342 
WWUS51 KBUF 122257
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
657 PM EDT Wed Aug 12 2026

NYC069-122315-
/O.CON.KBUF.SV.W.0092.000000T0000Z-260812T2315Z/
Ontario NY-
657 PM EDT Wed Aug 12 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR EAST CENTRAL ONTARIO COUNTY...

At 657 PM EDT, a severe thunderstorm was located over Rushville, or 9
miles south of Canandaigua, moving east at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Geneva, Rushville, Gorham, Seneca Castle, and Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4290 7718 4287 7698 4276 7697 4276 7730
TIME...MOT...LOC 2257Z 283DEG 21KT 4276 7721 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HSK
980 
WWUS51 KBUF 122313
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
713 PM EDT Wed Aug 12 2026

NYC069-122322-
/O.EXP.KBUF.SV.W.0092.000000T0000Z-260812T2315Z/
Ontario NY-
713 PM EDT Wed Aug 12 2026

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL ONTARIO COUNTY
WILL EXPIRE AT 715 PM EDT...

The storm which prompted the warning has weakened below severe 
limits, and no longer poses an immediate threat to life or property. 
Moderate rainfall is still possible over the next hour. Therefore, 
the warning will be allowed to expire.

&&

LAT...LON 4290 7718 4287 7698 4276 7697 4276 7730
TIME...MOT...LOC 2312Z 289DEG 22KT 4273 7710 

$$

Thomas

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Buffalo, NY wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 12, 1:48 PM EDT, 4 hours 29 minutes earlier. Its key messages:

  • 1) Scattered showers and thunderstorms this afternoon and evening across western NY. A few storms may be severe with strong winds and hail. 2) Mostly dry weather late this week with showers and thunderstorms looking to return Sunday.
Area forecast discussion, Aug 12, 1:48 PM EDT, 4 hours 29 minutes before
Area Forecast Discussion
National Weather Service Buffalo NY
148 PM EDT Wed Aug 12 2026

.WHAT HAS CHANGED...
No major changes with this update.

&&

.KEY MESSAGES...
1) Scattered showers and thunderstorms this afternoon and evening
across western NY. A few storms may be severe with strong winds and
hail.

2) Mostly dry weather late this week with showers and thunderstorms
looking to return Sunday.

&&

.DISCUSSION...

Key Message 1...Scattered showers and thunderstorms this afternoon
and evening across western NY. A few storms may be severe with
strong winds and hail.

Latest satellite and radar imagery showed widely scattered showers
and thunderstorms developing across the Niagara Frontier around
midday as well as across southwest ON ahead of enhanced northwest
flow moving into the region. Initial storms in Niagara Co quickly
dissipated over the lake modified air with southwest surface flow,
but additional storms have begun developing farther east along the
lake breeze boundary and subsequent outflows. Expecting an increase
in storm coverage through this afternoon, especially further
displaced from the lakes into the Finger Lakes region where
MLCAPE has grow 1000-1500 J/kg. Outside of shallow low-level
directional shear, hodographs are fairly unidirectional with
effective shear 35-40 kt. This will be supportive of organized
storm structures and splitting cells. Any discrete storms could
be capable of producing large hail (1-1.25 inch), but the messy
storm evolution will likely lead to strong winds and heavy
rainfall being the primary threat. PWATs are in the 1.3 to 1.5"
range, which is above-normal, but not excessively high. Looking
farther southwest into Chautauqua Co, considerable cloud cover
from upstream convection has overspread the western Southern
Tier. Additionally, forecast soundings suggest the area is
capped at the surface despite steep mid-level lapse rates near 7
degC/km. Any convection that develops mid-afternoon will likely
be elevated or delayed until this evening with additional
development in OH as the shortwave passes through.

Hi-res ensemble guidance (HREF/REFS) suggest storm potential will
continue into early this evening for the Niagara Frontier across to
the northern Finger Lakes region. The western Southern Tier may see
storms remain in the area through midnight. Lingering showers may
remain into early Thursday morning before turning mostly dry
throughout the remainder of the day as high pressure begins to build
into the upper Great Lakes.

Key Message 2...Mostly dry weather late this week with showers and
thunderstorms looking to return Sunday.

After mostly dry weather Friday and Saturday, a low pressure system
will track across northern Ontario early Sunday with a trailing cold
front that may bring the next round of showers and thunderstorms to
western and north-central NY. The timing of this low is still quite
uncertain owning to the ~50% PoPs lasting throughout much of the
day. While the severe convective environment appears better farther
south and west, latest model trends has begun to shift the axis of
greater instability north into the western Southern Tier.
Additionally, lingering upstream convection from Saturday night
across the Midwest will be another factor. Afterwards, high
pressure will build back into the Great Lakes with drier weather
for early next week.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A weak mid level shortwave passing through the northwest flow aloft
will interact with moderate instability and lake breeze boundaries
to produce scattered showers and thunderstorms this afternoon
through early to mid evening. The best coverage of showers and
thunderstorms will be across Western NY and the Finger Lakes, with a
smaller secondary area crossing the Saint Lawrence Valley. Any
storms will be capable of brief/local IFR conditions, gusty winds,
and small hail. Outside of thunderstorms, VFR will prevail in most
areas with some MVFR CIGS across the higher terrain of the
western Southern Tier.

Tonight, scattered showers and thunderstorms in the early evening
will diminish and mostly end by late evening with the loss of
daytime heating. Overnight, areas of IFR in low stratus and fog will
develop across the Southern Tier and Finger Lakes, with some VLIFR
possible. Elsewhere, expect mainly VFR conditions for lower
elevations and east of Lake Ontario.

Thursday, a somewhat drier airmass will build into the eastern Great
Lakes and allow for mainly dry weather to prevail. A few scattered
showers and thunderstorms may develop across the Saint Lawrence
valley in the afternoon and early evening in closer proximity to a
deepening trough across Quebec. Areas of IFR in fog and low stratus
across the Southern Tier and Finger Lakes will dissipate by mid to
late morning, with VFR elsewhere.

Outlook...

Friday through Saturday...Mainly VFR.

Sunday...VFR/MVFR with showers and thunderstorms likely. Local/brief
IFR possible in storms.

Monday...Mainly VFR. A chance of a few lingering scattered
showers.

&&

.MARINE...
An overall weak pressure gradient is expected to remain in place
through the remainder of the work week, with no more than mainly
light to gentle breezes expected, although a modest uptick in
northerly flow later Thursday night into Friday may bring some light
to moderate chop across Lake Ontario.

Scattered showers and thunderstorms this afternoon and evening may
produce strong winds and locally higher waves.

&&

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

&&

DISCUSSION...Brothers
AVIATION...Hitchcock
MARINE...Brothers/JM
Hazardous weather outlook, Aug 12, 1:52 PM EDT, 4 hours 25 minutes before
Hazardous Weather Outlook
National Weather Service Buffalo NY
152 PM EDT Wed Aug 12 2026

NYZ001>005-010>014-019>021-085-131800-
Niagara-Orleans-Monroe-Wayne-Northern Cayuga-Northern Erie-Genesee-
Wyoming-Livingston-Ontario-Chautauqua-Cattaraugus-Allegany-
Southern Erie-
152 PM EDT Wed Aug 12 2026

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

.DAY ONE...This afternoon and tonight.

There is a Marginal Risk (level 1 of 5) for severe thunderstorms
this afternoon and evening, with damaging winds as the primary
hazard, but hail and heavy rainfall are also possible.

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

No hazardous weather is 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>044-062>064-131800-
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 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-
152 PM EDT Wed Aug 12 2026

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

.DAY ONE...This afternoon and tonight.

There is a Marginal Risk (level 1 of 5) for severe thunderstorms
this afternoon and evening with strong winds and locally higher
waves as the primary hazards.

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

No hazardous weather is 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

NYZ006>008-131800-
Oswego-Jefferson-Lewis-
152 PM EDT Wed Aug 12 2026

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

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

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

No hazardous weather is 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

LOZ045-065-SLZ022-024-131800-
Lake Ontario nearshore waters from Mexico Bay to the Saint Lawrence
River-
Lake Ontario open waters from Mexico Bay to the Saint Lawrence River-
Saint Lawrence River from Cape Vincent to Ogdensburg-
Saint Lawrence River from Ogdensburg to Saint Regis-
152 PM EDT Wed Aug 12 2026

This Hazardous Weather Outlook is for portions of Lake Ontario and
Saint Lawrence River.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

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

No hazardous weather is 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

The office that day

Everything else NWS Buffalo, NY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 1:26 PM EDTSpecial Marine WarningBUF50 min
Aug 12, 1:42 PM EDTSpecial Marine WarningBUF81 min
Aug 12, 4:06 PM EDTSpecial Marine WarningBUF29 min
Aug 12, 6:24 PM EDTSevere Thunderstorm WarningBUFLivingston, Ontario51 min
Aug 12, 7:02 PM EDTSpecial Marine WarningBUF118 min

Nearby

Severe Thunderstorm Warnings in New York, 2026Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.