Alert archive / New York / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 12, NWS Buffalo, NY

April 21, 20254 counties in New York

NWS Buffalo, NY issued this severe thunderstorm warning at Apr 21, 2025, 5:23 PM EDT for 4 counties in New York. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 21, 2025, 5:23 PM EDT (21:23 UTC)
Expired
Apr 21, 2025, 5:57 PM EDT
In force
34 min
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

Counties Allegany County, NY, Cattaraugus County, NY, Erie County, NY, Wyoming County, NY

The radar

The Buffalo radar (KBUF), 60 km from the middle of the area, began a volume at 21:27 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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, 9.4 hours before the alert went out and 57 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 2025-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2025-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 366 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1489 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
366 m²/s²
0-3 km storm-relative helicity
423 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

064 
WUUS51 KBUF 212123
SVRBUF
NYC003-009-029-121-212230-
/O.NEW.KBUF.SV.W.0012.250421T2123Z-250421T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
Issued by National Weather Service Pittsburgh PA
523 PM EDT Mon Apr 21 2025

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  Southwestern Wyoming County in western New York...
  Northern Cattaraugus County in western New York...
  Southeastern Erie County in western New York...
  Northwestern Allegany County in western New York...

* Until 630 PM EDT.

* At 523 PM EDT, a severe thunderstorm was located near Ashford
  Hollow, or 14 miles north of Salamanca, moving northeast at 40 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...
  Fillmore, Cattaraugus, Ashford, Bliss, Ashford Hollow, New Albion,
  Yorkshire, Sandusky, Chaffee, and Eagle.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 4224 7885 4240 7900 4275 7832 4245 7810
TIME...MOT...LOC 2123Z 238DEG 33KT 4237 7881 

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

$$

MLB
2 follow-up statements
657 
WWUS51 KBUF 212143
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
Issued by National Weather Service Pittsburgh PA
543 PM EDT Mon Apr 21 2025

NYC003-212152-
/O.CAN.KBUF.SV.W.0012.000000T0000Z-250421T2230Z/
Allegany NY-
543 PM EDT Mon Apr 21 2025

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ALLEGANY COUNTY
IS CANCELLED...

The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

&&

LAT...LON 4243 7875 4262 7858 4269 7843 4251 7831
      4245 7831 4236 7871
TIME...MOT...LOC 2142Z 238DEG 33KT 4247 7860 

$$

NYC009-029-121-212230-
/O.CON.KBUF.SV.W.0012.000000T0000Z-250421T2230Z/
Wyoming NY-Cattaraugus NY-Erie NY-
543 PM EDT Mon Apr 21 2025

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR SOUTHWESTERN WYOMING...NORTHEASTERN CATTARAUGUS AND SOUTHEASTERN
ERIE COUNTIES...

At 542 PM EDT, a severe thunderstorm was located near Springville, or
20 miles south of East Aurora, moving northeast at 40 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Sardinia, Yorkshire, Springville, East Concord, West Valley, Lime
Lake-Machias, Sandusky, Delevan, Chaffee, and Ashford Hollow.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 4243 7875 4262 7858 4269 7843 4251 7831
      4245 7831 4236 7871
TIME...MOT...LOC 2142Z 238DEG 33KT 4247 7860 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DJS
984 
WWUS51 KBUF 212157
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
Issued by National Weather Service Pittsburgh PA
557 PM EDT Mon Apr 21 2025

NYC009-029-121-212207-
/O.CAN.KBUF.SV.W.0012.000000T0000Z-250421T2230Z/
Wyoming NY-Cattaraugus NY-Erie NY-
557 PM EDT Mon Apr 21 2025

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WYOMING...
NORTHEASTERN CATTARAUGUS AND SOUTHEASTERN ERIE COUNTIES IS
CANCELLED...

The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.  However, gusty winds are still possible with this
thunderstorm.

&&

LAT...LON 4243 7875 4262 7858 4269 7843 4251 7831
      4245 7831 4236 7871
TIME...MOT...LOC 2154Z 238DEG 33KT 4254 7844 

$$

DJS

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 Apr 21, 4:06 PM EDT, 1 hour 17 minutes earlier.

Area forecast discussion, Apr 21, 4:06 PM EDT, 1 hour 17 minutes before
Area Forecast Discussion
National Weather Service Buffalo NY
Issued by National Weather Service Cleveland OH
406 PM EDT Mon Apr 21 2025

.SYNOPSIS...
Low pressure across the Great Lakes will move into Ontario
province tonight, which will push a cold front across the area
late through this evening. This will produce a line of showers
along with some thunderstorms with its passage. High pressure
will then build into the Great Lakes, bringing mainly fair and
rain free weather for Tuesday through Thursday.

&&

.NEAR TERM /THROUGH TUESDAY/...
Low pressure and an associated mid level trough across the
central Great Lakes will move into Ontario province tonight,
which will push a cold front across the area through this
evening. Late this afternoon, radar shows a line of showers and
thunderstorms along the frontal boundary, and another broken
like of showers with embedded thunderstorms ahead of the front.

Wind profiles continue to show a strong 50 kt LLJ which is
resulting in ample wind shear to support strong thunderstorms.
However, surface based instability is limited and showers and
storms with a pre-frontal trough moved in quickly after breaks
of sunshine which will further limit surface based instability.
This has the potential to produce some storms with strong gusty
winds, with this risk mainly running through 8 p.m. this
evening. SPC has a marginal risk for severe weather across
Western NY.

Otherwise, this afternoon will be warm and breezy ahead of the
cold front, with temperatures in the 60s (and even low 70s)
before the showers move in through this evening. Winds will
gust to 35 to 40 mph at some higher elevations and downslope
from the Chautauqua Ridge.

Rain and scattered thunderstorms will end from west to east
this evening with the passage of the cold front, with partial
clearing overnight as drier air advects into the eastern Great
Lakes.

Dry weather will return Tuesday, with deeper moisture and forcing
associated with the mid level trough staying well north of the area
across Quebec. There may be some lingering cloud cover during
the first half of day, which will eventually scatter out. It
will also be quite breezy again, especially northeast of Lake
Erie and Lake Ontario where winds will gust in the 30-35 mph
range.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A weak surface ridge will provide mainly fair and dry weather
through the period. A zonal flow aloft will bring a few weak
shortwaves which will bring periodic cloud cover and a small
chance (20%) for a few light showers at times. Temperatures will
grow warmer with time, with highs reaching into the upper 60s
to mid 70s on Thursday.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Low pressure and an associated shortwave will move across the
area late Friday through Saturday morning. This is likely to
bring a round of showers as it moves across the region, with a
small chance of thunderstorms. Fairly good model agreement on
this feature. After this, high pressure will build back into
the region bringing a return to fair and dry weather Saturday
afternoon through Monday.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
A cold front will move from west to east across the region
through this evening. A line of showers has developed both along
and ahead of this front. Embedded within these will be some
thunderstorms, along with some heavier rains which may lower
vsby to 3SM and also there's a small chance these storms will
produce locally gusty winds.

Showers and embedded storms will end quickly from west to east
as the cold front moves through the area this evening. This will
leave mainly VFR cigs, with patchy MVFR cigs across the areas.

High pressure will then build on Tuesday. Possibly some
lingering MVFR cigs south of Lake Ontario which will scatter out
during the afternoon hours.

Outlook...

Tuesday through Thursday...Mainly VFR.

Friday...VFR deteriorating to MVFR with showers likely, mainly later
in the afternoon.

Saturday...Mainly MVFR early, improving to VFR in the afternoon
and evening.

&&

.MARINE...
Low pressure across the central Great Lakes late this afternoon
will move to western Quebec on Tuesday. Pre- frontal winds have
diminished, but winds will pick up again following the passage
of a cold front late this afternoon and evening. This will
support small craft headlines on eastern Lake Erie, the upper
Niagara River, and eastern Lake Ontario tonight and Tuesday.
The south shores of Lake Ontario will be close at times, but did
not have the confidence to issue headlines for there yet.

Winds will gradually diminish later Tuesday night and Wednesday
as high pressure builds into the Great Lakes.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory from 8 PM this evening to 5 PM EDT
         Tuesday for LEZ020.
         Small Craft Advisory from 8 PM this evening to 8 PM EDT
         Tuesday for LEZ040-041.
         Small Craft Advisory from 8 AM to 11 PM EDT Tuesday
         for LOZ044-045.

&&

SYNOPSIS...Apffel
NEAR TERM...Apffel
SHORT TERM...AR/Apffel
LONG TERM...AR/Apffel
AVIATION...Apffel
MARINE...Apffel
Hazardous weather outlook, Apr 21, 1:26 PM EDT, 3 hours 57 minutes before
Hazardous Weather Outlook
National Weather Service Buffalo NY
Issued by National Weather Service Cleveland OH
126 PM EDT Mon Apr 21 2025

NYZ003>005-013-014-221730-
Monroe-Wayne-Northern Cayuga-Livingston-Ontario-
126 PM EDT Mon Apr 21 2025

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

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

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>008-221730-
Oswego-Jefferson-Lewis-
126 PM EDT Mon Apr 21 2025

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...Tuesday through Sunday.

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

NYZ001-002-010>012-019>021-085-221730-
Niagara-Orleans-Northern Erie-Genesee-Wyoming-Chautauqua-Cattaraugus-
Allegany-Southern Erie-
126 PM EDT Mon Apr 21 2025

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

.DAY ONE...This afternoon and tonight.

There's a marginal risk for strong thunderstorms this afternoon
through early evening. Some storms may produce gusty to damaging
winds.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

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-LOZ030-221730-
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-
126 PM EDT Mon Apr 21 2025

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

.DAY ONE...This afternoon and tonight.

There's a marginal risk for strong thunderstorms this afternoon
through early evening. Some storms may produce gusty winds.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

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

LOZ042>045-062>065-SLZ022-024-221730-
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-
Saint Lawrence River from Cape Vincent to Ogdensburg-
Saint Lawrence River from Ogdensburg to Saint Regis-
126 PM EDT Mon Apr 21 2025

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...Tuesday through Sunday.

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

Apffel

In the hours before

Special weather statement, Apr 21, 5:08 PM EDT, 15 minutes before
Special Weather Statement
National Weather Service Buffalo NY
Issued by National Weather Service Cleveland OH
508 PM EDT Mon Apr 21 2025

NYZ001>003-010-011-212145-
Orleans NY-Genesee NY-Monroe NY-Niagara NY-Northern Erie NY-
508 PM EDT Mon Apr 21 2025

...A strong thunderstorm will impact portions of northeastern Erie,
Niagara, Orleans, northwestern Genesee and northwestern Monroe
Counties through 545 PM EDT...

At 500 PM EDT, a line of strong thunderstorms was reported over
North Tonawanda and Clarence, moving northeast at 50 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 4341 7863 4342 7810 4341 7800 4334 7789
      4290 7858 4305 7894
TIME...MOT...LOC 2105Z 219DEG 50KT 4303 7864

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH

HSK

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 1:05 AM EDTWind AdvisoryBUFChautauqua12 hr
Apr 21, 1:34 PM EDTSmall Craft AdvisoryBUF33 hr
Apr 21, 4:34 PM EDTSpecial Marine WarningBUF86 min
Apr 21, 5:08 PM EDTSpecial Weather StatementBUFOrleans37 min
Apr 21, 5:19 PM EDTSpecial Marine WarningBUF56 min
Apr 21, 5:33 PM EDTTornado WarningBUFAllegany, Cattaraugus, Erie, Wyoming27 min
Apr 21, 5:53 PM EDTSevere Thunderstorm WarningBUFCattaraugus, Chautauqua, Erie, Genesee, Niagara, Orleans and 1 more67 min
Apr 21, 6:03 PM EDTAreal Flood WarningBUFErie, Niagara95 min
Apr 21, 6:11 PM EDTSpecial Marine WarningBUF64 min
Apr 21, 6:19 PM EDTFlash Flood WarningBUFCattaraugus, Chautauqua3 hr
Apr 21, 6:41 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus, Erie, Wyoming58 min

Nearby

Severe Thunderstorm Warnings in New York, 2025Every severe thunderstorm warning in 2025

Sources

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