Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 107, NWS Buffalo, NY

September 12, 20216 counties in New York

NWS Buffalo, NY issued this severe thunderstorm warning at Sep 12, 2021, 11:49 PM EDT for 6 counties in New York. It was in force for 86 min. 3 reports 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
Sep 12, 2021, 11:49 PM EDT (03:49 UTC)
Expired
Sep 13, 2021, 1:15 AM EDT
In force
86 min
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Buffalo radar (KBUF), 76 km from the middle of the area, began a volume at 03:51 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
Sep 13, 12:14 AM EDTTSTM WND DMGLittle Valley, NYTREE DOWN ON POWERLINE.
Sep 13, 12:22 AM EDTTSTM WND DMGSalamanca, NYTREES DOWN ON ROADWAY.
Sep 13, 12:57 AM EDTTORNADO3 Nw Springwater, NYDOZENS OF HARDWOOD AND SOFTWOOD TREE TRUNKS WERE SHEARED IN HALF WITH DAMAGE TO THE ROOF OF AN OUTDOOR SHED. THE TRACK OF THE TORNADO STARTED JUST WEST OF ROUTE 15 AND ENDED JUST EAST OF MARROWBACK ROAD.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 12, 10:25 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 3.8 hours before the alert went out and 72 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 00:00Z on 2021-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 412 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 00:00Z on 2021-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 205 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
412 J/kg
Mixed-layer CIN
-125 J/kg
Mixed-layer LCL
706 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
205 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

222 
WUUS51 KBUF 130349
SVRBUF
NYC003-009-013-029-051-121-130515-
/O.NEW.KBUF.SV.W.0107.210913T0349Z-210913T0515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
1149 PM EDT Sun Sep 12 2021

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  Wyoming County in western New York...
  Cattaraugus County in western New York...
  Southeastern Erie County in western New York...
  Livingston County in western New York...
  Southeastern Chautauqua County in western New York...
  Allegany County in western New York...

* Until 115 AM EDT.

* At 1148 PM EDT, severe thunderstorms were located along a line
  extending from 14 miles northwest of Angola on the Lake to near
  Silver Creek to Mayville, moving east at 70 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines.

* Locations impacted include...
  West Seneca, Olean, Geneseo, East Aurora, Salamanca, Dansville,
  Wellsville, Allegany State Park, Letchworth State Park and Elma.

This includes the following highways...
 Interstate 390 between exits 4 and 8.
 Interstate 86 between exits 14 and 33.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with these storms. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4200 7923 4285 7871 4285 7761 4258 7761
      4258 7766 4253 7766 4253 7772 4200 7775
TIME...MOT...LOC 0348Z 282DEG 61KT 4282 7922 4252 7923 4227 7952 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

RSH
3 follow-up statements
028 
WWUS51 KBUF 130418
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
1218 AM EDT Mon Sep 13 2021

NYC003-009-013-029-051-121-130515-
/O.CON.KBUF.SV.W.0107.000000T0000Z-210913T0515Z/
Wyoming NY-Cattaraugus NY-Erie NY-Livingston NY-Chautauqua NY-
Allegany NY-
1218 AM EDT Mon Sep 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 AM EDT
FOR WYOMING...CATTARAUGUS...SOUTHEASTERN ERIE...LIVINGSTON...
SOUTHEASTERN CHAUTAUQUA AND ALLEGANY COUNTIES...

At 1217 AM EDT, severe thunderstorms were located along a line
extending from near Wales Center to near Ashford Hollow to 10 miles
west of Salamanca, moving east at 70 mph.

HAZARD...70 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
West Seneca, Olean, Geneseo, East Aurora, Salamanca, Dansville,
Wellsville, Allegany State Park, Letchworth State Park and Elma.

This includes the following highways...
 Interstate 390 between exits 4 and 8.
 Interstate 86 between exits 14 and 33.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A tornado watch remains in effect for the warned area. Tornadoes can
develop quickly from severe thunderstorms. Although a tornado is not
immediately likely, if one is spotted act quickly and move to a place
of safety inside a sturdy structure, such as a basement or small
interior room.

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

&&

LAT...LON 4200 7923 4285 7871 4285 7761 4258 7761
      4258 7766 4253 7766 4253 7772 4200 7775
TIME...MOT...LOC 0417Z 281DEG 61KT 4272 7856 4242 7863 4218 7892 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

RSH
316 
WWUS51 KBUF 130443
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
1243 AM EDT Mon Sep 13 2021

NYC013-029-130452-
/O.CAN.KBUF.SV.W.0107.000000T0000Z-210913T0515Z/
Erie NY-Chautauqua NY-
1243 AM EDT Mon Sep 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ERIE AND
SOUTHEASTERN CHAUTAUQUA COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning for Chautauqua and southern Erie 
county has been cancelled.

A Severe Thunderstorm Watch remains in effect until 200 AM EDT for
western New York.

LAT...LON 4200 7875 4285 7821 4285 7761 4258 7761
      4258 7766 4253 7766 4253 7772 4200 7775
TIME...MOT...LOC 0442Z 281DEG 65KT 4262 7802 4232 7809 4208 7838 

$$

NYC003-009-051-121-130515-
/O.CON.KBUF.SV.W.0107.000000T0000Z-210913T0515Z/
Wyoming NY-Cattaraugus NY-Livingston NY-Allegany NY-
1243 AM EDT Mon Sep 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 AM EDT
FOR WYOMING...EASTERN CATTARAUGUS...LIVINGSTON AND ALLEGANY
COUNTIES...

At 1242 AM EDT, severe thunderstorms were located along a line
extending from near Letchworth State Park to Belfast to Weston Mills,
moving east at 75 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

Locations impacted include...
Olean, Geneseo, Dansville, Wellsville, Letchworth State Park,
Allegany State Park, Alfred, Perry, Warsaw and Mount Morris.

This includes the following highways...
 Interstate 390 between exits 4 and 8.
 Interstate 86 between exits 23 and 33.

LAT...LON 4200 7875 4285 7821 4285 7761 4258 7761
      4258 7766 4253 7766 4253 7772 4200 7775
TIME...MOT...LOC 0442Z 281DEG 65KT 4262 7802 4232 7809 4208 7838 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

RSH
212 
WWUS51 KBUF 130512
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
112 AM EDT Mon Sep 13 2021

NYC003-009-051-121-130522-
/O.EXP.KBUF.SV.W.0107.000000T0000Z-210913T0515Z/
Wyoming NY-Cattaraugus NY-Livingston NY-Allegany NY-
112 AM EDT Mon Sep 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR WYOMING...EASTERN
CATTARAUGUS...LIVINGSTON AND ALLEGANY COUNTIES WILL EXPIRE AT 115 AM
EDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 200 AM EDT for
western New York.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Buffalo.

LAT...LON 4200 7875 4285 7821 4285 7761 4258 7761
      4258 7766 4253 7766 4253 7772 4200 7775
TIME...MOT...LOC 0512Z 282DEG 61KT 4253 7743 4223 7750 4199 7779 

$$

RSH

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 12, 10:53 PM EDTSpecial Marine WarningBUF82 min
Sep 12, 11:00 PM EDTSevere Thunderstorm Warning Considerable damage threatBUFCattaraugus, Chautauqua, Erie75 min
Sep 13, 12:09 AM EDTSevere Thunderstorm WarningBUFErie, Genesee, Wyoming66 min
Sep 13, 12:25 AM EDTFlash Flood WarningBUFErie, Genesee, Wyoming3 hr
Sep 13, 12:50 AM EDTSevere Thunderstorm WarningBUFLivingston, Ontario55 min
Sep 13, 1:09 AM EDTSpecial Weather StatementBUFGenesee, Monroe, Ontario, Wayne66 min

Nearby

Severe Thunderstorm Warnings in New York, 2021Every severe thunderstorm warning in 2021

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.