Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 99, NWS Buffalo, NY

August 11, 20215 counties in New York

NWS Buffalo, NY issued this severe thunderstorm warning at Aug 11, 2021, 7:46 AM EDT for 5 counties in New York. It was in force for 50 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: Aug 11, 2021, 7:46 AM EDT (11:46 UTC)
Expired: Aug 11, 2021, 8:36 AM EDT
In force: 50 min
Issued by: NWS Buffalo, NY
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Genesee County, NY, Livingston County, NY, Monroe County, NY, Ontario County, NY, Orleans County, NY

The radar

The Buffalo radar (KBUF), 64 km from the middle of the area, began a volume at 11:45 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

Time	Report	Where	Remark
Aug 11, 8:00 AM EDT	TSTM WND DMG	1 Ne Mumford, NY	TREES DOWN ON SCOTTSVILLE MUMFORD ROAD AND BELCODA RD.
Aug 11, 8:16 AM EDT	TSTM WND DMG	2 Ene Brighton, NY	TREES DOWN ON COUNCIL ROCK AVE IN BRIGHTON.
Aug 11, 8:16 AM EDT	TSTM WND DMG	2 Nw Brighton, NY	TREE DOWN ON POPLAR STREET IN ROCHESTER.

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

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 11.8 hours before the alert went out and 61 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1071 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 910 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 97 m²/s²
0-3 km storm-relative helicity: 170 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

184 
WUUS51 KBUF 111146
SVRBUF
NYC037-051-055-069-073-111300-
/O.NEW.KBUF.SV.W.0099.210811T1146Z-210811T1300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
746 AM EDT Wed Aug 11 2021

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  North central Livingston County in western New York...
  Southern Orleans County in western New York...
  Genesee County in western New York...
  Monroe County in western New York...
  Northwestern Ontario County in western New York...

* Until 900 AM EDT.

* At 746 AM EDT, a severe thunderstorm was located near Oakfield, or
  near Batavia, moving east at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Rochester, Greece, Irondequoit, Chili, Batavia, Brockport, East
  Rochester, Hilton, Brighton and Gates-North Gates.

This includes the following highways...
 Interstate 390 between exits 11 and 12.
 Interstate 90 between exits 48A and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4287 7841 4318 7844 4333 7763 4328 7755
      4295 7741
TIME...MOT...LOC 1146Z 264DEG 26KT 4302 7828 

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

$$

Reynolds

3 follow-up statements

908 
WWUS51 KBUF 111210 RRA
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
810 AM EDT Wed Aug 11 2021

NYC037-051-055-069-073-111300-
/O.CON.KBUF.SV.W.0099.000000T0000Z-210811T1300Z/
Livingston NY-Orleans NY-Genesee NY-Monroe NY-Ontario NY-
810 AM EDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 AM EDT
FOR NORTH CENTRAL LIVINGSTON...SOUTHEASTERN ORLEANS...EASTERN
GENESEE...MONROE AND NORTHWESTERN ONTARIO COUNTIES...

At 810 AM EDT, a severe thunderstorm was located near Byron, or 7
miles east of Batavia, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Rochester, Greece, Irondequoit, Chili, Batavia, Brockport, East
Rochester, Hilton, Brighton and Gates-North Gates.

This includes the following highways...
 Interstate 390 between exits 11 and 12.
 Interstate 90 between exits 48 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4321 7828 4333 7763 4328 7755 4295 7741
      4289 7816
TIME...MOT...LOC 1210Z 264DEG 26KT 4304 7804 

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

$$

Reynolds

855 
WWUS51 KBUF 111222
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
822 AM EDT Wed Aug 11 2021

NYC051-111231-
/O.CAN.KBUF.SV.W.0099.000000T0000Z-210811T1300Z/
Livingston NY-
822 AM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL LIVINGSTON
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 4310 7817 4322 7823 4333 7763 4328 7755
      4296 7742
TIME...MOT...LOC 1221Z 249DEG 27KT 4312 7783 

$$

NYC037-055-069-073-111300-
/O.CON.KBUF.SV.W.0099.000000T0000Z-210811T1300Z/
Orleans NY-Genesee NY-Monroe NY-Ontario NY-
822 AM EDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 AM EDT
FOR SOUTHEASTERN ORLEANS...NORTHEASTERN GENESEE...MONROE AND
NORTHWESTERN ONTARIO COUNTIES...

At 821 AM EDT, a severe thunderstorm was located over Churchville, or
near Chili, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Rochester, Greece, Irondequoit, Chili, Brockport, East Rochester,
Hilton, Brighton, Gates-North Gates and Henrietta.

This includes the following highways...
 Interstate 390 near exit 12.
 Interstate 90 near exit 46.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4310 7817 4322 7823 4333 7763 4328 7755
      4296 7742
TIME...MOT...LOC 1221Z 249DEG 27KT 4312 7783 

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

$$

Apffel

406 
WWUS51 KBUF 111236
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
836 AM EDT Wed Aug 11 2021

NYC037-055-069-073-111246-
/O.CAN.KBUF.SV.W.0099.000000T0000Z-210811T1300Z/
Orleans NY-Genesee NY-Monroe NY-Ontario NY-
836 AM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ORLEANS...
NORTHEASTERN GENESEE...MONROE AND NORTHWESTERN ONTARIO COUNTIES IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.

LAT...LON 4310 7817 4322 7823 4333 7763 4328 7755
      4296 7742
TIME...MOT...LOC 1234Z 264DEG 26KT 4313 7768 

$$

Reynolds

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 9:29 PM EDT	Special Weather Statement	BUF	Jefferson	31 min
Aug 10, 10:04 PM EDT	Special Weather Statement	BUF	Lewis	41 min
Aug 10, 10:47 PM EDT	Flash Flood Warning	BUF	Jefferson, Lewis	5 hr
Aug 11, 4:38 AM EDT	Special Weather Statement	BUF	Chautauqua, Erie, Niagara	52 min
Aug 11, 5:37 AM EDT	Special Weather Statement	BUF	Chautauqua	53 min
Aug 11, 5:41 AM EDT	Special Marine Warning	BUF		64 min
Aug 11, 6:09 AM EDT	Severe Thunderstorm Warning	BUF	Cattaraugus, Chautauqua, Erie	51 min
Aug 11, 6:27 AM EDT	Special Marine Warning	BUF		93 min
Aug 11, 6:40 AM EDT	Severe Thunderstorm Warning	BUF	Erie, Genesee, Wyoming	65 min
Aug 11, 6:48 AM EDT	Special Marine Warning	BUF		42 min
Aug 11, 7:16 AM EDT	Severe Thunderstorm Warning	BUF	Allegany, Cattaraugus, Genesee, Livingston, Monroe, Wyoming	59 min
Aug 11, 7:39 AM EDT	Special Weather Statement	BUF	Genesee, Monroe	81 min
Aug 11, 7:55 AM EDT	Severe Thunderstorm Warning	BUF	Livingston, Monroe, Ontario, Wayne	50 min
Aug 11, 8:09 AM EDT	Special Marine Warning	BUF		96 min
Aug 11, 8:25 AM EDT	Special Weather Statement	BUF	Wayne	65 min
Aug 11, 9:18 AM EDT	Special Weather Statement	BUF	Oswego	27 min
Aug 11, 1:44 PM EDT	Small Craft Advisory	BUF		6 hr
Aug 11, 6:52 PM EDT	Special Weather Statement	BUF	Chautauqua	38 min

Nearby

Severe Thunderstorm Warnings in New York, 2021 Every 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.