Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 100, NWS Buffalo, NY

August 11, 20214 counties in New York

NWS Buffalo, NY issued this severe thunderstorm warning at Aug 11, 2021, 7:55 AM EDT for 4 counties in New York. It was in force for 50 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 11, 2021, 7:55 AM EDT (11:55 UTC)
Expired: Aug 11, 2021, 8:45 AM EDT
In force: 50 min
Issued by: NWS Buffalo, NY
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Livingston County, NY, Monroe County, NY, Ontario County, NY, Wayne County, NY

The radar

The Buffalo radar (KBUF), 118 km from the middle of the area, began a volume at 12:00 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, 8:28 AM EDT	TSTM WND DMG	Shortsville, NY	TREES DOWN ON WEST MAIN STREET IN SHORTSVILLE.

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, 11.9 hours before the alert went out and 115 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.

333 
WUUS51 KBUF 111155
SVRBUF
NYC051-055-069-117-111245-
/O.NEW.KBUF.SV.W.0100.210811T1155Z-210811T1245Z/

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

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  Southwestern Wayne County in western New York...
  Northeastern Livingston County in western New York...
  South central Monroe County in western New York...
  Ontario County in western New York...

* Until 845 AM EDT.

* At 755 AM EDT, a severe thunderstorm was located near Lima, or 12
  miles west of Canandaigua, moving east at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Geneva, Canandaigua, Newark, Lyons, Palmyra, Victor, Honeoye Falls,
  Bristol, Lima and Clifton Springs.

This includes Interstate 90 between exits 44 and 42.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4258 7758 4294 7766 4315 7695 4278 7698
      4276 7700 4276 7731 4267 7737 4258 7737
TIME...MOT...LOC 1155Z 257DEG 40KT 4287 7753 

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

$$

Apffel

2 follow-up statements

708 
WWUS51 KBUF 111227
SVSBUF

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

NYC051-055-111236-
/O.CAN.KBUF.SV.W.0100.000000T0000Z-210811T1245Z/
Livingston NY-Monroe NY-
827 AM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LIVINGSTON AND
SOUTH CENTRAL MONROE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4284 7741 4294 7748 4299 7748 4315 7695
      4287 7697 4286 7698 4278 7698 4276 7700
      4276 7731
TIME...MOT...LOC 1226Z 249DEG 31KT 4292 7717 

$$

NYC069-117-111245-
/O.CON.KBUF.SV.W.0100.000000T0000Z-210811T1245Z/
Wayne NY-Ontario NY-
827 AM EDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 AM EDT
FOR SOUTH CENTRAL WAYNE AND ONTARIO COUNTIES...

At 826 AM EDT, a severe thunderstorm was located near Clifton
Springs, or near Canandaigua, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Geneva, Canandaigua, Newark, Lyons, Palmyra, Victor, Clifton Springs,
Phelps, Bloomfield and Rushville.

This includes Interstate 90 between exits 44 and 42.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4284 7741 4294 7748 4299 7748 4315 7695
      4287 7697 4286 7698 4278 7698 4276 7700
      4276 7731
TIME...MOT...LOC 1226Z 249DEG 31KT 4292 7717 

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

$$

Apffel

214 
WWUS51 KBUF 111247
SVSBUF

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

NYC069-117-111257-
/O.EXP.KBUF.SV.W.0100.000000T0000Z-210811T1245Z/
Wayne NY-Ontario NY-
847 AM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL WAYNE AND
ONTARIO COUNTIES HAS EXPIRED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been allowed to expire.

LAT...LON 4284 7741 4294 7748 4299 7748 4315 7695
      4287 7697 4286 7698 4278 7698 4276 7700
      4276 7731
TIME...MOT...LOC 1247Z 257DEG 40KT 4297 7689 

$$

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, 7:46 AM EDT	Severe Thunderstorm Warning	BUF	Genesee, Livingston, Monroe, Ontario, Orleans	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.