Alert archive / New York / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 77, NWS Buffalo, NY

July 20, 2017Allegany County, Cattaraugus County, Wyoming County, New York

NWS Buffalo, NY issued this severe thunderstorm warning at Jul 20, 2017, 1:23 PM EDT for Allegany County, Cattaraugus County, Wyoming County, New York. It was in force for 52 min. 7 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: Jul 20, 2017, 1:23 PM EDT (17:23 UTC)
Expired: Jul 20, 2017, 2:15 PM EDT
In force: 52 min
Issued by: NWS Buffalo, NY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 70.0 mph

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

The radar

The Buffalo radar (KBUF), 76 km from the middle of the area, began a volume at 17:26 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
Jul 20, 1:27 PM EDT	TSTM WND DMG	1 Nw Fillmore, NY	TREES DOWN ON MILLS ROAD.
Jul 20, 1:35 PM EDT	TSTM WND DMG	1 Ese Houghton, NY	SNAPPED ELECTRIC POLES...TREES AND WIRES DOWN COUNSIL HOUSE RD
Jul 20, 1:35 PM EDT	TSTM WND DMG	Caneadea, NY	TREES AND WIRES DOWN
Jul 20, 1:40 PM EDT	TORNADO	2 N Angelica, NY	STORM SURVEY CONFIRMED EF1 TORNADO. SEVERAL HOMES WERE DAMAGED AND A BARN SEVERELY DAMAGED. SEVERAL SHEDS OR SMALL OUTBUILDINGS WERE TIPPED AND MOVED. NUMEROUS LARGE TREES WERE SHREDDED AND DOWNED. LSR LOCATION IS CENTER POINT OF TRACK
Jul 20, 1:42 PM EDT	TSTM WND DMG	1 Ese Houghton, NY	TREES DOWN ON HOLIDAY ROAD.
Jul 20, 1:46 PM EDT	TSTM WND DMG	3 N Angelica, NY	NUMEROUS TREES DOWN NEAR COUNTY ROUTE 15 AND OLD STATE ROAD.
Jul 20, 1:54 PM EDT	TSTM WND DMG	4 W West Almond, NY	BARN BLOWN DOWN ALONG COUNTY ROUTE 16 NEAR DOWD RD.

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.

Issued	Product	Office	Lasted
Jul 20, 1:11 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 5.4 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-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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2004 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 131 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

791 
WUUS51 KBUF 201723
SVRBUF
NYC003-009-121-201815-
/O.NEW.KBUF.SV.W.0077.170720T1723Z-170720T1815Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
123 PM EDT THU JUL 20 2017

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  South central Wyoming County in western New York...
  Northeastern Cattaraugus County in western New York...
  Northern Allegany County in western New York...

* Until 215 PM EDT.

* At 122 PM EDT, a severe thunderstorm was located near Rushford, or
  19 miles southwest of Letchworth State Park, moving southeast at 40
  mph.

  HAZARD...70 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Minor damage to vehicles is possible. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings. 

* Locations impacted include...
  Alfred, Belfast, Rushford, Houghton, Caneadea, Eagle, Pike and
  Andover.

This includes Interstate 86 between exits 30 and 33.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

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

&&

LAT...LON 4244 7842 4262 7829 4254 7806 4253 7806
      4253 7804 4252 7804 4252 7800 4242 7772
      4208 7775
TIME...MOT...LOC 1722Z 294DEG 33KT 4246 7826 

HAIL...1.00IN
WIND...70MPH
 
$$

Mitchell

2 follow-up statements

580 
WWUS51 KBUF 201756
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
156 PM EDT THU JUL 20 2017

NYC009-121-201803-
/O.CAN.KBUF.SV.W.0077.000000T0000Z-170720T1815Z/
Wyoming NY-Cattaraugus NY-
156 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL WYOMING AND
NORTHEASTERN CATTARAUGUS COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.
However a severe warning remains in effect for Allegany County.

A severe thunderstorm watch remains in effect until 800 PM EDT for
western New York.

LAT...LON 4229 7814 4248 7790 4242 7772 4208 7775
TIME...MOT...LOC 1753Z 294DEG 33KT 4234 7791 

$$

NYC003-201815-
/O.CON.KBUF.SV.W.0077.000000T0000Z-170720T1815Z/
Allegany NY-
156 PM EDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM EDT
FOR NORTHEASTERN ALLEGANY COUNTY...

At 153 PM EDT, a severe thunderstorm was located 8 miles northwest of
Alfred, or 12 miles west of Hornell, moving southeast at 40 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Alfred, Andover, Belmont, Angelica, Almond, West Almond and Birdsall.

This includes Interstate 86 between exits 30 and 33.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

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

&&

LAT...LON 4229 7814 4248 7790 4242 7772 4208 7775
TIME...MOT...LOC 1753Z 294DEG 33KT 4234 7791 

HAIL...1.00IN
WIND...70MPH
 
$$

Mitchell

815 
WWUS51 KBUF 201814
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
214 PM EDT THU JUL 20 2017

NYC003-201824-
/O.EXP.KBUF.SV.W.0077.000000T0000Z-170720T1815Z/
Allegany NY-
214 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ALLEGANY COUNTY
WILL EXPIRE AT 215 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning will be allowed to expire.

A severe thunderstorm watch remains in effect until 800 PM EDT for
western New York.

LAT...LON 4229 7814 4248 7790 4242 7772 4208 7775
TIME...MOT...LOC 1814Z 294DEG 33KT 4227 7769 

$$

Apffel

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 11:44 AM EDT	Special Marine Warning	BUF		31 min
Jul 20, 11:47 AM EDT	Special Weather Statement	BUF	Genesee, Monroe, Niagara, Orleans, Wyoming	58 min
Jul 20, 12:11 PM EDT	Special Marine Warning	BUF		34 min
Jul 20, 12:21 PM EDT	Severe Thunderstorm Warning	BUF	Erie, Genesee, Livingston, Monroe, Niagara, Ontario and 2 more	54 min
Jul 20, 12:31 PM EDT	Severe Thunderstorm Warning	BUF	Allegany, Cattaraugus, Erie, Genesee, Livingston, Niagara and 1 more	59 min
Jul 20, 12:36 PM EDT	Tornado Warning	BUF	Cattaraugus, Erie, Wyoming	24 min
Jul 20, 12:55 PM EDT	Tornado Warning	BUF	Allegany, Cattaraugus, Erie, Wyoming	35 min
Jul 20, 1:35 PM EDT	Tornado Warning	BUF	Allegany	40 min
Jul 20, 1:44 PM EDT	Special Weather Statement	BUF	Erie	31 min
Jul 20, 2:07 PM EDT	Severe Thunderstorm Warning	BUF	Allegany, Cattaraugus, Erie, Wyoming	38 min
Jul 20, 2:46 PM EDT	Severe Thunderstorm Warning	BUF	Allegany	59 min

Nearby

Severe Thunderstorm Warnings in New York, 2017 Every severe thunderstorm warning in 2017

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.