Alert archive / New York / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 78, NWS Buffalo, NY

July 20, 20174 counties in New York

NWS Buffalo, NY issued this severe thunderstorm warning at Jul 20, 2017, 2:07 PM EDT for 4 counties in New York. It was in force for 38 min. 2 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, 2:07 PM EDT (18:07 UTC)
Expired: Jul 20, 2017, 2:45 PM EDT
In force: 38 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, Erie County, NY, Wyoming County, NY

The radar

The Buffalo radar (KBUF), 69 km from the middle of the area, began a volume at 18:05 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, 2:35 PM EDT	TSTM WND DMG	Short Tract, NY	TREES AND WIRES DOWN
Jul 20, 2:47 PM EDT	TSTM WND DMG	1 Nne Angelica, NY	TREE FELL ON A CAR NEAR ALLEGANY FAIRGROUNDS

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, 6.1 hours before the alert went out and 66 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.

841 
WUUS51 KBUF 201807
SVRBUF
NYC003-009-029-121-201845-
/O.NEW.KBUF.SV.W.0078.170720T1807Z-170720T1845Z/

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

The National Weather Service in Buffalo has issued a

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

* Until 245 PM EDT.

* At 207 PM EDT, a severe thunderstorm was located near East Concord,
  or 19 miles south of East Aurora, moving southeast at 40 mph.

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

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Arcade, Franklinville, Belfast, Cuba, Rushford, Houghton, Chaffee
  and Ashford Hollow.

This includes Interstate 86 between exits 28 and 31.
 
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.

&&

LAT...LON 4242 7872 4264 7851 4240 7781 4210 7803
TIME...MOT...LOC 1807Z 295DEG 35KT 4249 7856 

HAIL...0.75IN
WIND...60MPH
 
$$

Mitchell

2 follow-up statements

226 
WWUS51 KBUF 201833
SVSBUF

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

NYC029-121-201842-
/O.CAN.KBUF.SV.W.0078.000000T0000Z-170720T1845Z/
Wyoming NY-Erie NY-
233 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WYOMING AND
SOUTHEASTERN ERIE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled. However 
the severe warning for Cattaraugus and Allegany Counties remains in 
effect.

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

LAT...LON 4230 7846 4252 7819 4252 7814 4240 7781
      4210 7803
TIME...MOT...LOC 1832Z 295DEG 35KT 4239 7826 

$$

NYC003-009-201845-
/O.CON.KBUF.SV.W.0078.000000T0000Z-170720T1845Z/
Cattaraugus NY-Allegany NY-
233 PM EDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM EDT
FOR EAST CENTRAL CATTARAUGUS AND ALLEGANY COUNTIES...

At 232 PM EDT, a severe thunderstorm was located over Rushford, or 22
miles north of Olean, moving southeast at 40 mph.

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

SOURCE...Radar indicated. 

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

Locations impacted include...
Belfast, Cuba, Rushford, Houghton, Caneadea, Friendship, Scio and
Belmont.

This includes Interstate 86 between exits 28 and 31.
 
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.

&&

LAT...LON 4230 7846 4252 7819 4252 7814 4240 7781
      4210 7803
TIME...MOT...LOC 1832Z 295DEG 35KT 4239 7826 

HAIL...0.75IN
WIND...60MPH
 
$$

Mitchell

435 
WWUS51 KBUF 201849
SVSBUF

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

NYC003-009-201857-
/O.EXP.KBUF.SV.W.0078.000000T0000Z-170720T1845Z/
Cattaraugus NY-Allegany NY-
249 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CATTARAUGUS AND
ALLEGANY COUNTIES HAS EXPIRED...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning has been allowed to expire.

However, a new Severe Thunderstorm Warning has been issued for 
Allegany County.

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

LAT...LON 4230 7846 4252 7819 4252 7814 4240 7781
      4210 7803
TIME...MOT...LOC 1847Z 295DEG 35KT 4233 7809 

$$

Mitchell

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, 1:23 PM EDT	Severe Thunderstorm Warning	BUF	Allegany, Cattaraugus, Wyoming	52 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, 2:46 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.