Alert archive / New York / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 79, NWS Buffalo, NY

July 20, 2017Allegany County, New York

NWS Buffalo, NY issued this severe thunderstorm warning at Jul 20, 2017, 2:46 PM EDT for Allegany County, New York. It was in force for 59 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: Jul 20, 2017, 2:46 PM EDT (18:46 UTC)
Expired: Jul 20, 2017, 3:45 PM EDT
In force: 59 min
Issued by: NWS Buffalo, NY
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Allegany County, NY

The radar

The Buffalo radar (KBUF), 98 km from the middle of the area, began a volume at 18:49 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, 2:47 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, 6.8 hours before the alert went out and 95 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.

758 
WUUS51 KBUF 201846
SVRBUF
NYC003-201945-
/O.NEW.KBUF.SV.W.0079.170720T1846Z-170720T1945Z/

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

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  Allegany County in western New York...

* Until 345 PM EDT.

* At 246 PM EDT, a severe thunderstorm was located near Belfast, or
  15 miles northwest of Wellsville, moving southeast at 35 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...
  Wellsville, Alfred, Belfast, Whitesville, Houghton, Caneadea,
  Friendship and Scio.

This includes Interstate 86 between exits 29 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.

&&

LAT...LON 4229 7830 4250 7805 4238 7773 4200 7775
      4200 7793
TIME...MOT...LOC 1846Z 312DEG 29KT 4230 7813 

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

Mitchell

3 follow-up statements

788 
WWUS51 KBUF 201907
SVSBUF

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

NYC003-201945-
/O.CON.KBUF.SV.W.0079.000000T0000Z-170720T1945Z/
Allegany NY-
307 PM EDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR SOUTHEASTERN ALLEGANY COUNTY...

At 305 PM EDT, a severe thunderstorm was located near Wellsville,
moving southeast at 35 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...
Wellsville, Alfred, Whitesville, Friendship, Scio, Andover, Belmont
and Almond.

This includes Interstate 86 between exits 29 and 30, and between
exits 32 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.

&&

LAT...LON 4223 7822 4230 7798 4242 7785 4238 7773
      4200 7775 4200 7793
TIME...MOT...LOC 1905Z 312DEG 29KT 4219 7797 

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

Mitchell

723 
WWUS51 KBUF 201935
SVSBUF

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

NYC003-201945-
/O.CON.KBUF.SV.W.0079.000000T0000Z-170720T1945Z/
Allegany NY-
335 PM EDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR SOUTHEASTERN ALLEGANY COUNTY...

At 332 PM EDT, a severe thunderstorm was located just southeast of 
Wellsville, moving southeast at 35 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...
Wellsville, Whitesville, Andover, Stannards and Paynesville. 

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 4209 7804 4223 7774 4200 7775 4200 7793
TIME...MOT...LOC 1932Z 312DEG 29KT 4204 7775 

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

Mitchell

210 
WWUS51 KBUF 201943
SVSBUF

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

NYC003-201953-
/O.EXP.KBUF.SV.W.0079.000000T0000Z-170720T1945Z/
Allegany NY-
343 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ALLEGANY COUNTY
WILL EXPIRE AT 345 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning will be allowed to expire.

LAT...LON 4209 7804 4223 7774 4200 7775 4200 7793
TIME...MOT...LOC 1943Z 312DEG 29KT 4199 7767 

$$

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, 2:07 PM EDT	Severe Thunderstorm Warning	BUF	Allegany, Cattaraugus, Erie, Wyoming	38 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.