Alert archive / New York / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 70, NWS Buffalo, NY

July 29, 20205 counties in New York

NWS Buffalo, NY issued this severe thunderstorm warning at Jul 29, 2020, 2:49 PM EDT for 5 counties in New York. It was in force for 56 min. 5 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 29, 2020, 2:49 PM EDT (18:49 UTC)
Expired
Jul 29, 2020, 3:45 PM EDT
In force
56 min
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Allegany County, NY, Cattaraugus County, NY, Erie County, NY, Livingston County, NY, Wyoming County, NY

The radar

The Buffalo radar (KBUF), 76 km from the middle of the area, began a volume at 18:53 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

TimeReportWhereRemark
Jul 29, 2:57 PM EDTTSTM WND DMG1 S Delevan, NYTREES DOWN ON POWER LINES
Jul 29, 3:10 PM EDTTSTM WND DMGEagle, NYTREES AND POWER LINES DOWN ON ROUTE 39
Jul 29, 3:14 PM EDTTSTM WND DMG1 Ne Eagle, NYTREES DOWN
Jul 29, 3:30 PM EDTTSTM WND DMGPortageville, NYTREES AND POWERLINES DOWN
Jul 29, 3:35 PM EDTTSTM WND DMG1 N Nunda, NYMANY TREES DOWN NORTH OF NUNDA

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 12:00Z, 6.8 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-pSkew-T log-p diagram, Buffalo Intl Airport, NY at 12:00Z on 2020-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 95 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 12:00Z on 2020-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
95 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
995 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

669 
WUUS51 KBUF 291849
SVRBUF
NYC003-009-029-051-121-291945-
/O.NEW.KBUF.SV.W.0070.200729T1849Z-200729T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
249 PM EDT Wed Jul 29 2020

The National Weather Service in Buffalo has issued a

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

* Until 345 PM EDT..

* At 248 PM EDT, a severe thunderstorm was located near Ashford
  Hollow, or 18 miles north of Salamanca, moving east at 30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Dansville, Letchworth State Park, Springville, Arcade,
  Franklinville, Belfast, Rushford, Houghton, Portageville and
  Yorkshire.

 This includes Interstate 390 between exits 4 and 5.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION. This storm has a history 
of producing widespread wind damage across Chautauqua County. SEEK 
SHELTER NOW inside a sturdy structure and stay away from windows!

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Buffalo.

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

&&

LAT...LON 4250 7871 4267 7773 4253 7769 4253 7772
      4241 7773 4236 7773 4230 7857
TIME...MOT...LOC 1848Z 264DEG 28KT 4241 7861 

HAIL...1.00IN
WIND...60MPH
 
$$

Fries
2 follow-up statements
401 
WWUS51 KBUF 291912
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
312 PM EDT Wed Jul 29 2020

NYC029-291921-
/O.CAN.KBUF.SV.W.0070.000000T0000Z-200729T1945Z/
Erie NY-
312 PM EDT Wed Jul 29 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ERIE 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 4267 7773 4253 7769 4253 7772 4241 7773
      4236 7773 4232 7831 4254 7846
TIME...MOT...LOC 1911Z 255DEG 38KT 4252 7827 

$$

NYC003-009-051-121-291945-
/O.CON.KBUF.SV.W.0070.000000T0000Z-200729T1945Z/
Wyoming NY-Cattaraugus NY-Livingston NY-Allegany NY-
312 PM EDT Wed Jul 29 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR SOUTHERN WYOMING...NORTHEASTERN CATTARAUGUS...SOUTHWESTERN
LIVINGSTON AND NORTHERN ALLEGANY COUNTIES...

At 311 PM EDT, a severe thunderstorm was located 8 miles east of
Arcade, or 17 miles southwest of Letchworth State Park, moving east
at 45 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Dansville, Letchworth State Park, Arcade, Belfast, Rushford,
Houghton, Portageville, Caneadea, Nunda and Eagle.

 This includes Interstate 390 between exits 4 and 5.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION. This storm has a history 
of producing widespread wind damage. SEEK SHELTER NOW inside a 
sturdy structure and stay away from windows.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Buffalo.

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

&&

LAT...LON 4267 7773 4253 7769 4253 7772 4241 7773
      4236 7773 4232 7831 4254 7846
TIME...MOT...LOC 1911Z 255DEG 38KT 4252 7827 

HAIL...1.00IN
WIND...60MPH
 
$$

Fries
336 
WWUS51 KBUF 291930
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
330 PM EDT Wed Jul 29 2020

NYC009-291940-
/O.CAN.KBUF.SV.W.0070.000000T0000Z-200729T1945Z/
Cattaraugus NY-
330 PM EDT Wed Jul 29 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CATTARAUGUS
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 4267 7773 4253 7769 4253 7772 4241 7773
      4236 7773 4233 7819 4249 7814 4258 7824
TIME...MOT...LOC 1930Z 264DEG 38KT 4254 7797 

$$

NYC003-051-121-291945-
/O.CON.KBUF.SV.W.0070.000000T0000Z-200729T1945Z/
Wyoming NY-Livingston NY-Allegany NY-
330 PM EDT Wed Jul 29 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR SOUTHEASTERN WYOMING...SOUTHWESTERN LIVINGSTON AND NORTHERN
ALLEGANY COUNTIES...

At 330 PM EDT, a severe thunderstorm was located near Portageville,
or 7 miles south of Letchworth State Park, moving east at 45 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Dansville, Letchworth State Park, Belfast, Portageville, Houghton,
Caneadea, Nunda, Pike, Ossian and Canaseraga.

 This includes Interstate 390 between exits 4 and 5.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION. This storm has previously 
produced widespread wind damage across Chautauqua and Cattaraugus 
counties. SEEK SHELTER NOW inside a sturdy structure and stay away 
from windows.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Buffalo.

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

&&

LAT...LON 4267 7773 4253 7769 4253 7772 4241 7773
      4236 7773 4233 7819 4249 7814 4258 7824
TIME...MOT...LOC 1930Z 264DEG 38KT 4254 7797 

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

Fries

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 4:20 AM EDTSmall Craft AdvisoryBUF16 hr
Jul 29, 10:06 AM EDTSpecial Weather StatementBUFErie54 min
Jul 29, 10:51 AM EDTSpecial Weather StatementBUFGenesee54 min
Jul 29, 10:55 AM EDTSpecial Marine WarningBUF23 min
Jul 29, 11:35 AM EDTSpecial Weather StatementBUFLivingston55 min
Jul 29, 11:51 AM EDTSpecial Weather StatementBUFWyoming54 min
Jul 29, 12:21 PM EDTSpecial Weather StatementBUFWyoming39 min
Jul 29, 12:26 PM EDTSpecial Weather StatementBUFOntario34 min
Jul 29, 1:09 PM EDTSpecial Weather StatementBUFLivingston36 min
Jul 29, 1:19 PM EDTSevere Thunderstorm WarningBUFAllegany, Livingston, Ontario41 min
Jul 29, 1:28 PM EDTSevere Thunderstorm WarningBUFChautauqua62 min
Jul 29, 1:48 PM EDTSpecial Marine WarningBUF42 min
Jul 29, 2:10 PM EDTSevere Thunderstorm WarningBUFCattaraugus, Chautauqua65 min
Jul 29, 2:13 PM EDTSpecial Weather StatementBUFErie32 min
Jul 29, 2:25 PM EDTSpecial Marine WarningBUF50 min
Jul 29, 2:53 PM EDTSpecial Weather StatementBUFErie, Wyoming52 min
Jul 29, 3:27 PM EDTSevere Thunderstorm WarningBUFLivingston, Wyoming48 min
Jul 29, 3:41 PM EDTSevere Thunderstorm WarningBUFLivingston, Ontario64 min
Jul 29, 3:45 PM EDTSevere Thunderstorm WarningBUFAllegany, Livingston, Ontario45 min
Jul 29, 4:15 PM EDTSpecial Weather StatementBUFMonroe45 min
Jul 29, 4:20 PM EDTSevere Thunderstorm WarningBUFCayuga, Ontario, Wayne40 min
Jul 29, 4:40 PM EDTSevere Thunderstorm WarningBUFMonroe, Wayne38 min
Jul 29, 4:56 PM EDTSevere Thunderstorm WarningBUFCayuga, Oswego, Wayne64 min
Jul 29, 5:35 PM EDTSpecial Weather StatementBUFGenesee25 min
Jul 29, 5:42 PM EDTSevere Thunderstorm WarningBUFGenesee, Orleans48 min
Jul 29, 6:34 PM EDTSpecial Weather StatementBUFLivingston26 min
Jul 29, 6:37 PM EDTSevere Thunderstorm WarningBUFGenesee, Livingston, Monroe, Ontario51 min
Jul 29, 6:41 PM EDTSevere Thunderstorm WarningBUFGenesee, Orleans34 min
Jul 29, 6:50 PM EDTTornado WarningBUFLivingston, Monroe, Ontario28 min

Nearby

Severe Thunderstorm Warnings in New York, 2020Every severe thunderstorm warning in 2020

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.