Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 84, NWS Buffalo, NY

July 20, 2021Oswego County, New York

NWS Buffalo, NY issued this severe thunderstorm warning at Jul 20, 2021, 5:43 PM EDT for Oswego County, New York. It was in force for 62 min. 3 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, 2021, 5:43 PM EDT (21:43 UTC)
Expired
Jul 20, 2021, 6:45 PM EDT
In force
62 min
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Oswego County, NY

The radar

The Ft Drum radar (KTYX), 70 km from the middle of the area, began a volume at 21:47 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 20, 5:52 PM EDTTSTM WND DMGPhoenix, NYREPORTS OF WIDESPREAD DAMAGE IN THE TOWN OF PHOENIX WITH NUMEROUS TREES AND WIRES DOWN.
Jul 20, 6:00 PM EDTTSTM WND DMG3 Nw Sand Ridge, NYREPORT OF TREES AND WIRES DOWN IN THE TOWN OF SCHROEPPEL.
Jul 20, 6:23 PM EDTTSTM WND DMGConstantia, NYREPORTS OF WIDESPREAD DAMAGE INCLUDING NUMEROUS DOWNED TREES AND POWERLINES IN THE TOWN OF CONSTANTIA.

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.

IssuedProductOfficeLasted
Jul 20, 3:05 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 9.7 hours before the alert went out and 202 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, Albany, NY at 12:00Z on 2021-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 85 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2021-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939Sfc1 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
85 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
793 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

546 
WUUS51 KBUF 202143
SVRBUF
NYC075-202245-
/O.NEW.KBUF.SV.W.0084.210720T2143Z-210720T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Buffalo NY
543 PM EDT Tue Jul 20 2021

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  Southern Oswego County in central New York...

* Until 645 PM EDT..

* At 542 PM EDT, a severe thunderstorm was located over Fulton,
  moving east at 25 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...
  Fulton, Central Square, Battle Island State Park, Hastings, Volney,
  Constantia, West Monroe, Palermo, Phoenix and Cleveland.

 This includes Interstate 81 between exits 32 and 33.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4316 7588 4320 7608 4323 7610 4324 7616
      4327 7620 4324 7621 4322 7619 4320 7621
      4324 7627 4322 7626 4320 7627 4323 7631
      4323 7648 4325 7648 4326 7650 4337 7651
      4342 7609 4334 7588 4332 7586
TIME...MOT...LOC 2142Z 268DEG 22KT 4329 7640 

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

Welch
2 follow-up statements
495 
WWUS51 KBUF 202210
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
610 PM EDT Tue Jul 20 2021

NYC075-202245-
/O.CON.KBUF.SV.W.0084.000000T0000Z-210720T2245Z/
Oswego NY-
610 PM EDT Tue Jul 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR SOUTHERN OSWEGO COUNTY...

At 609 PM EDT, a severe thunderstorm was located over Central Square,
or 11 miles northeast of Baldwinsville, moving east at 25 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...
Fulton, Central Square, Battle Island State Park, Hastings, Volney,
Constantia, West Monroe, Palermo, Phoenix and Cleveland.

 This includes Interstate 81 between exits 32 and 33.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4316 7588 4320 7608 4323 7610 4324 7616
      4327 7620 4324 7621 4322 7619 4320 7621
      4324 7627 4322 7626 4320 7627 4323 7631
      4323 7648 4325 7648 4326 7650 4337 7651
      4342 7609 4334 7588 4332 7586
TIME...MOT...LOC 2209Z 269DEG 22KT 4328 7618 

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

Welch
416 
WWUS51 KBUF 202250
SVSBUF

Severe Weather Statement
National Weather Service Buffalo NY
650 PM EDT Tue Jul 20 2021

NYC075-202300-
/O.EXP.KBUF.SV.W.0084.000000T0000Z-210720T2245Z/
Oswego NY-
650 PM EDT Tue Jul 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN OSWEGO COUNTY HAS
EXPIRED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been allowed to expire.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
central New York.

LAT...LON 4316 7588 4320 7608 4323 7610 4324 7616
      4327 7620 4324 7621 4322 7619 4320 7621
      4324 7627 4322 7626 4320 7627 4323 7631
      4323 7648 4325 7648 4326 7650 4337 7651
      4342 7609 4334 7588 4332 7586
TIME...MOT...LOC 2250Z 268DEG 22KT 4329 7585 

$$

EAJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 2:13 PM EDTSpecial Marine WarningBUF62 min
Jul 20, 2:57 PM EDTSpecial Weather StatementBUFNiagara48 min
Jul 20, 3:14 PM EDTSpecial Marine WarningBUF61 min
Jul 20, 3:23 PM EDTSevere Thunderstorm WarningBUFNiagara67 min
Jul 20, 3:39 PM EDTSpecial Marine WarningBUF81 min
Jul 20, 3:48 PM EDTSpecial Marine WarningBUF87 min
Jul 20, 4:08 PM EDTSevere Thunderstorm WarningBUFJefferson, Lewis67 min
Jul 20, 4:23 PM EDTSevere Thunderstorm WarningBUFErie, Genesee, Niagara, Orleans67 min
Jul 20, 4:42 PM EDTSevere Thunderstorm WarningBUFNiagara48 min
Jul 20, 4:46 PM EDTSpecial Marine WarningBUF59 min
Jul 20, 4:49 PM EDTFlash Flood WarningBUFNiagara6 hr
Jul 20, 4:55 PM EDTSpecial Marine WarningBUF48 min
Jul 20, 4:58 PM EDTSpecial Marine WarningBUF92 min
Jul 20, 5:00 PM EDTSpecial Weather StatementBUFGenesee30 min
Jul 20, 5:10 PM EDTSpecial Marine WarningBUF2 hr
Jul 20, 5:13 PM EDTSevere Thunderstorm WarningBUFJefferson, Lewis, Oswego62 min
Jul 20, 5:28 PM EDTSpecial Weather StatementBUFOswego47 min
Jul 20, 5:30 PM EDTSevere Thunderstorm WarningBUFErie, Genesee, Niagara, Orleans60 min
Jul 20, 5:43 PM EDTSpecial Marine WarningBUF92 min
Jul 20, 5:56 PM EDTSpecial Weather StatementBUFGenesee, Monroe, Ontario, Orleans34 min
Jul 20, 6:07 PM EDTSevere Thunderstorm WarningBUFCayuga, Jefferson, Lewis, Oswego, Wayne38 min
Jul 20, 6:21 PM EDTFlash Flood WarningBUFErie, Niagara4 hr
Jul 20, 6:26 PM EDTSpecial Marine WarningBUF34 min
Jul 20, 6:30 PM EDTSpecial Weather StatementBUFErie, Genesee30 min
Jul 20, 6:37 PM EDTSevere Thunderstorm WarningBUFErie, Genesee, Niagara46 min
Jul 20, 6:46 PM EDTSpecial Weather StatementBUFLewis29 min
Jul 20, 6:52 PM EDTSpecial Marine WarningBUF67 min
Jul 20, 7:24 PM EDTSpecial Weather StatementBUFErie, Genesee, Livingston, Ontario, Wyoming36 min
Jul 20, 7:38 PM EDTSevere Thunderstorm WarningBUFLivingston, Monroe, Ontario, Wayne31 min
Jul 20, 7:58 PM EDTSpecial Weather StatementBUFLivingston, Wyoming92 min

Nearby

Severe Thunderstorm Warnings in New York, 2021Every 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.