Alert archive / New York / Special Weather Statements in 2021

Special Weather Statement, NWS Buffalo, NY

July 21, 2021Allegany County, New York

NWS Buffalo, NY issued this special weather statement at Jul 21, 2021, 12:31 AM EDT for Allegany County, New York. It was in force for 44 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 21, 2021, 12:31 AM EDT (04:31 UTC)
Expired
Jul 21, 2021, 1:15 AM EDT
In force
44 min
Issued by
NWS Buffalo, NY

County Allegany County, NY

The radar

The Buffalo radar (KBUF), 109 km from the middle of the area, began a volume at 04:33 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.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 4.5 hours before the alert went out and 106 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 00:00Z on 2021-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2021-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -176 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1459 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
-176 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

294 
WWUS81 KBUF 210431
SPSBUF

Special Weather Statement
National Weather Service Buffalo NY
1231 AM EDT Wed Jul 21 2021

NYZ020-021-210515-
Cattaraugus-Allegany-
1231 AM EDT Wed Jul 21 2021

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN CATTARAUGUS AND
SOUTHERN ALLEGANY COUNTIES...

At 1230 AM EDT, a strong thunderstorm was located over Weston Mills,
or near Olean, moving east at 35 mph.

Wind gusts up to 50 mph and penny size hail are possible with this
storm.

Locations impacted include...
Olean, Wellsville, Whitesville, Weston Mills, Hinsdale, Bolivar,
Portville, Alma, Richburg, Stannards, Rock City Park, Knight Creek,
Haskell Flats, West Clarksville, Paynesville, Little Genesee and
Ceres.

This includes Interstate 86 between exits 26 and 27.
 
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4200 7840 4201 7848 4219 7841 4209 7775
      4200 7775
TIME...MOT...LOC 0430Z 286DEG 29KT 4208 7833 
$$

Mitchell

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 8:07 PM EDTAreal Flood WarningBUFLivingston, Monroe, Ontario, Wayne81 min
Jul 20, 8:28 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus62 min
Jul 20, 8:39 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus, Erie, Livingston, Wyoming53 min
Jul 20, 9:16 PM EDTSevere Thunderstorm WarningBUFAllegany36 min
Jul 20, 9:45 PM EDTSpecial Marine WarningBUF60 min
Jul 20, 10:14 PM EDTAreal Flood WarningBUFNiagara9 hr
Jul 20, 10:19 PM EDTSevere Thunderstorm WarningBUFChautauqua56 min
Jul 20, 11:10 PM EDTSpecial Weather StatementBUFCattaraugus35 min
Jul 20, 11:29 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus, Chautauqua61 min

Nearby

Special Weather Statements in New York, 2021Every special weather statement 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.