Alert archive / New York / Special Weather Statements in 2021

Special Weather Statement, NWS Buffalo, NY

July 20, 20214 counties in New York

NWS Buffalo, NY issued this special weather statement at Jul 20, 2021, 5:56 PM EDT for 4 counties in New York. It was in force for 34 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 20, 2021, 5:56 PM EDT (21:56 UTC)
Expired: Jul 20, 2021, 6:30 PM EDT
In force: 34 min
Issued by: NWS Buffalo, NY

Counties Genesee County, NY, Monroe County, NY, Ontario County, NY, Orleans County, NY

The radar

The Buffalo radar (KBUF), 83 km from the middle of the area, began a volume at 21:54 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 12:00Z, 9.9 hours before the alert went out and 81 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: 574 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 893 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

579 
WWUS81 KBUF 202156
SPSBUF

Special Weather Statement
National Weather Service Buffalo NY
556 PM EDT Tue Jul 20 2021

NYZ002>004-011>014-202230-
Ontario-Livingston-Wyoming-Orleans-Wayne-Genesee-Monroe-
556 PM EDT Tue Jul 20 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WESTERN WAYNE...
NORTHEASTERN WYOMING...NORTHERN LIVINGSTON...ORLEANS...GENESEE...
MONROE AND NORTHERN ONTARIO COUNTIES...

At 556 PM EDT, radar indicated a line of strong thunderstorms were 
located along a line extending from 23 miles north of Webster to 
near Waterport. Movement was southeast at 20 mph.

Winds in excess of 40 mph and pea size hail are possible with these
storms.

Locations impacted include...
Rochester, Greece, Irondequoit, Chili, Batavia, Canandaigua,
Brockport, East Rochester, Albion, Hilton, Webster, Fairport,
Brighton, Gates-North Gates, Hamlin Beach State Park, Ontario,
Henrietta, Penfield, Newark and Williamson.

This includes the following highways...
 Interstate 390 between exits 9 and 12.
 Interstate 90 between exits 48 and 43.

Torrential rainfall is also occurring with these storms, 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.

These storms 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 4286 7835 4339 7829 4342 7817 4339 7775
      4328 7754 4332 7738 4333 7712 4285 7700
TIME...MOT...LOC 2156Z 308DEG 19KT 4355 7746 4331 7834 
$$

Reynolds

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 2:13 PM EDT	Special Marine Warning	BUF		62 min
Jul 20, 2:57 PM EDT	Special Weather Statement	BUF	Niagara	48 min
Jul 20, 3:14 PM EDT	Special Marine Warning	BUF		61 min
Jul 20, 3:23 PM EDT	Severe Thunderstorm Warning	BUF	Niagara	67 min
Jul 20, 3:39 PM EDT	Special Marine Warning	BUF		81 min
Jul 20, 3:48 PM EDT	Special Marine Warning	BUF		87 min
Jul 20, 4:08 PM EDT	Severe Thunderstorm Warning	BUF	Jefferson, Lewis	67 min
Jul 20, 4:23 PM EDT	Severe Thunderstorm Warning	BUF	Erie, Genesee, Niagara, Orleans	67 min
Jul 20, 4:42 PM EDT	Severe Thunderstorm Warning	BUF	Niagara	48 min
Jul 20, 4:46 PM EDT	Special Marine Warning	BUF		59 min
Jul 20, 4:49 PM EDT	Flash Flood Warning	BUF	Niagara	6 hr
Jul 20, 4:55 PM EDT	Special Marine Warning	BUF		48 min
Jul 20, 4:58 PM EDT	Special Marine Warning	BUF		92 min
Jul 20, 5:00 PM EDT	Special Weather Statement	BUF	Genesee	30 min
Jul 20, 5:10 PM EDT	Special Marine Warning	BUF		2 hr
Jul 20, 5:13 PM EDT	Severe Thunderstorm Warning	BUF	Jefferson, Lewis, Oswego	62 min
Jul 20, 5:28 PM EDT	Special Weather Statement	BUF	Oswego	47 min
Jul 20, 5:30 PM EDT	Severe Thunderstorm Warning	BUF	Erie, Genesee, Niagara, Orleans	60 min
Jul 20, 5:43 PM EDT	Special Marine Warning	BUF		92 min
Jul 20, 5:43 PM EDT	Severe Thunderstorm Warning	BUF	Oswego	62 min
Jul 20, 6:07 PM EDT	Severe Thunderstorm Warning	BUF	Cayuga, Jefferson, Lewis, Oswego, Wayne	38 min
Jul 20, 6:21 PM EDT	Flash Flood Warning	BUF	Erie, Niagara	4 hr
Jul 20, 6:26 PM EDT	Special Marine Warning	BUF		34 min
Jul 20, 6:30 PM EDT	Special Weather Statement	BUF	Erie, Genesee	30 min
Jul 20, 6:37 PM EDT	Severe Thunderstorm Warning	BUF	Erie, Genesee, Niagara	46 min
Jul 20, 6:46 PM EDT	Special Weather Statement	BUF	Lewis	29 min
Jul 20, 6:52 PM EDT	Special Marine Warning	BUF		67 min
Jul 20, 7:24 PM EDT	Special Weather Statement	BUF	Erie, Genesee, Livingston, Ontario, Wyoming	36 min
Jul 20, 7:38 PM EDT	Severe Thunderstorm Warning	BUF	Livingston, Monroe, Ontario, Wayne	31 min
Jul 20, 7:58 PM EDT	Special Weather Statement	BUF	Livingston, Wyoming	92 min

Nearby

Special Weather Statements in New York, 2021 Every 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.