Alert archive / New York / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 81, NWS Buffalo, NY

July 20, 2021Niagara County, New York

NWS Buffalo, NY issued this severe thunderstorm warning at Jul 20, 2021, 4:42 PM EDT for Niagara County, New York. It was in force for 48 min. 4 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, 4:42 PM EDT (20:42 UTC)
Expired: Jul 20, 2021, 5:30 PM EDT
In force: 48 min
Issued by: NWS Buffalo, NY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Niagara County, NY

The radar

The Buffalo radar (KBUF), 39 km from the middle of the area, began a volume at 20:45 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, 4:51 PM EDT	HAIL 0.75	4 Ne Lewiston, NY	DIME SIZED HAIL (0.75IN) REPORTED IN NORTHEAST LEWISTON.
Jul 20, 4:54 PM EDT	HAIL 0.5	Lewiston, NY	REPORT OF 0.5IN HAIL IN LEWISTON.
Jul 20, 5:05 PM EDT	HAIL 1	Lewiston, NY	QUARTER SIZED (1IN) HAIL REPORTED IN THE TOWN OF LEWISTON.
Jul 20, 5:13 PM EDT	HAIL 0.75	1 Ese Lewiston, NY	DIME SIZED (0.75IN) HAIL REPORTED IN THE TOWN OF LEWISTON.

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, 3:05 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 8.7 hours before the alert went out and 42 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.

544 
WUUS51 KBUF 202042
SVRBUF
NYC063-202130-
/O.NEW.KBUF.SV.W.0081.210720T2042Z-210720T2130Z/

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

The National Weather Service in Buffalo has issued a

* Severe Thunderstorm Warning for...
  West central Niagara County in western New York...

* Until 530 PM EDT..

* At 442 PM EDT, a severe thunderstorm was located near Youngstown,
  or 9 miles north of Niagara Falls, moving east at 20 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...
  Lewiston, Youngstown, Fort Niagara State Park and Model City. 

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 4330 7909 4332 7903 4332 7895 4309 7896
      4310 7906 4311 7906 4312 7907 4314 7904
      4317 7905 4325 7906 4328 7908 4329 7909
TIME...MOT...LOC 2042Z 271DEG 18KT 4322 7910 

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

Reynolds

1 follow-up statement

814 
WWUS51 KBUF 202058
SVSBUF

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

NYC063-202130-
/O.CON.KBUF.SV.W.0081.000000T0000Z-210720T2130Z/
Niagara NY-
458 PM EDT Tue Jul 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR WEST CENTRAL NIAGARA COUNTY...

At 457 PM EDT, a severe thunderstorm was located near Youngstown, or
9 miles north of Niagara Falls, moving east at 20 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...
Lewiston, Youngstown, Fort Niagara State Park and Model City. 

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 4330 7909 4332 7903 4332 7895 4309 7896
      4310 7906 4311 7906 4312 7907 4314 7904
      4317 7905 4325 7906 4328 7908 4329 7909
TIME...MOT...LOC 2057Z 271DEG 18KT 4322 7899 

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

EAJ

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, 4:46 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, 5:56 PM EDT	Special Weather Statement	BUF	Genesee, Monroe, Ontario, Orleans	34 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

Severe Thunderstorm Warnings in New York, 2021 Every 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.