Alert archive / Vermont / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 32, NWS Burlington, VT

July 20, 20218 counties in Vermont; Clinton County, Essex County, New York

NWS Burlington, VT issued this severe thunderstorm warning at Jul 20, 2021, 6:31 PM EDT for 8 counties in Vermont; Clinton County, Essex County, New York. It was in force for 59 min. 9 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, 6:31 PM EDT (22:31 UTC)
Expired: Jul 20, 2021, 7:30 PM EDT
In force: 59 min
Issued by: NWS Burlington, VT
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Clinton County, NY, Essex County, NY, Addison County, VT, Chittenden County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Rutland County, VT, Washington County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 25 km from the middle of the area, began a volume at 22:33 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.

What was reported inside it

Time	Report	Where	Remark
Jul 20, 6:38 PM EDT	TSTM WND DMG	Plattsburgh, NY	TREES DOWN ON RAILRAOD TRACKS.
Jul 20, 6:58 PM EDT	TSTM WND DMG	Alburgh, VT	TREE DOWN ON POWER LINES ON WEST SHORE RD.
Jul 20, 6:59 PM EDT	TSTM WND DMG	Burlington, VT	TREE DOWN ON CAR ON MARBLE AND ST. PAUL ST.
Jul 20, 6:59 PM EDT	TSTM WND DMG	Monkton, VT	TREE DOWN ACROSS HARDSCRABBLE ROAD.
Jul 20, 7:02 PM EDT	TSTM WND DMG	3 E South Burlington, VT	TREE DOWN ON I-89 BETWEEN EXIT 12 AND 13.
Jul 20, 7:04 PM EDT	TSTM WND DMG	Williston, VT	TREES DOWN.
Jul 20, 7:06 PM EDT	TSTM WND DMG	1 S Essex Center, VT	LARGE OAK TREE DOWN. ALSO A TREE DOWN ON RIVER RD.
Jul 20, 7:30 PM EDT	TSTM WND DMG	1 Nne Underhill, VT	TREES AND WIRES DOWN ON POKER HILL RD.
Jul 20, 7:34 PM EDT	TSTM WND DMG	Lincoln, VT	SEVERAL TREES AND POWERLINES DOWN.

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

Albany, NY (KALY), launched 12:00Z, 10.5 hours before the alert went out and 185 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: 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.

213 
WUUS51 KBTV 202231
SVRBTV
NYC019-031-VTC001-007-011-013-015-021-023-027-202330-
/O.NEW.KBTV.SV.W.0032.210720T2231Z-210720T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Burlington VT
631 PM EDT Tue Jul 20 2021

The National Weather Service in Burlington has issued a

* Severe Thunderstorm Warning for...
  Clinton County in northern New York...
  Essex County in northern New York...
  Lamoille County in northwestern Vermont...
  Addison County in central Vermont...
  Grand Isle County in northwestern Vermont...
  North central Rutland County in southern Vermont...
  Chittenden County in northwestern Vermont...
  Northwestern Windsor County in southern Vermont...
  Western Washington County in central Vermont...
  Franklin County in northwestern Vermont...

* Until 730 PM EDT.

* At 630 PM EDT, a line of severe thunderstorms over northeast New 
  York was located along a line extending from near Perry Mills to 
  near Harkness to 9 miles west of Schroon Falls, moving east at 40 
  mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect wind damage to trees and powerlines. Minor hail 
           damage to vehicles is possible. 

* Locations impacted include...
  Essex Junction, Plattsburgh International Airport, Burlington,
  Burlington International Airport, Plattsburgh, Middlebury, South
  Burlington, Vergennes, Peru, Beekmantown, Schuyler Falls, Moriah,
  Chazy, Saranac, Mooers, Altona, Willsboro, Crown Point, Morrisville
  and Enosburg Falls.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on Lake Champlain should seek safe harbor now! Strong winds
will cause higher waves and sudden wind shifts may overturn boats.

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

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage. SEEK SHELTER NOW inside a sturdy structure and stay 
away from windows! 
&&

LAT...LON 4501 7256 4439 7261 4371 7298 4378 7336
      4381 7338 4380 7345 4392 7408 4454 7376
      4500 7376
TIME...MOT...LOC 2230Z 283DEG 33KT 4503 7356 4452 7361 4395 7392 

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

Evenson/LaRocca

1 follow-up statement

968 
WWUS51 KBTV 202306
SVSBTV

Severe Weather Statement
National Weather Service Burlington VT
706 PM EDT Tue Jul 20 2021

NYC019-031-VTC001-007-011-013-015-021-023-027-202330-
/O.CON.KBTV.SV.W.0032.000000T0000Z-210720T2330Z/
Clinton NY-Essex NY-Lamoille VT-Addison VT-Grand Isle VT-Rutland VT-
Chittenden VT-Windsor VT-Washington VT-Franklin VT-
706 PM EDT Tue Jul 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR EASTERN CLINTON...EASTERN ESSEX...LAMOILLE...ADDISON...GRAND
ISLE...NORTH CENTRAL RUTLAND...CHITTENDEN...NORTHWESTERN WINDSOR...
WESTERN WASHINGTON AND FRANKLIN COUNTIES...

At 704 PM EDT, a line of severe thunderstorms over northwest Vermont 
and Essex County New York was located along a line extending from 
Shad Island to South Burlington to near Chilson, New York moving 
east at 35 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect wind damage to trees and powerlines. Minor hail 
         damage to vehicles is possible. 

Locations impacted include...
Essex Junction, Plattsburgh International Airport, Burlington,
Burlington International Airport, Plattsburgh, Middlebury, South
Burlington, Vergennes, Peru, Beekmantown, Moriah, Chazy, Willsboro,
Crown Point, Morrisville, Enosburg Falls, Westport, Elizabethtown,
Champlain and Waterbury Village.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on Lake Champlain should seek safe harbor now! Strong winds
will cause higher waves and sudden wind shifts may overturn boats.

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

This is a DANGEROUS SITUATION. These storms have produced widespread 
wind damage across northern New York. SEEK SHELTER NOW inside a 
sturdy structure and stay away from windows.
 
&&

LAT...LON 4501 7256 4439 7261 4371 7298 4378 7336
      4381 7338 4380 7345 4388 7389 4449 7354
      4500 7357
TIME...MOT...LOC 2304Z 284DEG 31KT 4501 7315 4445 7320 4382 7354 

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

Evenson/LaRocca

The office that day

Everything else NWS Burlington, VT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 5:35 PM EDT	Severe Thunderstorm Warning	BTV	Addison, Chittenden	55 min
Jul 20, 7:25 PM EDT	Special Weather Statement	BTV	Chittenden	110 min
Jul 20, 7:32 PM EDT	Severe Thunderstorm Warning	BTV	Addison, Caledonia, Chittenden, Essex, Franklin, Lamoille and 5 more	58 min
Jul 20, 3:53 PM EDT	Severe Thunderstorm Warning	BTV	Franklin, St. Lawrence	52 min
Jul 20, 4:44 PM EDT	Severe Thunderstorm Warning	BTV	Franklin, St. Lawrence	61 min
Jul 20, 5:50 PM EDT	Severe Thunderstorm Warning	BTV	Clinton, Essex, Franklin	40 min

Nearby

Severe Thunderstorm Warnings in Vermont, 2021 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.