Alert archive / Vermont / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 56, NWS Burlington, VT

August 24, 2020Chittenden County, Franklin County, Grand Isle County, Vermont; Clinton County, New York

NWS Burlington, VT issued this severe thunderstorm warning at Aug 24, 2020, 2:07 PM EDT for Chittenden County, Franklin County, Grand Isle County, Vermont; Clinton County, New York. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 24, 2020, 2:07 PM EDT (18:07 UTC)
Expired
Aug 24, 2020, 2:45 PM EDT
In force
38 min
Issued by
NWS Burlington, VT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Clinton County, NY, Chittenden County, VT, Franklin County, VT, Grand Isle County, VT

The radar

The Burlington radar (KCXX), 23 km from the middle of the area, began a volume at 18:10 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

Albany, NY (KALY), launched 12:00Z, 6.1 hours before the alert went out and 230 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 2020-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 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 2020-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
21 J/kg
Mixed-layer CIN
-214 J/kg
Mixed-layer LCL
1255 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Burlington, VT wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 24, 10:00 AM EDT, 4 hours 7 minutes earlier.

Area forecast discussion, Aug 24, 10:00 AM EDT, 4 hours 7 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Hazardous weather outlook, Aug 24, 4:21 AM EDT, 9 hours 46 minutes before
Hazardous Weather Outlook
National Weather Service Burlington VT
421 AM EDT Mon Aug 24 2020

NYZ026>031-034-035-087-VTZ001>012-016>019-250830-
Northern St. Lawrence-Northern Franklin-Eastern Clinton-
Southeastern St. Lawrence-Southern Franklin-Western Clinton-
Western Essex-Eastern Essex-Southwestern St. Lawrence-Grand Isle-
Western Franklin-Orleans-Essex-Western Chittenden-Lamoille-Caledonia-
Washington-Western Addison-Orange-Western Rutland-Windsor-
Eastern Franklin-Eastern Chittenden-Eastern Addison-Eastern Rutland-
421 AM EDT Mon Aug 24 2020

This Hazardous Weather Outlook is for northern New York, central
Vermont, northeast Vermont, northwest Vermont and southern Vermont.

.DAY ONE...Today and tonight.

Scattered showers and thunderstorms will develop this afternoon,
especially along the International Border. A few strong storms are
possible, with gusty winds, dangerous cloud to ground lightning, and
brief heavy rainfall the primary threats.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

A strong cold front will move across the region around sunrise on
Tuesday through the early afternoon. Scattered showers and
thunderstorms will develop along the front. The front will reach the
eastern Adirondacks and Champlain Valley by late morning and into
eastern Vermont during the afternoon. This region from the eastern
Adirondacks into Vermont will have the greatest chance of strong to
locally severe storms capable of damaging winds, frequent lightning,
and brief heavy rain.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Special weather statement, Aug 24, 12:54 PM EDT, 1 hour 13 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Special weather statement, Aug 24, 1:07 PM EDT, 1 hour before
Special Weather Statement
National Weather Service Burlington VT
107 PM EDT Mon Aug 24 2020

NYZ028-030-031-034-035-VTZ005-241745-
Eastern Clinton-Southern Franklin-Western Essex-Western
Clinton-Eastern Essex-Western Chittenden-
107 PM EDT Mon Aug 24 2020

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN CLINTON...SOUTHEASTERN
FRANKLIN...NORTHEASTERN ESSEX AND WEST CENTRAL CHITTENDEN COUNTIES...

At 106 PM EDT, a strong thunderstorm was located near Au Sable Forks,
moving east at 30 mph.

Winds in excess of 40 mph and dime size hail are possible with this
storm.

Locations impacted include...
Willsboro, Au Sable Forks, Keeseville, Port Kent, Shelburne,
Charlotte, Colchester, Black Brook, Brown Point, Union Falls, Hatch
Point, Willsboro Point, Clintonville, Ligonier Point, Harkness,
Boquet River Point, Ausable Forks, Hawkeye, The Four Brothers and
Frisbies Point.

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.

If you are on or near Lake Champlain, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.

LAT...LON 4444 7398 4456 7395 4455 7331 4431 7332
TIME...MOT...LOC 1706Z 277DEG 26KT 4449 7376

Clay
Special weather statement, Aug 24, 1:46 PM EDT, 21 minutes before
Special Weather Statement
National Weather Service Burlington VT
146 PM EDT Mon Aug 24 2020

NYZ028-031-034-035-241830-
Eastern Clinton-Western Essex-Western Clinton-Eastern Essex-
146 PM EDT Mon Aug 24 2020

...A STRONG CLUSTER THUNDERSTORM WILL AFFECT SOUTHERN CLINTON AND
NORTHEASTERN ESSEX COUNTIES...

At 145 PM EDT, a cluster of strong thunderstorm was located near
Peasleeville, moving east at 20 mph.

Winds in excess of 30 mph and half inch hail are possible with this
storm.

Locations impacted include...
Peru, Schuyler Falls, Peasleeville, Clayburg, Keeseville, Hawkeye,
South Plattsburgh, Valcour Island, Ausable Chasm, Day Point, Laphams
Mills, Clintonville, Valcour, Harkness and Bluff Point.

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.

If you are on or near Lake Champlain, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.

LAT...LON 4451 7386 4460 7387 4465 7341 4440 7346
TIME...MOT...LOC 1745Z 275DEG 16KT 4453 7371

Clay
Special weather statement, Aug 24, 1:48 PM EDT, 19 minutes before
Special Weather Statement
National Weather Service Burlington VT
148 PM EDT Mon Aug 24 2020

NYZ028-035-VTZ001-005-017-241830-
Eastern Clinton-Eastern Essex-Grand Isle-Eastern Chittenden-Western
Chittenden-
148 PM EDT Mon Aug 24 2020

...A CLUSTER OF STRONG THUNDERSTORM WILL AFFECT EASTERN
CLINTON...NORTHEASTERN ESSEX...SOUTHERN GRAND ISLE AND WEST CENTRAL
CHITTENDEN COUNTIES...

At 148 PM EDT, a cluster of strong thunderstorms was located over
Burlington, moving east at 20 mph.

Winds in excess of 30 mph and half inch hail are possible with this
storm.

Locations impacted include...
Essex Junction, South Burlington, Burlington International Airport,
Burlington, St. George, Winooski, Essex, Colchester, Essex Junction
Village, Williston, Shelburne, Westford, Hinesburg, Richmond, Milton,
Brown Point, North Williston, Appletree Point, Sunset Island and Red
Rock Point.

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.

If you are on or near Lake Champlain, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.

LAT...LON 4445 7340 4457 7338 4459 7301 4434 7306
TIME...MOT...LOC 1748Z 275DEG 16KT 4448 7329

Clay
Special weather statement, Aug 24, 1:53 PM EDT, 14 minutes before
Special Weather Statement
National Weather Service Burlington VT
153 PM EDT Mon Aug 24 2020

NYZ028-031-VTZ001-002-005-016-241845-
Eastern Clinton-Western Clinton-Western Franklin-Grand Isle-Western
Chittenden-Eastern Franklin-
153 PM EDT Mon Aug 24 2020

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL CLINTON...SOUTHERN
GRAND ISLE...NORTHWESTERN CHITTENDEN AND SOUTHWESTERN FRANKLIN
COUNTIES...

At 153 PM EDT, a strong thunderstorm was located over Beekmantown,
moving east at 40 mph.

Winds in excess of 30 mph and dime size hail are possible with this
storm.

Locations impacted include...
Plattsburgh, Beekmantown, Fairfax, Georgia, Grand Isle, Milton, South
Hero, Georgia Center, Colchester, St. Albans Town, Essex, North Hero,
Westford, Fairfield, Isle La Motte, Fletcher, Young Island, Wilcox
Point, Hazen Point and West Milton.

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 4475 7366 4485 7359 4478 7296 4450 7309
TIME...MOT...LOC 1753Z 290DEG 34KT 4476 7352

Clay
Special weather statement, Aug 24, 2:01 PM EDT, 6 minutes before
Special Weather Statement
National Weather Service Burlington VT
201 PM EDT Mon Aug 24 2020

NYZ026-087-241900-
Northern St. Lawrence-Southwestern St. Lawrence-
201 PM EDT Mon Aug 24 2020

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN ST. LAWRENCE
COUNTY...

At 200 PM EDT, a strong thunderstorm was located over Ogdensburg,
moving east at 20 mph.

Winds in excess of 30 mph and pea size hail are possible with this
storm.

Locations impacted include...
Ogdensburg, Lisbon, Morley, Madrid, Waddington, Chipman and West
Potsdam.

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 4467 7506 4463 7559 4470 7550 4471 7547
      4474 7545 4475 7540 4476 7542 4478 7540
      4482 7531 4484 7529 4485 7524 4486 7524
      4488 7522 4487 7519 4489 7517 4487 7516
      4489 7514
TIME...MOT...LOC 1800Z 256DEG 18KT 4474 7551

Neiles

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 8:19 PM EDTSpecial Weather StatementBTVWindsor26 min
Aug 23, 8:30 PM EDTSevere Thunderstorm WarningBTVWindsor30 min
Aug 23, 8:48 PM EDTSpecial Weather StatementBTVRutland27 min
Aug 23, 9:11 PM EDTSpecial Weather StatementBTVWindsor19 min
Aug 23, 9:13 PM EDTSpecial Weather StatementBTVAddison32 min
Aug 23, 10:30 PM EDTSpecial Weather StatementBTVOrange45 min
Aug 24, 1:48 PM EDTSpecial Weather StatementBTVChittenden42 min
Aug 24, 1:53 PM EDTSpecial Weather StatementBTVGrand Isle52 min
Aug 24, 2:19 PM EDTSpecial Weather StatementBTVChittenden56 min
Aug 24, 2:40 PM EDTSpecial Weather StatementBTVChittenden50 min
Aug 24, 2:56 PM EDTSpecial Weather StatementBTVAddison49 min
Aug 24, 3:10 PM EDTSevere Thunderstorm WarningBTVAddison, Chittenden, Washington50 min
Aug 24, 3:17 PM EDTSevere Thunderstorm WarningBTVAddison, Rutland29 min
Aug 24, 3:57 PM EDTSpecial Weather StatementBTVWashington48 min
Aug 24, 4:01 PM EDTSpecial Weather StatementBTVCaledonia59 min
Aug 24, 4:03 PM EDTSpecial Weather StatementBTVRutland57 min
Aug 24, 4:11 PM EDTSevere Thunderstorm WarningBTVAddison, Rutland64 min
Aug 24, 4:13 PM EDTSpecial Weather StatementBTVOrange47 min
Aug 24, 4:37 PM EDTSpecial Weather StatementBTVEssex38 min
Aug 24, 5:11 PM EDTSevere Thunderstorm WarningBTVRutland49 min
Aug 24, 5:59 PM EDTSpecial Weather StatementBTVRutland46 min
Aug 24, 6:20 PM EDTFlash Flood WarningBTVRutland3 hr
Aug 24, 7:07 PM EDTSpecial Weather StatementBTVRutland38 min
Aug 24, 7:38 PM EDTSpecial Weather StatementBTVOrleans52 min
Aug 24, 7:41 PM EDTSpecial Weather StatementBTVRutland34 min
Aug 23, 10:21 PM EDTSpecial Weather StatementBTVSt. Lawrence54 min
Aug 23, 11:11 PM EDTSpecial Weather StatementBTVSt. Lawrence64 min
Aug 24, 12:09 AM EDTSpecial Weather StatementBTVClinton, Franklin66 min
Aug 24, 12:54 PM EDTSpecial Weather StatementBTVClinton51 min
Aug 24, 1:07 PM EDTSpecial Weather StatementBTVClinton38 min
Aug 24, 1:46 PM EDTSpecial Weather StatementBTVClinton44 min
Aug 24, 2:01 PM EDTSpecial Weather StatementBTVSt. Lawrence59 min
Aug 24, 3:01 PM EDTSpecial Weather StatementBTVWarren44 min

Nearby

Severe Thunderstorm Warnings in Vermont, 2020Severe Thunderstorm Warnings in New York, 2020Every severe thunderstorm warning in 2020

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.