An upper level disturbance ahead of a strong cold front moved into a marginally unstable airmass to trigger scattered thunderstorms across eastern NY that continued to move east into VT and intensify. One particular cluster of thunderstorms moved from Addison county across central and eastern VT with a path of damaging winds that knocked down numerous trees and utility lines.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BTV wrote it up.
An upper level disturbance ahead of a strong cold front moved into a marginally unstable airmass to trigger scattered thunderstorms across eastern NY that continued to move east into VT and intensify. One particular cluster of thunderstorms moved from Addison county across central and eastern VT with a path of damaging winds that knocked down numerous trees and utility lines. Power outages affected nearly 35,000 total customers with a peak outage of 20,000 customers.
The local office's own words before the first event, 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 the first event at May 26, 1:05 PM EST, 1 hour 28 minutes earlier.
Area Forecast Discussion National Weather Service Burlington VT 205 PM EDT Wed May 26 2021 .SYNOPSIS... Scattered strong to severe thunderstorms are expected across portions of the area today in advance of a strong cold front. The front will cross the area tonight, behind which dry and much cooler air arrives for the back end of the work week. && .NEAR TERM /THROUGH THURSDAY NIGHT/... As of 150 PM EDT Wednesday...No big changes for the 130 pm update this afternoon. Showers and thunderstorms currently pushing across the area, not severe thus far. Forecast is on track. Previous discussion follows. The challenge for today is pinning down overall coverage of scattered showers/stronger storms across the area, not uncommon in springtime setups across our region. The overall idea of scattered convection developing by early to mid afternoon across eastern NY and progressing into VT by mid to late afternoon still appears reasonable. Ample CAPE/shear should exist across the area as sfc dewpoints climb into the upper 50s to mid 60s. However, low level convergence along a pre-frontal trough advancing east from central/ern NY is not that impressive, and we really don't have a strong shortwave forcing mechanism or steep mid-level lapse rates to drive upward motions. Still, synoptic scale wind fields remain unidirectional and quite robust (35-50 kt) with hodograph profiles supporting a straight line wind threat should something organized form and concur with SPC's Slight Risk continuation for SWODY1. At this point, analysis suggests the highest threat of this will occur from the Hudson Valley/Essex Co., NY east into central/southern VT from mid to late afternoon with potential formation of a QLCS-type structure advancing eastward. This is not an uncommon type of evolution in our area with the Adirondack dome largely throwing a disruption to the low level flow. As such, the SLV and much of far northern NY/northwestern VT is forecast to see somewhat less coverage at this point- sort of in a no-mans-land north/west of the pre-frontal trough where less instability and low level convergence exist. Time will tell and this is a modest confidence assessment to be sure. Highs today quite warm - mainly 80s to locally near 90 by early afternoon in the warmest locales of the Champlain and CT River Valleys. By this evening main convection should be exiting east leaving just some scattered light shower activity across northern counties in advance of a strong cold front dropping south from southern ON/QE. This front will cross the area generally after midnight into the pre- dawn hours with little fanfare other than a few light showers and a wind shift to the north/northwest. Given the late arrival of the frontal passage, overnight lows will still hold near seasonable late May norms from 45 to 55. Then trending partly to mostly sunny on Thursday in a refreshingly cool post-frontal CP airmass under modestly gusty northerly flow. Highs generally in the upper 50s to mid 60s north, and 65 to 70 south. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... As of 136 PM EDT Wednesday...Continues to appear that the next shortwave trough will only brush the southern portion of our forecast area as the system tracks ewd in confluent mid-level flow from the Ohio Valley to the waters south of New England late Friday thru Friday night. Consistent with previous forecast, continued with the idea of increasing mid-upper level cloud cover during the day Friday, but only 20-35% PoPs for light rain, highest across s-central VT around 00Z Saturday. Strong surface ridge remains anchored across Ontario and southern Quebec. Will see continued light north winds, with daytime highs only in the mid-upper 50s, and possibly low 60s in the CT River Valley. These readings will be 10-15deg below the 30-year climo average for late May across the region. Friday night will feature gradual decrease in cloud cover from west to east as aforementioned shortwave trough departs to our south and east. Should see good radiative cooling especially late, which may be sufficient for additional frost/freeze concerns late Friday night/Saturday morning with lows in the 30s away from Lake Champlain. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 136 PM EDT Wednesday...Mainly dry and quiet weather conditions expected for the extended forecast period. Large surface ridge extending from Quebec swwd across the Great Lakes will generally remain the controlling weather feature through the forecast period. Only issue will be closed mid- level low, which lingers over New England Sunday afternoon into Monday morning. Included just a slight chance of showers associated with this feature, but dry low-level air mass should keep precipitation chances low Sunday night/Monday morning (around 20%). Any precipitation amounts should be light. Should see a slow moderation in temperatures through the period. Valley highs on Saturday are expected in the mid 60s, and then into the upper 60s for Sunday. Daytime highs should moderate back into the low-mid 70s for Monday and Tuesday of next week, and then into the upper 70s to lower 80s for Wednesday. Low humidity levels will persist, with dewpoints mostly in the 30s over the weekend, and then into the 40s for Monday-Wednesday of next week. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Through 18Z Thursday...Mainly VFR expected through the TAF period except for in strong/locally severe thunderstorms this afternoon with sub-hourly reductions to IFR/MVFR likely at MPV and RUT in the 19-22Z time frame. Have included tempo groups at all terminals except MSS. With any convection, strong to locally severe turbulence and gusty west winds to 40+ kt possible. After 23Z threat of convection ends with SCT/BKN VFR cigs from 035-070 AGL. Cold frontal passage then expected in the 06-10Z time frame with scattered light showers, a wind shift to north/northwesterly at 8-15 kts and CIG reductions to low VFR/MVFR expected. Highest confidence in MVFR cigs to occur at KMPV, KEFK and KSLK. Outlook... Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: VFR. Slight chance SHRA. Saturday: VFR. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Memorial Day: VFR. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && SYNOPSIS...JMG/Neiles NEAR TERM...JMG/Neiles SHORT TERM...Banacos LONG TERM...Banacos AVIATION...Neiles
Hazardous Weather Outlook National Weather Service Burlington VT 256 AM EDT Wed May 26 2021 NYZ026>031-034-035-087-VTZ001>012-016>019-270900- 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- 256 AM EDT Wed May 26 2021 This Hazardous Weather Outlook is for northern New York, central Vermont, northeast Vermont, northwest Vermont and southern Vermont. .DAY ONE...Today and tonight. Scattered to numerous showers and thunderstorms are expected to develop across the area this afternoon. Some of the storms may become strong to severe with damaging wind gusts the primary threat. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. 93
Special Weather Statement National Weather Service Burlington VT 156 PM EDT Wed May 26 2021 VTZ005>010-012-017-018-261900- Caledonia-Windsor-Eastern Chittenden-Western Chittenden-Washington-Western Addison-Eastern Addison-Lamoille-Orange- 156 PM EDT Wed May 26 2021 ...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTH CENTRAL LAMOILLE...WESTERN CALEDONIA...NORTHWESTERN ORANGE...CENTRAL ADDISON...SOUTHEASTERN CHITTENDEN...NORTHWESTERN WINDSOR AND WASHINGTON COUNTIES... At 155 PM EDT, radar indicated strong thunderstorms were located along a line extending from Hinesburg to Bridport. Movement was east at 30 mph. Winds in excess of 30 mph are possible with these storms. Locations impacted include... Barre, Middlebury, Montpelier, Cornwall, Calais, Braintree Hill, Weybridge, Monkton Ridge, Waterbury Village, Lincoln, Monkton, Monkton Boro, New Haven, Worcester, Middlesex, Granville, Cabot Village, Ripton, Woodbury and Moretown. 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 4447 7225 4394 7266 4395 7337 4438 7304 TIME...MOT...LOC 1755Z 265DEG 26KT 4433 7307 4399 7333 Lahiff
Special Weather Statement
National Weather Service Burlington VT
246 PM EDT Wed May 26 2021
VTZ009>012-018-019-261945-
Eastern Rutland-Western Rutland-Windsor-Western Addison-Eastern
Addison-Orange-
246 PM EDT Wed May 26 2021
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTHWESTERN ORANGE...
SOUTHEASTERN ADDISON...NORTHERN RUTLAND AND NORTHWESTERN WINDSOR
COUNTIES...
At 246 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Brandon to West Haven. Movement was
east at 30 mph.
Winds in excess of 30 mph and pea size hail are possible with these
storms.
Locations impacted include...
Rutland, Castleton, Sudbury, Killington, Rutland City, Benson,
Rochester, Chittenden, Fair Haven, West Rutland, West Castleton,
Hubbardton, Stockbridge, Proctor, Brandon, Mendon, Pittsfield,
Pittsford, West Haven and Bethel.
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 4358 7343 4359 7343 4362 7342 4364 7343
4365 7342 4369 7341 4373 7337 4378 7335
4393 7267 4358 7271 4358 7329 4362 7330
4363 7332 4363 7337 4358 7339
TIME...MOT...LOC 1846Z 259DEG 26KT 4377 7305 4363 7337
LahiffSpecial Weather Statement
National Weather Service Burlington VT
315 PM EDT Wed May 26 2021
NYZ034-035-VTZ008>012-017-018-262000-
Western Essex-Eastern Essex-Western Rutland-Windsor-Eastern
Chittenden-Washington-Western Addison-Eastern Addison-Orange-
315 PM EDT Wed May 26 2021
...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN ESSEX...WEST
CENTRAL ORANGE...ADDISON...NORTHWESTERN RUTLAND...SOUTHEASTERN
CHITTENDEN...NORTHWESTERN WINDSOR AND SOUTHWESTERN WASHINGTON
COUNTIES...
At 314 PM EDT, a strong thunderstorm was located over Crown Point
Center, moving east at 45 mph.
Wind gusts up to 50 mph are possible with this storm.
Locations impacted include...
Middlebury, Crown Point, Cornwall, Braintree Hill, Weybridge,
Salisbury, Bristol, Lincoln, Waitsfield, Whiting, New Haven,
Granville, Hancock, Shoreham, Warren, Ripton, Crown Point Center,
Roxbury, Leicester and Braintree.
LAT...LON 4399 7364 4421 7276 4393 7266 4380 7341
4379 7360
TIME...MOT...LOC 1914Z 259DEG 49KT 4394 7347
LahiffPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BURLINGTON VT
317 PM EDT WED MAY 26 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0314 PM HAIL PITTSFIELD 43.78N 72.82W
05/26/2021 M0.25 INCH RUTLAND VT PUBLIC
&&
EVENT NUMBER BTV2101005
TABERThe Burlington radar (KCXX), 63 km away, was scanning. The volume nearest the first event began at 19:32 UTC.
12 thunderstorm wind. Local standard time, as filed.
Media report of partial roof off small building supply company and utilities reporting several downed wires due to trees or branches between Bridport and Cornwall.
Several reports of scattered trees and powerlines down in most sections of Middlebury, including Court Street and Route 116.
Several reports of scattered trees and powerlines down between East Middlebury and Bristol along Route 116.
Several 12 inch diameter branches and other scattered tree damage across Waitsfield.
Numerous trees down and utility lines down due to damaging winds in Barre City, including Route 14 and Cassie Street.
Numerous trees down and utility lines down due to damaging winds in Barre Town including Church Hill road.
Trees and wires down, with trees snapped 15 to 20 feet above the ground.
Trees and powerlines down on Route 2 and School Street.
Numerous trees and wires down.
Trees and utility lines downed by thunderstorm winds.
Several trees and wires downed by thunderstorm winds.
Several reports of trees, branches down and on utility lines in the Wethersfield area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Vermont in 2021Every state in 2021This day in weather historyWarnings in Vermont, May 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 951204, 951149, 951150, 951151, 951152, 951153, 951154, 951155, 951157, 951158, 951159, 951203.