An upper low across the Gulf of Maine continually rotated showers and thunderstorms across VT with a focused path across portions of the western slopes of VT's Green Mountains. During the late afternoon of June 30th, thunderstorms back-built in the Hinesburg, Monkton, Starksboro area quickly producing 4+ inches of rainfall within two hours.
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 low across the Gulf of Maine continually rotated showers and thunderstorms across VT with a focused path across portions of the western slopes of VT's Green Mountains. During the late afternoon of June 30th, thunderstorms back-built in the Hinesburg, Monkton, Starksboro area quickly producing 4+ inches of rainfall within two hours. This led to some localized flash flooding, especially gravel roads in the area.
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 Jun 30, 2:43 PM EST, 2 hours 17 minutes earlier.
Area Forecast Discussion National Weather Service Burlington VT 343 PM EDT Tue Jun 30 2020 .SYNOPSIS... Continued scattered showers and thunderstorms are possible again on Wednesday as upper level low remains overhead. Hot weather is expected on Wednesday with highs in the upper 80s to low 90s before a weak cold front brings slightly cooler readings for the upcoming holiday weekend. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... As of 340 PM EDT Tuesday...Increasing convective coverage this afternoon will give way to largely beneficial rains across most of VT and into areas of eastern NY. The heavier of these storms are putting down around 1-1.5" of rain in an hour or so, therefore continue to think the threat for isolated flooding may be possible if locations see training storms. This threat will be highly localized, and given recent dryness, likely minimal in impact resulting in ponding of water in poor drainage areas along with minor washouts possible. Tonight, expect low clouds and fog to return as has happened the last couple nights with lows in the around 60 mountains/mid 60s valleys. As upper level circulation remains overhead again on Wednesday, anticipate similar evolution to the day as today. Convective threat looks maybe slightly more organized for Wednesday as temperatures warm into the upper 70s to around 80, with CAPE values around 700-1000 J/kg and 15- 25kt of bulk shear creeps into our western NY zones. Given better lapse rates and layer deep shear, in addition to the threat for heavy rainfall, briefly gusty winds may be possible as well. The nearly stationary area of low pressure off the MA coastline will finally begin to drift southward Wednesday night and we should finally see the return of drier weather Wednesday night heading into Thursday. Nearly similar low temps in the upper 50s/low 60s are expected Wednesday night. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... As of 340 PM EDT Tuesday...Hot weather expected Thursday as a departing upper level system will allow for a ridge axis to shift into our region. Warm air advection and mostly clear skies will drive temperatures into the mid to upper 80s across the high terrain and near 90 across the valleys. The influence of the ridge will cause warming aloft, making conditions less favorable for showers and thunderstorms. Thus, mostly dry conditions are expected Thursday afternoon, though a few showers and storms could spark along the mountain ridges mid-day. Looking at dewpoints, values should remain in the low to mid 60s, which will bring heat indices to 92-93 in the Champlain and St. Lawrence Valleys - just below advisory level. Still, for prolonged activity, taking a few precautions and knowing the signs of heat exhaustion is always beneficial. The better focus for precipitation will be with a backdoor cold front late into evening into the overnight hours. Upstream instability and shear should allow storms to develop over southern Quebec Province, aided by a jet streak aloft. The question becomes whether that convection can sustain itself during the evening hours as it heads into our environment of less shear, waning instability, and lack of inflow ahead of the convection. The front will slowly sag south and may not be clear of the area by Friday morning. Thus, another warm night with upper 50s to mid 60s will be in store. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 340 PM EDT Tuesday...Still looking at some scattered convection across the Adirondacks and south-central Vermont as a weak cold front slowly sags south on Friday. Then, large scale ridging off to the west tries to nose into our region, but will flatten as it comes in. This will maintain northwest flow aloft that will allow weak, embedded shortwaves to cross the area into the new week. With above normal temperatures (mid to upper 80s) and dewpoints in the lower 60s, diurnally driven showers and thunderstorms will be possible each day. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... Through 18Z Wednesday...Mix of MVFR/VFR out there this afternoon. Similar to yesterday, daytime convection will bring chances for heavy rainfall and brief IFR visibilities across the airspace this afternoon. Have included VCTS in all VT TAF sites as timing of exact airport impact is difficult given cellular nature of storms today. Tonight, expect aviation conditions to deteriorate back down to MVFR/IFR once again as low level moisture remains socked in place. Ceilings/visibilities will lift towards 13/14z similar to today. Winds will be out of the N/NW around 5-15kt this afternoon, trending light overnight before increasing around 5-15kt again tomorrow. Outlook... Wednesday Night: VFR. Slight chance SHRA, Slight chance TSRA. Thursday: VFR. Slight chance SHRA, Slight chance TSRA. Thursday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Friday: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Friday Night: VFR. Slight chance SHRA. Independence Day: VFR. Slight chance SHRA. Saturday Night: VFR. NO SIG WX. Sunday: VFR. Slight chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && SYNOPSIS...LaRocca NEAR TERM...LaRocca SHORT TERM...Haynes LONG TERM...Haynes AVIATION...LaRocca
Hazardous Weather Outlook National Weather Service Burlington VT 340 AM EDT Tue Jun 30 2020 NYZ026>031-034-035-087-VTZ001>012-016>019-010745- 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- 340 AM EDT Tue Jun 30 2020 This Hazardous Weather Outlook is for northern New York, central Vermont, northeast Vermont, northwest Vermont and southern Vermont. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Special Weather Statement National Weather Service Burlington VT 208 PM EDT Tue Jun 30 2020 VTZ010-012-019-302015- Orange-Windsor-Eastern Rutland- Including the cities of Bradford, Randolph, Springfield, White River Junction, East Wallingford, and Killington 208 PM EDT Tue Jun 30 2020 ...Very Heavy Downpours Expected Across South Central Vermont... Expect showers and thunderstorms to continue across much of south central Vermont, mainly over much of Orange County, northern Windsor County, and portions of eastern Rutland County through 400 pm this afternoon. Activity is moving southwest and any of the showers or storms could produce a half inch to one inch of rain in a very short period of time. Additional showers and thunderstorms over west central New Hampshire will be moving into south central Vermont and additional rainfall is expected. This could result in ponding of water on roadways and low lying areas as well as sharp rises on area waterways. Seek shelter as storms approach and do not drive through flooded roads. Evenson
Special Weather Statement National Weather Service Burlington VT 308 PM EDT Tue Jun 30 2020 NYZ035-VTZ008>012-018-302000- Eastern Essex-Western Rutland-Windsor-Washington-Western Addison-Eastern Addison-Orange- 308 PM EDT Tue Jun 30 2020 ...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN ESSEX...WEST CENTRAL ORANGE...SOUTHERN ADDISON...NORTH CENTRAL RUTLAND... NORTHWESTERN WINDSOR AND SOUTHWESTERN WASHINGTON COUNTIES... At 306 PM EDT, a strong thunderstorm was located over Roxbury, Vermont moving southwest at 15 mph. Frequent lightning, heavy downpours, and wind gusts to 30 mph can be expected with this storm. Rainfall amounts of a half inch to one inch in a short period of time are possible. Locations impacted include... Middlebury, Cornwall, Braintree Hill, Sudbury, Weybridge, Salisbury, Lincoln, Orwell, Randolph, Rochester, Whiting, Granville, Goshen, Hancock, Shoreham, Warren, Ripton, Northfield, Roxbury and Leicester. LAT...LON 4417 7267 4393 7257 4376 7329 4401 7341 TIME...MOT...LOC 1906Z 071DEG 23KT 4404 7273 Evenson
Special Weather Statement National Weather Service Burlington VT 324 PM EDT Tue Jun 30 2020 VTZ011-019-302100- Western Rutland-Eastern Rutland- Including the cities of Rutland, East Wallingford, and Killington 324 PM EDT Tue Jun 30 2020 ...Localized Flooding Possible Over Parts Of Rutland County... Showers and isolated thunderstorms have produced localized heavy rain over parts of Rutland County Vermont today. Areas west and north of the town of Rutland may have already seen at least an inch of rain this afternoon. Additional showers and thunderstorms moving in from the northeast this afternoon may produce an additional half inch to an inch of rain. This could result in ponding of water on roadways, localized field flooding, and sharp rises on area waterways. Do not drive through flooded roadways. Evenson
Special Weather Statement
National Weather Service Burlington VT
330 PM EDT Tue Jun 30 2020
VTZ012-019-302030-
Eastern Rutland-Windsor-
330 PM EDT Tue Jun 30 2020
...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN RUTLAND AND
SOUTHWESTERN WINDSOR COUNTIES...
At 327 PM EDT, a strong thunderstorm was located over West Windsor
in Windsor County Vermont, moving southwest at 15 mph.
Frequent lightning, heavy downpours, and wind gusts to 30 mph can be
expected with this storm. Rainfall amounts of a half inch to one
inch in a short period of time are possible. Do not drive your
vehicle through flooded roadways. Seek safe shelter as this storm
approaches.
Locations impacted include...
Chester, Woodstock, Windsor, Mount Holly, Ludlow, Cavendish, Andover,
Weston, Ludlow Village, Perkinsville Village, Ascutney, Reading,
Baltimore, Weathersfield, West Windsor, Mount Tabor, Springfield,
Plymouth, Hartland and Perkinsville.
LAT...LON 4325 7281 4326 7282 4330 7282 4330 7287
4336 7294 4358 7252 4347 7239 4340 7240
4323 7261 4322 7269
TIME...MOT...LOC 1927Z 049DEG 12KT 4346 7252
EvensonSpecial Weather Statement National Weather Service Burlington VT 353 PM EDT Tue Jun 30 2020 VTZ008-010-302015- Washington-Orange- 353 PM EDT Tue Jun 30 2020 ...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL ORANGE AND CENTRAL WASHINGTON COUNTIES... At 352 PM EDT, a strong thunderstorm was located over Plainfield Vermont in Washington County, moving southwest at 15 mph. Frequent lightning, heavy downpours, pea size hail, and wind gusts to 30 mph can be expected with this storm. Rainfall amounts of a half inch to one inch in a short period of time are also possible. Do not drive your vehicle through flooded roadways. Seek safe shelter as this storm approaches. Locations impacted include... Barre, Montpelier, Barre Town, Plainfield, Moretown, Websterville, East Montpelier, Barre City, Berlin, E F Knapp State Airport, Northfield Village, Orange, Williamstown, Northfield, Calais, Middlesex, Marshfield, Riverton, West Berlin and Upper Graniteville. LAT...LON 4433 7245 4417 7235 4410 7261 4426 7274 TIME...MOT...LOC 1952Z 062DEG 22KT 4422 7251 Evenson
Special Weather Statement National Weather Service Burlington VT 424 PM EDT Tue Jun 30 2020 VTZ005-008-009-017-018-302115- Eastern Chittenden-Western Chittenden-Washington-Western Addison-Eastern Addison- 424 PM EDT Tue Jun 30 2020 ...LOCALIZED FLOODING POSSIBLE OVER PARTS OF SOUTHERN CHITTENDEN AND NORTHEAST ADDISON COUNTY... At 419 PM EDT, a line of showers and isolated thunderstorms was moving southwest across southern Chittenden and northeast Addison counties in Vermont. A storm report from Huntington, Vermont indicated 2.52 inches of rain had fallen in the area and with additional rainfall of a half inch to inch this afternoon... localized flooding is possible. Watch for the ponding of water on roadways, field flooding, and sharp rises on area waterways. Locations impacted include... Starksboro, Hinesburg, Huntington, Buels Gore, Bristol, Monkton Ridge, Lincoln, Monkton, New Haven, Fayston, Richmond, Duxbury, Bolton, Jerusalem, South Lincoln, East Monkton, Hanksville, New Haven Mills, West Lincoln and Huntington Center. LAT...LON 4436 7286 4407 7296 4408 7315 4436 7311 TIME...MOT...LOC 2019Z 089DEG 1KT 4431 7301 Evenson
The Burlington radar (KCXX), 29 km away, was scanning. The volume nearest the first event began at 21:57 UTC.
1 flash flood. Local standard time, as filed.
Flooded roads and partial gravel road washouts along State Prison Road in Starksboro and Monkton as well as water lapping several roads in the neighboring vicinity.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Vermont in 2020Every state in 2020This day in weather historyWarnings in Vermont, June 2020
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: 891809.