A cold front moved southeastward into New Hampshire which triggered a couple of severe thunderstorms on the afternoon of the 27th. Activity remained isolated with most of the thunderstorm activity occurring across southern New England where better moisture was present.
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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 GYX wrote it up.
A cold front moved southeastward into New Hampshire which triggered a couple of severe thunderstorms on the afternoon of the 27th. Activity remained isolated with most of the thunderstorm activity occurring across southern New England where better moisture was present.
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 Gray, ME wrote its last area forecast discussion before the first event at Jul 27, 1:54 PM EST, 2 hours earlier.
Area Forecast Discussion National Weather Service Gray ME 254 PM EDT Tue Jul 27 2021 .SYNOPSIS... A cold front will cross the region this evening with a round of showers and thunderstorms. Behind the front conditions will clear with drier air and high pressure moving in for Wednesday. The next front will cross the region on Thursday with another chance of showers. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A cold front is located in NY state and will move eastwards crossing our area this evening. Ahead of the front temperatures in the low 80s with dewpoints in the mid 60s have brought SB CAPE to around 2000 J/kg ahead of the line. Bulk shear of 45kts is sufficient to support severe storms, and the strongest portion of the developing line will pass through southern New Hampshire this evening. SPC has upgraded southern NH to slight risk for severe weather, which seems appropriate. Most of the forcing is with the stronger southern end of the front although a few isolated cells further north are not completely out of the question. Overall the highest threat is across Cheshire and Hillsborough county NH where a Severe thunderstorm watch has been issued. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/... Overnight behind the front, will see dewpoints drop, and don't expect widespread fog as a result of this drying. Some valley fog is possible in the CT river valley where the moisture can linger longer and will hold onto it through this region. Wednesday high pressure builds into the region. Temperatures will be cooler than the past few days, with highs in the mid 70s, along with dewpoints in the mid 50s which combined with sunny skies will make for a pleasant day for outdoor activity. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Overall pattern favors below cooler conditions across the region over the weekend and into next week as the area remains under the influence of an upper level trough. Surface high pressure slides offshore on Thursday allowing a brief period of return flow out of the SW. Expect upstream convection ahead of an approaching cold front to move into NH during the day and expand in coverage overnight as a low pressure system moves along the boundary. Can't rule out thunderstorm development, but advancing cloud cover could reduce instabilities. Showers will continue into Friday as the system pushes east, with cooler air filling in behind the front. Saturday will be cool with temperatures struggling to reach the 70s for much of the area along with a NW breeze and low humidities. Despite a drier airmass and weak surface high pressure trying to build in Saturday into Sunday, can't rule out some isol/sct showers thanks to the cold pool aloft and steepening lapse rates. These will mainly be diurnally driven and coverage and amounts look limited unless some shortwave energy supports some expansion. By Monday, the ECMWF couples the two upper jets over New England with the potential for a weak surface low offshore, bringing some higher rain chances. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... Short Term... Still some areas of restricted visibility in wildfire smoke this afternoon but overall an improvement in visibility over yesterday. Cold front in NY will cross the region this evening, as it does expect a line of thunderstorms to impact MHT CON and PSM. Further north and east the strength of the storms will decrease with only scattered showers. Valley fog is possible again tonight for LEB and HIE. Tomorrow drier NWly flow moves in behind the front and conditions will remain VFR across the region. Long Term...Rain chances will expand across the area on Thursday with increasing coverage into Friday night. Non- VFR likely with showers and thunderstorms on Thursday into Friday. && .MARINE... Short Term...Cold front will cross the waters this evening with scattered showers and thunderstorms. Behind the front NWly flow will move in with drier conditions and calm skies. Long Term...A cold front will push offshore on Friday night with NW flow. Breeze conditions will develop on Saturday due to mixing, but winds should remain 15kt or less on the water due to cold and more stable conditions. By Sunday night a weak low pressure system should skirt along the coast with increasing southerly flow 15-20kt possible and waves building to 4 ft. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH... Severe Thunderstorm watch for NHZ011-012-015 MARINE...None. && SYNOPSIS...Curtis NEAR TERM...Curtis SHORT TERM...Curtis LONG TERM...Jamison AVIATION...Curtis/Jamison MARINE...Curtis/Jamison
Hazardous Weather Outlook National Weather Service Gray ME 251 PM EDT Tue Jul 27 2021 MEZ007>009-012>014-018>028-033-NHZ001>010-013-014-281900- Northern Oxford-Northern Franklin-Central Somerset-Southern Oxford- Southern Franklin-Southern Somerset-Interior York- Central Interior Cumberland-Androscoggin-Kennebec-Interior Waldo- Coastal York-Coastal Cumberland-Sagadahoc-Lincoln-Knox-Coastal Waldo- Interior Cumberland Highlands-Northern Coos-Southern Coos- Northern Grafton-Northern Carroll-Southern Grafton-Southern Carroll- Sullivan-Merrimack-Belknap-Strafford-Interior Rockingham- Coastal Rockingham- 251 PM EDT Tue Jul 27 2021 This Hazardous Weather Outlook is for Maine, south central Maine, southwest Maine, west central Maine, western Maine, central New Hampshire, northern New Hampshire and southern New Hampshire. .DAY ONE...This afternoon and tonight. The probability for widespread hazardous weather is low. .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. NHZ011-012-015-281900- Cheshire-Eastern Hillsborough-Western And Central Hillsborough- 251 PM EDT Tue Jul 27 2021 ...SEVERE THUNDERSTORM WATCH 396 IN EFFECT UNTIL 10 PM EDT THIS EVENING... This Hazardous Weather Outlook is for New Hampshire and southern New Hampshire. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Severe Thunderstorm Watch. .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. ANZ150>154-281900- Coastal Waters from Stonington, ME to Port Clyde, ME out 25 NM- Penobscot Bay- Coastal Waters from Port Clyde, ME to Cape Elizabeth, ME out 25 NM- Casco Bay- Coastal Waters from Cape Elizabeth, ME to Merrimack River, MA out 25 NM- 251 PM EDT Tue Jul 27 2021 This Hazardous Weather Outlook is for Atlantic coastal waters. .DAY ONE...This afternoon 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.
The Burlington radar (KCXX), 151 km away, was scanning. The volume nearest the first event began at 20:52 UTC.
4 thunderstorm wind. Local standard time, as filed.
Severe thunderstorm wind gusts downed multiple trees on RT 12 Near Ponderosa Park.
Severe thunderstorm wind gusts downed multiple trees and wires in Alstead.
Severe thunderstorm wind gusts downed trees and power lines in Newmarket.
Severe thunderstorm wind gusts downed a few trees on Esker Avenue.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New Hampshire in 2021Every state in 2021This day in weather historyWarnings in New Hampshire, July 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: 976899, 976597, 976598, 976599.