Good upper-level divergence associated with a jet streak ahead of an approaching shortwave combined with low-level instability to produce showers and thunderstorms on the afternoon of the 20th. Several reports of wind damage were reported with these storms.
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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.
Good upper-level divergence associated with a jet streak ahead of an approaching shortwave combined with low-level instability to produce showers and thunderstorms on the afternoon of the 20th. Several reports of wind damage were reported with these storms.
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 20, 10:07 AM EST, 4 hours 33 minutes earlier.
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</html>The Portland,ME radar (KGYX), 98 km away, was scanning. The volume nearest the first event began at 19:38 UTC.
3 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm downed trees on wires on Tolend Road in Barrington.
A severe thunderstorm downed trees in Madbury.
A severe thunderstorm downed trees on Route 9 in Dover.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New Hampshire in 2017Every state in 2017This day in weather historyWarnings in New Hampshire, July 2017
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 2026-10-01. Each event’s entry at NCEI: 712915, 712916, 712917.