On the afternoon of July 17th a pre-frontal upper level disturbance interacted with hot and unstable conditions to allow for the development of isolated thunderstorms across Maine. Most storms remained weak, but one storm became severe and downed a few trees.
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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.
On the afternoon of July 17th a pre-frontal upper level disturbance interacted with hot and unstable conditions to allow for the development of isolated thunderstorms across Maine. Most storms remained weak, but one storm became severe and downed a few trees.
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 17, 1:47 PM EST, 1 hour 6 minutes earlier.
Area Forecast Discussion National Weather Service Gray ME 247 PM EDT Thu Jul 17 2025 .SYNOPSIS... Showers and thunderstorms are occuring along and ahead of a cold front through this evening. A few storms may be strong to severe, and all rain may be heavy at times considering how humid the air mass is. Much drier weather arrives Friday, with comfortable temperatures and breezy westerly winds. The cooler and drier weather will continue into the weekend. && .NEAR TERM /THROUGH TONIGHT/... Impacts and Key Messages: * The threat for severe storms and torrential rain will continue into this evening. Coverage of showers and thunderstorms are increasing this afternoon with favorable instability and shear for a few strong to severe storms to develop. The limiting factor will be very weak lapse rates, but any robust storms will be capable of producing gusty winds and maybe even a brief weak tornado in the north where shear profiles are more favorable. All storms will be capable of producing torrential rainfall with some rates around 2" an hour already observed with the more developed storms. The HREF continues to be very isolated with QPF bulleyes around 1.5" owing to progressive storm motions, but if a location gets run over by a few of these over a short period of time, a localized flood threat may develop. Storms will quickly decrease in coverage and intensity after sunset. The front will then clear the area overnight and a tightening pressure gradient will bring about wind gusts 20-30 mph overnight. This will keep areas south of the mountains from decoupling, but with the drier air filling in temperatures will fall into the low to mid 60s which will be sweet relief from today's heat and humidity. Northwest flow will likely bank clouds up in the mountains, but again the cooler and drier airmass alone will allow for temperatures to fall into the low to mid 50s. Some patchy valley fog is possible in more sheltered locations, especially if they see rain this afternoon and evening. Some marine fog advecting on shore is possible early on in the night, but flow will turn around with the frontal passage so it should eventually get blown back out later in the night. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... Impacts and Key Messages: * No significant weather impacts expected High pressure builds into the region Friday with a cooler and drier airmass in place. It looks like a great end to the work week with clear skies and temperatures in the mid to upper 70s south of the mountains, and near 80 on the coastal plain. North of the mountains will be even cooler with high temperatures in the low 70s. Forecast soundings show good mixing up to 850 mb Friday morning which would make for a breezy first part of the day with gusts around 25 mph. These will subside heading toward the late afternoon/early evening, but it will be enough to add some chop to the local lakes and near shore ocean waters. For those planning to enjoy the pleasant day on the water, keep this in mind. Winds will go calm overnight and with clear skies this should amount to some degree of radiational cooling and bringing about some of the coolest temperatures we have seen of late. Areas north of the mountains look to bottom out in the upper 40s and low 50s, with locations to the south falling to the low to mid 50s. The Midcoast and southern coastal plain have the best chance of staying in the upper 50s to near 60. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Overview: High pressure will be quickly passing through southern New England Saturday morning with dry conditions. Return flow will increase low level moisture in the evening and overnight hours as clouds build. Broad upper level trough will move unsettled weather through the region into Sunday, with another area of high pressure moving in to start next week. Potential Forecast Impacts: * Thunderstorm potential (particularly intensity) on Sunday hinges on placement of low pressure and associated warm/cold front. Widespread rain showers. Details: High pressure over southern New England will bring a dry Saturday to the region with temperatures running a few degrees above normal. Do expect clouds to increase through the day as flow shifts southerly. Rain chances increase Saturday evening and overnight as a upper jet lifts north of Maine followed by sharpening upper level trough across the eastern Great Lakes. This will bring lift across New England, resulting in periods of rain with embedded thunder. Elevated instability appears to wash across much of the forecast area early Sunday morning, but large amounts of shear may limit any individual storm depth. Second period of thunder may be into the Sunday afternoon hours and could be surface based if recovery occurs between overnight showers. Disclaimer here is there has been a lack of consistency how this unsettled period materializes. Therefore confidence in thunderstorm risk is low, but rain chances likely. Front/low pressure clears the coast Sunday night, with NW flow bringing drier and cooler conditions in for Monday and the early week. Daytime highs Monday top out in the upper 70s while upslope clouds could keep values in the mid to upper 60s for N/NW side of the mountains. After a period of dry weather through midweek, the next chance of precipitation comes with an approaching front from the west around the Thursday night/Friday time period. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... Short Term...RKD is likely to stay IFR/LIFR for a good portion of the night, elsewhere elevated winds should stave off any dense fog and keep many locations VFR as a front scours out the low level moisture. Low level wind shear is not expected at this time, but wind gusts behind the front tomorrow may reach 25 kts during the morning at all terminals. Long Term...High pressure shifts east through the day Saturday with VFR conditions. Clouds thicken and lower in the evening, potentially towards MVFR/IFR. This continues through Sunday afternoon with SHRA and some TS, but coverage is uncertain. Flow shifts NW Monday, with improving conditions. && .MARINE... Short Term...Wind gusts and seas will stay just shy of SCA criteria through Friday night, but wind gusts nearing 25 kts during the morning will likely add some chop to the near shore waters. Long Term...Conditions remain below SCA through the period. High pressure will exit the coast Saturday, with low pressure nearing Sunday. The moist airmass may allow for marine fog/stratus development. Winds shift NW behind this system with a period of dry weather through midweek. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...Heat Advisory until 8 PM EDT this evening for NHZ012-013. MARINE...None. && NEAR/SHORT TERM...Baron LONG TERM...Cornwell
Hazardous Weather Outlook National Weather Service Gray ME 234 PM EDT Thu Jul 17 2025 NHZ012-013-181845- Eastern Hillsborough-Interior Rockingham- 234 PM EDT Thu Jul 17 2025 ...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING... This Hazardous Weather Outlook is for 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. Heat Advisory. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. MEZ033-NHZ007>009-011-015-181845- Interior Cumberland Highlands-Sullivan-Merrimack-Belknap-Cheshire- Western And Central Hillsborough- 234 PM EDT Thu Jul 17 2025 This Hazardous Weather Outlook is for western Maine, New Hampshire, central New Hampshire and southern New Hampshire. .DAY ONE...This afternoon and tonight. Showers and thunderstorms will be possible this afternoon and evening along and ahead of an approaching cold front. Some storms may be strong to severe, and will be capable of gusty winds and torrential rain. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. MEZ007>009-012>014-NHZ001>006-181845- Northern Oxford-Northern Franklin-Central Somerset-Southern Oxford- Southern Franklin-Southern Somerset-Northern Coos-Southern Coos- Northern Grafton-Northern Carroll-Southern Grafton-Southern Carroll- 234 PM EDT Thu Jul 17 2025 ...SEVERE THUNDERSTORM WATCH 521 IN EFFECT UNTIL 9 PM EDT THIS EVENING... This Hazardous Weather Outlook is for south central Maine, west central Maine, western Maine and northern 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...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. MEZ018>028-NHZ010-014-181845- Interior York-Central Interior Cumberland-Androscoggin-Kennebec- Interior Waldo-Coastal York-Coastal Cumberland-Sagadahoc-Lincoln- Knox-Coastal Waldo-Strafford-Coastal Rockingham- 234 PM EDT Thu Jul 17 2025 This Hazardous Weather Outlook is for Maine, south central Maine, southwest Maine, central New Hampshire and southern New Hampshire. .DAY ONE...This afternoon and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. ANZ150>154-181845- 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- 234 PM EDT Thu Jul 17 2025 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...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The Portland,ME radar (KGYX), 67 km away, was scanning. The volume nearest the first event began at 19:53 UTC.
2 thunderstorm wind. Local standard time, as filed.
Severe thunderstorm outflow winds downed a tree that took powerlines down across School Street in Canton.
Severe thunderstorm outflow winds downed a large tree down on ME-133 in Jay.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maine in 2025Every state in 2025This day in weather historyWarnings in Maine, July 2025
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: 1288496, 1288497.