Thunderstorms developed during the afternoon of the 14th in advance of a cold front crossing the region. An isolated severe thunderstorm produced damaging winds in Hancock county.
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 CAR wrote it up.
Thunderstorms developed during the afternoon of the 14th in advance of a cold front crossing the region. An isolated severe thunderstorm produced damaging winds in Hancock county.
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 Caribou, ME wrote its last area forecast discussion before the first event at Aug 14, 10:12 AM EST, 4 hours earlier.
Area Forecast Discussion National Weather Service Caribou ME 1112 AM EDT Sat Aug 14 2021 .SYNOPSIS... A cold front will push through the region this afternoon and off the coast tonight. High pressure builds over the area Sunday through Monday, then slowly slides offshore through Tuesday night. A trough of low pressure enters Maine on Wednesday. && .NEAR TERM /THROUGH TONIGHT/... 11:10 AM Update...The leading line of convection, now across northern Penobscot County, has been dissipating except for one strong storm in north central Penobscot County. The main line of convection associated with the cold front is now moving into our western border and expected to cross the area through early afternoon. Updated pops to reflect current movement of lines of storms and adjusted temps up in the northeast where some sunshine has warmed the air a bit faster than initially expected. Previous Discussion... The pre-frontal trof is forecast to slide east this morning ahead of the main cold front, which was still sitting back across the St. Lawrence River. Showers and tstms will accompany the pre-frontal trof. After collaborating w/GYX, decided to stay w/enhanced wording for strong wind gusts and heavy rainfall. The severe threat looks to be marginal today as the steepest lapse rates run out ahead of the main activity expected to hit the area earlier this afternoon. With that being said, instability is definitely there w/CAPE of 1000-1500 joules. 0-6km shear of 30 kts w/PWS 1.7 to 2+ inches will be enough to keep tstms going along the pre-frontal trof. Modest lapse rates ahead of the trof could allow a few cells to get quite strong w/even a cell hitting severe limits briefly. This would mainly be for eastern Aroostook, northern Piscataquis and northern Penobscot County. Getting back to the main activity that is expected to set up ahead of the cold front this afternoon, there will be tstms developing in a broken line that will progress eastward into the afternoon. The main focus for organized convection and strong storms will across east- central Aroostook County down into the Penobscot and Downeast region. The NAMNEST and HRRR matched up this morning and seem to be close w/what is occurring on radar attm. This guidance shows this line of convection pushing east w/the individual cells moving ene. Given the very high PWs, warm cloud layer and a mid- level punch of 35-40 kts aligning w/the storm movement, some training of cells could occur w/the threat for some very high rainfall rates. The threat is also there for some urban/street flooding if this training sets up. This will need to be monitored by the daycrew. Activity looks to wind down rather quickly this evening as the cold front slides off to the ese w/showers and storms exiting their way into New Brunswick. Cooler and much drier air will follow in behind the cold front tonight. Overnight low temps are expected to be in the mid to upper 50s. What a difference over the last week w/temps at night in the 60s and lower 70s w/record high minimum temps being set. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... The axis of a northern stream trough will cross the area on Sunday. However, with limited moisture to work with, only a few passing high clouds could mark its passage. Sunday will be noticeably cooler than today, with highs mainly from the mid 70s to around 80, except lower 70s across the North Woods and near the immediate coast. These values are near to slightly below normal for the date. The region will be under zonal flow aloft Sunday night and Monday. With no significant shortwave progged to be embedded in the flow, and continued dry mid to upper levels of the atmosphere, it should be dry with minimal cloud cover. Lows Sunday night should run around 5 degrees below normal (mainly from the upper 40s to mid 50s), and highs on Monday should be near to slightly above normal. Deep layered ridging begins to build in Monday night, with associated subsidence keeping things dry, with minimal cloud cover. Lows Monday night should be near normal. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Deep layered ridging continues to build over the area Tuesday, with its axis progged to slide to the east Tuesday night. Once again, subsidence under the ridge should keep things dry. A series of northern stream shortwaves work there way over the top of the ridge Wednesday-Thursday (exact timing varies from model to model - but the general idea is the same on the whole). For now it appears that any isolated showers/thunderstorms on Wednesday should be limited to portions of the North Woods, then the potential should increase over the entire CWA Wednesday night, with more scattered showers/thunderstorms on Thursday as northern stream troughing gradually becomes established over the region. Temperatures should be above normal Tuesday-Thursday but not as warm as the past couple of days. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR today w/some MVFR early this morning in fog mainly for KBHB and possibly KPQI. Expecting showers and tstms today which could lower conditions to MVFR/IFR for a 2 hr window. Some of the tstms could be strong and perhaps severe. The main activity will be this afternoon. Strong wind gusts and heavy rainfall the main threats. SSW winds 5 to 10 kt. Tonight...VFR all terminals w/some patchy fog possible later tonight into Sunday morning. Light NW winds around 5 kts. SHORT TERM: Sunday-Wednesday: VFR. && .MARINE... NEAR TERM: S winds < 10 kts becoming SW later this morning and then turning W at 10 kt by the evening. Seas 1-2 ft. Showers and tstms later this afternoon into early evening. Tonight...W wind around 10 kt becoming NW 10-15 kts. Seas around 2 ft. SHORT TERM: A relaxed pressure gradient should limit winds to around 10 kt or less Sunday-Wednesday. As a result seas on the coastal ocean waters should be 3 ft or less and on the intra- coastal waters 2 ft or less through this time frame. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && Near Term...Hewitt/MCB Short Term...Maloit Long Term...Maloit Aviation...Hewitt/Maloit Marine...Hewitt/Maloit
Hazardous Weather Outlook National Weather Service Caribou ME 436 AM EDT Sat Aug 14 2021 MEZ001-003-004-150845- Northwest Aroostook-Northern Somerset-Northern Piscataquis- 436 AM EDT Sat Aug 14 2021 This Hazardous Weather Outlook is for Far Northern Maine and North Woods Maine. .DAY ONE...Today and tonight. Thunderstorms are expected today with a few storms containing gusty winds and small hail. .DAYS TWO THROUGH SEVEN...Sunday through Friday. 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. MEZ002-005-006-010-031-150845- Northeast Aroostook-Northern Penobscot-Southeast Aroostook- Central Piscataquis-Southern Piscataquis- 436 AM EDT Sat Aug 14 2021 This Hazardous Weather Outlook is for Central Highlands Maine, Far Eastern Maine and Far Northern Maine. .DAY ONE...Today and tonight. Thunderstorms are expected later this morning into this afternoon. Some thunderstorms could be strong to possibly severe with strong wind gusts and very heavy rainfall. .DAYS TWO THROUGH SEVEN...Sunday through Friday. 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. MEZ011-015>017-029-030-032-150845- Central Penobscot-Southern Penobscot-Interior Hancock- Central Washington-Coastal Hancock-Coastal Washington- Northern Washington- 436 AM EDT Sat Aug 14 2021 This Hazardous Weather Outlook is for Coastal DownEast Maine, Far Eastern Maine, Interior DownEast Maine and Penobscot Valley Maine. .DAY ONE...Today and tonight. Thunderstorms expected this afternoon into the early evening. A few storms could be strong to possibly severe with strong wind gusts and very heavy rainfall. The heavy rainfall could lead to some minor street flooding. .DAYS TWO THROUGH SEVEN...Sunday through Friday. 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. ANZ050>052-150845- Coastal Waters from Eastport, ME to Schoodic Point, ME out 25 NM- Coastal Waters from Schoodic Point, ME to Stonington, ME out 25 NM- Intra Coastal Waters from Schoodic Point, ME to Stonington, ME- 436 AM EDT Sat Aug 14 2021 This Hazardous Weather Outlook is for Atlantic Coastal Waters. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Sunday through Friday. 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.
Special Weather Statement
National Weather Service Caribou ME
1031 AM EDT Sat Aug 14 2021
MEZ005-006-141515-
Southeast Aroostook ME-Northern Penobscot ME-
1031 AM EDT Sat Aug 14 2021
...A strong thunderstorm will impact portions of central Penobscot
County through 1115 AM EDT...
At 1031 AM EDT, Doppler radar was tracking a strong thunderstorm near
Millinocket, moving northeast at 30 mph.
HAZARD...Winds in excess of 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Millinocket, East Millinocket, Medway, Stacyville, Grindstone,
Norcross, Benedicta and Molunkus.
This includes the following highways...
Interstate 95 between mile markers 246 and 261.
State Highway 11 between Norcross and East Millinocket, and between
Grindstone and Stacyville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4568 6883 4574 6883 4590 6846 4566 6836
4554 6887 4566 6896
TIME...MOT...LOC 1431Z 240DEG 25KT 4562 6883
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
BloomerSpecial Weather Statement
National Weather Service Caribou ME
1129 AM EDT Sat Aug 14 2021
MEZ002-005-006-141630-
Southeast Aroostook ME-Northeast Aroostook ME-Northern Penobscot ME-
1129 AM EDT Sat Aug 14 2021
...A strong thunderstorm will impact portions of southeastern
Aroostook and north central Penobscot Counties through 1230 PM EDT...
At 1128 AM EDT, Doppler radar was tracking a strong thunderstorm near
Patten, moving northeast toward Houlton and vicinity at 30 mph.
HAZARD...Winds in excess of 40 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Houlton, Patten, Hodgdon, Sherman, Island Falls, Bridgewater, Smyrna,
Amity, Mount Chase, Dudley Township, Sherman Station, Cary
Plantation, Shin Pond, Smyrna Mills, northeastern Katahdin Woods and
Waters National Monument, Littleton, Linneus, Monticello, Oakfield
and Blaine.
This includes the following highways...
Interstate 95 between mile markers 259 and 304.
US Highway 1 between North Amity and Bridgewater.
State Highway 11 between Sherman and Knowles Corner.
LAT...LON 4573 6839 4609 6863 4650 6779 4595 6778
TIME...MOT...LOC 1528Z 237DEG 27KT 4595 6843
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
BloomerPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CARIBOU ME
1131 AM EDT SAT AUG 14 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1050 AM HAIL 2 NW MILLINOCKET 45.68N 68.74W
08/14/2021 E0.50 INCH PENOBSCOT ME TRAINED SPOTTER
VERY HEAVY RAINFALL WITH MINOR FLOODING AND
0.25 TO 0.5 INCH HAIL.
&&
LFSpecial Weather Statement
National Weather Service Caribou ME
224 PM EDT Sat Aug 14 2021
MEZ015-016-141930-
Interior Hancock ME-Southern Penobscot ME-
224 PM EDT Sat Aug 14 2021
...A strong thunderstorm will impact portions of west central Hancock
and south central Penobscot Counties through 330 PM EDT...
At 223 PM EDT, Doppler radar was tracking a strong thunderstorm near
Dixmont, moving east at 30 mph.
HAZARD...Winds in excess of 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Bangor, Ellsworth, Bucksport, Orono, Brewer, Hampden, Hermon, Veazie,
Dedham, Orrington, Holden, Milford, Carmel, Eddington, Orland,
Newburgh, Bradley, Etna, Dixmont and Clifton.
This includes the following highways...
Interstate 95 between mile markers 172 and 191.
State Highway 9 between Dixmont and Clifton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4461 6882 4463 6884 4467 6881 4468 6881
4469 6883 4470 6884 4465 6919 4471 6920
4497 6846 4467 6833 4460 6872 4460 6873
4459 6880 4459 6881
TIME...MOT...LOC 1823Z 249DEG 27KT 4462 6918
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
FoisySpecial Weather Statement
National Weather Service Caribou ME
243 PM EDT Sat Aug 14 2021
MEZ002-141930-
Northeast Aroostook ME-
243 PM EDT Sat Aug 14 2021
...Strong thunderstorms will impact portions of east central
Aroostook County through 330 PM EDT...
At 242 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Woodland to 6 miles west of Mars Hill.
Movement was northeast at 30 mph.
HAZARD...Winds in excess of 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Presque Isle, Caribou, Fort Fairfield, Limestone, Mapleton, Washburn,
Mars Hill, Easton, Woodland, Bridgewater, Loring, Blaine, New Sweden,
Westfield, Chapman, Connor, Perham, Caswell, Wade and Hamlin.
This includes US Highway 1 between Blaine and Caribou.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4707 6779 4648 6778 4642 6806 4688 6820
4708 6781
TIME...MOT...LOC 1842Z 242DEG 25KT 4685 6810 4652 6800
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
FoisySpecial Weather Statement
National Weather Service Caribou ME
302 PM EDT Sat Aug 14 2021
MEZ016-029-142015-
Interior Hancock ME-Coastal Hancock ME-
302 PM EDT Sat Aug 14 2021
...Strong thunderstorms will impact portions of southern Hancock
County through 415 PM EDT...
At 302 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Winterport to near Camden. Movement was
east at 25 mph.
HAZARD...Winds in excess of 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Ellsworth, Bucksport, Blue Hill, Deer Isle, Dedham, Castine,
Stonington, Verona Island, Penobscot Township, Hancock, Franklin,
Orrington, Orland, Lamoine, Trenton, Surry, Penobscot, Sullivan,
Sedgwick and Brooksville.
This includes US Highway 1 between Orland and Hancock.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4405 6849 4409 6862 4416 6864 4412 6871
4420 6873 4421 6871 4421 6886 4422 6887
4422 6868 4434 6875 4423 6885 4429 6884
4426 6886 4426 6887 4438 6876 4438 6877
4469 6879 4473 6805
TIME...MOT...LOC 1902Z 267DEG 19KT 4464 6876 4426 6910
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH
FoisyThe Portland,ME radar (KGYX), 142 km away, was scanning. The volume nearest the first event began at 19:12 UTC.
1 thunderstorm wind. Local standard time, as filed.
Several trees were toppled along Turkey Path Road by wind gusts estimated at up to 60 mph. The time is estimated.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maine in 2021Every state in 2021This day in weather historyWarnings in Maine, August 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: 978485.