A surface trof and cold pool aloft with an upper low crossed the region during the afternoon of the 10th. Showers and thunderstorms developed during the afternoon.
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.
A surface trof and cold pool aloft with an upper low crossed the region during the afternoon of the 10th. Showers and thunderstorms developed during the afternoon. Some of the thunderstorms became severe...mostly producing large hail due to the cold pool aloft. Most of the severe thunderstorms occurred across Aroostook county...with an isolated severe thunderstorm also occurring in coastal 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 10, 11:56 AM EST, 2 hours 39 minutes earlier.
Area Forecast Discussion National Weather Service Caribou ME 1256 PM EDT Sat Aug 10 2019 .SYNOPSIS... An upper trough will cross the region today. High pressure will cross the region Sunday. A cold front will cross the area Monday. Low pressure will track south of Maine late Tuesday into Wednesday. && .NEAR TERM /THROUGH TONIGHT/... Update... An upper level low and surface cold front/trof will cross the region this afternoon and evening with showers and thunderstorms. Mid level lapse rates steepen with the cold pool aloft and will support the possibility of at least small hail with any thunderstorms. Afternoon high temperatures will range from the lower to mid 60s north, to the lower 70s Downeast. Have updated the forecast to adjust for current conditions along with afternoon temperatures, clouds and shower/thunderstorm chances. Previous Discussion... The trough axis exits to the east quickly early this evening, so while there could be some lingering showers or thunderstorms early along the eastern border with Canada, it should be mainly dry from this evening into the overnight hours. A 700 hPa shortwave approaches late tonight, so have slight chance pops over far W zones late. Lows tonight should be near normal. && .SHORT TERM /SUNDAY THROUGH MONDAY/... An upper trough exits into the Maritimes Sun with a west to northwest flow in the wake of the trough. The combination of cold air aloft (especially across the northern half of the FA) along with a weak shortwave/weakly cyclonic flow, and some moisture will likely generate a decent cumulus field along with scattered showers. The PoPs were increased to the north of the Katahdin Region from late morning through late afternoon. To the south, it should be a partly to mostly sunny day Down East along with seasonable temperatures and comfortable humidity levels. Did lower the highs a few degrees in the north to account for more clouds and a few showers. Any diurnal showers will rapidly dissipate with the loss of heating by early evening; however, another fast approaching shortwave may generate a few more showers after midnight across mainly the North Woods and Saint John Valley. On Monday, a cold front will cross the FA with scattered showers and the chance of a thunderstorm. The front looks to push through northern areas in the morning, so the threat of any stronger storms is low. The best chance of a stronger storm will likely be in the afternoon from the Katahdin Region south to interior Down East where there will be more opportunity for surface heating. Confidence on stronger storms is not high enough at this time to include any enhanced wording as it is day 3, and conditions are marginal for stronger to severe storms. Given the model soundings the biggest threat would likely be gusty wind. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... The showers and any thunderstorms associated with the cold front should wind down across the Down East region Mon evening. There is a lot more model and forecast uncertainty heading into Tue. The GFS takes a wave of low pressure out of the Great Lakes and tracks it along a stalled frontal boundary and would bring rain to the southern half of the FA Tue that would push offshore during the evening. The latest ECMWF is further south with the low, and the Canadian is in between the two. The operational GFS is an outlier with most of the ensemble members further south. Most of the 12Z ECMWF ensemble members that were reviewed also have the low further south. As such, will have chance PoPs Down East and keep northern areas dry. The trends will need to be watched closely the next couple of days as further adjustments will likely be required once forecast confidence is higher. Once this low pushes through Wed is looking mainly dry with another cold front Thu or Thu night with some showers. High pressure likely builds into the region with dry and seasonable weather at the end of the week. && .AVIATION /17Z SATURDAY THROUGH THURSDAY/... NEAR TERM: Variable conditions will occur with any showers/thunderstorms this afternoon into the evening. Any thunderstorms this afternoon could produce at least small hail. VFR conditions are expected tonight. SHORT TERM: Sun and Sun night...VFR with brief MVFR possible in any afternoon showers from KPQI north. Possible MVFR late Sun night at KFVE in showers. Mon & Mon night...VFR most of the time, but MVFR or even brief IFR possible in scattered showers and thunderstorms Monday afternoon and evening. Gusty and erratic wind possible in/near t-storms, especially south of KPQI. Tue...VFR, with low confidence on MVFR or IFR at KBGR and KBHB in possible rain, but at this time it looks like most of the rain will remain south of the region. Wed...VFR. && .MARINE... NEAR TERM: Winds/seas will remain below small craft advisory levels this afternoon through tonight. Visibilities could be reduced in showers/thunderstorms this afternoon into the evening. SHORT TERM: It looks likely that conditions will remain below small craft advisory levels Sun through Wed. There is low confidence that seas could approach 5 feet on the coastal waters late Tue or Tue night, but for now will go with 3 to 5 foot seas as model and forecaster confidence is low on the track of low pressure approaching from the west/southwest. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && Near Term...Norcross/Maloit Short Term...CB Long Term...CB Aviation...Norcross/CB Marine...Norcross/CB
Hazardous Weather Outlook National Weather Service Caribou ME 347 AM EDT Sat Aug 10 2019 ANZ050>052-MEZ001>006-010-011-015>017-029>032-110800- 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- Northwest Aroostook-Northeast Aroostook-Northern Somerset- Northern Piscataquis-Northern Penobscot-Southeast Aroostook- Central Piscataquis-Central Penobscot-Southern Penobscot- Interior Hancock-Central Washington-Coastal Hancock- Coastal Washington-Southern Piscataquis-Northern Washington- 347 AM EDT Sat Aug 10 2019 This Hazardous Weather Outlook is for Atlantic Coastal Waters, Central Highlands Maine, Coastal DownEast Maine, Far Eastern Maine, Far Northern Maine, Interior DownEast Maine, North Woods Maine and Penobscot Valley Maine. .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. Maloit
Special Weather Statement
National Weather Service Caribou ME
1042 AM EDT Sat Aug 10 2019
MEZ032-101500-
Northern Washington-
1042 AM EDT Sat Aug 10 2019
...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL WASHINGTON
COUNTY...
At 1041 AM EDT, strong thunderstorms were located near Codyville
Plantation, or 10 miles southeast of Danforth, moving northeast at
25 mph.
Half inch hail is possible with these storms.
Locations impacted include...
Danforth, Vanceboro, Topsfield, Codyville Plantation, Codyville,
Lambert Lake, Brookton, Forest, Forest City and Eaton.
This includes US Highway 1 between Brookton and Eaton.
If outdoors, consider seeking shelter inside a building.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
LAT...LON 4556 6743 4542 6773 4559 6788 4568 6777
4566 6772 4569 6773 4567 6770 4563 6768
4561 6765 4562 6764 4559 6752 4559 6750
4560 6748 4560 6745 4557 6742
TIME...MOT...LOC 1441Z 231DEG 22KT 4555 6772
CornwellSpecial Weather Statement
National Weather Service Caribou ME
1155 AM EDT Sat Aug 10 2019
MEZ031-101630-
Southern Piscataquis-
1155 AM EDT Sat Aug 10 2019
...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL PISCATAQUIS
COUNTY...
* At 1153 AM EDT, a strong thunderstorm was located near Guilford,
moving east at 20 mph.
* Half inch hail is possible with this storm.
Locations impacted include...
Dover-Foxcroft, Guilford, Milo, Charleston, Sangerville, Brownville,
Parkman, Sebec, Atkinson, Willimantic, Bowerbank, Williamsburg and
Barnard.
If you are on or near Sebec Lake, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.
Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.
LAT...LON 4525 6941 4533 6902 4512 6899 4510 6914
4512 6939
TIME...MOT...LOC 1553Z 265DEG 16KT 4518 6932
DumontSpecial Weather Statement
National Weather Service Caribou ME
1258 PM EDT Sat Aug 10 2019
MEZ030-101730-
Coastal Washington-
1258 PM EDT Sat Aug 10 2019
...A STRONG THUNDERSTORM WILL AFFECT ...
* At 1258 PM EDT, a strong thunderstorm was located over Lubec,
moving east at 55 mph.
* Half inch hail is possible with this storm.
Locations impacted include...
Lubec, Eastport and Perry.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4478 6695 4478 6706 4493 6708 4494 6705
4496 6706 4495 6704 4496 6705 4497 6703
4491 6697 4486 6698 4483 6697 4482 6695
TIME...MOT...LOC 1658Z 265DEG 49KT 4488 6697
DumontSpecial Weather Statement National Weather Service Caribou ME 129 PM EDT Sat Aug 10 2019 MEZ011-032-101800- Central Penobscot-Northern Washington- 129 PM EDT Sat Aug 10 2019 ...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN WASHINGTON AND EAST CENTRAL PENOBSCOT COUNTIES... * At 128 PM EDT, a strong thunderstorm was located near Springfield, or 12 miles east of Lincoln, moving east at 30 mph. * Half inch hail is possible with this storm. Locations impacted include... Danforth, Springfield, Lakeville, Lee, Mattawamkeag, Chester, Winn, Prentiss, Kingman and Carroll. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. If you are on or near a lake, get out of the water and move indoors or inside a vehicle. Remember, lightning can strike out to 10 miles from the parent thunderstorm. If you can hear thunder, you are close enough to be struck by lightning. Move to safe shelter now! Do not be caught on the water in a thunderstorm. LAT...LON 4531 6832 4548 6842 4559 6790 4531 6786 TIME...MOT...LOC 1728Z 261DEG 25KT 4541 6826 Dumont
Special Weather Statement
National Weather Service Caribou ME
216 PM EDT Sat Aug 10 2019
MEZ015-101845-
Southern Penobscot-
216 PM EDT Sat Aug 10 2019
...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN PENOBSCOT COUNTY...
* At 215 PM EDT, a strong thunderstorm was located near Pittsfield,
moving east at 30 mph.
* Winds in excess of 40 mph and penny size hail are possible with
this storm.
Locations impacted include...
Newport, Hampden, Hermon, Carmel, Newburgh, Plymouth, Etna, Dixmont,
Detroit and Jackson.
This includes the following highways...
Interstate 95 between mile markers 159 and 176.
State Highway 9 between Dixmont and Newburgh.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
LAT...LON 4472 6920 4473 6922 4472 6926 4480 6929
4482 6928 4484 6892 4469 6893 4464 6918
TIME...MOT...LOC 1815Z 271DEG 26KT 4472 6932
DumontSpecial Weather Statement
National Weather Service Caribou ME
323 PM EDT Sat Aug 10 2019
MEZ016-029-102000-
Interior Hancock-Coastal Hancock-
323 PM EDT Sat Aug 10 2019
...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL HANCOCK COUNTY...
* At 323 PM EDT, a strong thunderstorm was located over Verona
Island, or near Bucksport, moving east at 30 mph.
* Half inch hail is possible with this storm.
Locations impacted include...
Ellsworth, Bucksport, Blue Hill, Castine, Verona Island, Penobscot
Township, Orland, Surry, Penobscot, Sedgwick and Verona.
This includes US Highway 1 near Orland.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
LAT...LON 4441 6873 4445 6872 4445 6871 4447 6873
4447 6874 4446 6873 4444 6873 4443 6876
4443 6874 4442 6875 4443 6882 4445 6878
4450 6877 4453 6880 4457 6879 4457 6881
4459 6881 4465 6848 4438 6846
TIME...MOT...LOC 1923Z 271DEG 26KT 4450 6877
DumontThe Portland,ME radar (KGYX), 150 km away, was scanning. The volume nearest the first event began at 19:34 UTC.
4 hail, 1 thunderstorm wind. Local standard time, as filed.
Numerous large trees were toppled near Toddy Pond by wind gusts estimated at 65 mph. Dime size hail was also reported.
Hail up to 1.50 inches was reported. The hail covered the ground.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maine in 2019Every state in 2019This day in weather historyWarnings in Maine, August 2019
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: 843717, 843718, 843719, 843720, 843723.