A cluster of thunderstorms developed over eastern North Dakota and northwestern Minnesota the evening of Wednesday July 20th. The outflow from the storms coalesced into a couple of main bow echoes that quickly sped across northeast and central Minnesota during the wee hours of the morning of Thursday July 21st.
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 DLH wrote it up.
A cluster of thunderstorms developed over eastern North Dakota and northwestern Minnesota the evening of Wednesday July 20th. The outflow from the storms coalesced into a couple of main bow echoes that quickly sped across northeast and central Minnesota during the wee hours of the morning of Thursday July 21st. The multi-bow storm quickly spread across northern and central Minnesota in the hours before sunrise, causing extensive damage across the region from widespread straight-line winds of 60 to 80 mph. One of the hardest hit areas was Duluth, with a couple wind gust reports around 100 mph. The bow echo that moved through far northern Minnesota killed two people in Quetico Provincial Park, only about 1 mile into Canada from the Boundary Waters Wilderness area of far northern Minnesota. Power was out to 75,000 customers. many homes were without power for as long as a week. lost power because of so many downed power lines. One hundred power poles were damaged and needed replacing. Minnesota Power, the main provider of power in northeast Minnesota, described the storm and its resulting devastation in Duluth, as the worst in at least a half century.
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 Duluth, MN wrote its last area forecast discussion before the first event at Jul 20, 11:23 PM CST, 28 minutes earlier.
Area Forecast Discussion National Weather Service Duluth MN 1223 AM CDT THU JUL 21 2016 .SHORT TERM...(This evening through Thursday) Issued at 410 PM CDT Wed Jul 20 2016 Elevated convection continues to bubble across west central Wisconsin within the broad synoptic scale warm frontal zone this afternoon. Ongoing warm/moist advective processes could initiate additional isolated/scattered TStorms just about anywhere from NCent/NE Minnesota south-southeastward along this frontal zone tonight, so we have maintained low chances for precip in these areas. The next item of concern related to precip will be the potential for an MCS propagating eastward along the International Border region overnight and Thursday morning, and we have raised chances for precip in this area in anticipation of some complex of TStorms moving across northern Minnesota after midnight. There likely will be at least some attendant severe weather threat, primarily wind damage and heavy rainfall. The other major item of concern is the heat and humidity. The persistent stratus deck across the western parts of our area still continues to hang on as of 4 PM, and has basically rendered the excessive heat warning for Cass/Crow Wing Counties as dead. We have replaced that warning with an advisory, and also replaced the watch for NW Wisconsin with an advisory. In an attempt to simplify things a bit, we also have all heat advisory headlines starting immediately, and lasting until 9 pm Thursday evening. If things set up correctly (i.e. clouds or convection, or both) just ahead of the boundary Thursday, we could skirt with warning thresholds across NW Wisconsin with dewpoints pooling into the mid/upper 70s, and this leaves the door open for a local upgrade if it were to become necessary. .LONG TERM...(Thursday night through Wednesday) Issued at 409 PM CDT Wed Jul 20 2016 Main concerns this afternoon are focused on the potential for strong/severe thunderstorms Saturday and Saturday night. Cooler conditions will arrive Thursday night across the Northland behind a departing cool front. Temperatures will return to more seasonal levels for the remainder of the work week as a quasi-zonal flow pattern develops. A potent, but compact, shortwave trough will push east across the Northern Plains and into the Upper Midwest Friday night and Saturday. Showers and thunderstorms will redevelop and may become strong. Another shortwave trough will push eastward into the Northland Saturday afternoon. Strong to severe thunderstorms are expected with the passage of this feature Saturday afternoon and evening. Damaging wind gusts and torrential rainfall will be the main threat. However, the most rambunctious thunderstorms will be capable of producing very large hail. Quieter weather settles in for the second half of the weekend through Monday as upper ridging follows on the heels of the departing trough. An unsettled pattern returns once again by Monday night and Tuesday continuing through the end of the period. Several rounds of showers and thunderstorms are expected, but there is no clear signal regarding timing or an especially favorable setup for severe weather. Will need to keep an eye on these trends through the weekend. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1221 AM CDT Thu Jul 21 2016 Strong to severe thunderstorms will move through northeastern Minnesota this morning, bringing intense winds and some hail. This will result in some high winds at the TAF sites, along with some very heavy rain and hail. Some IFR CIG's and VSBY's will also be possible overnight, in addition to MVFR and even some VFR at first. Conditions will gradually improve most areas during the day on Thursday. && .CLIMATE... Issued 409 PM CDT Wed Jul 20 2016 Provided below are the record high temperatures for various locations across northeast Minnesota and northwest Wisconsin. Please note that other than our two official climate sites (Duluth and International Falls) the records are considered "unofficial." Record Highs for Wednesday July 20... Duluth................98 in 1901 International Falls...97 in 1923 =>Please note stations below are not official climate sites Brainerd..............97 in 1977 Hibbing...............91 in 2011 Grand Portage.........90 in 1977 Superior..............94 in 2011 Hayward...............102 in 1901 Spooner...............95 in 1940 Hurley................88 in 2011 Grantsburg............94 in 1977 Madeline Island.......88 in 2004 Record Highs for Thursday July 21... Duluth................93 in 1960 International Falls...96 in 1923 =>Please note stations below are not official climate sites Brainerd..............99 in 1901 Hibbing...............90 in 2014 Grand Portage.........83 in 1977 Superior..............95 in 1963 Hayward...............95 in 1901 Spooner...............96 in 1934 Hurley................95 in 2011 Grantsburg............96 in 2011 Madeline Island.......92 in 2011 && .PRELIMINARY POINT TEMPS/POPS... DLH 70 91 65 87 / 50 50 10 0 INL 71 87 63 86 / 60 30 0 0 BRD 74 93 65 90 / 20 20 10 0 HYR 73 93 64 90 / 30 40 10 0 ASX 72 92 66 87 / 40 40 10 0 && .DLH Watches/Warnings/Advisories... WI...Heat Advisory until 9 PM CDT this evening for WIZ001>004-006>009. MN...Heat Advisory until 9 PM CDT this evening for MNZ025-033>038. LS...None. && AVIATION...DAP
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DULUTH MN 347 PM CDT WED JUL 20 2016 MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-211300- KOOCHICHING-NORTH ST. LOUIS-NORTHERN COOK/NORTHERN LAKE- NORTH ITASCA-CENTRAL ST. LOUIS-SOUTHERN LAKE/NORTH SHORE- SOUTHERN COOK/NORTH SHORE-NORTH CASS-SOUTH ITASCA-SOUTH CASS- CROW WING-NORTHERN AITKIN-SOUTH AITKIN-CARLTON/SOUTH ST. LOUIS- PINE-DOUGLAS-BAYFIELD-ASHLAND-IRON-BURNETT-WASHBURN-SAWYER-PRICE- 347 PM CDT WED JUL 20 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT DANGEROUSLY HOT CONDITIONS WILL CONTINUE ACROSS MUCH OF THE NORTHLAND OVERNIGHT. HIGH HUMIDITY VALUES AND OVERNIGHT LOW TEMPERATURES IN THE UPPER 60S TO UPPER 70S WILL PROVIDE LITTLE RELIEF. PLEASE REFER TO THE LATEST HEAT ADVISORY PRODUCTS FOR ADDITIONAL DETAILS. THUNDERSTORMS ARE EXPECTED TO DEVELOP IN WESTERN NORTH DAKOTA THIS AFTERNOON AND ADVANCE EASTWARD INTO THE NORTHLAND LATE TONIGHT. SOME OF THE STORMS MAY BE SEVERE WITH DAMAGING WINDS AND HEAVY RAINFALL THE GREATEST THREATS. THE MOST VIGOROUS STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY IT WILL BE HOT AND HUMID ONCE AGAIN ON THURSDAY. TEMPERATURES ARE EXPECTED TO CLIMB WELL INTO THE 80S AND LOW 90S WITH HEAT INDEX VALUES FROM 95 TO 105 EXPECTED. PLEASE REFER TO THE LATEST HEAT ADVISORY PRODUCTS FOR ADDITIONAL DETAILS. THERE IS A CHANCE STRONG TO POSSIBLY SEVERE THUNDERSTORMS FROM THE OVERNIGHT PERIOD WILL LINGER INTO THURSDAY MORNING. THE GREATEST THREAT FROM THESE STORMS WILL BE TORRENTIAL RAINFALL AND DAMAGING WIND GUSTS. A FEW OF THE MORE VIGOROUS STORMS WOULD SUPPORT LARGE HAIL. STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE AGAIN SATURDAY AND SATURDAY NIGHT. THE MAIN THREAT WILL ONCE AGAIN BE DAMAGING WINDS AND TORRENTIAL RAINFALL...WITH A SECONDARY THREAT OF LARGE HAIL. ADDITIONAL THUNDERSTORM CHANCES RETURN MONDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTERS MAY BE NEEDED LATE TONIGHT AND EARLY THURSDAY MORNING. LSZ121-140>148-211300- BAYFIELD TO OAK POINT WI-GRAND PORTAGE TO GRAND MARAIS MN- GRAND MARAIS TO TACONITE HARBOR MN- TACONITE HARBOR TO SILVER BAY HARBOR MN- SILVER BAY HARBOR TO TWO HARBORS MN-TWO HARBORS TO DULUTH MN- DULUTH MN TO PORT WING WI-PORT WING TO SAND ISLAND WI- SAND ISLAND TO BAYFIELD WI-OAK POINT TO SAXON HARBOR WI- 347 PM CDT WED JUL 20 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE NEARSHORE WATERS OF WESTERN LAKE SUPERIOR. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A CHANCE OF THUNDERSTORMS LATE OVERNIGHT OVER WESTERN LAKE SUPERIOR. SOME OF THE STORMS MAY BE STRONG TO SEVERE WITH WIND GUSTS GREATER THAN 30 KNOTS...FREQUENT CLOUD TO WATER LIGHTNING...LARGE HAIL...AND TORRENTIAL RAINFALL. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SEVERAL ROUNDS OF THUNDERSTORMS WILL AFFECT WESTERN LAKE SUPERIOR THROUGH THE PERIOD. THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING BRIEF GUSTY WINDS TO 30 KNOTS...SMALL HAIL...FREQUENT CLOUD TO WATER LIGHTNING...AND HEAVY RAINFALL. HUYCK MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB ADDRESS: HTTP://WWW.WEATHER.GOV/DULUTH (ALL LOWER CASE)
The Duluth radar (KDLH), 193 km away, was scanning. The volume nearest the first event began at 05:51 UTC.
71 thunderstorm wind. Local standard time, as filed.
There were a few trees blown down on County Road 31 and Highway 6 in Big Falls.
There were numerous trees blown down near Big Bass Lake, including at least 130 trees on Big Bass Lake Drive.
There were numerous trees blown down in Backus.
An 18 to 24 diameter tree was blown down.
Trees were uprooted on the south side of Lake Kabetogama.
There were over 70 trees blown over on and near Browns Lake.
There were two 2.5' diameter trees uprooted near the Ash River.
There were numerous large trees blown down along Highway 1.
Many trees were blown down.
Trees and power lines were blown down in Longville.
Many trees were blown down.
Fifteen trees were blown down in the individual's yard.
Several large oak trees were blown down.
Many trees were blown down near Washburn Lake.
Trees were blown down in the Cook area.
The gust was recorded by the Cass Lake remote automatic weather station.
A 12 diameter tree broke near the ground and partially uprooted. There were several other smaller trees snapped off higher up off the ground.
The emergency manager estimated gusts to around 60 mph.
There were numerous trees blown down.
Numerous trees were damaged or blown down near Little Pine Lake and Hickory Lake.
The wind caused downed trees and structural damage to a home. A previously secured deck was thrown to the other side of a home.
There were numerous trees snapped near Hill City.
There were numerous trees blown down in Tower. A vehicle was damaged by a fallen tree.
There were numerous trees blown down in the Aitkin area.
There were numerous trees blown down, including an uprooted 12 diameter spruce.
There were large tree branches up to 10 in diameter blown down on the northeast side of Grand Rapids.
There were trees blown down near Antler Lake.
There were about 200 trees blown down at Camp Van Vac on Burntside Lake.
The boathouse at the historic Burntside Lodge was destroyed and numerous trees were blown down.
There were multiple trees and power lines blown down near Big Sandy Lake Reservoir and Lake Minnewawa.
There were over 70 trees blown over on and near Browns Lake.
A softball dugout was destroyed.
There were multiple trees and power lines blown down in and around Ely. A roof was blown off an enclosed softball shed at the school.
There were many trees blown down, including some that were uprooted.
There was at least one large tree blown down at the Kawishiwi Lodge on Lake One.
Severe thunderstorm winds knocked down numerous trees near the Prairie Portage area of Basswood Lake right on and near the Canadian border. Trees were blown down near the campsite of 9 campers who were affiliated with the Boy Scouts of America. One woman (age 39) and one boy (age 13) were killed when trees fell on their tent. Two other campers were injured with non-life-threatening injuries. The campers were technically in Canada, but added this to the event record for historical purposes since the campers were so close to the US border.
The winds blew down a 100 yard wide swath of trees just south of Alborn near Highway 7.
A larger than 10 diameter popple tree fell with power lines wrapped in it along the west side Aerie Lake. There were many 8 to 10 diameter popple trees down along Highway 47.
This measurement was from station HCYM5.
There were a lot of large trees blown down along Highway 53 south of Canyon.
There were numerous trees blown down.
Campers and recreational vehicles were damaged when numerous trees were blown down at the Big Lake Shores Campground.
Numerous trees were blown down between Chub Lake and Hay Lake.
Numerous trees were blown down on the northwest side of Caribou Lake on Birch Point Road. A pontoon boat was flipped over on Caribou Lake.
There were numerous trees blown down across Cloquet, which was reported from a retired NWS employee.
There were numerous trees down along Minnesota Highway 194 just west of Highway 53.
There was a power line down at the corner of Highway 53 and Ugstad Road. There numerous trees and large branches down near this location.
There were trees down along Ugstad Road.
There were two large birch trees snapped off. The power was out.
There were a few large trees blown down in front of the Deerfield Townhomes.
A tree fell down onto the wires for a 150' tall radio tower, which pulled down the tower. The tower crashed onto part of a home and caused damage.
A large branch was down at the National Weather Service office in Duluth, near the airport, and which narrowly missed the cars of two employees.
There were multiple power lines down along Anderson Road near Duluth's Coffee Creek neighborhood between Central Entrance and Highway 53 in Duluth.
A Holiday gas station near the intersection of Arrowhead and Rice Lake Roads in Duluth took heavy damage to its roof structure over the gas pumps.
There were several trees down on the roads.
The Duluth Board of Trade Building in downtown Duluth was damaged. The chimney was first struck by lightning, then strong winds knocked it down and it crashed through the roof of the seventh floor. The damage also affected the storage room for costumes for the Minnesota Ballet. The anemometer is on top of the nearby county government building, which measured gusts to around 100 mph.
This was a Minnesota Department of Transportation weather station on Interstate 35 at Thompson Hill. The station is MM248.
A large tree fell and damaged a vehicle.
There were numerous trees down in the Lakeside neighborhood on London Road.
A 90' tall tree was blown down and laying across 52nd Avenue East.
This was the weather station DULM5.
There were many trees blown down. The largest diameter trees were 16 to 20. There were some trees uprooted and sheared off.
This was the maximum wind gust hear over the voice line into the weather station. It was not reported in the following observation.
There were multiple large popple and spruce trees down.
This was the station at Sky Harbor Airport. The station's identification is DYT.
Three trees were blown down. One downed tree was a 2 to 3 foot diameter pine tree.
A tree fell on a cabin.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Thunderstorm Wind, Lake | 2016-07-21 | 39 | Female | Camping | Direct |
| Thunderstorm Wind, Lake | 2016-07-21 | 13 | Male | Camping | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2016Every state in 2016This day in weather historyWarnings in Minnesota, July 2016
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: 639406, 639419, 641422, 639407, 641423, 639455, 641480, 639408, 639409, 641464, 639410, 639454, 641469, 641479, 639456, 639457, 641461, 639458, 639413, 639459, 639445, 641463, 641465, 641467, 639448, 641459, 639415, 639418, 641468, 639447, 639446, 641462, 641466, 639420, 639460, 639461, 641458, 641438, 641445, 641424, and more.