As it happened: A chronology of the July 21, 2016 severe storms in the Northland

The storms that caused severe damage in the Northland on Thursday morning, July 21, 2016, developed the day before, and marched steadily across North Dakota, Minnesota and Wisconsin all night long. They arrived while many Northland residents were sleeping, jolting people awake with intense thunder and wind.

Here's a chronology of the storms and the immediate aftermath, compiled from National Weather Service reports, News Tribune staff reports and posts to the News Tribune's Facebook page.  

• MORE CONTENT: One year after the storm

Wednesday afternoon, July 20

The National Weather Service in Duluth, in its twice-daily hazardous weather outlook, notes that "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."

As forecast, storms develop in North Dakota, prompting severe weather watches and warnings there during the evening.

8:35 p.m.

A severe thunderstorm watch is issued for northwestern Minnesota, including Bemidji, as the storms continue marching east with damaging winds.

Between midnight and 1 a.m. Thursday, July 21

The National Weather Service in Grand Forks receives reports of wind damage in Waskish, Detroit Lakes and Park Rapids.

12:30 a.m.

The National Weather Service's Storm Prediction Center issues a severe thunderstorm watch for Northeastern Minnesota and parts of Northwestern Wisconsin. "This bowing complex of thunderstorms with a history of damaging and severe gusts is expected to proceed quickly east-southeastward across the watch area toward western Lake Superior and Northwestern Wisconsin. The main threat will continue to be wind damage," forecasters report.

1:03 a.m.

Severe thunderstorm warning issued for parts of Cass and Itasca counties, including the Walker area, which is hosting the Moondance Jam music festival.

1:13 a.m.

Authorities in Bemidji report trees down and roofing blown off of buildings.

1:34 a.m.

In issuing a severe thunderstorm warning for parts of Cass, Crow Wing and Aitkin counties, the National Weather Service in Duluth warns: "This is a dangerous situation. These storms are producing widespread wind damage."

2:01 a.m.

Severe thunderstorm warning issued for parts of Cass, Itasca, Koochiching, Aitkin and St. Louis counties. Weather Service relays reports of 70 mph winds as storms hit Moondance Jam.

2:14 a.m.

Severe thunderstorm warning issued for parts of Carlton, Aitkin, Pine and Crow Wing counties.

2:17 a.m.

Severe thunderstorm warning issued for northeastern St. Louis and northern Lake counties-including Ely and much of the western Boundary Waters Canoe Area Wilderness-for the possibility of damaging winds. Two campers in Quetico Provincial Park, just across the Canadian border from the BWCAW, died after being hit by falling trees as the storms moved through.

2:20 a.m.

Numerous trees downed by storm in Hill City

2:24 a.m.

Large tree branches reported down in Grand Rapids

2:38 a.m.

Trees and power lines reported down in Ely

3 a.m.

Severe thunderstorm warning issued for southern St. Louis, northern Carlton and northwestern Douglas counties - including the Twin Ports and Cloquet - until 4 a.m. Weather Service again warns of widespread wind damage.

3:14 a.m.

Severe thunderstorm issued for the eastern BWCAW, including the Gunflint Trail.

3:20 a.m.

Numerous trees snapped off or blown down on Caribou Lake near Twig. Pontoon boat flipped by strong winds

Line of storms rolls through Duluth, Rice Lake and Superior with damaging winds, torrential rain and at-times-constant lightning. Hundreds of trees are knocked down and thousands of homes and business lose power. Homes are damaged by falling trees.

A weather station atop the St. Louis County Government Services Center downtown records a wind gust of 100 mph; at the nearby Board of Trade Building, the wind knocks down a large chimney, damaging the building below.

3:30 a.m.

The captain of the freighter Algoma Guardian successfully fights to keep control of his ship as the storm hits right while it's in the Duluth ship canal, entering the harbor.

3:40 a.m. to 3:50 a.m.

Among the first comments about the storm posted by Duluth-area readers to the News Tribune Facebook page:

• "Power outage Woodland area. High winds, rolling lighting. This storm is insane!"
• "No power in Kenwood. Constant lightning strikes, and winds so strong that the yard is covered in shredded leaves and tree branches everywhere. Looks like a battlefield!!"
• "Power out in Hunters Park area. Thunder was like gunshots and we have a very large tree down in the street."

3:41 a.m.

Severe thunderstorm warning issued for east-central St. Louis County and southern Lake County, northeast of Duluth, as the line of storms moves east at about 45 mph.

3:50 a.m.

Severe thunderstorm warning issued for areas south of Duluth - parts of Carlton, Pine, Douglas, Burnett and Washburn counties, which had seen significant flooding from storms the previous week.

3:53 a.m.

Severe thunderstorm warning issued / extended for parts of southeastern St. Louis and northwestern Douglas counties.

4 a.m.

After the storm has exited the Duluth area, vehicles have to slow down to dodge fallen trees and power lines blocking the driving lanes of roads.

4:05 a.m.

Severe thunderstorm warning issued for Bayfield County and parts of Douglas and Ashland counties until 5 a.m. As the storms hit near Washburn at about 4:20 a.m., falling trees trapped campers at the Birch Grove Campground west of town. Four campers suffered non-life-threatening injuries.

Additional warnings were issued for Northwestern Wisconsin through 6 a.m., as the storms moved through and then into the Upper Peninsula of Michigan.

4:30 a.m.

In downtown Duluth, near the Civic Center, traffic signals are blown down but continue to show red, green and yellow. Trees are damaged or entirely down near City Hall; newspaper boxes have been blown over and out into the street near the News Tribune office.

Weather spotters report many trees down in the city of Ashland.

4:53 a.m.

Duluth Fire Department issues a message "advising NO TRAVEL this morning. ... There are multiple lines down ... and many streets remain blocked. Please refrain from traveling until later in the morning if at all possible."

Sunrise in Duluth. Before that, at first light, Northland residents - many of whom had never gone back to sleep after the storm - got their first good look at the damage in their yards and neighborhoods.

6:15 a.m.

Crews work to clear fallen trees obstructing traffic on London Road, among other local roads. Near the Duluth Entertainment Convention Center, workers with chainsaws remove trees that blew over onto the tracks of the North Shore Scenic Railroad.

6:28 a.m.

City of Duluth issues a statement recommending "conservation of water use today due to the electrical outage affecting our main water pumping station."

6:45 a.m.

More comments posted to the News Tribune's Facebook page as residents have the chance to survey damage after sunrise:

• "Gnesen Township, roof torn off my barn and swing set blown across yard. Lots of trees down, no power."
• "Duluth Heights - power out and trees down everywhere. On top of my vehicles and my house. This is devastating. It was scary hearing the winds whip through and before I knew it the trees were down."
• "Woodland area is a disaster. Woodland Ave. blocked in several areas."
• "Tree came through my roof in Lakeside and a second tree just missed my neighbor's house."

7:20 a.m.

Passersby stop to look at the damaged canopy of the Holiday station at the corner of Arrowhead and Rice Lake roads.

8 a.m.

Drivers heading to work contend with where traffic signals that aren't functioning because of the power outage, turning those intersections into four-way stops.

9:13 a.m.

The St. Louis County Sheriff's Office advises no unnecessary in the county because of downed trees and power lines from Duluth north to Ely.

10:29 a.m.

Minnesota Power reports that it is conducting aerial assessments of the power grid in the wake of the storm, which has left tens of thousands of customers without power across the region. At the peak, the three largest utility companies in the Northland - Minnesota Power, Lake Country Power and Xcel Energy - report more than 75,000 customers without power.

11:16 a.m.

The Duluth Area Family YMCA opens its doors to those without power, offering free use of the facility including showers, water and Wi-Fi. A cooling center also is set up at Amsoil Arena to offer a place for people to go on the sweltering day with temperatures near 90.

1 p.m.

Minnesota Power, Lake Country Power and Xcel Energy - the three largest utilities in the Northland - report a combined total of more than 75,000 customers without power across the region. Minnesota Power estimated that a third of Duluth's 65,000 customers were without power at one point - the worst storm to affect the city's electrical grid in 15 years, since the April 2001 ice storm.

- - - - -

By evening, the number of customers without power was down to 54,000 - and the number would keep dropping Friday as local and out-of-state utility crews worked long hours in the heat to restore service. Thousands of Northland residents, though, entered their third day without power on Saturday morning.

Officials in Duluth and Rice Lake announced free storm debris drop-off sites - which saw a lot of traffic Friday and Saturday. The storm was long gone - but the storm recovery was just starting.

1/4: Traffic on Glenwood Street maneuvers around a fallen tree on Thursday morning after severe storms moved through Duluth. (Andrew Krueger / akrueger@duluthnews.com)

2/4: Downed trees cover the North Shore Scenic Railroad tracks near the Northwest Passage skywalk in Duluth on Thursday morning. (Andrew Krueger / akrueger@duluthnews.com)

3/4: Thursday's severe storms damaged the Holiday gas station at the corner of Arrowhead and Rice Lake roads in Duluth. (Andrew Krueger / akrueger@duluthnews.com)

4/4: Radar shows the line of storms as it approaches the Twin Ports early Thursday. (Image courtesy of National Weather Service)