During the evening of Friday, July 17th, a line of strong to severe thunderstorms that developed across northwest Minnesota, propagated south-southeast across central Minnesota and became a well defined bow echo segment. There were two areas that had the worst damage. One occurred in Stevens County where a swath of wind damage extended 3/4 of a mile to the southeast of Chokio, and about 1/4 of a mile wide. Many trees were snapped off just above the base, while others were uprooted. The second area was associated with straight-line winds, occasional downbursts, and two tornadoes that hit northern Isanti, and northern Chisago Counties.
There was ample instability and wind shear during the evening to hold supercell characteristics along this bow echo segment. As the storm bowed out to the southeast late in the evening, less instability and wind shear diminished the organized nature of the bow segment. However, a one bow echo segment allowed for two tornadic storms near Day and Rush City.
There was continued weakening of this bow echo overnight, with more individual line segments which caused brief, and isolated wind damage. Even local airport wind sensors, and private wind sensors were measuring wind gusts in the 40 to 50 mph range past midnight LST. The exception was in the Twin Cities metro area where the Flying Cloud airport measured a wind gust of 59 mph, and the Minneapolis/St. Paul airport measured a wind gust of 55 mph.

Thunderstorm Wind in CHISAGO, MINNESOTA
From 18-JUL-20 00:25:00 to 18-JUL-20 00:25:00 (CST-6)
Location: RUSH CITY
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A few trees were blown down in Rush City, along Highway 61.

Thunderstorm Wind in FREEBORN, MINNESOTA
From 18-JUL-20 04:45:00 to 18-JUL-20 04:45:00 (CST-6)
Location: ALBERT LEA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A large tree limb fell on a parked car in Albert Lea.

Tornado in CHISAGO, MINNESOTA
From 18-JUL-20 00:17:00 to 18-JUL-20 00:19:00 (CST-6)
Location: RUSH PT
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A brief tornado cross the southern portion of West Rush Lake, uprooting trees and knocking down numerous large branches. It flipped several boat docks and pontoons. Some debris from the docks was blown 1/2 mile downwind into some trees.

Thunderstorm Wind in RENVILLE, MINNESOTA
From 18-JUL-20 00:00:00 to 18-JUL-20 00:00:00 (CST-6)
Location: HECTOR
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several large tree branches, some 18 inches in diameter were blown down near Hector.

Thunderstorm Wind in SIBLEY, MINNESOTA
From 18-JUL-20 01:28:00 to 18-JUL-20 01:28:00 (CST-6)
Location: GIBBON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A power pole was blown down on County Road 2 in Gibbon.

Thunderstorm Wind in FREEBORN, MINNESOTA
From 18-JUL-20 04:50:00 to 18-JUL-20 04:50:00 (CST-6)
Location: ALBERT LEA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several large tree limbs were snapped off, some as large as 8 inches in diameter.

Thunderstorm Wind in STEVENS, MINNESOTA
From 17-JUL-20 23:25:00 to 17-JUL-20 23:25:00 (CST-6)
Location: HANCOCK
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were several large tree limbs blown down near Hancock.

Thunderstorm Wind in TODD, MINNESOTA
From 17-JUL-20 21:08:00 to 17-JUL-20 21:11:00 (CST-6)
Location: STAPLES
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several trees were blown down along with power lines.

Thunderstorm Wind in STEVENS, MINNESOTA
From 17-JUL-20 22:13:00 to 17-JUL-20 22:18:00 (CST-6)
Location: CHOKIO
Magnitude: 59.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A swath of wind damage extended 3/4 of a mile to the southeast of Chokio, including parts of Chokio. The damage area was about 1/4 of a mile wide, with many trees snapped off just above the base, while others were uprooted. A light tower of a local baseball field was blown over.

Thunderstorm Wind in WRIGHT, MINNESOTA
From 18-JUL-20 01:10:00 to 18-JUL-20 01:10:00 (CST-6)
Location: BUFFALO
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree limb was snapped off northwest of Buffalo.

Thunderstorm Wind in DAKOTA, MINNESOTA
From 18-JUL-20 02:05:00 to 18-JUL-20 02:05:00 (CST-6)
Location: LAKEVILLE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several large tree branches were blown down in Apple Valley.

Tornado in ISANTI, MINNESOTA
From 17-JUL-20 23:59:00 to 18-JUL-20 00:05:00 (CST-6)
Location: DAY
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado made contact just west of Day and traveled just north of a few houses, then hit a farm where multiples trees were uprooted or broken. A partially filled grain bin was also blown off its foundation. The tornado continued across open fields and wooded areas before dissipating. An anemometer on the southern edge of the tornado measured 87 mph.

Thunderstorm Wind in ISANTI, MINNESOTA
From 18-JUL-20 00:07:00 to 18-JUL-20 00:20:00 (CST-6)
Location: SPRINGVALE
Magnitude: 61.00 EG
Property damage: 250.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A NWS Storm Survey indicated that numerous trees were blown down across north central and northeast Isanti County. The damage was in a swath about two miles wide. The hardest hit areas were west of Stanchfield, through the town, and to the east of Stanchfield. Several large sheds were also damaged in this area.

Thunderstorm Wind in SCOTT, MINNESOTA
From 18-JUL-20 02:00:00 to 18-JUL-20 02:00:00 (CST-6)
Location: JORDAN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree was blown down in Jordan. Minor damage was reported.

Thunderstorm Wind in SCOTT, MINNESOTA
From 18-JUL-20 02:01:00 to 18-JUL-20 02:01:00 (CST-6)
Location: SHAKOPEE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A tree fell onto a road in Shakopee. Minor damage was reported.

Thunderstorm Wind in POPE, MINNESOTA
From 17-JUL-20 22:35:00 to 17-JUL-20 22:37:00 (CST-6)
Location: STARBUCK
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

There were numerous large tree branches that blew down around Starbuck.

Thunderstorm Wind in KANDIYOHI, MINNESOTA
From 18-JUL-20 00:20:00 to 18-JUL-20 00:22:00 (CST-6)
Location: WILLMAR
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several large tree branches were blown down in the city of Willmar.

Thunderstorm Wind in TODD, MINNESOTA
From 17-JUL-20 22:20:00 to 17-JUL-20 22:20:00 (CST-6)
Location: BERTHA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large 10 inch diameter tree was blown down at County Road 24, and 157th Avenue.

Thunderstorm Wind in STEVENS, MINNESOTA
From 17-JUL-20 22:35:00 to 17-JUL-20 22:35:00 (CST-6)
Location: MORRIS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree was blown down across Highway 3, east of Morris.

Hail in TODD, MINNESOTA
From 17-JUL-20 20:47:00 to 17-JUL-20 20:47:00 (CST-6)
Location: HEWITT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in LAC QUI PARLE, MINNESOTA
From 17-JUL-20 23:25:00 to 17-JUL-20 23:25:00 (CST-6)
Location: MARIETTA
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in MILLE LACS, MINNESOTA
From 17-JUL-20 23:41:00 to 17-JUL-20 23:41:00 (CST-6)
Location: FORESTON
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in CHISAGO, MINNESOTA
From 18-JUL-20 00:20:00 to 18-JUL-20 00:25:00 (CST-6)
Location: HARRIS
Magnitude: 61.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A NWS Storm Survey determined that severe straight-line winds and occasional downburst winds, damaged hundreds of trees between Harris and Rush City along County Road 30. Some of the trees landed on vehicles, roofs and sheds. One machine shed had its roof blown off.

Thunderstorm Wind in MILLE LACS, MINNESOTA
From 17-JUL-20 23:45:00 to 17-JUL-20 23:45:00 (CST-6)
Location: MILACA
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Farm equipment was blown over and damaged. In addition, 800 pound hay bales were blown across the farm.

Thunderstorm Wind in KANABEC, MINNESOTA
From 18-JUL-20 00:00:00 to 18-JUL-20 00:00:00 (CST-6)
Location: WARMAN
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A measured wind report of 53 knots from a private weather station.

Thunderstorm Wind in SHERBURNE, MINNESOTA
From 17-JUL-20 23:55:00 to 17-JUL-20 23:58:00 (CST-6)
Location: BECKER
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Numerous trees were blown down, including one blown down on a house.

Thunderstorm Wind in HENNEPIN, MINNESOTA
From 18-JUL-20 02:02:00 to 18-JUL-20 02:04:00 (CST-6)
Location: FLYING CLOUD ARPT
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

This was a measured wind gust at the Flying Cloud airport in southern Hennepin County.
There was another measured wind report of a 55 mph that occurred at the Minneapolis, St. Paul airport.