During the late morning through the afternoon of Monday August 10th, a line of intense thunderstorms known as a derecho brought widespread severe wind damage across Iowa, northern Illinois and northern Indiana.
In northwest Indiana alone, the winds downed hundreds of trees, as well as caused damage to homes, businesses and infrastructure.  There were two injuries reported in northwest Indiana within the NWS Chicago/Romeoville County Warning Area (CWA) due to falling trees. It was estimated that over 200,000 customers lost power at the height of the derecho across all of northern Indiana.  While much of the damage was due to straight line winds, there was also one tornado documented in northwest Indiana.
The combination of high moisture, explosive instability and very strong atmospheric wind flow for mid-summer had developed quickly over the Corn Belt region on the morning of August 10th.  This resulted in a progressive, well-organized complex of storms for hundreds of miles and at times traveling nearly 70 mph.  After bringing extensive damage from extreme wind speeds in Iowa that morning, the damage transitioned across northern Illinois from widespread wind damage to narrow, brief and intense swaths associated with compact circulations within the thunderstorm line, some of which were associated with tornadoes.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:08:00 to 10-AUG-20 15:09:00 (CST-6)
Location: ST JOHN
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several trees were snapped in St. John.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:15:00 to 10-AUG-20 15:15:00 (CST-6)
Location: MUNSTER
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A private weather station measured a wind gust to 61 mph.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:16:00 to 10-AUG-20 15:16:00 (CST-6)
Location: CROWN PT
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree was snapped in Crown Point.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:29:00 to 10-AUG-20 15:29:00 (CST-6)
Location: WINFIELD
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A private weather station measured a wind gust to 60 mph.

Thunderstorm Wind in NEWTON, INDIANA
From 10-AUG-20 15:25:00 to 10-AUG-20 15:25:00 (CST-6)
Location: EFFNER
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A private weather station measured a wind gust to 73 mph.

Thunderstorm Wind in NEWTON, INDIANA
From 10-AUG-20 15:20:00 to 10-AUG-20 15:20:00 (CST-6)
Location: ADE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Power lines were blown down across Route 41 near Route 16.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:17:00 to 10-AUG-20 15:17:00 (CST-6)
Location: CROWN PT
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

The Sparta Dome, in Crown Point, deflated after the winds ripped two 10 to 15 feet holes in its side.

Thunderstorm Wind in NEWTON, INDIANA
From 10-AUG-20 15:21:00 to 10-AUG-20 15:22:00 (CST-6)
Location: MOROCCO
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Multiple tree limbs were blown down in Morocco and a brick chimney was blown down.

Tornado in NEWTON, INDIANA
From 10-AUG-20 15:15:00 to 10-AUG-20 15:16:00 (CST-6)
Location: ADE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A brief tornado with peak winds of 70 mph touched down southwest of Brook.  The tornado made a path through corn fields, indicating a convergent pattern.  The only damage was to metal farm buildings west of Route 41 and south of W 1000 S Road.  One had a portion of its metal roof peeled off and doors were blown out of another.  The path of this tornado was determined, in part, using high resolution satellite imagery.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:15:00 to 10-AUG-20 15:15:00 (CST-6)
Location: CEDAR LAKE
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A six inch diameter tree limb was blown down near 141st Avenue and Parrish Avenue in Cedar Lake.

Thunderstorm Wind in PORTER, INDIANA
From 10-AUG-20 15:31:00 to 10-AUG-20 15:31:00 (CST-6)
Location: SEDLEY
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trees were blown down and a trampoline was thrown across a yard.

Thunderstorm Wind in PORTER, INDIANA
From 10-AUG-20 15:32:00 to 10-AUG-20 15:32:00 (CST-6)
Location: VALPARAISO
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Four tree limbs, 8 to 10 inches in diameter, were snapped.

Thunderstorm Wind in PORTER, INDIANA
From 10-AUG-20 15:39:00 to 10-AUG-20 15:39:00 (CST-6)
Location: KOUTS
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 70 mph in Kouts.

Thunderstorm Wind in PORTER, INDIANA
From 10-AUG-20 15:40:00 to 10-AUG-20 15:40:00 (CST-6)
Location: CRISMAN
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The roof of a strip mall was damaged along Central Avenue in Portage.

Thunderstorm Wind in PORTER, INDIANA
From 10-AUG-20 15:40:00 to 10-AUG-20 15:40:00 (CST-6)
Location: WILLOW CREEK
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A ten inch diameter tree limb was blown down on Lute Road in Portage.

Thunderstorm Wind in PORTER, INDIANA
From 10-AUG-20 15:41:00 to 10-AUG-20 15:41:00 (CST-6)
Location: VALPARAISO
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A semi truck was blown over near Valparaiso.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:16:00 to 10-AUG-20 15:16:00 (CST-6)
Location: HAMMOND
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

A 64 year old woman was taken to a hospital after a tree fell on her car in Hammond.

Thunderstorm Wind in LAKE, INDIANA
From 10-AUG-20 15:31:00 to 10-AUG-20 15:32:00 (CST-6)
Location: LAKE STATION
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Trees, tree limbs and power lines were blown down in Lake Station.  Several homes were damaged.  A man was pinned to his couch and trapped when a large tree fell on his home in Lake Station.  Other people in the house were able to exit.  The man was later taken to a hospital with non-life threatening injuries.