A warm front extended from eastern Nebraska to western Illinois and was lifting northward on June 16-17, 2014. An extremely unstable air mass was over the area on June 16 along with strong deep layer shear. This allowed scattered supercells to form during the afternoon and evening which produced two tornadoes, very large hail and damaging winds. A weak tornado formed 4 miles south of Lamont, Iowa in Buchanan County, tracked about 1 mile to the northeast before crossing into Delaware County. In Delaware County the tornado continued for about 13 miles to the northeast to Edgewood, Iowa. Another weak tornado briefly touched down in Benton County, Iowa. Strengthening mid level winds along with a strong low level jet in place later in the evening and overnight on June 17 produced widespread damaging winds of 60 to 70 mph. Strong warm air advection triggered more severe thunderstorms during the late evening of June 17.

Thunderstorm Wind in JO DAVIESS, ILLINOIS
From 17-JUN-14 03:19:00 to 17-JUN-14 03:19:00 (CST-6)
Location: STOCKTON
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Wind measured on wind equipment.

Thunderstorm Wind in JO DAVIESS, ILLINOIS
From 17-JUN-14 03:20:00 to 17-JUN-14 03:20:00 (CST-6)
Location: STOCKTON
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Measured on home weather station.

Hail in HANCOCK, ILLINOIS
From 16-JUN-14 15:35:00 to 16-JUN-14 15:35:00 (CST-6)
Location: BENTLY
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported ping pong ball size hail.

Thunderstorm Wind in CARROLL, ILLINOIS
From 17-JUN-14 03:14:00 to 17-JUN-14 03:14:00 (CST-6)
Location: MT CARROLL
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Large tree limbs were blown down and power outages.

Thunderstorm Wind in JO DAVIESS, ILLINOIS
From 17-JUN-14 03:20:00 to 17-JUN-14 03:20:00 (CST-6)
Location: STOCKTON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large grain bin was blown onto Willow Road near Stockton.

Thunderstorm Wind in JO DAVIESS, ILLINOIS
From 17-JUN-14 03:30:00 to 17-JUN-14 03:30:00 (CST-6)
Location: STOCKTON
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The emergency manager reported widespread wind damage with Highway 20 closed from Stockton east into Stephenson county.  Several other highways were closed due to trees blocking the roads.

Thunderstorm Wind in STEPHENSON, ILLINOIS
From 17-JUN-14 03:30:00 to 17-JUN-14 03:30:00 (CST-6)
Location: FREEPORT
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The public reported considerable tree damage on the west side of Freeport.  The largest tree was 2.5 feet in diameter.

Thunderstorm Wind in STEPHENSON, ILLINOIS
From 17-JUN-14 03:33:00 to 17-JUN-14 03:33:00 (CST-6)
Location: FREEPORT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree limb was down in a yard that was about 5 inches in diameter.

Thunderstorm Wind in STEPHENSON, ILLINOIS
From 17-JUN-14 03:36:00 to 17-JUN-14 03:36:00 (CST-6)
Location: LENA
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported power lines down in Lena.