A strong storm system was approaching the region. Several rounds of thunderstorms moved through from the afternoon hours of May 30th through late morning on May 31st.  There were numerous reports of damaging winds, large hail and flash flooding with these storms.  A more significant round of storms moved through the region during the evening hours of May 31st.

Thunderstorm Wind in RANDOLPH, ILLINOIS
From 30-MAY-13 17:15:00 to 30-MAY-13 17:15:00 (CST-6)
Location: MENARD
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds blew down several large tree limbs on the north side of Chester.

Thunderstorm Wind in ST. CLAIR, ILLINOIS
From 30-MAY-13 17:25:00 to 30-MAY-13 17:25:00 (CST-6)
Location: FREEBURG
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm winds blew down a 12 inch diameter tree limb which fell on top of a building at a car dealership.

Thunderstorm Wind in ST. CLAIR, ILLINOIS
From 30-MAY-13 17:28:00 to 30-MAY-13 17:29:00 (CST-6)
Location: WILLARD
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm winds blew over a large tree in O'Fallon.  Also, the ASOS unit at Scott Air Force Base recorded at 67 MPH wind gust with the storms.

Thunderstorm Wind in ST. CLAIR, ILLINOIS
From 30-MAY-13 17:33:00 to 30-MAY-13 17:35:00 (CST-6)
Location: OLD MARISSA
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down several medium to large trees as well as several power lines around town.  A few shingles were blown off of a couple of homes.

Thunderstorm Wind in WASHINGTON, ILLINOIS
From 30-MAY-13 17:40:00 to 30-MAY-13 17:45:00 (CST-6)
Location: BIDDLEBORN
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds damaged several sheds in an area from just east of St. Libory to near Venedy.

Thunderstorm Wind in CLINTON, ILLINOIS
From 30-MAY-13 18:03:00 to 30-MAY-13 18:03:00 (CST-6)
Location: TRENTON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm winds blew down several large trees in town.

Thunderstorm Wind in BOND, ILLINOIS
From 30-MAY-13 18:20:00 to 30-MAY-13 18:20:00 (CST-6)
Location: GREENVILLE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down numerous large tree limbs around town.

Thunderstorm Wind in CALHOUN, ILLINOIS
From 30-MAY-13 16:10:00 to 30-MAY-13 16:10:00 (CST-6)
Location: HAMBURG
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down a large tree on the south side of Hamburg.

Thunderstorm Wind in MONTGOMERY, ILLINOIS
From 30-MAY-13 18:30:00 to 30-MAY-13 18:32:00 (CST-6)
Location: DONNELLSON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down a large walnut tree about 6 miles south of Taylor Springs.  Also, several large trees were blown down around Hillsboro.  One tree fell on top of an unoccupied vehicle, causing major damage.

Thunderstorm Wind in MONTGOMERY, ILLINOIS
From 30-MAY-13 18:39:00 to 30-MAY-13 18:39:00 (CST-6)
Location: HONEY BEND
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down several large tree limbs.

Thunderstorm Wind in MACOUPIN, ILLINOIS
From 30-MAY-13 18:45:00 to 30-MAY-13 18:45:00 (CST-6)
Location: NILWOOD
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm winds blew down several large trees along Emmerson Airline Road.

Thunderstorm Wind in MONROE, ILLINOIS
From 30-MAY-13 17:15:00 to 30-MAY-13 17:15:00 (CST-6)
Location: HECKER
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds snapped a large tree off at the ground.

Thunderstorm Wind in WASHINGTON, ILLINOIS
From 30-MAY-13 17:55:00 to 30-MAY-13 17:55:00 (CST-6)
Location: OKAWVILLE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down a couple of trees as well as numerous tree limbs around town.  Also, several homes sustained minor shingle damage.