A strong cold front moved through the region, triggering showers and thunderstorms.  There were numerous reports of large hail and damaging winds, as well as a tornado.

Hail in CLINTON, ILLINOIS
From 25-SEP-12 15:47:00 to 25-SEP-12 15:49:00 (CST-6)
Location: NEW BADEN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CLINTON, ILLINOIS
From 25-SEP-12 15:54:00 to 25-SEP-12 16:04:00 (CST-6)
Location: TRENTON
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large hail fell across Trenton. Some of the hail stones were up to tennis ball size.  Several cars had their windows broken out or cracked.

Hail in CLINTON, ILLINOIS
From 25-SEP-12 15:50:00 to 25-SEP-12 15:55:00 (CST-6)
Location: DAMIANSVILLE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CLINTON, ILLINOIS
From 25-SEP-12 15:58:00 to 25-SEP-12 15:58:00 (CST-6)
Location: AVISTON
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large hail up to tennis ball size damaged shingles on numerous homes in Aviston.

Hail in CLINTON, ILLINOIS
From 25-SEP-12 16:00:00 to 25-SEP-12 16:00:00 (CST-6)
Location: ALBERS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in WASHINGTON, ILLINOIS
From 25-SEP-12 16:26:00 to 25-SEP-12 16:28:00 (CST-6)
Location: ADDIEVILLE
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Rear flank downdraft winds associated with a tornadic thunderstorm destroyed an empty grain bin on a farm on Canary Road, just south of I-64. Then the winds blew over an east bound tractor trailer on I-64 near where the interstate crosses over County Road 4.  The driver sustained minor injuries.

Thunderstorm Wind in ST. CLAIR, ILLINOIS
From 25-SEP-12 17:15:00 to 25-SEP-12 17:15:00 (CST-6)
Location: MONSANTO
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm winds blew down several power lines along Illinois Route 3 in Sauget.

Thunderstorm Wind in ST. CLAIR, ILLINOIS
From 25-SEP-12 17:25:00 to 25-SEP-12 17:25:00 (CST-6)
Location: PONTIAC
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down numerous large tree limbs and a couple of trees in Fairview Heights.

Hail in MARION, ILLINOIS
From 25-SEP-12 17:15:00 to 25-SEP-12 17:15:00 (CST-6)
Location: CENTRALIA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MADISON, ILLINOIS
From 25-SEP-12 19:07:00 to 25-SEP-12 19:10:00 (CST-6)
Location: TROY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ST. CLAIR, ILLINOIS
From 25-SEP-12 15:40:00 to 25-SEP-12 15:45:00 (CST-6)
Location: MASCOUTAH
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Tornado in CLINTON, ILLINOIS
From 25-SEP-12 16:17:00 to 25-SEP-12 16:18:00 (CST-6)
Location: DAMIANSVILLE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado briefly touched down in a field just northwest of Damiansville.  No damage or injuries were reported with this tornado.

Tornado in WASHINGTON, ILLINOIS
From 25-SEP-12 16:23:00 to 25-SEP-12 16:29:00 (CST-6)
Location: OKAWVILLE
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down near I-64 on the north side of Okawville where it blew an eastbound tractor trailer to the southwest into the median.  The driver sustained minor injuries.  The tornado travelled east and damaged a barn and other outbuildings at a farm along Illinois Route 177 about a quarter of a mile west of Cord Road.  Roof panels were blown off, some large tree limbs blown down and several calf hutches blown about, some of which had calves in them.  At Cord Road and Illinois Route 177, tin roof panels were blown off of another barn.  About a quarter of a mile east of Cord Road, along Illinois Route 177, power lines were blown down, a small barn lost its roof and a mason block building was blown down.  The tornado continued to move almost due east along Illinois Route 177 where it damaged a home at the intersection of IL Route 177 and Phobe Road.  Roof shingles were blown off and several large tree branches were broken.  One branch went through the roof of the garage and another damaged a car in the driveway.  All of the damage so far was EF0.  Near the intersection of Illinois Route 177 and County Road 4, the tornado destroyed a small barn.  This damage was rated EF1 with a maximum wind speed of 100 mph.  The tornado then turned a bit to the southeast and quickly dissipated over open fields.  Overall, the path length was approximately 4 miles with a max path width of 100 yards.

Hail in WASHINGTON, ILLINOIS
From 25-SEP-12 17:05:00 to 25-SEP-12 17:05:00 (CST-6)
Location: HOYLETON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ST. CLAIR, ILLINOIS
From 25-SEP-12 15:30:00 to 25-SEP-12 15:30:00 (CST-6)
Location: (BLV)SCOTT AFB BELLE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter