A frontal boundary was slowly sinking south across forecast area. Several rounds of storms developed and  moved east along the front dumping up to 8 inches of rain in a 24 hour period from 7 am June 25th to 7 am June 26th.  This caused considerable flash flooding, especially in Lincoln County Missouri and Calhoun County Illinois. There were also numerous reports of damaging winds and large hail.

Thunderstorm Wind in CALHOUN, ILLINOIS
From 25-JUN-15 16:50:00 to 25-JUN-15 17:05:00 (CST-6)
Location: BRUSSELS
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds flattened several corn fields near Brussels and Golden Eagle. Also, numerous tree limbs were blown down.

Hail in JERSEY, ILLINOIS
From 25-JUN-15 17:00:00 to 25-JUN-15 17:00:00 (CST-6)
Location: OTTERVILLE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in MACOUPIN, ILLINOIS
From 25-JUN-15 17:50:00 to 25-JUN-15 17:50:00 (CST-6)
Location: HETTICK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in MADISON, ILLINOIS
From 25-JUN-15 18:10:00 to 25-JUN-15 18:17:00 (CST-6)
Location: GRANITE CITY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail up to one inch in diameter fell for about 10 minutes over Granite City.

Flash Flood in ADAMS, ILLINOIS
From 26-JUN-15 07:40:00 to 26-JUN-15 13:00:00 (CST-6)
Location: MEYER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Up to 5 inches of rain fell in a short amount of time on already saturated soils causing flash flooding.  Numerous roads were flooded including Illinois Route 94 north of Golden and Illinois Route 61 between Loraine and Golden.

Flash Flood in CALHOUN, ILLINOIS
From 25-JUN-15 17:35:00 to 26-JUN-15 06:30:00 (CST-6)
Location: BATCHTOWN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Up to 5 inches of rain fell in about a three to four hour period onto already saturated soils. This caused flash flooding. Numerous roads were flooded including the Mississippi River Road which had at least a foot of water over it near Batchtown.  Illinois Route 1 was flooded in several locations between Hardin and Brussels.

Hail in MACOUPIN, ILLINOIS
From 25-JUN-15 18:25:00 to 25-JUN-15 18:25:00 (CST-6)
Location: NILWOOD
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ST. CLAIR, ILLINOIS
From 25-JUN-15 18:26:00 to 25-JUN-15 18:30:00 (CST-6)
Location: CASEYVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm Wind in ST. CLAIR, ILLINOIS
From 25-JUN-15 18:50:00 to 25-JUN-15 18:55:00 (CST-6)
Location: SWANSEA
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down several large trees and numerous tree limbs around Belleville. Also, a few power lines were blown down.

Thunderstorm Wind in MADISON, ILLINOIS
From 25-JUN-15 18:20:00 to 25-JUN-15 18:20:00 (CST-6)
Location: COLLINSVILLE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds snapped an 18 inch diameter ash tree about 10 feet up from the base.