A strong spring storm system brought multiple rounds of thunderstorms and heavy rain to the southeast half of Missouri during the weekend of April 29th-30th.  Rainfall totals surpassed nine inches in some locations and this led to flash flooding and historic flooding along some of the tributaries of the Missouri and Mississippi Rivers. Areas along the Meramec River were especially hard hit as new records were set at Steelville, Sullivan, and Eureka. The previous records had just recently been set during the late December flooding of 2015. Two major highways, I-44 and I-55 were shut down for a number of days due to the record river flooding from this event. A few thunderstorms also became severe during the afternoon of April 29th, with two weak tornadoes documented.

Hail in MONTGOMERY, ILLINOIS
From 29-APR-17 15:54:00 to 29-APR-17 15:54:00 (CST-6)
Location: HARVEL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MONTGOMERY, ILLINOIS
From 29-APR-17 15:54:00 to 29-APR-17 15:54:00 (CST-6)
Location: HARVEL
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MONTGOMERY, ILLINOIS
From 29-APR-17 15:45:00 to 29-APR-17 15:50:00 (CST-6)
Location: FARMERSVILLE
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds blew down numerous large trees, tree limbs and power lines. Also, 2 semi trucks were blown over on Interstate 55 between mile markers 72 and 73. Two miles southwest of Farmersville, metal roof of a shed was blown off and several power poles snapped off. A construction trailer was flipped onto it's side. In Farmersville, a large uprooted tree fell onto a house causing moderate damage.

Thunderstorm Wind in MONTGOMERY, ILLINOIS
From 29-APR-17 15:55:00 to 29-APR-17 15:55:00 (CST-6)
Location: LITCHFIELD
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds blew down several power lines on the east side of town.

Thunderstorm Wind in MADISON, ILLINOIS
From 29-APR-17 15:00:00 to 29-APR-17 15:10:00 (CST-6)
Location: ALTON
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down numerous tree limbs around town. Also, a few trees were either uprooted or snapped off.

Thunderstorm Wind in MACOUPIN, ILLINOIS
From 29-APR-17 15:08:00 to 29-APR-17 15:15:00 (CST-6)
Location: BRIGHTON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down several trees and power lines, as well as numerous tree limbs between Brighton and Medora.

Tornado in JERSEY, ILLINOIS
From 29-APR-17 15:02:00 to 29-APR-17 15:04:00 (CST-6)
Location: DELHI
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A weak tornado developed in east central Jersey County, about two tenths of a mile north of Oak Rest Lane, just west of intersection with Oak Rest Road. It travelled to the northeast, crossing Crystal Lake Road just south of Lards Road. Most of the damage to this point was minimal. As it crossed Oak Rest Road, it caused extensive tree damage with numerous trees uprooted, snapped and twisted. The tornado then moved across a field and caused EF1 damage to a property on Gun Club Road, just west of Stonebrooke Drive. Here at least a dozen mature trees were snapped and twisted. The detached garage was destroyed and the single family home had minor damage including windows broken out of the house. The tornado continued northeast for about half a mile before crossing into Macoupin County, 3 miles north of Brighton.

Thunderstorm Wind in MARION, ILLINOIS
From 29-APR-17 16:52:00 to 29-APR-17 16:52:00 (CST-6)
Location: PATOKA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down three large trees.

Thunderstorm Wind in MARION, ILLINOIS
From 29-APR-17 17:15:00 to 29-APR-17 17:15:00 (CST-6)
Location: KINMUNDY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds caused minor roof damage to one house. Also, two barns sustained minor roof damage and a power pole was bent.

Flash Flood in RANDOLPH, ILLINOIS
From 29-APR-17 08:15:00 to 30-APR-17 00:45:00 (CST-6)
Location: DANLEY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Between four and seven inches of rain fell over 3 days causing flash flooding. Numerous roads were flooded.

Hail in ST. CLAIR, ILLINOIS
From 29-APR-17 08:57:00 to 29-APR-17 09:06:00 (CST-6)
Location: BELLEVILLE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ST. CLAIR, ILLINOIS
From 29-APR-17 15:56:00 to 29-APR-17 15:56:00 (CST-6)
Location: LEBANON
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in MACOUPIN, ILLINOIS
From 29-APR-17 15:04:00 to 29-APR-17 15:05:00 (CST-6)
Location: PIASA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

After the tornado crossed into Macoupin County, it continued to the northeast. It crossed Illinois Routes 111/267 just south of intersection with Bachman Road. In this location it broke off numerous large tree limbs as it crossed Bachman Road. Then the tornado dissipated two tenths of a mile north of Bachman Road, about 3.4 miles north of Brighton. Damage was rated EF0 in Macoupin County. Overall, the tornado was rated EF1 with a path length of 2.36 miles and a max path width of 50 yards.

Thunderstorm Wind in JERSEY, ILLINOIS
From 29-APR-17 14:50:00 to 29-APR-17 14:52:00 (CST-6)
Location: BELTREES
Magnitude: 78.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A damaging microburst caused extensive damage to the Piasa Marina. One large boat dock was destroyed. An unoccupied building sustained moderate roof damage.  Several trees were snapped off in an area extending from the marina northward along Lockhaven Road for about half a mile.

Flash Flood in MONTGOMERY, ILLINOIS
From 29-APR-17 19:30:00 to 30-APR-17 00:15:00 (CST-6)
Location: COALTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Between 3 and 6 inches of rain fell over a 3 day period causing flash flooding. Numerous roads were flooded including Illinois Route 127 in numerous locations.

Hail in MADISON, ILLINOIS
From 29-APR-17 15:49:00 to 29-APR-17 15:49:00 (CST-6)
Location: LIVINGSTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MACOUPIN, ILLINOIS
From 29-APR-17 15:55:00 to 29-APR-17 15:55:00 (CST-6)
Location: VIRDEN
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager