A warm front slowly lifted northward from central Missouri into eastern Iowa and northern Illinois May 12th and 13th.  Several rounds of showers and thunderstorms moved across the area producing widespread torrential rains and some large hail. As a result of the heavy rains, flash flooding was common.  There were two corridors of heavy rain; one across Highway 20 with amounts around 2 to 3 inches and a second heavier corridor of 2 to 6 inches from Memphis, Missouri to near Geneseo, Illinois.   Temperatures in the upper 40s to middle 60s on May 12 continued to rise during the early morning hours May 13, reaching into the lower 50s to upper 60s by daybreak.

Hail in BENTON, IOWA
From 12-MAY-10 19:43:00 to 12-MAY-10 19:43:00 (CST-6)
Location: VAN HORNE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A power outage was also observed.

Hail in BUCHANAN, IOWA
From 12-MAY-10 19:50:00 to 12-MAY-10 19:50:00 (CST-6)
Location: INDEPENDENCE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong Wind in LINN, IOWA
From 12-MAY-10 20:45:00 to 12-MAY-10 21:45:00 (CST-6)
Magnitude: 35.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Trained Spotter

Some trees about 8 inches in diameter and 15 feet tall were uprooted on the northeast side of Cedar Rapids due to saturated soils and gradient wind gusts of 30 to 40 mph that occurred between 745 pm and 845 pm May 12.

Hail in BUCHANAN, IOWA
From 12-MAY-10 14:44:00 to 12-MAY-10 14:44:00 (CST-6)
Location: MONTI
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BUCHANAN, IOWA
From 12-MAY-10 15:15:00 to 12-MAY-10 15:15:00 (CST-6)
Location: BUFFALO CREEK CO PARK
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to half dollar-sized hail fell 3 miles east of Winthrop, IA around 415 pm May 12. This report was relayed by the emergency manager.

Hail in DELAWARE, IOWA
From 12-MAY-10 15:20:00 to 12-MAY-10 15:25:00 (CST-6)
Location: MANCHESTER ARPT
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in LEE, IOWA
From 12-MAY-10 21:40:00 to 12-MAY-10 21:40:00 (CST-6)
Location: MONTROSE
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Ping pong ball-sized hail fell in Montrose, IA at 1040 pm May 12.  The hail covered the ground.

Hail in BUCHANAN, IOWA
From 12-MAY-10 20:12:00 to 12-MAY-10 20:12:00 (CST-6)
Location: LAMONT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Quarter-sized hail fell in Lamont, IA at 912 pm May 12.

Hail in BUCHANAN, IOWA
From 12-MAY-10 20:10:00 to 12-MAY-10 20:10:00 (CST-6)
Location: AURORA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DELAWARE, IOWA
From 12-MAY-10 20:35:00 to 12-MAY-10 20:35:00 (CST-6)
Location: MANCHESTER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Quarter-sized hail fell just south of Manchester, IA at 935 pm May 12.

Hail in LEE, IOWA
From 12-MAY-10 21:35:00 to 12-MAY-10 21:35:00 (CST-6)
Location: KEOKUK ARPT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Half dollar-sized hail fell about 6 miles north northwest of Keokuk, IA at 1035 pm May 12.

Hail in DELAWARE, IOWA
From 12-MAY-10 15:27:00 to 12-MAY-10 15:27:00 (CST-6)
Location: MANCHESTER ARPT
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BUCHANAN, IOWA
From 12-MAY-10 15:43:00 to 12-MAY-10 15:43:00 (CST-6)
Location: INDEPENDENCE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in DES MOINES, IOWA
From 12-MAY-10 23:09:00 to 13-MAY-10 01:00:00 (CST-6)
Location: PLEASANTGROVE
Flood cause: Heavy Rain
Property damage: 3.95M
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rains resulted in the flash flooding of parts of Des Moines County during the early morning hours of May 12.  The Burlington area and locations north were some of the hardest hit areas. The flood waters were 10 to 12 inches deep south of Agency Road.  In addition, the intersection of Highway 61 and Roosevelt Avenue was flooded with some vehicles stalled out in the flood waters.  Several homes and businesses had water in basements with some flooded with over 7 feet of water.  Parts of Tama Road and Plank Road were washed out. In other areas, landslides spilled onto some streets. Several businesses along Jefferson Street also sustained flood damage and loss of property.

Flash Flood in LEE, IOWA
From 12-MAY-10 22:00:00 to 13-MAY-10 01:00:00 (CST-6)
Location: VIELE
Flood cause: Heavy Rain
Property damage: 859.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rains resulted in some flash flooding of several streets in Fort Madison, IA during the late evening hours of May 12 and early morning hours of May 13.  The flood waters were 1 to 1.5 feet deep along 14th Street.  Several creeks overflowed their banks.