An upper level disturbance combined with a strong cold front allowed severe thunderstorms to develop in the late afternoon and evening hours across Eastern Iowa.  Training of storms allowed very heavy rain amounts to occur in short time periods causing mainly nuisance flooding.  In Linn County Iowa, training of storms across the Cedar Rapids metropolitan area caused flash flooding closing many streets and sending Indian Creek out of its banks.

Heavy Rain in JOHNSON, IOWA
From 17-MAY-04 18:40:00 to 17-MAY-04 19:40:00 (CST)
Location: CORALVILLE
Magnitude: 1 
Reported by: TRAINED SPOTTER

1 inch in the past hour.

Hail in MUSCATINE, IOWA
From 17-MAY-04 19:45:00 to 17-MAY-04 19:49:00 (CST)
Location: MUSCATINE
Magnitude: 0.88 
Crop damage: 5K
Reported by: TRAINED SPOTTER

Funnel Cloud in JONES, IOWA
From 17-MAY-04 19:00:00 to 17-MAY-04 19:05:00 (CST)
Location: OXFORD JCT
Reported by: TRAINED SPOTTER

Hail in SCOTT, IOWA
From 17-MAY-04 20:14:00 to 17-MAY-04 20:18:00 (CST)
Location: MAYSVILLE
Magnitude: 1.00 
Property damage: 2K
Crop damage: 10K
Reported by: GENERAL PUBLIC

Hail in LINN, IOWA
From 17-MAY-04 18:21:00 to 17-MAY-04 18:22:00 (CST)
Location: FAIRFAX
Magnitude: 0.75 
Crop damage: 2K
Reported by: TRAINED SPOTTER

Hail in JOHNSON, IOWA
From 17-MAY-04 19:06:00 to 17-MAY-04 19:10:00 (CST)
Location: SHUEYVILLE
Magnitude: 0.88 
Crop damage: 5K
Reported by: GENERAL PUBLIC

Hail in JACKSON, IOWA
From 17-MAY-04 19:23:00 to 17-MAY-04 19:27:00 (CST)
Location: MAQUOKETA
Magnitude: 1.00 
Property damage: 2K
Crop damage: 10K
Reported by: OFFICIAL NWS OBS.

Reported by Co-op observer

Hail in CEDAR, IOWA
From 17-MAY-04 19:35:00 to 17-MAY-04 19:40:00 (CST)
Location: MECHANICSVILLE
Magnitude: 1.75 
Property damage: 2K
Crop damage: 15K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in CEDAR, IOWA
From 17-MAY-04 19:35:00 to 17-MAY-04 19:40:00 (CST)
Location: MECHANICSVILLE
Magnitude: 57 EG
Property damage: 2K
Crop damage: 10K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in LINN, IOWA
From 17-MAY-04 18:51:00 to 17-MAY-04 18:55:00 (CST)
Location: FAIRFAX
Magnitude: 65 EG
Property damage: 15K
Crop damage: 10K
Reported by: TRAINED SPOTTER

Hail in LINN, IOWA
From 17-MAY-04 19:01:00 to 17-MAY-04 19:05:00 (CST)
Location: (CID)CEDAR RAPIDS AR
Magnitude: 1.00 
Property damage: 10K
Reported by: OFFICIAL NWS OBS.

Also reported by spotters

Funnel Cloud in LINN, IOWA
From 17-MAY-04 19:01:00 to 17-MAY-04 19:05:00 (CST)
Location: (CID)CEDAR RAPIDS AR
Reported by: TRAINED SPOTTER

Heavy Rain in LINN, IOWA
From 17-MAY-04 18:55:00 to 17-MAY-04 19:09:00 (CST)
Location: CEDAR RAPIDS
Magnitude: 1 
Reported by: EMERGENCY MANAGER

Streets filling with water

Hail in LINN, IOWA
From 17-MAY-04 19:13:00 to 17-MAY-04 19:17:00 (CST)
Location: MT VERNON
Magnitude: 0.75 
Crop damage: 5K
Reported by: BROADCAST MEDIA

Heavy Rain in SCOTT, IOWA
From 17-MAY-04 21:35:00 to 17-MAY-04 23:00:00 (CST)
Location: DAVENPORT
Magnitude: 1.4 
Reported by: OFFICIAL NWS OBS.

Street flooding in downtown Davenport with Duck Creek rising quickly.

Heavy Rain in BENTON, IOWA
From 17-MAY-04 18:20:00 to 17-MAY-04 18:35:00 (CST)
Location: BELLE PLAINE
Magnitude: 1 
Reported by: EMERGENCY MANAGER

1 inch in 15 minutes

Heavy Rain in LINN, IOWA
From 17-MAY-04 18:45:00 to 17-MAY-04 19:00:00 (CST)
Location: FAIRFAX
Magnitude: 1 
Reported by: TRAINED SPOTTER

Ditches full with creeks near bankfull.

Hail in LINN, IOWA
From 17-MAY-04 18:51:00 to 17-MAY-04 18:55:00 (CST)
Location: FAIRFAX
Magnitude: 1.00 
Property damage: 5K
Crop damage: 10K
Reported by: TRAINED SPOTTER

Hail in LINN, IOWA
From 17-MAY-04 18:31:00 to 17-MAY-04 18:34:00 (CST)
Location: CEDAR RAPIDS
Magnitude: 1.00 
Property damage: 5K
Reported by: EMERGENCY MANAGER

Hail ranging from 0.75 to 1 inch

Thunderstorm Wind in DELAWARE, IOWA
From 17-MAY-04 17:13:00 to 17-MAY-04 17:15:00 (CST)
Location: GREELEY
Magnitude: 52 EG
Property damage: 10K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Trees and power lines down; grain bin off foundation

Hail in DELAWARE, IOWA
From 17-MAY-04 17:24:00 to 17-MAY-04 17:26:00 (CST)
Location: COLESBURG
Magnitude: 0.75 
Crop damage: 5K
Reported by: GENERAL PUBLIC

Thunderstorm Wind in DUBUQUE, IOWA
From 17-MAY-04 17:39:00 to 17-MAY-04 17:43:00 (CST)
Location: HOLY CROSS
Magnitude: 61 EG
Property damage: 15K
Crop damage: 10K
Reported by: EMERGENCY MANAGER

Approximately 40 percent of the roof from a historic church was removed.  Significant water damage occurred inside since 1.5 inches of rain fell within 15 minutes.  Several trees were downed with one falling on top of a car.

Heavy Rain in LINN, IOWA
From 17-MAY-04 15:00:00 to 17-MAY-04 19:55:00 (CST)
Location: CEDAR RAPIDS
Magnitude: 2 
Reported by: TRAINED SPOTTER

Streets flooding

Flash Flood in LINN, IOWA
From 17-MAY-04 20:00:00 to 17-MAY-04 23:30:00 (CST)
Location: CEDAR RAPIDS
Magnitude: 2.5 
Property damage: 10K
Reported by: EMERGENCY MANAGER

Streets closed due to high water with orange construction barrels floating down the road.  Most of the rain fell within a 90 minute time period.