A tropical airmass was in place over Iowa as a weak cold front moved southeast into the state.  At the same time, a tropical feature lifted north across Texas into Oklahoma and fed moisture into the state.  Dew points south of the front rose into the mid 70s by the late morning hours.  Precipitable water values were in the one and one half to two inch range with CAPE values across the state ranging from 1500 J/kg along the front to 3500 J/kg a ways ahead of the front.  Zero to 3 km CAPE values were between 100 and 175 J/kg.  During the mid morning hours thunderstorms fired up in northwest Iowa as the MCV from the previous nights MCS moved northeast into western Iowa.  The thunderstorms expanded through the morning into the afternoon hours.  Most of the storms were tropical in nature, but did produce pea to marble size hail at many locations.  There were a few reports of hail up to an inch in diameter.  As the event unfolded, a few of the storms produced downburst winds.  Wind gusts were limited to around 60 MPH.  Two barns were blown down in Webster County by the high winds.  The main event was the heavy tropical rainfall.  A band of heavy rainfall extended from west central into north central Iowa.  A band of two to four inch rainfall extended from near Sac City toward Fort Dodge into the Mason City area.  Locally heavier amounts of 4 to 5 inches were received.  Numerous roads were flooded in Webster County with a main bridge into Fort Dodge close due to high water.  Fifteen roads were flooded in Cerro Gordo County.  In Calhoun County, U.S. Highway 20 east of Rockwell City was under water with numerous county roads flooded.  Heavy rainfall in Des Moines caused flash flooding with water flowing over 2 feet deep over U.S. Highway 6 in town.  Nearly two inches of rain fell within a 30 minute period in the area to produce the flash flood.

Hail in SAC, IOWA
From 16-JUN-04 12:23:00 to 16-JUN-04 12:23:00 (CST)
Location: AUBURN
Magnitude: 1.00 
Property damage: 2K
Reported by: LAW ENFORCEMENT

Hail in DECATUR, IOWA
From 16-JUN-04 16:40:00 to 16-JUN-04 16:40:00 (CST)
Location: LEON
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Dime size hail

Thunderstorm Wind in WEBSTER, IOWA
From 16-JUN-04 13:20:00 to 16-JUN-04 13:20:00 (CST)
Location: FT DODGE
Magnitude: 52 EG
Property damage: 2K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in BOONE, IOWA
From 16-JUN-04 13:00:00 to 16-JUN-04 13:00:00 (CST)
Location: MADRID
Magnitude: 61 EG
Property damage: 15K
Reported by: EMERGENCY MANAGER

Flash Flood in SAC, IOWA
From 16-JUN-04 12:45:00 to 16-JUN-04 14:15:00 (CST)
Location: COUNTYWIDE
Property damage: 50K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in FRANKLIN, IOWA
From 16-JUN-04 14:41:00 to 16-JUN-04 14:41:00 (CST)
Location: LATIMER
Magnitude: 53 MG
Property damage: 3K
Reported by: AWOS,ASOS,MESONET,ETC

Flash Flood in CALHOUN, IOWA
From 16-JUN-04 12:30:00 to 16-JUN-04 15:30:00 (CST)
Location: COUNTYWIDE
Property damage: 50K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Hail in SAC, IOWA
From 16-JUN-04 11:56:00 to 16-JUN-04 11:56:00 (CST)
Location: LAKE VIEW
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Dime size hail

Hail in JASPER, IOWA
From 16-JUN-04 15:45:00 to 16-JUN-04 15:45:00 (CST)
Location: NEWTON
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Dime size hail

Thunderstorm Wind in WEBSTER, IOWA
From 16-JUN-04 12:40:00 to 16-JUN-04 12:40:00 (CST)
Location: BARNUM
Magnitude: 61 EG
Property damage: 15K
Reported by: LAW ENFORCEMENT

Flash Flood in POLK, IOWA
From 16-JUN-04 12:00:00 to 16-JUN-04 13:30:00 (CST)
Location: DES MOINES
Magnitude: 50 
Reported by: NEWSPAPER

Hail in POLK, IOWA
From 16-JUN-04 12:29:00 to 16-JUN-04 12:29:00 (CST)
Location: URBANDALE
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Dime size hail

Hail in POLK, IOWA
From 16-JUN-04 12:20:00 to 16-JUN-04 12:20:00 (CST)
Location: CLIVE
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Dime size hail

Thunderstorm Wind in CALHOUN, IOWA
From 16-JUN-04 12:50:00 to 16-JUN-04 12:50:00 (CST)
Location: LOHRVILLE
Magnitude: 52 EG
Property damage: 5K
Reported by: LAW ENFORCEMENT

Flash Flood in WEBSTER, IOWA
From 16-JUN-04 13:30:00 to 16-JUN-04 16:30:00 (CST)
Location: NORTH PORTION
Property damage: 75K
Crop damage: 10K
Reported by: EMERGENCY MANAGER

Flash Flood in CERRO GORDO, IOWA
From 16-JUN-04 15:30:00 to 16-JUN-04 18:45:00 (CST)
Location: COUNTYWIDE
Property damage: 50K
Crop damage: 10K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in WRIGHT, IOWA
From 16-JUN-04 14:20:00 to 16-JUN-04 14:20:00 (CST)
Location: CLARION
Magnitude: 52 EG
Property damage: 5K
Reported by: LAW ENFORCEMENT