A cold front moved into Iowa from the northwest, while a warm front pushed into the southwest part of Iowa from the south during the afternoon and evening hours.  Initially the airmass was very dry, however a strong push of moisture increased surface dew points into the upper 60s to low 70s by mid afternoon.  Precipitable water values increased to 1.25 to 1.5 inches.  The atmosphere destabilized by mid to late afternoon.  Most unstable CAPE increased to 5000 J/kg as the lifted index fell to -9 to -12 C.  The freezing level was relative low, around 12,000 feet.  Available CAPE in the -10 to -30 C layer of the atmosphere increased to between 500 and 1000 J/kg.  Downdraft CAPE was between 800 and 1000 J/kg.  The atmosphere was moderately sheared with 40 to 55 kts of effective shear in the near storm environment.  With the relatively dry air initially on the leading edge of the developing storms, the LCL was a relatively high 1500 meters.  Thunderstorms formed in two areas.  The first was over northwest Iowa along the cold frontal boundary.  The second area developed over eastern Nebraska and tracked east in the warm advection area along and north of the warm frontal boundary.  The two areas of storms combined during the evening hours, becoming a full fledged MCC by mid evening.  All modes of severe weather occurred with this system, though the predominate mode was large hail.  Thunderstorms formed rapidly along the warm frontal boundary during the mid and late afternoon.  Hail up to baseball size was reported in southwest Iowa with these storms.  Rapid intensification led to golf ball and larger hail in Taylor, Ringgold, Adams, and Union Counties.  One of the storms produced a tornado as it moved through Ringgold County in the Tingley area.  A large farmstead was hit, causing $4,000,000 damage.  Eight buildings were damaged or destroyed, as well as the farmstead itself.  Based upon extensive destruction to a 400 foot long metal cattle barn on the farmstead, it was determined that the tornado was of EF-2 strength with winds of up to 130 MPH.  Other buildings, including the home, received extensive damage but not as widespread.  Three head of cattle were killed when the cattle barn was destroyed.  During the early evening the storm system transitioned into more of a high wind event.  Several reports of 50 to 70 MPH winds were received.  A wind gust in excess of 60 MPH threw house debris onto the street in Ottumwa.  The storms produced heavy rainfall of 2 inches or more per hour.  Fortunately they were moving relatively quickly.  Storms trained over parts of Guthrie County.  Over 4 inches of rain fell north and west of Guthrie Center.  The heavy rainfall caused minor flooding with ditches filled and minor road flooding.  A small area of flash flooding was reported along Seely Creek in Guthrie County with water a few feet over the road.  Lightning caused at least two house fires.  A house was struck east of Des Moines by one thunderstorm.  The house was set on fire by the lightning.  A second house was struck and set ablaze north of Ankeny.

Tornado in RINGGOLD, IOWA
From 01-JUN-10 16:08:00 to 01-JUN-10 16:11:00 (CST-6)
Location: TINGLEY
Tornado F-scale: EF2
Property damage: 4.00M
Crop damage: 10.00K
Reported by: NWS Storm Survey

A cone shape tornado was reported.  Path was intermittent and the NWS survey suggests that the tornado hit a farmstead then lifted briefly skipping over some farms before setting back down and damaging another farmstead.  Eyewittnesses also recount the tornado briefly lifting.

Funnel Cloud in PALO ALTO, IOWA
From 01-JUN-10 13:34:00 to 01-JUN-10 13:34:00 (CST-6)
Location: DEPEW
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Relayed by Emergency Management.

Funnel Cloud in WARREN, IOWA
From 01-JUN-10 19:44:00 to 01-JUN-10 19:44:00 (CST-6)
Location: ST MARYS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in EMMET, IOWA
From 01-JUN-10 13:36:00 to 01-JUN-10 13:36:00 (CST-6)
Location: WELLINGFORD
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 5.00K
Reported by: Public

Hail in RINGGOLD, IOWA
From 01-JUN-10 15:25:00 to 01-JUN-10 15:25:00 (CST-6)
Location: BENTON
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in ADAMS, IOWA
From 01-JUN-10 15:25:00 to 01-JUN-10 15:25:00 (CST-6)
Location: MERCER
Magnitude: 2.00 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Public

Hail in EMMET, IOWA
From 01-JUN-10 14:00:00 to 01-JUN-10 14:00:00 (CST-6)
Location: RALEIGH
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Hail in TAYLOR, IOWA
From 01-JUN-10 15:26:00 to 01-JUN-10 15:26:00 (CST-6)
Location: CLEARFIELD
Magnitude: 2.00 
Property damage: 50.00K
Crop damage: 10.00K
Reported by: Fire Department/Rescue

Golf ball to near baseball size hail reported.

Hail in RINGGOLD, IOWA
From 01-JUN-10 15:37:00 to 01-JUN-10 15:37:00 (CST-6)
Location: KNOWLTON
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in ADAMS, IOWA
From 01-JUN-10 15:35:00 to 01-JUN-10 15:35:00 (CST-6)
Location: CORNING
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Thunderstorm Wind in WAPELLO, IOWA
From 01-JUN-10 21:02:00 to 01-JUN-10 21:02:00 (CST-6)
Location: EDDYVILLE
Magnitude: 50.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in WAPELLO, IOWA
From 01-JUN-10 20:52:00 to 01-JUN-10 20:52:00 (CST-6)
Location: EDDYVILLE
Magnitude: 50.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in RINGGOLD, IOWA
From 01-JUN-10 16:00:00 to 01-JUN-10 16:00:00 (CST-6)
Location: TINGLEY
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 5.00K
Reported by: Public

Thunderstorm Wind in WARREN, IOWA
From 01-JUN-10 20:05:00 to 01-JUN-10 20:05:00 (CST-6)
Location: LACONA
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Public

Willow tree, along with 5-6 inch diameter limbs blown down.

Thunderstorm Wind in ADAIR, IOWA
From 01-JUN-10 18:45:00 to 01-JUN-10 18:45:00 (CST-6)
Location: GREENFIELD
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Tree limbs down, 10 inches in diameter.

Hail in ADAMS, IOWA
From 01-JUN-10 16:05:00 to 01-JUN-10 16:05:00 (CST-6)
Location: WILLIAMSON
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 5.00K
Reported by: Public

Hail in RINGGOLD, IOWA
From 01-JUN-10 16:15:00 to 01-JUN-10 16:35:00 (CST-6)
Location: ELLSTON
Magnitude: 2.00 
Property damage: 25.00K
Crop damage: 100.00K
Reported by: Trained Spotter

Hail lasted over 20 minutes with the largest hail falling for 5 minutes.

Hail in ADAIR, IOWA
From 01-JUN-10 16:50:00 to 01-JUN-10 16:55:00 (CST-6)
Location: ROSSERDALE
Magnitude: 1.25 
Property damage: 10.00K
Crop damage: 50.00K
Reported by: Public

One and one half inch of rain also fell.

Hail in AUDUBON, IOWA
From 01-JUN-10 17:10:00 to 01-JUN-10 17:10:00 (CST-6)
Location: FISCUS
Magnitude: 1.25 
Property damage: 5.00K
Crop damage: 5.00K
Reported by: Public

Hail in GUTHRIE, IOWA
From 01-JUN-10 17:35:00 to 01-JUN-10 17:35:00 (CST-6)
Location: PANORA
Magnitude: 1.25 
Property damage: 3.00K
Crop damage: 5.00K
Reported by: Public

Four inches of rain also reported.

Hail in RINGGOLD, IOWA
From 01-JUN-10 19:55:00 to 01-JUN-10 19:55:00 (CST-6)
Location: REDDING
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 20.00K
Reported by: Trained Spotter

Also the top of a green house was blown off.

Thunderstorm Wind in RINGGOLD, IOWA
From 01-JUN-10 16:15:00 to 01-JUN-10 16:15:00 (CST-6)
Location: ELLSTON
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Numerous branches down with winds estimated at 60 to 70 MPH.

Thunderstorm Wind in TAYLOR, IOWA
From 01-JUN-10 19:24:00 to 01-JUN-10 19:24:00 (CST-6)
Location: NEW MARKET
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several tree limbs were downed by winds in New Market.

Thunderstorm Wind in WARREN, IOWA
From 01-JUN-10 19:47:00 to 01-JUN-10 19:47:00 (CST-6)
Location: MEDORA
Magnitude: 65.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Pieces of tin reported in the road at the intersecton of 80th Ave and Quebec
St.

Heavy Rain in GUTHRIE, IOWA
From 01-JUN-10 17:00:00 to 01-JUN-10 20:00:00 (CST-6)
Location: FANSLERS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of around 4 inches in the past 3 hours resulted in water inundation of fields in the area.

Heavy Rain in CASS, IOWA
From 01-JUN-10 18:08:00 to 01-JUN-10 18:23:00 (CST-6)
Location: ATLANTIC
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Rainfall amount in the last 15 minutes was 0.67 inches.  Water was reported as curb-high along Highway 6.

Thunderstorm Wind in WARREN, IOWA
From 01-JUN-10 19:47:00 to 01-JUN-10 19:47:00 (CST-6)
Location: MEDORA
Magnitude: 65.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Two 12 inch diameter trees were blown down at 80th Ave and Quebec St.

Thunderstorm Wind in WARREN, IOWA
From 01-JUN-10 19:48:00 to 01-JUN-10 19:48:00 (CST-6)
Location: INDIANOLA ARPT
Magnitude: 69.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Fifteen to twenty trees ranging in size from 4 to 6 inches in diameter were scattered everywhere near the intersection of 93rd Ave and Quebec St.

Flash Flood in GUTHRIE, IOWA
From 01-JUN-10 20:30:00 to 01-JUN-10 21:30:00 (CST-6)
Location: PANORA
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Seely Creek was out of its banks near the confluence of the South Raccoon.  A few roads were inundated a few feet by the rising water.

Hail in FRANKLIN, IOWA
From 01-JUN-10 15:45:00 to 01-JUN-10 15:45:00 (CST-6)
Location: FAULKNER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Also wind gusts to around 30 MPH.

Hail in RINGGOLD, IOWA
From 01-JUN-10 15:30:00 to 01-JUN-10 15:30:00 (CST-6)
Location: CLEARFIELD
Magnitude: 2.75 
Property damage: 50.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in ADAMS, IOWA
From 01-JUN-10 15:57:00 to 01-JUN-10 15:57:00 (CST-6)
Location: WILLIAMSON
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Hail in UNION, IOWA
From 01-JUN-10 15:45:00 to 01-JUN-10 15:45:00 (CST-6)
Location: ARISPE
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in ADAIR, IOWA
From 01-JUN-10 16:21:00 to 01-JUN-10 16:21:00 (CST-6)
Location: ORIENT
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Hail in GUTHRIE, IOWA
From 01-JUN-10 17:54:00 to 01-JUN-10 17:54:00 (CST-6)
Location: GUTHRIE CENTER
Magnitude: 0.88 
Property damage: 1.00K
Crop damage: 5.00K
Reported by: Law Enforcement

A few nickel sized hail stones with the rest dime and pea size.

Thunderstorm Wind in CASS, IOWA
From 01-JUN-10 18:25:00 to 01-JUN-10 18:25:00 (CST-6)
Location: DEWEY
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large tree was blown down with numerous 3 to 4 inch branches blown down.

Thunderstorm Wind in DAVIS, IOWA
From 01-JUN-10 21:45:00 to 01-JUN-10 21:45:00 (CST-6)
Location: BLOOMFIELD ARPT
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Numerous branches down, largest was 12 inches.

Thunderstorm Wind in WAPELLO, IOWA
From 01-JUN-10 21:15:00 to 01-JUN-10 21:15:00 (CST-6)
Location: KIRKVILLE
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winds estimated between 60 and 70 MPH.  Sixteen inch diameter trees blown down with numerous other branches broken.

Thunderstorm Wind in DECATUR, IOWA
From 01-JUN-10 20:13:00 to 01-JUN-10 20:13:00 (CST-6)
Location: GARDEN GROVE
Magnitude: 65.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Grain bin destroyed.

Thunderstorm Wind in WAPELLO, IOWA
From 01-JUN-10 18:50:00 to 01-JUN-10 18:50:00 (CST-6)
Location: OTTUMWA
Magnitude: 57.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

House debris on Rutledge Rd and 120th.

Thunderstorm Wind in ADAMS, IOWA
From 01-JUN-10 19:00:00 to 01-JUN-10 19:00:00 (CST-6)
Location: PRESCOTT
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several 6-8 inch diameter tree limbs down northeast of Prescott.

Thunderstorm Wind in TAYLOR, IOWA
From 01-JUN-10 19:35:00 to 01-JUN-10 19:35:00 (CST-6)
Location: BEDFORD
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several tree limbs and power lines were downed throughout the town of Bedford.

Heavy Rain in GUTHRIE, IOWA
From 01-JUN-10 16:30:00 to 01-JUN-10 19:53:00 (CST-6)
Location: FANSLERS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Total rainfall since 1630 CST was 4.00 inches.

Lightning in POLK, IOWA
From 01-JUN-10 18:23:00 to 01-JUN-10 18:23:00 (CST-6)
Location: CAPITOL HGTS
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Lightning struck a residence and started the house on fire.

Lightning in POLK, IOWA
From 01-JUN-10 20:36:00 to 01-JUN-10 20:36:00 (CST-6)
Location: ANKENY
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Lightning struck a residence and started the house on fire.

Hail in TAYLOR, IOWA
From 01-JUN-10 19:35:00 to 01-JUN-10 19:35:00 (CST-6)
Location: GRAVITY
Magnitude: 0.88 
Property damage: 1.00K
Crop damage: 5.00K
Reported by: Emergency Manager

Thunderstorm Wind in MONROE, IOWA
From 01-JUN-10 18:06:00 to 01-JUN-10 18:06:00 (CST-6)
Location: AVERY
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Estimated wind gust, heavy rain as well.

Thunderstorm Wind in WAPELLO, IOWA
From 01-JUN-10 18:21:00 to 01-JUN-10 18:21:00 (CST-6)
Location: (OTM)OTTUMWA INDSTRL
Magnitude: 53.00 MG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Thunderstorm Wind in ADAMS, IOWA
From 01-JUN-10 19:00:00 to 01-JUN-10 19:00:00 (CST-6)
Location: PRESCOTT
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter estimated wind gusts to 70 MPH with tree and power line damage.

Thunderstorm Wind in TAYLOR, IOWA
From 01-JUN-10 19:35:00 to 01-JUN-10 19:35:00 (CST-6)
Location: BEDFORD
Magnitude: 52.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm Wind in TAYLOR, IOWA
From 01-JUN-10 19:35:00 to 01-JUN-10 19:35:00 (CST-6)
Location: GRAVITY
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High winds downed several power lines in Gravity.

Thunderstorm Wind in TAYLOR, IOWA
From 01-JUN-10 19:41:00 to 01-JUN-10 19:41:00 (CST-6)
Location: CONWAY
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High winds blew a roof off of a shed.

Thunderstorm Wind in DECATUR, IOWA
From 01-JUN-10 20:25:00 to 01-JUN-10 20:25:00 (CST-6)
Location: LAMONI
Magnitude: 65.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported damage by estimated 75 MPH winds.

Thunderstorm Wind in LUCAS, IOWA
From 01-JUN-10 20:30:00 to 01-JUN-10 20:30:00 (CST-6)
Location: RUSSELL
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Power lines were reported down across the road and a car blown into the ditch on U.S. Highway 34.

Thunderstorm Wind in MAHASKA, IOWA
From 01-JUN-10 20:55:00 to 01-JUN-10 20:55:00 (CST-6)
Location: OSKALOOSA
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winds gusting to near 60 MPH were reported near Highway 92 at the intersection of U.S. Highway 63.

Hail in ADAMS, IOWA
From 01-JUN-10 15:36:00 to 01-JUN-10 15:36:00 (CST-6)
Location: CORNING
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue