A very dynamic weather situation took place over Iowa during the afternoon of the 1st.  The dynamics were sufficient to overcome the shortcomings in moisture available for the system.  A cold front dropped southeast out of the Dakotas into Iowa during the afternoon.  Surface dew points were generally in the mid 50s ahead of the front, though a narrow ribbon of upper 50s to lower 60s was found just ahead of the front.  As the cold front dropped southeast, a very strong closed low at 500 mb was also dropping into the area.  This helped to destabilize the atmosphere as freezing levels fell to the 8000 to 10,000 foot range by evening.  A small area of thunderstorms developed by mid day over north central Iowa.  The storms intensified rapidly during the maximum heating of the day.  Thunderstorms fired southwest of the original area and became severe quickly.  For the most part the storms produced hail and small tornadoes.  The first tornado touched in Crawford County.  The county Emergency Manager reported seeing 7 funnel clouds and two brief touchdowns with the initial cell.  The tornadoes were all small and were only on the ground briefly.  Several other brief touchdowns occurred in the County before the storm moved east.  The strongest tornado touched down on the edge of the town of Denison.  A 14 x 50 metal building was destroyed.  A fire hydrant was damaged in the vicinity by flying debris.  It was reported that water could be seen being sucked out of the hydrant by the tornado.  The tornado threat shifted into northeast Iowa for the rest of the afternoon.  Several tornadoes touched down in Bremer, Butler, and Black Hawk Counties.  Most of these were quite small and did little damage however.  The longest track tornado touched down in the Janesville area of Bremer County and tracked over 8 miles to the east, lifting just east of the town of Denver.  The countryside is quite open between these two locations.  For this reason, damage was minimal as the tornado actually missed both of the towns.  With the cold air aloft, hail was a significant factor.  There were reports of at least half inch diameter hail with nearly all of the storms.  Numerous reports of hail of an inch up to golf ball size were received.  The storms produced three inch diameter hail on the north side of Belmond, causing significant damage to the area and reportedly covering the ground.  One of the storms became very intense over Butler County during the early afternoon.  Softball size hail was reported with this cell, causing significant damage south of the town of Allison.  The storms over southwest Iowa underwent a transition into more of a wind event.  High winds were reported in Cass County as the storms moved through the Griswold area.  By mid afternoon, the storms in southern Iowa had taken on a bow configuration.  As the storms moved through Adair County, very strong winds swept through the northeast part of the county.   The winds toppled power lines northeast of Greenfield.  As the storms continued east, the intensity decreased.  The storms still produced gusty winds, but speeds were generally in the 45 to 55 MPH range.

Hail in HARDIN, IOWA
From 01-JUN-01 14:57:00 to 01-JUN-01 14:57:00 (CST)
Location: ACKLEY
Magnitude: 1.00 
Property damage: 5K
Crop damage: 3K
Reported by: TRAINED SPOTTER

Tornado in BREMER, IOWA
From 01-JUN-01 15:12:00 to 01-JUN-01 15:25:00 (CST)
Location: JANESVILLE
Tornado F-scale: F1
Property damage: 30K
Crop damage: 3K
Reported by: EMERGENCY MANAGER

Tornado swept through open countryside across Southern Bremer County.  Damage was limited to mainly outbuildings and crops.

Tornado in BUTLER, IOWA
From 01-JUN-01 15:13:00 to 01-JUN-01 15:13:00 (CST)
Location: SINCLAIR
Tornado F-scale: F0
Reported by: EMERGENCY MANAGER

Brief touchdown in open country.

Hail in BUTLER, IOWA
From 01-JUN-01 15:17:00 to 01-JUN-01 15:17:00 (CST)
Location: NEW HARTFORD
Magnitude: 0.75 
Crop damage: 3K
Reported by: UNKNOWN

Hail in BREMER, IOWA
From 01-JUN-01 15:24:00 to 01-JUN-01 15:24:00 (CST)
Location: JANESVILLE
Magnitude: 1.75 
Property damage: 5K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Tornado in BLACK HAWK, IOWA
From 01-JUN-01 15:25:00 to 01-JUN-01 15:25:00 (CST)
Location: FINCHFORD
Tornado F-scale: F0
Reported by: LAW ENFORCEMENT

Brief touchdown in open country east of town.

Hail in BREMER, IOWA
From 01-JUN-01 15:28:00 to 01-JUN-01 15:28:00 (CST)
Location: JANESVILLE
Magnitude: 1.75 
Property damage: 10K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Tornado in BLACK HAWK, IOWA
From 01-JUN-01 15:30:00 to 01-JUN-01 15:30:00 (CST)
Location: DUNKERTON
Tornado F-scale: F0
Reported by: LAW ENFORCEMENT

Brief touchdown in open area east of town.

Tornado in BLACK HAWK, IOWA
From 01-JUN-01 15:30:00 to 01-JUN-01 15:30:00 (CST)
Location: CEDAR FALLS
Tornado F-scale: F0
Property damage: 3K
Reported by: EMERGENCY MANAGER

Brief touchdown on the edge of town.

Tornado in BLACK HAWK, IOWA
From 01-JUN-01 15:52:00 to 01-JUN-01 15:54:00 (CST)
Location: GILBERTVILLE
Tornado F-scale: F0
Property damage: 5K
Reported by: FIRE DEPT/RESCUE SQUAD

Weak tornado moved into the area, but was only on the ground briefly.

Hail in HARDIN, IOWA
From 01-JUN-01 16:05:00 to 01-JUN-01 16:05:00 (CST)
Location: BUCKEYE
Magnitude: 0.75 
Crop damage: 3K
Reported by: TRAINED SPOTTER

Hail in HARDIN, IOWA
From 01-JUN-01 16:15:00 to 01-JUN-01 16:20:00 (CST)
Location: BUCKEYE
Magnitude: 0.75 
Crop damage: 10K
Reported by: OFFICIAL NWS OBS.

Hail in HARDIN, IOWA
From 01-JUN-01 16:18:00 to 01-JUN-01 16:18:00 (CST)
Location: ELDORA
Magnitude: 1.50 
Property damage: 10K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in WRIGHT, IOWA
From 01-JUN-01 12:35:00 to 01-JUN-01 12:35:00 (CST)
Location: BELMOND
Magnitude: 3.00 
Property damage: 150K
Crop damage: 10K
Reported by: NEWSPAPER

Tornado in CRAWFORD, IOWA
From 01-JUN-01 12:25:00 to 01-JUN-01 12:25:00 (CST)
Location: DENISON
Tornado F-scale: F0
Reported by: EMERGENCY MANAGER

Emergency manager reported spotting 7 funnel clouds from the parent cell with two brief touchdowns in open country.

Hail in CRAWFORD, IOWA
From 01-JUN-01 12:30:00 to 01-JUN-01 12:30:00 (CST)
Location: DENISON
Magnitude: 0.88 
Property damage: 2K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in FRANKLIN, IOWA
From 01-JUN-01 12:55:00 to 01-JUN-01 12:55:00 (CST)
Location: ALEXANDER
Magnitude: 1.00 
Property damage: 3K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Hail in FRANKLIN, IOWA
From 01-JUN-01 13:20:00 to 01-JUN-01 13:20:00 (CST)
Location: ALEXANDER
Magnitude: 1.00 
Property damage: 2K
Crop damage: 5K
Reported by: EMERGENCY MANAGER

Hail in FRANKLIN, IOWA
From 01-JUN-01 13:36:00 to 01-JUN-01 13:36:00 (CST)
Location: HANSELL
Magnitude: 1.00 
Property damage: 5K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in BUTLER, IOWA
From 01-JUN-01 13:45:00 to 01-JUN-01 13:45:00 (CST)
Location: DUMONT
Magnitude: 0.88 
Property damage: 2K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in BUTLER, IOWA
From 01-JUN-01 13:47:00 to 01-JUN-01 13:47:00 (CST)
Location: DUMONT
Magnitude: 0.75 
Crop damage: 2K
Reported by: TRAINED SPOTTER

Hail in CASS, IOWA
From 01-JUN-01 13:57:00 to 01-JUN-01 13:57:00 (CST)
Location: GRISWOLD
Magnitude: 1.00 
Property damage: 3K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in CASS, IOWA
From 01-JUN-01 13:57:00 to 01-JUN-01 13:57:00 (CST)
Location: GRISWOLD
Magnitude: 52 E
Property damage: 1K
Reported by: LAW ENFORCEMENT

Hail in BUTLER, IOWA
From 01-JUN-01 14:03:00 to 01-JUN-01 14:03:00 (CST)
Location: ALLISON
Magnitude: 4.50 
Property damage: 20K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in ADAIR, IOWA
From 01-JUN-01 14:06:00 to 01-JUN-01 14:06:00 (CST)
Location: GREENFIELD
Magnitude: 70 E
Property damage: 15K
Reported by: LAW ENFORCEMENT

Hail in BUTLER, IOWA
From 01-JUN-01 14:07:00 to 01-JUN-01 14:07:00 (CST)
Location: ALLISON
Magnitude: 0.88 
Property damage: 2K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in BUTLER, IOWA
From 01-JUN-01 14:15:00 to 01-JUN-01 14:15:00 (CST)
Location: SHELL ROCK
Magnitude: 1.75 
Property damage: 5K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in CERRO GORDO, IOWA
From 01-JUN-01 14:18:00 to 01-JUN-01 14:18:00 (CST)
Location: MASON CITY
Magnitude: 0.75 
Crop damage: 3K
Reported by: TRAINED SPOTTER

Tornado in CRAWFORD, IOWA
From 01-JUN-01 12:40:00 to 01-JUN-01 12:40:00 (CST)
Location: CHARTER OAK
Tornado F-scale: F0
Property damage: 25K
Reported by: EMERGENCY MANAGER

Brief touchdown near edge of town.

Hail in WRIGHT, IOWA
From 01-JUN-01 12:40:00 to 01-JUN-01 12:40:00 (CST)
Location: BELMOND
Magnitude: 1.00 
Property damage: 5K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Tornado in CRAWFORD, IOWA
From 01-JUN-01 12:50:00 to 01-JUN-01 12:50:00 (CST)
Location: MANILLA
Tornado F-scale: F0
Reported by: AMATEUR RADIO

Brief touchdown in open country.

Tornado in BLACK HAWK, IOWA
From 01-JUN-01 14:35:00 to 01-JUN-01 14:35:00 (CST)
Location: CEDAR FALLS
Tornado F-scale: F0
Reported by: TRAINED SPOTTER

Brief touchdown in open country.

Hail in HARDIN, IOWA
From 01-JUN-01 14:40:00 to 01-JUN-01 14:40:00 (CST)
Location: BUCKEYE
Magnitude: 1.75 
Property damage: 5K
Crop damage: 5K
Reported by: GENERAL PUBLIC

Hail in HARDIN, IOWA
From 01-JUN-01 14:46:00 to 01-JUN-01 14:46:00 (CST)
Location: IOWA FALLS
Magnitude: 1.75 
Property damage: 30K
Crop damage: 5K
Reported by: TRAINED SPOTTER