A cold front dropped southeast across the state during the day on the 1st into the evening hours.  By midnight...the front extended east-northeast to west-southwest across southern Iowa.  The soundings indicated a considerable amount of dry air in the low levels, thus preventing the formation of tornadoes.  The LCL was in the 5500 to 6000 foot range during the event.  High temperatures warmed into the upper 80s over far northwest Iowa, to the 95 to 100 degree range over the south.  Dew points were generally in the upper 50s to mid 60s except along the frontal boundary.  Moisture pooled along the boundary with dew points rising into the low 70s.  The atmosphere became quiet unstable with lifted indices around -9 C. and CAPE values in the 3500 to 4500 J/kg range.  There was some shear available, but it wasn't all that strong.  Generally shear in the zero to 3 km layer was in the 25 to 30 kt range.  The freezing level was quite high, being in the 14,500 to 15,000 foot range.  Thunderstorms fired initially just to the north of the boundary in northwest and north central Iowa, along the north edge of the mid level cap.  The storm development was enhanced as a jet speed max raced across southern North Dakota into Wisconsin during the late afternoon, putting Iowa in the 3rd quadrant, or right entrance region, of the jet.  These storms produced three quarter to one inch diameter hail in a few areas.  The largest hail occurred in the Clear Lake area and was the size of half dollars.  Gusty winds were also reported, however most were in the 35 to 50 MPH range.  One wind gust to around 60 MPH downed tree limbs in Humboldt County at Bradgate.  As the evening progressed, an outflow boundary from the convection in the north pushed south into central Iowa.  Scattered thunderstorms developed along the boundary, but most were not severe.  One storm produced a 62 MPH wind gust as it passed over Grimes in Polk County.  The storm had formed along the outflow boundary, but weakened quickly as the outflow boundary undercut the storm.  Thunderstorms continued to fire during the night to the north of the actual frontal boundary.  These were quite elevated.  One of the storms became severe briefly and dropped one inch diameter hail southeast of Boxholm in Boone County.

Hail in CERRO GORDO, IOWA
From 01-JUL-06 16:30:00 to 01-JUL-06 16:30:00 (CST)
Location: CLEAR LAKE
Magnitude: 1.00 
Property damage: 5K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in CERRO GORDO, IOWA
From 01-JUL-06 16:58:00 to 01-JUL-06 16:58:00 (CST)
Location: MASON CITY
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in POLK, IOWA
From 01-JUL-06 18:48:00 to 01-JUL-06 18:48:00 (CST)
Location: GRIMES
Magnitude: 54 MG
Property damage: 1K
Reported by: AWOS,ASOS,MESONET,ETC

Hail in BOONE, IOWA
From 01-JUL-06 22:34:00 to 01-JUL-06 22:34:00 (CST)
Location: BOXHOLM
Magnitude: 1.00 
Property damage: 2K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Hail in HANCOCK, IOWA
From 01-JUL-06 16:05:00 to 01-JUL-06 16:05:00 (CST)
Location: BRITT
Magnitude: 0.75 
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in CERRO GORDO, IOWA
From 01-JUL-06 16:28:00 to 01-JUL-06 16:28:00 (CST)
Location: CLEAR LAKE
Magnitude: 1.25 
Property damage: 10K
Crop damage: 5K
Reported by: AMATEUR RADIO

Hail in POCAHONTAS, IOWA
From 01-JUL-06 15:25:00 to 01-JUL-06 15:25:00 (CST)
Location: PLOVER
Magnitude: 0.75 
Crop damage: 5K
Reported by: GENERAL PUBLIC

Hail in KOSSUTH, IOWA
From 01-JUL-06 16:15:00 to 01-JUL-06 16:15:00 (CST)
Location: WESLEY
Magnitude: 0.88 
Property damage: 2K
Crop damage: 5K
Reported by: BROADCAST MEDIA

Hail in HANCOCK, IOWA
From 01-JUL-06 16:23:00 to 01-JUL-06 16:23:00 (CST)
Location: BRITT
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in CERRO GORDO, IOWA
From 01-JUL-06 16:25:00 to 01-JUL-06 16:25:00 (CST)
Location: VENTURA
Magnitude: 1.00 
Property damage: 3K
Crop damage: 5K
Reported by: GENERAL PUBLIC

Hail in KOSSUTH, IOWA
From 01-JUL-06 15:44:00 to 01-JUL-06 15:44:00 (CST)
Location: ALGONA
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in HUMBOLDT, IOWA
From 01-JUL-06 15:45:00 to 01-JUL-06 15:45:00 (CST)
Location: BRADGATE
Magnitude: 52 EG
Property damage: 2K
Reported by: TRAINED SPOTTER