A strong low pressure system moved across Kansas and into eastern Nebraska during the afternoon and evening of the 8th.  A warm front extended east from the low and lifted north to the southern Nebraska border into central Missouri by evening.  At the same time, a strong dry line moved across Kansas south of the low.  To the south of the warm front, temperatures were in the 80s with dew point readings in the upper 60s to mid 70s.  North of the front, temperatures were in the 50s.  Strong low level winds of 40 to 50 kts were impinging on the warm front.  Strong thunderstorms erupted north of the warm front by late afternoon.  With Iowa being well north of the warm front during the event, severe weather was limited to hail.  Most of the severe weather occurred with a cluster of thunderstorms that developed well ahead of the main synoptic squall line.  The cells raced northeast across the state at 55 to 65 MPH.  Many of the storms that developed in Iowa produced pea to marble size hail.  The stronger storms produced nickel to golf ball size hail.  The largest hail occurred early in the development of the thunderstorms.  Baseball size hail pelted portions of Wayne and Appanoose Counties.  Windows were broken out by the baseball size hail north of Promise City in Wayne County.  As the storms moved into Mahaska County, very large hail fell north of Oskaloosa with a report of softball size hail there.  The storms weakened quite rapidly after sunset as a strong push of dry air aloft moved into the area.

Hail in BREMER, IOWA
From 08-MAY-03 19:49:00 to 08-MAY-03 19:49:00 (CST)
Location: TRIPOLI
Magnitude: 1.00 
Property damage: 5K
Reported by: TRAINED SPOTTER

Hail in BREMER, IOWA
From 08-MAY-03 19:35:00 to 08-MAY-03 19:35:00 (CST)
Location: DENVER
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in MARION, IOWA
From 08-MAY-03 18:00:00 to 08-MAY-03 18:00:00 (CST)
Location: BUSSEY
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in TAMA, IOWA
From 08-MAY-03 18:57:00 to 08-MAY-03 18:58:00 (CST)
Location: TAMA
Magnitude: 1.00 
Property damage: 10K
Reported by: TRAINED SPOTTER

Hail in WAYNE, IOWA
From 08-MAY-03 18:05:00 to 08-MAY-03 18:05:00 (CST)
Location: PROMISE CITY
Magnitude: 2.75 
Property damage: 50K
Reported by: LAW ENFORCEMENT

Hail in BLACK HAWK, IOWA
From 08-MAY-03 19:33:00 to 08-MAY-03 19:33:00 (CST)
Location: WATERLOO
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in TAMA, IOWA
From 08-MAY-03 19:19:00 to 08-MAY-03 19:19:00 (CST)
Location: TRAER
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in BLACK HAWK, IOWA
From 08-MAY-03 19:35:00 to 08-MAY-03 19:35:00 (CST)
Location: WATERLOO
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in BLACK HAWK, IOWA
From 08-MAY-03 19:32:00 to 08-MAY-03 19:32:00 (CST)
Location: WATERLOO
Magnitude: 1.00 
Property damage: 10K
Reported by: TRAINED SPOTTER

Hail in MONROE, IOWA
From 08-MAY-03 18:00:00 to 08-MAY-03 18:00:00 (CST)
Location: MELROSE
Magnitude: 1.75 
Property damage: 10K
Reported by: LAW ENFORCEMENT

Hail in BREMER, IOWA
From 08-MAY-03 19:45:00 to 08-MAY-03 19:45:00 (CST)
Location: DENVER
Magnitude: 1.75 
Property damage: 10K
Reported by: TRAINED SPOTTER

Hail in APPANOOSE, IOWA
From 08-MAY-03 18:05:00 to 08-MAY-03 18:05:00 (CST)
Location: CENTERVILLE
Magnitude: 2.75 
Property damage: 100K
Reported by: BROADCAST MEDIA

Hail in APPANOOSE, IOWA
From 08-MAY-03 18:06:00 to 08-MAY-03 18:06:00 (CST)
Location: PLANO
Magnitude: 1.75 
Property damage: 25K
Reported by: UNKNOWN

Hail in MONROE, IOWA
From 08-MAY-03 18:20:00 to 08-MAY-03 18:20:00 (CST)
Location: LOVILIA
Magnitude: 1.75 
Property damage: 10K
Reported by: LAW ENFORCEMENT

Hail in BLACK HAWK, IOWA
From 08-MAY-03 19:35:00 to 08-MAY-03 19:35:00 (CST)
Location: WATERLOO
Magnitude: 1.75 
Property damage: 25K
Reported by: BROADCAST MEDIA

Hail in WAYNE, IOWA
From 08-MAY-03 18:07:00 to 08-MAY-03 18:07:00 (CST)
Location: PROMISE CITY
Magnitude: 1.75 
Property damage: 25K
Reported by: UNKNOWN

Hail in MAHASKA, IOWA
From 08-MAY-03 18:15:00 to 08-MAY-03 18:15:00 (CST)
Location: OSKALOOSA
Magnitude: 1.75 
Property damage: 20K
Reported by: TRAINED SPOTTER

Hail in BLACK HAWK, IOWA
From 08-MAY-03 19:37:00 to 08-MAY-03 19:37:00 (CST)
Location: DUNKERTON
Magnitude: 0.75 
Reported by: EMERGENCY MANAGER

Hail in BUTLER, IOWA
From 08-MAY-03 19:50:00 to 08-MAY-03 19:50:00 (CST)
Location: GREENE
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Hail in MAHASKA, IOWA
From 08-MAY-03 18:22:00 to 08-MAY-03 18:22:00 (CST)
Location: OSKALOOSA
Magnitude: 1.00 
Property damage: 10K
Reported by: EMERGENCY MANAGER

Hail in POLK, IOWA
From 08-MAY-03 18:47:00 to 08-MAY-03 18:47:00 (CST)
Location: WEST DES MOINES
Magnitude: 1.00 
Property damage: 5K
Reported by: TRAINED SPOTTER

Hail in TAMA, IOWA
From 08-MAY-03 19:04:00 to 08-MAY-03 19:04:00 (CST)
Location: TOLEDO
Magnitude: 1.00 
Property damage: 10K
Reported by: LAW ENFORCEMENT

Hail in MAHASKA, IOWA
From 08-MAY-03 18:26:00 to 08-MAY-03 18:26:00 (CST)
Location: NEW SHARON
Magnitude: 1.00 
Property damage: 5K
Reported by: EMERGENCY MANAGER

Hail in MAHASKA, IOWA
From 08-MAY-03 18:24:00 to 08-MAY-03 18:24:00 (CST)
Location: OSKALOOSA
Magnitude: 4.75 
Property damage: 50K
Reported by: EMERGENCY MANAGER

Hail in BLACK HAWK, IOWA
From 08-MAY-03 19:35:00 to 08-MAY-03 19:35:00 (CST)
Location: WATERLOO
Magnitude: 1.00 
Property damage: 5K
Reported by: TRAINED SPOTTER