A weak trough of low pressure was over southern Iowa as a reinforcing cold front dropped southeast into the state.  The airmass was moderately unstable with dew point readings in the 60s.  Surface low tracked east across central Missouri during the mid part of the day.  Thunderstorms erupted across southern Iowa.  They formed into a line and became severe.  The main severe weather mode was hail.  There were numerous reports of three quarter inch to one and one quarter inch diameter hail over far southern Iowa.  Golf ball size hail pelted parts of Decatur County.  The combination of one inch diameter hail and 50 MPH winds caused considerable crop damage in Taylor County.  A swath 8 miles long and 3 miles wide was destroyed in an area extending from the hamlet of Siam, ease-southeast to the county border south of Bedford.  Heavy rainfall at the rage of of one to two inches per hour resulted in flash flooding in Ringgold County with water running over roads north of Mount Ayr.

Hail in DECATUR, IOWA
From 27-MAY-04 10:47:00 to 27-MAY-04 10:47:00 (CST)
Location: LEON
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in RINGGOLD, IOWA
From 27-MAY-04 10:52:00 to 27-MAY-04 10:52:00 (CST)
Location: DIAGONAL
Magnitude: 0.75 
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in TAYLOR, IOWA
From 27-MAY-04 12:22:00 to 27-MAY-04 12:22:00 (CST)
Location: BEDFORD
Magnitude: 1.00 
Property damage: 2K
Crop damage: 150K
Reported by: TRAINED SPOTTER

Hail in DECATUR, IOWA
From 27-MAY-04 10:45:00 to 27-MAY-04 10:45:00 (CST)
Location: LEON
Magnitude: 0.75 
Crop damage: 5K
Reported by: EMERGENCY MANAGER

Flash Flood in RINGGOLD, IOWA
From 27-MAY-04 11:45:00 to 27-MAY-04 13:15:00 (CST)
Location: MT AYR
Property damage: 20K
Crop damage: 5K
Reported by: LAW ENFORCEMENT

Hail in TAYLOR, IOWA
From 27-MAY-04 12:06:00 to 27-MAY-04 12:06:00 (CST)
Location: NEW MARKET
Magnitude: 1.00 
Property damage: 2K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in TAYLOR, IOWA
From 27-MAY-04 12:17:00 to 27-MAY-04 12:17:00 (CST)
Location: BEDFORD ARPT
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in TAYLOR, IOWA
From 27-MAY-04 10:12:00 to 27-MAY-04 10:12:00 (CST)
Location: NEW MARKET
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: EMERGENCY MANAGER

Hail in TAYLOR, IOWA
From 27-MAY-04 10:35:00 to 27-MAY-04 10:35:00 (CST)
Location: LENOX
Magnitude: 1.00 
Property damage: 2K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in TAYLOR, IOWA
From 27-MAY-04 12:18:00 to 27-MAY-04 12:18:00 (CST)
Location: BEDFORD
Magnitude: 61 EG
Property damage: 5K
Reported by: TRAINED SPOTTER

Hail in DECATUR, IOWA
From 27-MAY-04 10:36:00 to 27-MAY-04 10:36:00 (CST)
Location: DECATUR CITY
Magnitude: 0.75 
Crop damage: 15K
Reported by: GENERAL PUBLIC

Hail in WAYNE, IOWA
From 27-MAY-04 12:15:00 to 27-MAY-04 12:15:00 (CST)
Location: PROMISE CITY
Magnitude: 0.75 
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in DECATUR, IOWA
From 27-MAY-04 10:40:00 to 27-MAY-04 10:40:00 (CST)
Location: LEON
Magnitude: 1.25 
Property damage: 5K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in DECATUR, IOWA
From 27-MAY-04 10:40:00 to 27-MAY-04 10:40:00 (CST)
Location: LEON
Magnitude: 1.00 
Property damage: 2K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in TAYLOR, IOWA
From 27-MAY-04 12:08:00 to 27-MAY-04 12:08:00 (CST)
Location: BEDFORD ARPT
Magnitude: 52 EG
Property damage: 1K
Reported by: TRAINED SPOTTER

Hail in DECATUR, IOWA
From 27-MAY-04 11:45:00 to 27-MAY-04 11:45:00 (CST)
Location: LEON
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in DECATUR, IOWA
From 27-MAY-04 10:52:00 to 27-MAY-04 10:52:00 (CST)
Location: DECATUR CITY
Magnitude: 1.75 
Property damage: 10K
Crop damage: 5K
Reported by: TRAINED SPOTTER

Hail in WAYNE, IOWA
From 27-MAY-04 11:26:00 to 27-MAY-04 11:26:00 (CST)
Location: ALLERTON
Magnitude: 0.88 
Property damage: 1K
Crop damage: 5K
Reported by: POST OFFICE