An upper level storm system approached eastern Colorado during the afternoon of the 4th. As the upper level storm system approached a surface low pressure center developed over southeast Colorado, with a warm front extending to the east over the Kansas and Oklahoma border, and a dry line extending south-southeast into western Oklahoma. The dry line retreated to near the Texas and Oklahoma border by late afternoon, and thunderstorms developed east of the dry line over the northeast Texas panhandle. Other thunderstorms developed and quickly became supercells in northwest Oklahoma. Very large hail and tornadoes - some damaging - were reported with these thunderstorms. Monetary values for the tornado damage were estimated.

Hail in ELLIS, OKLAHOMA
From 04-MAY-07 17:06:00 to 04-MAY-07 17:06:00 (CST-6)
Location: ARNETT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

One inch hail was reported.

Tornado in ELLIS, OKLAHOMA
From 04-MAY-07 17:45:00 to 04-MAY-07 17:45:00 (CST-6)
Location: ARNETT
Tornado F-scale: EF0
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The tornado remained over open country throughout its life span.  A few trees, power poles, and power lines were damaged. Monetary damages were estimated.

Hail in ELLIS, OKLAHOMA
From 04-MAY-07 18:12:00 to 04-MAY-07 18:12:00 (CST-6)
Location: FARGO
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in WOODWARD, OKLAHOMA
From 04-MAY-07 18:12:00 to 04-MAY-07 18:12:00 (CST-6)
Location: SHARON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in WOODWARD, OKLAHOMA
From 04-MAY-07 18:15:00 to 04-MAY-07 18:15:00 (CST-6)
Location: SHARON
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in WOODWARD, OKLAHOMA
From 04-MAY-07 18:15:00 to 04-MAY-07 18:15:00 (CST-6)
Location: SHARON
Magnitude: 3.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ELLIS, OKLAHOMA
From 04-MAY-07 16:55:00 to 04-MAY-07 16:55:00 (CST-6)
Location: SHATTUCK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ELLIS, OKLAHOMA
From 04-MAY-07 17:15:00 to 04-MAY-07 17:15:00 (CST-6)
Location: ARNETT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in WOODWARD, OKLAHOMA
From 04-MAY-07 18:30:00 to 04-MAY-07 18:30:00 (CST-6)
Location: SHARON
Magnitude: 3.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in HARPER, OKLAHOMA
From 04-MAY-07 18:37:00 to 04-MAY-07 18:37:00 (CST-6)
Location: BUFFALO
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in WOODWARD, OKLAHOMA
From 04-MAY-07 18:40:00 to 04-MAY-07 18:40:00 (CST-6)
Location: WOODWARD
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in ELLIS, OKLAHOMA
From 04-MAY-07 17:43:00 to 04-MAY-07 17:43:00 (CST-6)
Location: ARNETT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in ELLIS, OKLAHOMA
From 04-MAY-07 17:55:00 to 04-MAY-07 17:55:00 (CST-6)
Location: GAGE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HARPER, OKLAHOMA
From 04-MAY-07 18:04:00 to 04-MAY-07 18:04:00 (CST-6)
Location: LAVERNE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Tornado in ELLIS, OKLAHOMA
From 04-MAY-07 17:21:00 to 04-MAY-07 17:45:00 (CST-6)
Location: ARNETT
Tornado F-scale: EF1
Property damage: 110.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Windows were blown out of a house west of Arnett. Surrounding the house, a barn and several outbuildings were destroyed. Farm equipment at the home was also destroyed. Numerous tree limbs and power lines were downed. Monetary damages were estimated.

Hail in ELLIS, OKLAHOMA
From 04-MAY-07 18:02:00 to 04-MAY-07 18:02:00 (CST-6)
Location: HARMON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media