For your protection move to an interior room on the lowest floor of a building. — A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM MDT FOR WESTERN HAAKON AND SOUTHERN ZIEBACH COUNTIES... At 1159 PM MDT, a severe thunderstorm was located 4 miles north of Grindstone Butte, or 16 miles north of Philip, moving northeast at 25 mph. HAZARD...60 mph wind gusts and quarter size hail. SOURCE...Radar indicated. IMPACT...Hail damage to vehicles is expected. Expect wind damage to roofs, siding, and trees. Locations impacted include... Cherry Creek, Milesville, Bridger, Billsburg, Takini and Grindstone Butte. HAIL...1.00IN WIND...60MPH.