The National Weather Service in Des Moines has issued a * Severe Thunderstorm Warning for... Northeastern Marion County in south central Iowa... Northwestern Mahaska County in south central Iowa... Southern Jasper County in central Iowa... * Until 515 PM CDT. * At 430 PM CDT, a severe thunderstorm was located over Prairie City, or 10 miles southwest of Newton, moving southeast at 35 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... Newton, Pella, Colfax, Monroe, Prairie City, Lake Red Rock, Iowa Speedway, Sully, Lynnville, Harvey, Lambs Grove, Reasnor, Pella Municipal Airport, Prairie City Krohn Airport, Elk Rock State Park and Newton Municipal Airport. This includes Interstate 80 between mile markers 155 and 175. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building.