A new severe thunderstorm warning was issued Thursday night for northwestern Caribou County, north central Bannock County, northeastern Power County and south central Bingham County until 11:15 p.m., according to the National Weather Service.
As of 10:37 p.m., a storm capable of producing quarter-size hail was located near Portneuf Gap, about 8 miles south of Pocatello, moving northeast at 30 mph. The storm's path includes Pocatello, Chesterfield Reservoir, American Falls Reservoir, Chubbuck, Inkom, Fort Hall Buffalo Lodge, Portneuf Gap, Fort Hall Townsite, Fort Hall Mount Putnam, Fort Hall Bannock Creek Lodge, the Pocatello Airport, Fort Hall Putnam Lodge and Mink Creek Pass.
The weather service said large hail, damaging wind and continuous cloud-to-ground lightning are occurring with the storm, and urged residents to move indoors immediately. Torrential rainfall accompanying the storm could lead to flash flooding, and drivers were warned not to attempt to cross flooded roadways.
The storm is the latest in a line of severe thunderstorms to sweep across East Idaho Thursday night, prompting flash flood and severe thunderstorm warnings in several local cities and counties, with hail large enough to damage vehicles reported in much of the region.
The National Weather Service issued a flash flood warning for north central Bonneville County and south central Jefferson County until 2 a.m. Friday. As of 10 p.m. Thursday, radar indicated thunderstorms producing heavy rain across the area, with flash flooding ongoing or expected to begin shortly. The warning covers the Idaho Falls, Ammon, Rigby, Lorenzo, Ucon, Menan and Lewisville areas.
The weather service warned of flooding to small creeks and streams, urban areas, highways, streets, underpasses and other low-lying, poorly drained areas.
A separate flash flood warning was issued for central Madison County, including Rexburg, until 2:45 a.m. Friday, after radar indicated heavy rain producing ongoing or imminent flash flooding as of 9:51 p.m. Thursday.
The National Weather Service also issued two additional severe thunderstorm warnings Thursday night.
The first covered south central Jefferson County, northwestern Bonneville County and central Bingham County until 11 p.m. Thursday.
As of 10:11 p.m., a storm capable of producing half-dollar-size hail was located near Rose, about 9 miles north of Blackfoot, moving northeast at 20 mph. That storm's path included the Idaho Falls, Ammon, Shelley, Iona, Firth, Rose, Basalt, Osgood and Wapello areas.
A second severe thunderstorm warning covered northwestern Oneida County, central Bannock County, southeastern Power County and southwestern Bingham County until 10:45 p.m. Thursday. As of 10:04 p.m., a storm also producing half-dollar-size hail was located near Fort Hall Bannock Peak, about 16 miles southeast of Neeley, moving northeast at 25 mph, threatening American Falls, American Falls Reservoir, Rockland, Fort Hall Bannock Peak, Pauline and Mink Creek Pass.
The National Weather Service said hail from the storms is expected to damage vehicles, and urged local residents in the storms' paths to move to an interior room on the lowest floor of a building for protection.
Anyone encountering flooded roadways was warned to turn around rather than attempt to drive through.
Most flood deaths occur in vehicles, according to the weather service.