At 142 PM MDT, strong thunderstorms were clustered over East Helena,
or near Helena, extending south to near Clancy and extending east to
near Winston and just north of Townsend. Movement of these storms is
east at 25 mph.
Winds in excess of 40 mph and penny size hail are possible with this
Locations impacted include…
Helena, Townsend, Boulder, East Helena, Montana City, Wickes, York,
Alhambra, Corbin, Spring Meadow Lake State Park, Elkhorn State Park,
Winston, Silos, Clancy, Black Sandy State Park, Jefferson City and
This includes the following highways…
Interstate 15 between mile markers 165 and 203.
Highway 12 between mile markers 1 and 17, and between mile markers
40 and 83.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
If you are on or near Canyon Ferry Lake, get out of the water and
move indoors or inside a vehicle. Remember, lightning can strike out
to 10 miles from the parent thunderstorm. If you can hear thunder,
you are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.
Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.