Special Weather Statement issued July 30 at 6:22PM MDT by NWS Great Falls MT

Posted at 6:22 PM, Jul 30, 2019
and last updated 2019-07-30 20:22:00-04

At 618 PM MDT, a strong thunderstorm was located near Montana City,
or 10 miles southeast of Helena, moving east at 20 mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include…
Silos, Clancy, Winston and Alhambra and Canyon Ferry Lake.

This includes the following highways…
Interstate 15 between mile markers 179 and 186.
Highway 12 between mile markers 54 and 71.

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.