“This afternoon is when the first round of violent thunderstorms will ignite”

Strong thunderstorms capable of unleashing damaging winds and hail will not just threaten the eastern-third of the United States this weekend, but also some major Western cities.

This afternoon is when the first round of violent thunderstorms will ignite across the West with the interior Northwest the target.

Cities that lie in the threat zone include Spokane and Walla Walla, Wash.; Pendleton and Burns, Ore.; and Boise, Idaho.

Damaging winds and hail are the main concerns with the thunderstorms. Any tornado that touches down would be an isolated incident.

As the severe weather danger diminishes across the Northwest’s interior tonight, potent thunderstorms will shift to the northern and central California coastline. This includes Crescent City, Santa Rosa and San Francisco.

These thunderstorms will expand to Red Bluff, Sacramento and other communities across the Sacramento and northern San Joaquin valleys on Sunday.

A pocket of extremely cold air above the surface will not just lead to snow in the Cascades and Sierra on Sunday, but will also set the stage for hail to fall out of the thunderstorms across northern and central California.

Exceptionally large hail that is more common across the Plains is not expected across California tonight into Sunday. Still, hailstones capable of putting small dents in vehicles will be produced.

It is not out of the question that a tornado briefly touches down across northern and central California on Sunday.

Residents and visitors all across the West should seek shelter this weekend even if storm-related warnings are not issued. Any thunderstorm is capable of sparking potentially deadly lightning regardless of its intensity.

The storm system igniting the stronger thunderstorms each day this weekend has also raised concerns for flooding across the Northwest as reported by AccuWeather.com Expert Senior Meteorologist Alex Sosnowski.