Lightning storms move across Northern California: See where strikes hit

Thousands of lightning strikes were recorded around Northern California on Wednesday as residual moisture from a tropical storm was swept into the region. The National Weather Service office in Sacramento released a map showing where the strikes hit. less Thousands of lightning strikes were recorded around Northern California on Wednesday as residual moisture from a tropical storm was swept into the region. The National Weather Service office in Sacramento ... more Photo: National Weather Service Photo: National Weather Service Image 1 of / 10 Caption Close Lightning storms move across Northern California: See where strikes hit 1 / 10 Back to Gallery

Thousands of lightning strikes were recorded around Northern California on Wednesday as residual moisture from a tropical storm swept into the region.

The National Weather Service office in Sacramento released a map showing where the strikes hit: You can see a high concentration in Lassen, Shasta and east Modoc counties. A stretch of strikes also lit up the sky in the foothills east of Chico, and scattered lightning was observed around Red Bluff.

"We had a trough of low pressure moving up and it grabbed that moisture that was left over from the tropical system, " says Craig Shoemaker, a meteorologist with the National Weather Service office in Sacramento. "It was enough to get the thunderstorms going."

Tropical Storm Ivo reached landfall in Baja California on Monday and remnants from the system have been moving north ever since.

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As fast-moving storm cells rolled across Northern California, light to moderate rain fell, mainly in Lassen County. One gauge near Susanville recorded a half-inch.

Several fires were started by the lightning, including the Red Fire near the McCloud River and the Green Fire near Lake Shasta. These have been put out or are contained.

One lightning-sparked fire 13 miles northeast of Susanville is still highly active and has grown to more than 1,000 acres. The Ranch Fire was zero percent contained as of 8:30 a.m. on Thursday and dry, breezy conditions could spread flames east and northeast toward Horse Lake Flat, according to the Bureau of Land Management.

Most of Northern California will be dry with below-normal temperatures on Thursday, but thunderstorms remain in the forecast north of Mount Shasta and along the California-Oregon border.

Amy Graff is a digital reporter for SFGATE. Email her at agraff@sfgate.com.