Thunderstorms will taper off for weekend

A spate of thunderstorms that sparked two dozen fires over the past two days in Tuolumne and Calaveras counties appeared to be winding down Thursday.

The unusual weather for the first week of September came from a combination of remnants of Tropical Storm John which formed Monday off the Baja California coast and moisture coming in from the California coast, according to Holly Osborne, a Sacramento-based meteorologist with the National Weather Service.

“We should be seeing it wrap up by (Thursday) evening and a high-pressure system building again Friday and Saturday,” Osborne said.

High-pressure systems tend to bring in drier air. A special weather statement issued Thursday morning by the NWS said isolated thunderstorms would continue throughout the day in much of Central California, but no significant rainfall was expected. The forecast for the weekend calls for sunny skies and temperatures in the low to mid-90s.

As much as one-tenth of an inch of rainfall was reported Wednesday in Columbia. Showers apparently missed Groveland and Phoenix Lake, where no precipitation was reported. Sonora recorded 0.04 inches Wednesday and trace amounts were reported in Angels Camp.

Lightning strikes caused 24 fires in Tuolumne and Calaveras counties, all of which had been extinguished as of Thursday morning, said Lisa Williams, a spokeswoman for the Tuolumne-Calaveras Unit of Cal Fire in San Andreas.

The largest blaze, the Salt Fire north of Copperopolis, consumed 84 acres but caused no injuries nor threatened any structures. About 50 personnel from Cal Fire, Copperopolis Fire Protection District and California Department of Corrections and Rehabilitation crews worked to put out the fire.

The remainder were very small fires, Williams said, but crews remained active throughout the unit Thursday.

“They are still monitoring places where fires might pop up as the temperature goes back up and it dries out,” Williams said.

While the last gasps of the tropical storm, which formed about 300 miles off the southern tip of the Baja coast, sparked fires in the Mother Lode, its rains arrived as a welcome guest to firefighters battling a fire of more than 4,000 acres in the Angeles National Forest of Southern California. Containment of that fire nearly doubled to 48 percent aided by cooler temperatures and rain Wednesday resulting from the storm.