Southern California Weather Force has issued a Thunderstorm Watch effective now through the evening, effective for Big Bear, Wrightwood, The High Desert, Ridgecrest, Tehachapi, Riverside County Mountains (Not on the map), and Yucaipa to Cherry Valley.
A ridge similar to that of the monsoon will move into place today. Instability is expected to develop further by this afternoon and evening, with the upper-level lifting zone moving into the region as well. As this happens, rapid moisture influx will bring precipitation to the area. The onshore flow combined with the offshore component will have storms developing in the San Bernardino Mountains, with the northeast flow pushing them into the Yucaipa / Cherry Valley forecast area.
Unlike yesterday, storms will also affect the Kern County Mountains, including Tehachapi.
In addition to the lightning, some hail, at times large, and strong winds will accompany the storm.