For the second time this week, drenching rains spread across San Diego County during the overnight hours. And it will happen again late this evening and early Thursday, says the National Weather Service. So far, the rainfall has been impressive, in a cumulative sense. Since early Monday, parts of San Diego have received more than two inches of rain, including Palomar Observatory, which got 2.87 inches, Henshaw Dam, which got 2.25 inches, and Julian, which got 2.16 inches. San Onofre received 1.63 inches.