Bracing for the sizzle, Southern Californians are about to experience temperatures well above the seasonal norm, the National Weather Service in San Diego warns. Residents in the Inland Empire should prepare to face highs nearing the 100°F mark, while those in low deserts can expect the mercury to exceed 100°F by week’s end. But, as the NWS forecast office indicates, this heat spell is just an overture to the weekend’s main event, a tropical moisture infusion to bring showers across the region.
According to NWS San Diego, the most likely onset of showers is late Saturday, continuing through late Sunday, with the SD County mountains especially poised to get wet. The weekend wetness comes from a weak upper-level low-pressure system off the Baja coast that is predicted “to draw some tropical moisture northward into the area,” the NWS forecast discussion states. This system will likely give rise to a slight chance of thunderstorms, particularly Sunday afternoon and evening.
The inland valleys and Inland Orange County, having basked in greater warmth Friday, will subsequently see a cooling trend that “will begin on Saturday and continue through Tuesday,” according to the Area Forecast Discussion by the NWS. This cooldown has a silver lining: Lower temperatures will be maintained by a cloud cover expected to linger into the night, offering some reprieve from the preceding heat…