With summer around the corner, Sunday was expected to be the last day of spring weather for a while, as San Diego County transitions to more of a summer pattern, the National Weather Service said.
Skies were generally clear Sunday morning, except for patchy marine clouds just offshore, forecasters said. High temperatures along the coast were predicted to be 69 to 74 degrees with overnight lows of 55 to 60.
Highs in the western valleys were expected to be around 77, and 75-83 near the foothills with overnight lows in the 50s. Highs in the mountains were expected to be 75 to 83 with overnight lows of 48 to 57, and highs in the deserts were predicted to be 96 to 101 with overnight lows of 66 to 74.
Fire weather conditions were expected to remain elevated Sunday over the mountains and deserts, especially below the passes where westerly winds could be gusty at times, but not as strong as Saturday. Minimum relative humidity values of 10 to 20% were likely by afternoon over the mountains and adjacent deserts, according to the NWS. Winds may turn offshore after midnight and could be gusty below the major passes.
For the remainder of the week, the NWS predicts near or above average temperatures, fewer coastal low clouds, more high clouds, and perhaps even some monsoonal thunder at times. The best chance for any measurable rain was expected to be over the mountains and deserts.
The atmosphere may begin to destabilize on Tuesday — the first day of summer — as moisture arrives.
By Wednesday, moisture was expected to increase dramatically, the NWS said. Depending on the amount of cloud cover, wind and instability, the county could see some showers, and even some thunderstorms.
Some drying was possible after Wednesday, but additional high-level moisture may continue over the region, continuing some chance of thunder over the mountains and deserts into the weekend.
Breezy northwest winds gusting at up to 25 knots were expected in coastal waters Sunday afternoon and evening. The strongest winds were expected in the outer coastal waters, especially near San Clemente Island. Otherwise, no hazardous marine weather was expected through Thursday.
–City News Service