Fair and cooler weather was forecast for San Diego County on Sunday, while onshore winds are expected to strengthen through Tuesday, becoming strong and gusty over mountains and deserts as a storm moves in from the north, said the National Weather Service.
Light and scattered showers could develop as early as Monday, but will be more prevalent Tuesday through Wednesday, with snow at lower elevations in the mountains, the NWS said.
Clouds and fog hit coastal areas Sunday morning, with some areas reporting dense fog less than a quarter mile away. These clouds were expected to continue to dissipate throughout the morning providing another day of mostly sunny skies.
High temperatures along the coast on Sunday are forecast to be 63 to 68 degrees with overnight lows of 47 to 52. Valley highs will be 66 to 71, with overnight lows of 41 to 49. Peaks in the mountains should be 61-68 with overnight lows of 34-40, and highs in the deserts will be 78-83 with overnight lows of 47-55.
“Elevated confidence continues for gusty winds across the mountains, hence our new high wind watch announced Monday morning through late Tuesday evening for deserts and mountains in San Diego County,” said forecasters.
Peak gusts in wind-prone passes and foothills could reach 70mph at times and 60mph over deserts, with considerable blowing dust.
“The headliner of this series will arrive Tuesday night through Wednesday as a strong short wave bursts south along the California coast, bringing with it a dollop of cold Canadian air,” the NWS said. “Cold air aloft will further destabilize the atmosphere, leading to widespread showers and possible thunderstorms.”
The snow level is expected to fall to around 3,000 feet Wednesday morning, likely shrouding all of the mountains in winter storm conditions. Fog, blowing snow and slippery roads must have made travel dangerous, even in the lower passes.
Wednesday was expected to be the coldest day of the week as high temperatures were expected to be 15 to 20 degrees below normal. High temperatures are not expected to return to average until the end of the week.
No hazardous sea conditions were forecast until Monday evening. Strong west-northwesterly winds of 20 knots or more and rough seas are expected to develop late Monday evening. The winds were expected to strengthen on Tuesday and Wednesday with gusts of 25 to 30 knots. These winds and seas can create dangerous conditions for small vessels.
Short-period northwesterly wind swells could bring high waves at times Monday through Wednesday, primarily to west-facing beaches in southern San Diego County. A high risk of rip current can accompany waves at all beaches in San Diego County during this time. Surf will peak at around 6 feet on Tuesday in southern San Diego County.