A slow warming trend in San Diego County was predicted to continue Tuesday, the last day of spring, into Wednesday, but with Wednesday high temperatures for inland areas still 5 to 10 degrees below average, the National Weather Service said.
While the marine layer was still around 2,500- to 3,000-feet deep early Tuesday morning, coverage of coastal low clouds overnight were more patchy, forecasters said.
Along the coast Tuesday, it was expected to be mostly sunny with high temperatures from 68 to 73, the NWS said. The valleys were expected to be mostly sunny with highs from 76 to 81. It will be mostly sunny in the mountains with highs from 72 to 82. The deserts were expected to be mostly sunny with highs from 97 to 102.
A decrease in marine layer depth was possible for Tuesday night into Wednesday morning with coastal low clouds spreading inland into the western valleys, then a slight increase in depth for Wednesday night into Thursday morning with coastal low clouds extending inland into portions of the inland valleys.
It should remain cooler on Friday with high temperatures for the mountains and inland valleys 15 to 20 degrees below average. The marine layer could deepen for Thursday night into Friday morning to around 3,000 to 3,500 feet with coastal low clouds covering most of the valleys early Friday morning if not extending onto the lower coastal mountain slopes.
The marine layer should slowly decrease in depth over the weekend, but with night and morning coastal low clouds still extending well inland into the valleys. Temperatures should be higher over the weekend with Sunday high temperatures for the mountains and inland valleys 5 to 10 degrees below average. High temperatures could be nearing average for the lower deserts.
West-northwest winds may gust near 20 knots in the outer coastal waters each afternoon and evening through early next week.
