Warm start to week in San Diego County, then cooling trend with chance of rain

Warmer-than-normal weather will stick around in San Diego County into the early part of the week as high pressure remains over the region, according to the National Weather Service.

Forecasters said the marine layer will slowly deepen through the week, increasing the chances of nighttime and morning clouds and fog along the coast. Gusty, locally stronger winds are possible in the mountains on Tuesday.

Highs Tuesday are expected to reach about 70 near the coast, 73 to 76 inland, 74 to 79 in the western valleys, 62 to 72 in the mountains and around 76 in the deserts, the NWS said.

A cooling trend is forecast to begin Wednesday and continue into late week as a low-pressure system approaches, further strengthening the marine layer and onshore flow.

More widespread low clouds are expected to push into the western valleys during the overnight and morning hours.

Temperatures are expected to drop a few degrees each day from Wednesday through Friday. The approaching system could also bring a 10% to 20% chance of measurable rainfall by Friday and into next weekend.

Dry conditions are expected to return Sunday, along with a warming trend and prevailing offshore winds, meteorologists said.