Cooler temperatures and rain expected around San Diego this week

San Diego County is expected to transition from unseasonably warm weather to cooler conditions and periods of rain this week as a low-pressure system moves in from the northwest, forecasters said Sunday.

The change is expected to begin Tuesday, with the greatest chance of widespread rain from Wednesday night into Thursday, according to the National Weather Service. Forecasters also expect stronger southwest winds in the mountains and deserts.

Along the coast, temperatures should ease as onshore winds return, bringing low clouds and fog early in the week, according to the NWS.

A beach hazards statement is in effect through Tuesday morning for San Diego County coastal areas, with surf of 3 to 6 feet and dangerous rip currents expected. Beachgoers were urged to avoid hazardous water conditions and stay off rock jetties.

The mountains could see periods of rain Wednesday night and Thursday, along with elevated southwest winds. Forecasters say there is a 25% to 55% chance of rainfall exceeding 1 inch in parts of the coastal basin and mountains, with locally heavier showers possible if thunderstorms develop.

The deserts are expected to remain comparatively dry, although temperatures there will cool and southwest winds may strengthen. Rainfall chances are lower there than along the coast and in the mountains, forecasters said.

The weather service said there is a 10% to 15% chance of thunderstorms from the coast to the mountains Thursday. If storms form, locally heavy rainfall is possible.

Conditions are expected to become drier Friday, with sunshine returning in many areas.