Rain will bookend the Southern California weather week
Southern California weather this week will be book-ended with rain on Mother’s Day in some areas, with a chance for still more rain next week, while the familiar gray skies of May and June begin settling in from the coast to the inland valleys.
Small amounts of rain fell throughout the area Monday and was expected to depart for Tuesday and Wednesday, when most areas will have overcast skies in the morning giving way to afternoon sunshine, with generally mild temperatures. There will be gusty winds in the passes.
A chance of rain is forecast for Thursday afternoon or evening and linger through Friday and Saturday, with a slight chance of showers Sunday for coastal and inland Orange County and the Inland Empire.
The Los Angeles area, the San Gabriel Valley and the San Fernando Valley are forecast — as of Monday — to escape the Mother’s Day rain.
And there may be another rain system next week, said Joe Dandrea, a meteorologist with the National Weather Service’s San Diego office.
The rain comes from a pattern more normal for early spring, he said, describing them as low-pressure systems from the north.
“At some point we might say this is getting a little crazy,” he said. “We could get a wetter-than-normal May,” after March and April had a bit less rain than usual, he said.
The rain patterns are different from the system bringing the overcast skies — colloquially called May Gray and June Gloom — a familiar pattern for Southern Californians.
More technically called the Catalina Eddy, the overcast system forms as the ocean water remains cool but the land begins to heat up, bringing a layer of condensation held in place by warmer air overhead, called an inversion.
The eddy is the flow of wind from the ocean to inland, which can be compressed in passes and bring gusty winds that push the overcast into inland valleys. The depth and duration of the overcast varies, “but once it gets to a fairly deep level, it’s kind of hard to scour it out,” Dandrea said.