Sunny skies should return for the weekend, the National Weather Service says, and gusty winds today should be the only trace of the unusual rainstorm that swept through San Diego this week.
San Diegans who thought spring's arrival signaled an end to showers seemed mystified by the storm that brought steady winds and spurts of rain Wednesday and Thursday.
The strength of the storm surprised even forecasters. The storm not only was centered far north, allowing only the fringe of the system to reach San Diego, but also moved into San Diego County at an extremely low level.
The radar at 6,500-foot elevation on Mt. Laguna did not pick up any rain "echoes" during the storm. "If a storm is strong and brings rain, it usually has depth, and we see it on the radar," said Wilbur Shigehara, a National Weather Service forecaster.
Thunderstorms here normally have a depth that begins at 20,000 to 25,000 feet. This time the rain clouds were below 6,000 feet--and beneath the radar station. Weather at the top of Mt. Laguna was probably clear and sunny.
The rain was driven by winds that were blowing twice to three times normal speed--up to 30 m.p.h. in coastal and inland areas and up to 40 m.p.h. in the mountains and deserts.
The rain continued Thursday morning between outbreaks of sunshine when the storm stalled. "It was dragging its feet leaving here," Shigehara said.
Rainfall amounts varied throughout the county, ranging from .30 of an inch at Lindbergh Field to over an inch in eastern and northern parts of the county.
March is the second wettest month of the year, and normally 1.6 inches of rain fall during the month. After the storm, this month's rainfall was only .57 of an inch.
"This month has been very disappointing for rainfall," Shigehara said. "People get nervous when we have rain for two days. But it (the rain) is normal for this time of year."
This year's seasonal total, which is measured beginning July 1, is comfortably ahead of the average. The normal rainfall for the season is 8.06 inches, and the total to date this season is 9.32 inches.
Warmer, drier weather is expected to return today when a high pressure system arrives, but winds may continue at an above-average clip. A small craft advisory along coastal waters was expected to continue today, and forecasters warned of blowing sand in the deserts.
Humidity that hovered in the 80% to 90% range Wednesday and Thursday should drop to 25% to 50% over the weekend.
As skies clear, nights will get colder. Temperatures may drop to freezing in agricultural areas of the county, forecasters said. But daytime temperatures in the 60s today should climb to the 70s along the coast and inland Saturday, and may hit the 80s inland by Sunday.
Mountain temperatures in the 40s during the day are expected to drop to the 25- to 35-degree range at night.
Desert highs up to 76 degrees may top 84 degrees by Saturday, and lows are expected to be 46 degrees to 55 degrees at night.