Some Rainfall on the Way, Along With Warmer Air

Freezing nights will begin to warm up as Pacific winds replace Arctic air this weekend, but the westerly flow will bring more than a blanket of clouds. Rain is expected throughout the county today and Saturday.

A week of cold nights brought this year’s tally of frost days up to 31--a number that comes close to the average yearly total.

“It looks like it is turning out to be a fairly cool winter. The average number of frost days is about 32, and we still have more nights of cold coming,” said National Weather Service forecaster Wilbur Shigehara.

Citrus growers flipped the switch on heaters and wind machines as temperatures fell to the 20s in agricultural areas in Escondido, Pauma Valley and Fallbrook this week. Even Point Loma--usually protected by its proximity to the water--received frost Tuesday morning.

Nighttime lows dipped to 40 at Lindbergh Field and the week’s low in El Cajon was 29.

Upper winds began to shift from a northerly to a westerly flow Thursday. The Pacific winds are milder--but laden with moisture picked up north of the Hawaiian Islands. Coupled with winds from the Gulf of Alaska, the new weather pattern will bring a rainstorm here tonight, forecasters said.

No more than half an inch of rain is expected today and Saturday, however, and partly sunny days are expected to return Sunday.

The increased humidity and cloudy nights should keep temperatures above freezing in most areas through the weekend, Shigehara said.

Nighttime lows are expected to be in the mid 40s to 50s along the coast and in the 40s inland today and Saturday. Highs should be in the upper 50s to low 60s.

Mountain highs ranging from 36 to 45 degrees should dip to 25 to 35 degrees at night.