A low pressure trough descending over San Diego County will cause nighttime temperatures to tumble well below freezing through the weekend, according to the National Weather Service. Forecasters issued a frost advisory for Friday night, and a freeze warning for Saturday night into Sunday morning when temperatures are expected to plunge into the 20s from the coast to the inland valleys.
Winter Shelter's Needed Donations
- Socks
- Blankets
- Sleeping Bags
- Plastic
- Warm Clothes
The frigid conditions could be life-threatening for homeless people who will have to endure the bitter cold on the streets.
“We’re doing our best to take plastic and blankets and jackets and socks to people, but we’ve literally run out," said Bob McElroy, CEO of the Alpha Project, and manager of San Diego's winter homeless shelter. "So if anybody wants to bring down stuff, they can bring it right to the shelter," he said. "Or they can hand it out themselves to save a life."
Temperatures around the county will range from 28-34 degrees overnight on Friday, and 23-28 degrees from Saturday night into Sunday morning, according to the National Weather Service.
Low-lying areas in Mission Bay and Oceanside will feel some of the coldest effects, said Robert Balfour, senior forecaster with the National Weather Service in San Diego.
"Any place pretty much where there’s a river flowing down to the coast," he said. "The cold air almost acts like water – it’s dense, it’s heavier than the normally moist and warmer air, and so it sinks and it just kind of rolls down hill."
San Diego Farm Bureau Chief Eric Larson said growers aren't going to get much sleep this weekend. "They'll probably be up all night watching those temperatures and being prepared to put freeze protection measures into play."
Those measures include blanketing low-lying plants, such as strawberries and nursery plants, and turning on wind machines for citrus trees and taller crops.
"Wind machines tend to try to mix the lower cold air with the higher warm air to protect their trees," Larson explained.
He said growers can also turn on the water. "When the water comes out of the ground it’s going to be warmer than the cold air and then if it freezes on the plants, believe it or not it actually creates a coating of protection for the plant for the temperature going even lower than freezing," said Larson.
The last big freeze in 2007 caused several million dollars in crop losses, especially to the avocado industry.
"That might be comparable to what could happen tonight or early tomorrow morning," warned Larson.
