Parts of Southern California are gearing up for another potentially damaging round of Santa Ana winds that could destroy trees and power lines and increase the risk of fire.
The gusts of local north winds will shift northeast from Saturday night to Sunday, peaking in the early morning hours before dissipating in the afternoon, said David Sweet, a meteorologist at the National Weather Service in Oxnard.
“This will be a Santa Ana and it will be quite strong,” said Sweet.
Stronger winds are expected in the mountains of Ventura and Los Angeles counties, which can have gusts of 70 mph, with gusts of 105 mph possible in the Santa Monica mountains and the Santa Clarita valley, Sweet said. Gusts can reach 50 mph in the San Fernando and Ventura County valleys and along the coast, with 40 mph gusts possible between Hollywood Hills and Leo Carrillo Beach in Malibu, he said.
The winds are expected to push into the port of Avalon, creating wind waves of three to five feet, Sweet said.
Unlike land winds, which bring moisture when blowing from the ocean over land, the Santa Ana winds originate inland, gaining speed, heating and drying as they move from higher to lower elevations and squeeze through canyons and narrow passages.
“This is a typical Santa Ana wind event that results from a low pressure system going around east of us and causing a difference in surface pressure between the high pressure on the Great Basin and the low pressure along the coast of Los Angeles. ”Said Sweet.
Air from high pressure areas flows to those of lower pressure, and the gradient, or difference, causes the strong winds.
The National Weather Service issued strong wind warnings for the Ventura and LA County mountains, including the Santa Monica mountain range and the Santa Clarita Valley, which are in effect from Saturday night to Sunday afternoon. Many other areas are under wind alerts.
Conditions are quite common for this time of year, although this winter has seen more events in Santa Ana than usual, said Sweet.
“We were very attached to a specific weather pattern this winter, which has been favorable for the Santa Ana winds,” he said.
Unfortunately, the same did not happen with rain. February is normally the rainiest month in the region and, in a normal year, 10.7 inches would have fallen in downtown Los Angeles between October 1 and now, Sweet said. So far in this rainy season, only 4.39 inches has fallen.
Midweek, there is a chance of rain on Tuesday night through Wednesday, but forecasters are treating it as a “very low confidence call” because models are divided over whether this will happen or not, said Sweet. Another system seems more likely to bring rain to the area the following week, but it is too far to be sure, he said.
Still, the rain is unlikely to be significant enough to greatly reduce the deficit: meteorologists said it would take a “mega-miracle” to bring Los Angeles into a normal rainy year.