National Weather Service says Santa Ana winds could trigger wildfires in multiple areas – The San Diego Union-Tribune

National Weather Service says Santa Ana winds could trigger wildfires in multiple areas - The San Diego Union-Tribune
Critical Fire Weather Conditions On The Way For Much Of Southern California
LOS ANGELES (CBSLA) — The dreaded Santa Ana winds are returning to Southern California, and much of the region is bracing for extreme fire weather and possible preemptive power outages.

The National Weather Service are predicting “critical fire weather conditions” in much of Southern California from early Thursday through Friday afternoon due to wind gusts of 45 and 70 miles per hour and humidity bottoming out as low as 3 percent. Coupled with abundant, now-dry vegetation that sprang up after last winter’s record rainfall, forecasters are expecting extreme fire weather.

Which, in turn, means more announcements like this: red flag warnings have been issued by the National Weather Service for parts of Los Angeles, Orange, San Bernardino and Riverside counties. The L.A. area should expect critical fire weather conditions from late Wednesday night through early Saturday morning, as 55-70 mph Santa Ana wind gusts, temperatures in the upper 80s and relative humidity levels of 3-10% create dangerous conditions.

San Diego County residents prepare for possible outages

A red flag warning will be in effect early Thursday through 6 p.m. Friday for the San Gabriel and Santa Monica mountains and the Angeles National Forest, areas that could see winds of 25 to 45 mph and 70-mph gusts. The same warning will be in effect during the same time for the San Fernando, Santa Clarita and San Gabriel valleys, county coastal areas and downtown Los Angeles.

As usually happens, we can look to the middle of the country for an explanation. A strong high pressure system is moving in behind a cold front over the Northern Plains. Cool air will travel over the Great Basin towards a lower pressure system along our coast. As the cool winds stream over our mountains, theyll compress, warm up, dry out and slam right into us.

Take extra precautions during fire weather watch, peak fire season

A similar warning is in effect for much of Ventura County and coastal Orange County from 3 a.m. Thursday until 8 a.m. Friday.

So where are the #SantaAnaWinds expected later this week? Here is a snapshot of high-res model output of gusts (kt) valid at 10am Thu. The strongest winds are expected over LA and VTA counties. Expect gusts up to 55mph for coast/valleys and 70mph for mtns on Thu. #SoCal #CAwx pic.twitter.com/EfLMxlFJ1f

So where are the #SantaAnaWinds expected later this week? Here is a snapshot of high-res model output of gusts (kt) valid at 10am Thu. The strongest winds are expected over LA and VTA counties. Expect gusts up to 55mph for coast/valleys and 70mph for mtns on Thu. #SoCal #CAwx pic.twitter.com/EfLMxlFJ1f

The forecast prompted Southern California Edison to warn more than 173,000 customers they could be part of a “public safety power shutoff.”

LOS ANGELES – Gusty Santa Ana winds and "very low humidity" will combine to create "widespread critical fire weather conditions" in much of the Southland from early Thursday through Friday afternoon, the National Weather Service announced Wednesday. 

“Were pretty much getting into the heart of our typical Santa Ana season in the fall and winter,” said Stephanie Sullivan, meteorologist with the National Weather Service in San Diego. “So, its right on time.”

Wind gusts of between 45 and 70 miles per hour are expected from mid-morning Thursday to mid-afternoon as humidity levels fall to between 3 and 10 percent, it said.

SoCal Edison is considering whether to shut off power to more than 173,000 customers. In Central and Northern California, Pacific Gas and Electric could shut off power to 800,000 for days.

Given an abundance of dry vegetation, "critical fire weather conditions are expected," the NWS said in a statement.

While for the rest of the nation fall means changing leaves and crisp sweater weather, here in Southern California it means Santa Ana winds season.

The red flag warning will be in force in the San Gabriel and Santa Monica mountains and the Angeles National Forest — areas where winds blowing at a sustained 25 to 45 mph are expected, along with 70-mph gusts and humidity levels of 3-10 percent — from 3 a.m. Thursday until 6 p.m. Friday.

The warning will also be in force at the same time in the San Fernando, Santa Clarita and San Gabriel valleys, along the L.A. County coast and in metropolitan Los Angeles, including Downtown L.A. Additionally, it will be in effect in much of Ventura County, including the Los Padres National Forest adjoining the Angeles National Forest, and in coastal Orange County from 3 a.m. Thursday until 8 a.m. Friday.

“Caltrans is advising motorists that (traffic) signalization on state routes throughout Riverside and San Bernardino counties may be affected during the power outages, according to an agency statement. “The signals will continue to cycle regularly for approximately three hours after the outage and will then cycle to `red-flash for another three to six hours. If the outage remains in place for more than six hours, the signals will then go to `blackout mode.

Video: Cal Fire spokesperson talks fire weather, wildfire prevention and PG&E power shutoffs

SDG&E plans for possible power shut-offs during spell of Santa Ana weather

This alert could be extended if atmospheric conditions hold up. FOX 11 will be closely monitoring the possibility of the addition of wind advisories, high wind watch/warnings, and red flag alerts in our area. 

Porter stressed the need for people to take basic preventative steps, such as not mowing lawns during high winds, not driving vehicles over extremely dry vegetation, where sparks or hot engine components might touch off a blaze, limiting campfires to designated places and being on the lookout for suspicious behavior that could be arson-related.

"If fire ignition occurs, conditions may be favorable for extreme fire behavior, which would threaten life and property," according to the statement.

The warning is in effect from 3 a.m. Thursday to 6 p.m. Friday throughout California. The Weather Service said a ridge of high pressure will begin to settle over the Great Basin in Nevada and Utah mid-week, churning up offshore winds that will be particularly fierce in mountains and passes.

Fire Weather Watch for San Diego County signals shift in conditions

Southern California Edison, meanwhile, cautioned some customers that they could lose power. It said it may order "Public Safety Power Shutoffs" aimed at reducing fire risks. Edison officials noted Tuesday that the power cuts — which would de-energize lines that might be in danger of being damaged and igniting fires in high-wind conditions — are only "under consideration."

The shutoffs, also known as “de-energization, are permissible during high fire danger to prevent electricity lines from arcing, or transformers from throwing sparks and igniting fires, particularly in places not easily accessible to firefighters.

According to the utility, more than 106,000 customers throughout SCE's service area live in the neighborhoods being considered for potential rolling power cuts.

Caltrans District 8, which serves the inland region, issued a statement warning motorists that light signals could go out if utilities implement “public safety power shutoffs, which are permitted by the California Public Utility Commission.

In Los Angeles County, there are roughly 30,700 customers facing possible cuts, primarily in the northern reaches of the county such as Lancaster, Palmdale, Santa Clarita and areas such as Acton, Agua Dulce, Lake Hughes and Canyon Country. San Fernando is also included in the potentially affected area.

RIVERSIDE (CNS) – With the autumn seasons first significant Santa Ana wind event forecast this week, state and local officials today advised Riverside County residents to be prepared for wildfires and do what they can to prevent them.

Cal Fire announced that it is increasing staffing over the coming days to be prepared for potential wildfires, but the Los Angeles Fire Department did not order red flag parking restrictions on narrow hilly streets.

The National Weather Service issued a Red Flag Warning, meaning “critical fire weather stemming from extremely low relative humidity is anticipated for the duration of the easterly winds.

"With some of the most destructive and deadliest fires occurring October through December, we need Californians to not be complacent," Cal Fire Chief Thom Porter said. "Wind-driven fires move fast, and residents need to be ready to evacuate at a moment's notice in the event of a wildfire. We have increased our staffing, but need the public to remain vigilant. It is important to follow evacuation orders and leave early as fires move very fast under these conditions."


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