97 mph! Santa Ana winds knock out power, down trees in LA
Mark J. Terrill / AP 2 Days Ago Updated at 6:00 a.m. ET
Power outages and downed trees were reported in several regions of Los Angeles County Wednesday night due to strong winds, NBC LA reported.
A major change in the weather pattern is expected to bring powerful gusts of up to 85 miles per hour and possible hurricane force winds into the Los Angeles region for two days.
The National Weather Service issued warnings that the high winds and low humidy could cause wildfires.
On Wednesday night, a wind gust of 97 mph was recorded at Whitaker Peak in Los Angeles County, according to the weather service.
Los Angeles International Airport was affected with power going in and out at the airport Wednesday.
Some containers and equipment that were unsecured rolled onto runways, LAX spokesperson Nancy Castles told KCAL9.
Castles was told by the Federal Aviation Administration that the some arrival flights would be delayed for about 10 to 15 minutes.
Some flights, including three international flights, were diverted to other airports.
Federal Aviation Administration spokesman Ian Gregor said about 20 diverted flights were sent to Ontario International Airport in San Bernardino County Wednesday because of severe crosswinds and two runways were closed due to strewn debris.
Marina Peninsula and beach areas of Venice suffered power outages as well, some of which have since been restored.
Several areas incurred damage from fallen trees.
A large Eucalyptus tree fell on a power line and a house in Beverly Hills, according to the Los Angeles Fire Department.
In addition, traffic was backed up through most of Marina del Rey along westbound Admiralty Way because of downed trees.
The National Weather Service issued a red flag warning for Wednesday night through to late Friday afternoon over Los Angeles and Ventura counties.
Watch NBCLosAngeles.com forecast video
The wind was forecasted to be so powerful, it could be “the strongest offshore wind event we have seen in the past few years,” according to an advisory by the National Weather Service.
Fears of a possible brush fire guided the decision to suspend the Metro Green Line service between the Redondo Beach and El Segundo stations, according to Metro.
“Residents in the warning area are advised to take precautions now before the winds reach their peak,” the NWS said. “Close all windows and secure all outdoor objects such as lawn furniture.”
For the latest weather conditions, click here.
The Santa Ana winds are generated during cooler months when westward flowing currents reach fierce speeds as they squeeze through mountain ranges of Southern California, lowering humidity and making vegetation susceptible to fire.
Update… Worst Santa Anas in more than ten years…
Unusual weather system produces destructive winds
The gusts that pummeled the western San Gabriel Valley, including Pasadena and La Cañada-Flintridge, were produced by two separate weather systems that channeled cold air from the north into the L.A. area.
By Hector Becerra, Matt Stevens and Rong-Gong Lin II, Los Angeles Times December 2, 2011
The winds reached 97 mph at one mountain peak. More than 380,000 homes lost power. Thousands of trees snapped, blocking roads and damaging property. Scores of schools were closed, as was Griffith Park. And motorists battled gridlock caused by broken traffic signals and blowing debris.
The storm, which produced some of the strongest wind gusts in more than a decade, was caused by a highly unusual weather system that even had experts marveling at its power.
While Santa Ana winds are common this time of year, this storm was anything but.
The winds were produced by two separate weather systems that channeled cold air from the north into the Los Angeles area.
A clockwise high-pressure system was parked over Northern California and the Great Basin as a counter-clockwise low-pressure system hovered over Arizona.
Like two massive gears spinning in opposite directions, the systems funneled the winds.
“In some places we’ve seen gusts over hurricane force, which for the Southwest part of the country is not something that usually happens,” said Brian Edwards, a meteorologist for AccuWeather.com. “This is a one-every-10-years kind of thing.”
Indeed, the blustery conditions extended across the Southwest, including Utah, Nevada, Wyoming, Arizona and New Mexico. In some places, including Utah, wind gusts topped 100 mph.
Experts said one reason for the extensive damage was that the winds were remarkably choppy and unpredictable.
In some places, winds suddenly shifted from 10 mph or 20 mph to more than 80 mph. The shift made trees as well as roofs and power lines vulnerable.
“Everything lined up perfectly,” said Bill Patzert, a climatologist for Jet Propulsion Laboratory in La Cañada-Flintridge.
Trees were no match for the winds, especially those with heavy canopies. Patzert noted that trees in urban Southern California neighborhoods don’t have the strong root systems found in more natural environments.
“L.A. trees don’t have deep roots. The urban forest is artificial and is primarily watered by lawn sprinklers,” Patzert said. “So what keeps our urban forest alive is people watering their lawns, which are not natural, so you don’t have deep root systems. So our trees are very vulnerable to Santa Ana events.”
Walter Warriner, a Santa Monica arborist and community forester, agreed, adding that the large canopies of many local trees lack strong foundations.
“When you look at a tree above ground there’s a ratio of 20 to 1 compared to below ground, so there’s not that many roots holding our big trees in place,” he said.
While damage was reported across the Southland, communities in the western San Gabriel Valley were particularly hard-hit, including Pasadena, South Pasadena, San Marino, Altadena and La Cañada-Flintridge.
National Weather Service meteorologist Eric Boldt said this, too, was unusual.
Typically, the San Fernando Valley and Ventura County get the brunt of such windstorms.
But Boldt said that these Santa Ana winds came more directly from the north rather than from the northeast.
The air was colder than the traditional Santa Anas, causing the winds to sink to lower elevations.
“You’ve got that air building up on the other side of the mountains right there above Pasadena, and then it comes like a bowling ball rolling down the hillsides right into the lower elevations,” he said. “Colder air is going to sink a lot faster. In a typical Santa Ana, the winds will be up high, and not really get down to where we live.”
Another factor was the difference in the levels of pressure between the two weather systems.
“The stronger the difference, the stronger the winds. In this case, we had a very strong difference in pressure,” Edwards said. “Add in the terrain, the mountain passes, the canyons and things like that, and you get these local enhancements, like a funneling effect, which in turn creates even stronger winds.”
The winds are expected to stay through Friday, gradually losing their strength.
But Patzert said the region should not get comfortable just yet.
“This is not going away any time soon,” he said. “This is local. This is not global warming or El Niño or La Niña or anything like that. These are Santa Anas and this is the time of the year they occur.”
By Bob Mims and Lindsay Whitehurst
First published Dec 01 2011 07:04AM Updated Dec 2, 2011 07:30AM
The Salt Lake Tribune
Hurricane-force winds topping 100 mph in some places ripped through Utah Thursday, overturning semi-trailer rigs on Interstate 15, toppling trees and triggering widespread power outages affecting nearly 50,000 homes and businesses.
The Utah Highway Patrol reported 16 semis overturned by the wind on the state’s highways Thursday, including three on Legacy Parkway and 10 more on Interstate 15 in Davis County, where winds lashed at 102 mph, said Cpl. Todd Johnson. None of the drivers suffered more than minor injuries.
The winds weren’t quite as fierce by Thursday afternoon, but still gusting at more than 55 mph in places, the Utah Department of Transportation reported.
In Davis County, the winds had slowed to 30 mph by Thursday afternoon and were expected to continue to slow, according to the county sheriff’s office.
But the wind damage left behind prompted the county to issue a disaster declaration Thursday night saying infrastructure damage exceeds $3.5 million. It will also close all schools in the Davis School District on Friday. Twenty-eight of those schools were closed Thursday as the wind knocked out power, downed trees, damaged rooftop equipment and shattered windows in 30 school buses.
II Peter 3:12
… looking forward to the day of God and hurrying it along. On that day, he will set the heavens on fire, and the elements will melt away in the flames…