How strong are Santa Ana winds charging Los Angeles wildfires?

Forest fires are deadly and devastating Tearing up the Los Angeles areaThe strong winds literally fan the flames.

As of Wednesday afternoon, four fast-moving fires had killed two people, injured many more and destroyed more than 1,000 buildings, while threatening 28,000 others and forcing at least 70,000 people to evacuate.

Here’s how wind makes wildfires more dangerous and harder to fight.

What types of wind are these and why are they so strong?

Santa Ana winds are strong winds that blow from dry inland areas toward the coast, generally in the cooler months, for a few days to a week.

The National Weather Service says Santa Ana winds reached 129 km/h in some areas around Los Angeles by early Wednesday, and could reach 160 km/h in the mountains and foothills.

Los Angeles County fire crews said Wednesday that winds were expected to reach 95 km/h through Thursday.

These winds come from the dry desert regions of Nevada, Utah, Idaho, and southeastern Oregon, and become drier as they sweep through the mountains.

Peter Mullinax, a meteorologist at the National Weather Service’s office in College Park, Maryland, described what the area is witnessing as “very critical fire weather conditions,” due to a combination of strong wind gusts over the highest terrain and very low humidity.

How do winds affect the spread of forest fires?

The faster the wind, the faster the fire will spread. Basic rule Used by wildland firefighters Is that fires spread at a speed of 10 percent of the wind speed. For example, a wind speed of 25 km/h will allow a fire to spread at 2.5 km/h.

There are several reasons for this.

• The wind helps supply the fire with air and oxygen.
• It also flattens and bends the fire toward the dead wood and other fuel in front of you. This can lead to preheating, blowing sparks and embers into new dry fuel sources, causing spot fires.
• The National Weather Service says wind direction often determines the direction a fire spreads.
• The wind also dries plants and turns them into more combustible fuel.

The Santa Ana winds’ ability to dry vegetation to the lowest level of humidity of the year is one of its “really serious impacts,” said Lyndon Pronto, a senior fire management expert at the European Fire Institute.

“The fuel itself becomes very available to the fire and can ignite and carry the fire very quickly,” he told Reuters.

This exacerbates the increased fire danger and worse fire conditions already caused by climate change.

Climate change has created generally hotter and drier conditions in the region, “and that creates a kind of powder box,” said Sylvia Dee, an assistant professor and climate scientist at Rice University in Houston.

How does this affect firefighting efforts?

As of midday Wednesday, 1,400 firefighters were deployed on the ground, but aerial efforts were hampered by the fact that winds were too strong for firefighting planes to fly, the Associated Press reported.

Winds can generate turbulence, especially in mountainous terrain, or even damage aircraft if they are too strong.