First strong Santa Ana winds of the season bring critical fire hazard to California



CNN

The first strong showing of the season in Santa Ana will bring harsh winds across Southern California through Thursday, setting the stage for critical fire conditions and the possibility of a fire spreading rapidly.

Strong wind warnings have been issued for much of the area, affecting nearly 15 million Persons.

Strong wind warnings are in place for parts of Southern California as winds peak in Santa Ana on Wednesday.

“We will see wind speeds of 55 to 75 miles per hour. These are very strong, damaging northeast wind gusts,” Carol Smith, meteorologist for the Los Angeles National Weather Service, told CNN. “At the same time, the humidity is falling over the mountains, in the valleys and in the coastal areas.”

From the Santa Monica mountains and areas to the south, winds will be 40 to 60 miles per hour, according to Smith, with areas in the foothills potentially seeing winds of up to 70 miles per hour.

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These strong Santa Anas are fueled by low pressure sliding down the coast on Wednesday and Thursday.

It’s in just the right place for strong northeast winds to drive Southern California.

The winds intensify as they are channeled through the mountain passes and gorges. In the region, winds blow from the drier desert regions, and as the winds sweep down the western slopes, the air warms and dries even more. This can quickly absorb residual moisture from the rains of the last week, which is why the danger is so great even after the wet week.

Watch: What are Santa Ana winds?

The region was drenched in rain last week, but Smith said it wasn’t enough to extinguish the fire threat.

“Fuels are still susceptible to rapid fire spread in much of this area,” Smith said. “So with these strong winds and dropping humidity on Wednesday, any fire that is started is likely to spread very quickly and present extreme fire behavior and a clear threat to life and property.”

San Diego saw up to 9 inches of rain last week. While the risk of fire is not as great as elsewhere, the risk of ignition remains.

“Relative humidity is generally around 20 to 25 percent during the time of the strongest winds on Wednesday morning, falling to 10 to 15 percent in the late morning and afternoon. The combination of strong winds and low relative humidity will result in a period of critical fire weather conditions Wednesday,” the San Diego Weather Service Office said.

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One of the biggest concerns is trees falling onto power lines and starting fires.

According to Smith, this threat can sometimes lead to preventive blackouts.

“This is a big cause of fires in our area and that’s why (utilities) will do the power cuts a lot,” Smith explained. “That’s common, although we weren’t sure if they will with the recent rains.”

Residents are encouraged to participate in the READY, SET, GO program that Los Angeles County runs to prepare people for events like this. Smith urges people to have a list and bag of documents, medication, items for your pets and more.

Fire conditions should gradually improve through Thursday. But another round of winds could hit the region later in the week. Santa Ana winds are more common in the cooler months.

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