Santa Ana winds bring EXTREME fire risk to parts of Southern California today

A Santa Ana wind event will bring an 'extreme' fire danger to parts of Southern California throughout the day today [Tuesday] which is the highest possible wildfire risk. Areas included in this extreme risk include parts of Los Angeles and Ventura counties where wildfires that ignite will spread rapidly and erratically posing a significant risk to property and life.

Today's fire risk

Due to the extreme fire risk, the Los Angeles National Weather Service issued a rare 'particularly dangerous situation' Red Flag Warning from the east side of Santa Maria south through Los Angeles and Ventura counties and all the way down to the Mexico border on the east side of San Diego.

Red Flag Warning

The extreme fire conditions are fueled by strong, gusty Santa Ana winds gusting between 40-60 mph [with some higher gusts in the mountain canyons on the western facing slops up to 90 mph in isolated instances], paired with dry vegetation and low relative humidity.

These Santa Ana winds are setting up as a strong area of high pressure builds over the Great Basin along with relatively lower atmospheric pressure off the coast of California. This setup favors winds to flow [blow] from the high-pressure system [over the Great Basin] toward the lower pressure [off the coast of California], with winds as they flow from east to west being forced up and over the mountains, and these winds are enhanced as they're squeezed at the ridges of the mountains, rushing down the west sides of the mountains in Southern California. The winds as they come down the west sides of the mountains tend to dry things out and warm it up, so it leads to warm temperatures and very low relative humidity. This type of environment creates the extreme fire conditions that're forecast today.

The weather pattern that typically favors the development of Santa Ana winds events tends to occur during the months of October through March.