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Public Safety

Strong Santa Ana Winds Blowing Into San Diego County, Meteorologist Warns

Alex Tardy, meteorologist with the National Weather Service San Diego, explains the phenomenon behind Santa Ana winds from his Rancho Bernardo office, on Oct. 2, 2013.
Susan Murphy
Alex Tardy, meteorologist with the National Weather Service San Diego, explains the phenomenon behind Santa Ana winds from his Rancho Bernardo office, on Oct. 2, 2013.

A red flag warning has been issued from 2 a.m. Friday to 6 p.m. Sunday

A red flag fire warning has been issued for most of San Diego County from 2 a.m. Friday through 6 p.m. Sunday as strong Santa Ana winds are expected to blow into the region.

Moderate Santa Ana Winds Blowing Into San Diego County, Meteorologist Warns
A red flag fire warning has been issued for most of San Diego County as moderate Santa Ana winds are expected to blow into the region.

This map shows the areas of San Diego County that are under a red flag warning due to high Santa Ana winds and low humidity levels.
National Weather Service
This map shows the areas of San Diego County that are under a red flag warning due to high Santa Ana winds and low humidity levels.

Staying Safe Amid Red Flag Warning

A few helpful reminders and fire prevention tips include:

  • Don’t mow or use a weed-eater to trim dry grass on windy days.
  • Ensure campfires are allowed, and if so, be sure to extinguish them completely.
  • Never pull over your vehicle in dry grass.
  • Never burn landscape debris like leaves or branches on “NO Burn Days” or when it’s windy.
  • Make sure all portable gasoline-powered equipment have spark arresters.

Source: CAL FIRE

The National Weather Service warned wind gusts could reach 60 mph in the mountains and 30 mph in the inland valleys. Humidity levels will dip to the single digits and temperatures are expected to be in the low 90s in inland areas.

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How Santa Ana Winds Form

The Santa Ana weather event is a result of high pressure building over the Colorado region and lower pressure hovering along the Southern California coast.

The combination will create a strong difference of pressure gradient that will push air from east to west in order to alleviate that pressure, said Alex Tardy, meteorologist with the National Weather Service.

"Our problem is we have these big beautiful mountains and canyons and valleys," Tardy explained, as he pointed toward the mountains from his panoramic office window in Rancho Bernardo. "Wind gets blocked and it funnels and goes around, and goes over those barriers so that our wind gets enhanced."

Tardy said when the wind comes from the desert, rather than the ocean, there’s not a moisture source and the air is very dry. The usual marine layers get pushed way out to sea.

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"As the air comes over the mountains, it compresses and warms, and that lowers the humidity even more," Tardy added.

Tardy said this Santa Ana event will be weaker than the one that caused the 2007 wildfires, but it could still be dangerous.

"It’s extreme conditions...fire behavior could be very erratic, and the fuels are unquestionably ready to go," said Tardy.

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