Another round of gusty winds was forecast for later Wednesday and through much of the day on Thursday for parts of Northern California dealing with devastating wildfires.

A red flag warning was issued because of the "very high fire danger," the National Weather Service in Monterey, Calif., warned.

High-elevation areas will see wind gusts in the 45- to 55-mph range, while valley areas should see gusts peaking in the 20- to 30-mph range, the weather service said.

Humidity levels will also be low. The humidity plus the winds could further exacerbate the fires already burning as well as start new ones.

More than a dozen wildfires have scorched nearly 156 square miles in California's wine country.

So far, at least 21 people have been killed, more than 100 have been injured, and more than 3,500 businesses and homes have been destroyed in wildfires that began late Sunday.

There will be a brief break in the winds before the weekend: Winds will decrease starting Thursday afternoon with much quieter conditions likely Thursday night through Friday.

However, by Friday evening northerly winds will once again be on the increase.

"The risk of wildfire ignition and rapid spread will increase this weekend," AccuWeather meteorologist Evan Duffey said.

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The weekend winds will be due to an area of high pressure that's forecast to build from the Northwest toward the Great Basin this weekend. This high pressure area is about as strong as one that helped bring the furious winds from last weekend.

The fall season typically brings hot, dry and gusty winds across California. These "Diablo" winds are driven by high-pressure areas over the Great Basin, according to NASA.

Winds blow from northeast to southwest over California’s mountain ranges and down through the valleys and coastal regions. These downslope winds can quickly whip up a fire and carry burning embers to the next neighborhood or patch of woodland.

Additionally, no rain is in the forecast through this weekend in California. There is a chance some rain falls on part of northern California later next week, AccuWeather said.