Red flag warning issued in Northern California. How is it different from fire weather watch?
During wildfire season, the National Weather Service has two advisories that inform people of dangerous conditions that could lead to blazes: a fire weather watch and a red flag warning.
The difference between the two is the amount of time before the weather conditions start, said Anna Wanless, a meteorologist with the weather service’s Sacramento office.
A watch is issued up to 48 hours before the weather event starts, while a red flag warning is issued when critical fire conditions are expected within the next 24 hours.
“For a warning, it’s more like the conditions are happening right now, while the watch is more like in the next couple days, we’re going to see the conditions,” Wanless told The Sacramento Bee in 2022.
Red flag warning issued for Sacramento Valley, Sierra foothills
On Friday, the National Weather Service issued a red flag warning for much of the Sacramento Valley and nearby Sierra Nevada foothills, lasting from 11 p.m. Saturday to 8 p.m. Sunday.
The agency previously issued a fire weather watch for the area in the same time period.
According to the red flag warning, the highest threats are in the northern and central Sacramento Valley, especially west of Interstate 5 and elevations below 2,000 feet.
A red flag warning means that there are either critical fire weather conditions occurring or will happen soon.
“A combination of strong winds, low relative humidity and warm temperatures can contribute to extreme fire behavior,” the service said in the warning.
What’s the difference between fire watch and warning?
The weather service will usually issue a warning after a watch with a few exceptions, according to Wanless.
In addition, the weather service alerts suggest different measures people should take.
A watch warns people to be ready for potentially critical conditions, while a warning urges people to take action.
“Red flag warning is to take action now, and a watch is more be prepared,” Wanless said.
How can I prepare for wildfires?
During a watch, people who live in fire-prone areas should clear debris outside of their homes and create defensible space for safety, Wanless said.
During a warning, people should avoid outdoor burning and using equipment that could create a spark.
Other fire safety tips include obeying local burn bans and not driving or parking vehicles in dry grass, which can be prone to catching fire.