What they mean and what you should do: NPR
Spring has arrived, bringing with it warmer weather and red flag warnings in many parts of the United States.
People in states from Minnesota to Maryland to Massachusetts saw those alerts on their weather apps this week. The notices warn of an increased risk of wildfires due to a combination of warm temperatures, low humidity and strong winds.
The National Weather Service (NWS) issues warnings in cooperation with local and state agencies, explains NWS spokesman and meteorologist John Moore.
“This means that the right conditions are in place for wildfires to start spreading,” Moore says. “It also means critical weather conditions are happening now or will happen soon… so we’re asking people to be very careful if you’re burning… or doing anything with fire outside.”
He adds that it’s important to practice good fire safety habits at all times, since wildfires don’t just happen on red flag warning days.
The origin of the name is quite literal, says Tamara Wall, a research professor at the Nevada Desert Research Institute.
“If there is a significant fire risk, local fire stations will raise a red flag up the flagpole,” she says. “It was a very visible form of mass communication to signal to people in the area that this was a high-risk day.”
Electronic red flags warn of hazardous conditions in the next 12 to 24 hours. It differs in timing from the fire weather watch, which warns of the possibility of these conditions developing during the next 72 hours.
The latter term was created to further differentiate between “warning” and “monitoring” in firefighters’ radio communications, Wall says. But it ends up confusing a lot of people, who wrongly assume one is more dangerous than the other.
This assumption is likely due to the way the terms are used in other weather alerts – for example, a tornado watch means tornadoes are possible in the area, while a tornado warning means a tornado has been seen. Wall says red flag warnings and fire weather watches can be for equally extreme conditions, it’s just that the watch extends over a longer period of time.
“Fire is a little tricky, because unlike tornado warnings or watches or other warning watch products, we don’t know if it’s actually going to happen or not,” Wall says.
Here’s what to know — and do — about these warnings.
What should you do if you receive an alert?
Wall says a red flag warning is essentially a warning.
People should prepare for the possibility of a fire or evacuation, such as keeping their phones charged and making sure they know where their loved ones — especially people with disabilities or mobility issues — are located during the day. They will want to make a plan for what to do with any pets or livestock as well.
Before people leave the house for the day, they should make sure all their home and car windows are closed, and they can also bring flammable materials such as outdoor pillows inside the house or garage.
Other precautions included removing any dead shrubs around your home that could spark a fire, keeping your vehicle away from dry grass and avoiding using power equipment that causes sparks.
Wall says fire department staff will also take these warnings into account, such as changing staffing numbers or proactively moving resources to a specific area in case something happens. She says that if there is a possibility of a particularly dangerous event, local authorities may consider making policy decisions such as banning campfires or closing certain areas.
In red flag days, more than ever, “you don’t want to be reckless with fire,” Moore says. So avoid doing things that could accidentally start a wildfire, whether that’s starting a bonfire, burning trash in the yard, or throwing a cigarette out a car window.
“It’s primarily telling people… to make preparations,” Moore says. “If you plan to do something that day, it’s best to reschedule it.”
What are the red flag warning criteria?
Red flag events typically require a combination of critical fuel conditions — as determined by land management agencies — and critical weather conditions, the NWS says.
Basic criteria include relative humidity of 15% or less with sustained or frequent surface winds of 25 mph or greater. Both conditions must occur simultaneously for at least three hours of a 12-hour period.
The main considerations are wind speed, humidity and how dry the ground is, though exact conditions vary by region, Moore says.
Every year, each weather forecasting office creates an annual operating plan (AOP) that lists the criteria they will use when deciding whether to issue a red flag warning or a fire weather watch, Wall explains.
“For example, 20% humidity in Florida is a very different potential fire weather condition than 20% humidity in Nevada,” she adds.
Moore says the NWS takes the information and expertise of state and local partners into account when making those decisions.
“We can issue red flag warnings, but we can’t issue burn bans or things like that, and local restrictions, those are all subject to the decisions of state and local authorities,” he adds. “So we’re working closely with them to determine those thresholds as well.”
Where and when do we usually see them?
Red flag situations can occur in any part of the country at any time of the year.
“Almost anywhere there is the potential for an uncontrollable fire,” Wall says.
She adds that there is some seasonality to them. The fire season in the Southwest begins sometime around March and continues across the northern Rockies into August and September, while the fire season in California is typically in the fall.
“It’s very common across the country,” Moore says. “In my experience as a meteorologist, every area I’ve lived in has had red flag warning days.”
Moore points out that there are natural variations in weather patterns and the warnings they require, so he can’t necessarily say there’s been an upward trend in red flag warnings in recent years.
But more people have access to weather information — whether through iPhone apps or social media posts — than ever before, which he sees as a good thing.
“We want more people to care about the weather,” Moore says. “Especially on days when it could have an impact not only on you, but on your community as well, if you’re not careful, we want people to be aware of that.”
Will the warning system change?
Could the constant stream of red flag warnings and weather watches have the opposite effect, by reducing people’s sensitivity to fire risks?
Moore says there may be a risk that people will get used to these warnings, but they still serve the important purpose of raising awareness about particularly dangerous conditions.
“I always want to reiterate not to do these (essential) things, whether the weather conditions are dangerous or not,” Moore says. “But we want to add more to it as we remind people of those really dangerous days.”
He acknowledges the confusion between the two terms and says this is “something we are looking at internally.”
Wall — who works closely with programs funded by the National Oceanic and Atmospheric Administration (which includes the NWS) — doesn’t think the name “Red Flag Warning” should change, because it’s so entrenched, especially in the West. But she believes the process can be improved.
She explained that the NRA has long been working on a “risk simplification” effort that would narrow the numbers of watches and warnings to help the public better understand them.
It says there are concerns about “over-issuance” in some parts of the US, with parts of the West seeing red flag warnings on a daily basis during extremely dry summers, which has sparked efforts to revamp the system.
Wall is among the experts who are speaking with nuclear-weapon states about possible solutions, and advocates using a severity system of red flag warnings where the risk is classified as either moderate or, in the case of more extreme circumstances, as extremely dangerous.
While improving communication and taking precautions is important, she says, she believes, “Really, what we’re ultimately headed toward is fire-adapted communities” and creating wildfire-resistant communities.
“I kind of feel like if you keep things relatively simple, you’ll do a better job of getting people’s attention,” Wall says. “But in wildfire-prone areas, this is now the way of life. You have to pay attention and be prepared.”