What is a Red Flag Warning? This is the criteria used during increased fire risk

This means warm temperatures, low humidities and stronger winds are expected to combine to produce an increased risk of wildfires.

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Thursday, April 13, 2023
How our weather conditions increase threat of brushfires
"Dry air, a little bit of a gusty wind, these are all criteria the Weather Service has for us to get into a fire watch or fire warning," Meteorologist Sam Champion said.

Have you ever opened your weather app and noticed a Red Flag Warning?

The National Weather Service said a Red Flag Warning means warm temperatures, very low humidities and stronger winds are expected to combine to produce an increased risk of wildfires.

What is a Red Flag Warning?

Red Flag Warnings alert fire managers on federal lands to conditions that are highly unfavorable for scheduled burns and that may lead to especially dangerous wildfire growth.

The warnings are usually issued during the spring and fall fire weather seasons: Feb. 15 through April 30 and Oct. 1 through Dec. 15.

When the warnings are issued, officials know to be on the lookout for wildfires and curtail planned burns.

What is needed to issue a Red Flag Warning?

The NWS says the following criteria must be met to issue a warning:

  • 10-hour fuels of 8% or less. This describes how much water is held by small vegetation such as grass, leaves and mulch that take only about 10 hours to respond to changes in dry/wet conditions
  • Relative humidity less than 25% for several hours.
  • Winds 20 feet off the ground of at least 15 mph for several hours

In some states, dry lightning and unstable air are criteria. A Fire Weather Watch may be issued prior to the Red Flag Warning.

What to do during Red Flag Warnings

The NWS offered the following tips:

  • If you are allowed to burn in your area, all burn barrels must be covered with a weighted metal cover, with holes no larger than 3/4 of an inch.
  • Do not throw cigarettes or matches out of a moving vehicle. They may ignite dry grass on the side of the road and become a wildfire.
  • Extinguish all outdoor fires properly. Drown fires with plenty of water and stir to make sure everything is cold to the touch. Dunk charcoal in water until cold. Do not throw live charcoal on the ground and leave it.
  • Never leave a fire unattended. Sparks or embers can blow into leaves or grass, ignite a fire, and quickly spread.