Fire & Aviation
Fire Danger Rating System
The various factors of fuels, weather, topography and risk are combined to assess the daily fire potential on an area.
Fire Danger
Rating and Color
Code |
Description |
Low (L)
(Green)
|
Fuels do not ignite readily from small firebrands although
a more intense heat source, such as lightning, may start fires in
duff or punky wood. Fires in open cured grasslands may burn freely
a few hours after rain, but woods fires spread slowly by creeping
or smoldering, and burn in irregular fingers. There is little danger
of spotting. |
Moderate (M)
(Blue)
|
Fires can start from most accidental causes, but with
the exception of lightning fires in some areas, the number of starts
is generally low. Fires in open cured grasslands will burn briskly
and spread rapidly on windy days. Timber fires spread slowly to moderately
fast. The average fire is of moderate intensity, although heavy concentrations
of fuel, especially draped fuel, may burn hot. Short-distance spotting
may occur, but is not persistent. Fires are not likely to become serious
and control is relatively easy. |
High (H)
(Yellow)
|
All fine dead fuels ignite readily and fires start easily
from most causes. Unattended brush and campfires are likely to escape.
Fires spread rapidly and short-distance spotting is common. High-intensity
burning may develop on slopes or in concentrations of fine fuels.
Fires may become serious and their control difficult unless they are
attacked successfully while small. |
Very High (VH)
(Orange)
|
Fires start easily from all causes and, immediately
after ignition, spread rapidly and increase quickly in intensity.
Spot fires are a constant danger. Fires burning in light fuels may
quickly develop high intensity characteristics such as long-distance
spotting and fire whirlwinds when they burn into heavier fuels. |
Extreme (E)
(Red)
|
Fires start quickly, spread furiously, and burn intensely.
All fires are potentially serious. Development into high intensity
burning will usually be faster and occur from smaller fires than in
the very high fire danger class. Direct attack is rarely possible
and may be dangerous except immediately after ignition. Fires that
develop headway in heavy slash or in conifer stands may be unmanageable
while the extreme burning condition lasts. Under these conditions
the only effective and safe control action is on the flanks until
the weather changes or the fuel supply lessens. |
To learn more about the National
Wildfire Coordinating Group, visit the NWCG website
at http://www.nwcg.gov.
|