INFORMATION AND SAFETY RULES
Although wildfires are not
an actual weather phenomenon, wildfires are directly related to weather. The
wildfire threat across the Inland Northwest normally increases significantly
after the middle of June. This threat usually peaks in early July and remains
high through August and early September. Wildfires across the Inland Northwest
average about 2000 each year.
Wildfire on a mountain
side at the 30 Mile Fire near Wintrop of June 2001
Most forest fires in the
Inland Northwest are ignited by lightning. Many rangeland and wheatfield fires
are also started by lightning. The majority of these lightning caused wildfires
occur in the absence or very little rain. When this occurs, the lightning is
commonly referred to as "dry lightning". Gusty winds often accompany
thunderstorms which produce "dry lightning". These gusty winds accelerate
the spread of fires.
Lightning which strikes
the ground is usually divided into two categories; negative and positive strikes,
depending on the ionic source region of the thunderstorm. The negative strikes
are far more common than positive strikes. The positive strikes are more intense
than the negative strikes and are more likely to ignite a fire. Advances in
lightning detection technology now provide land manages, firefighters and weather
forecasters with the ability to identify the general location and charge category
of each lightning strike within the continental U.S.
Lightning is often accompanied
by winds associated with thunderstorms. Occasionally, the winds are in the form
of strong microbursts resulting from rapid cooling of air below the thunderstorm
where rain has evaporated. These thunderstorm winds can quickly turn smoldering
organic material into a raging fire. Thunderstorm winds tend to be erratic in
direction and speed, posing one of the greatest dangers for firefighters.
National Weather Service
forecasters help land managers and firefighters by producing fire weather forecasts
on a daily basis during the warm season. "Spot" fire weather forecasts
are also provided for those who work on prescribed burns or specific wildfires.
Forecasters also issue red flag warnings for use by land managers when the combination
of dry vegetation and critical weather conditions will result in a high fire
danger. Land managers, in turn, typically inform the general public of the fire
danger in National Parks, Forests and other public lands.
PERIODS WHEN A HIGH FIRE POTENTIAL EXISTS IN FORESTS AND RANGELANDS...
- You should avoid being
in areas where you might become trapped by a wildfire.
- You should avoid the
use of matches or anything else which could ignite a fire.
- Make sure that hot parts
of motorized equipment, such as mufflers, are not allowed to come in contact
with dry grasses or other potentially flammable material.
- If you become trapped
or cut-off by a fire, seek shelter in areas with little or no fuel such as
rock slide areas or lakes.
For more information on
wildfires and safety, please check out the NWS Spokane
Fire weather web page.