27 June 2011
Posted in WFTV Severe Weather Center 9
Wildfires are a product of temperature, wind and moisture. High temperatures, high winds and low humidity are conditions that are of concern, especially to those in the West now. These are what can be called red flag conditions. Conditions like these contribute to intense fire behavior and rapid fire growth much like what has been seen recently with the Arizona and New Mexico wildfires.
High temperatures are what serve to induce the first spark to the fire. The ground, including plants, sticks and underbrush, absorbs radiant heat from the sun, which serves to heat and dry potential fuels. Warmer temperatures combined with low humidity or dry air allow for fuels to ignite and burn faster, adding to the rate that wildfires spread. For this reason, wildfires tend to rage in the afternoon, when temperatures are hotter. In New Mexico, the Las Conchas wildfire grew to cover over 43,000 acres in a little less than a day.
Note: This is the first in a three part article describing the recent wildfirs in the Western US and what causes wildfires in general. Check back for the second part on how wind adds to the dangerous mix.