Description

Maximum wind speed and 10-hour timelag fuel moisture were the two most important variables for predicting the ignition of dry cow dung by medium and large firebrands. For punky wood, the easiest fuel to ignite, 10-hour timelag fuel moisture and days since precipitation were the best predictors. Judging by data from 32 prescribed burns, air temperature was the best predictor for the maximum distance of spot fires. Firebrands (flaming and non-flaming) did not ignite materials beyond 100 feet when the air temperature was below 60°F. Above 60°F, the distance of spot fires from the leading edge of the fire was an exponential function of air temperature.