toward suppression. The score of 130 appears to be close to this separation point. Of 

 those burning attempts made during the project, conditions above 131 were not tested and 

 no fires became dangerous or burned excessive acreages beyond the expected limits. 



It is certain there are numerous and more complex variables involved in fire spread 

 potential; however, this simple score seems to work as a general rule of thumb and it 

 provides a guide for the land manager. 



CONCLUSION 



Land managers wanting to do out-of-f ire-season burning are sometimes reluctant be- 

 cause they are not sure of the conditions needed to carry a fire. Many times, a day is 

 spent in preparation and travel to the proposed burn site only to find that conditions 

 are not adequate to carry a fire. A simple rule of thumb would aid in this burn or no- 

 bum decision. The managers needs to know only the sum of the maximum windspeed in 

 miles per hour, the air temperature in degrees Fahrenheit, and the percent vegetative 

 cover (mi/h + °F + percent veg. cover = score) to predict if his fire will be successful. 



A score of less than 110 will not provide conditions necessary for burning. A 

 score of 110 to 125 indicates conditions prevail for burning; however, the area will 

 need to be continually reignited during the entire burn period and unburned islands 

 will occur. A score of 125 to 130 is optimum. After the ignition area is lit, the 

 fire will carry by itself burning the area clean, with only some reignition necessary. 

 A score above 130 indicates a hazardous condition in the scattered and dense pinyon- 

 juniper communities when burning should not be attempted. 



If the percent cover of vegetation is measured prior to burning and the desired 

 wind direction is known for ignition points, the manager can predict his chances for a 

 successful burn from the daily weather forecasts. 



10 



