Prediction of Fire Success 



There are many variable conditions at the time of each burn (table 1). Many of 

 the atmospheric conditions compensate for each other; a low value of one can be offset 

 by a high value of another. When maximum windspeed, air temperature, and percent vege- 

 tation cover are added together, this composite score becomes a good indicator of burn- 

 ing success in the scattered and dense pinyon- juniper communities (table 2) . The score 



Table 2 . --Composite score and hvm ratings during 1974-76 bums at White River and 



Blaakwell Canyon, Nevada 



Burn date 



: Windspeed 



: Tempera - 

 : ture 



: Vegetation: 

 : cover : 



Score-^ : 



Simple : 

 score : 

 rating^ : 



Discriminant 

 analysis 

 rating^ 



: Actual 

 : rating 





Mi/h 



op 



Percent 











No burn prediction (score <110) 













9 Dec 76 



10 



35 



49 



94 



3 



3 



3 



10 Nov 76 







50 



51 



101 



3 



3 



3 



Continual 



retorching necessary (score 110-125) 











15 Nov 75 



7 



55 



56 





Z 





O 



Z 



9 Oct 75 



10 



53 



56 



119 



2 



2 



2 



16 May 75 



5 



65 



50 



120 



2 



2 



2 



10 May 76 



8 



70 



43 



121 



2 



3 



3 



2 May 75 



8 



58 



56 



122 



2 



2 



2 



3 May 75 



10 



56 



56 



122 



2 



2 



2 



Clean bum 



prediction 



(score 126- 



130) 











9 Nov 76 



8 



55 



63 



126 





2 



1 



17 May 76 



12 



72 



43 



127 





1 



1 



27 May 76 



6 



78 



43 



127 





2 



3 



22 Jun 76 



18 



66 



43 



127 





1 



1 



17 Nov 74 



10 



51 



66 



127 





1 



1 



9 May 75 



8 



65 



55 



128 





2 



1 



23 Jun 76 



15 



71 



43 



129 





1 



1 



12 Jun 75 



12 



77 



42 



130 





1 



1 



Hazardous 



burning conditions (score >130) 











24 Apr 75 



25 



60 



46 



131 



'^l 



1 



1 



3 May 76 



8 



78 



48 



134 







__5 



__5 



Score is derived by using the following formula: maximum windspeed (mi/h) + 

 temperature (°F) + percent vegetation cover = score. 



^3 = no burn (score <110); 2 = continual retorching necessary (score 110-125); 

 1 = clean burn, fire carries (score 126-130); = too hazardous to burn (score >130). 



^From Klecka (1975). 



'^This burn made one short run outside of the intended boundaries. It was felt 

 that we were very close to or into the hazardous conditions for burning. 



^The USPS Class I Fire Boss would not allow ignition this date, so no comparative 

 or actual ratings were made. 



8 



