Spot fire distance equations for pocket calculators
Document Type: Report
Author(s): Carolyn H. Chase
Publication Year: 1981

Cataloging Information

  • spot fire distance
  • spotting
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Record Last Modified: December 13, 2016
FRAMES Record Number: 8158


This note presents equations for calculating maximum spot fire distance from firebrand sources in the Intermountain West based on prevailing windspeed, vegetation cover, and terrain in the area. The equations include the capability to predict spotting distance from a torching tree(s) or from a continuous flame source such as slash piles or jackpots of heavy fuels. The equations can be used on a programmable pocket calculator. Potential uses are seen in fire management planning and real-time fire behavior predictions. For copies of a program for the Texas Instruments TI-59, send seven blank TI-59 magnetic cards to the author.

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Chase, Carolyn H. 1981. Spot fire distance equations for pocket calculators. Research Note INT-RN-310. Ogden, UT: USDA Forest Service, Intermountain Forest and Range Experiment Station. 21 p.