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Type: Conference Proceedings
Author(s): Paul Sopko; Donald J. Latham; Isaac C. Grenfell
Editor(s): Bret W. Butler; Wayne A. Cook
Publication Date: 2007

A Lightning Ignition Efficiency map was added to the suite of daily maps offered by the Wildland Fire Assessment System (WFAS) in 1999. This map computes a lightning probability of ignition (POI) based on the estimated fuel type, fuel depth, and 100-hour fuel moisture interpolated from the Remote Automated Weather Station (RAWS) network. An attempt to verify the efficiency map was made using cloud-to-ground (CG) lightning discharge data acquired at the Missoula Fire Lab (through the Vaisala Corporation network), lightning fire location data from within USDA Forest Service (FS) Region 1 boundaries, and daily 100-hour fuel moisture values retrieved from historical National Fire Danger Rating System (NFDRS) archives for the 2003 fire season. Daily POI maps were recomputed for 153 days (May through September). Daily CG lightning density grids for the same timeframe were computed from lightning discharge data and were multiplied by the POI grid to yield a daily 1-km predicted number-of-fires or fire 'possibility' grid. A daily lightning-caused fire density grid was produced using various agency fire occurrence databases from May through September. While preliminary spatial neighborhood analysis showed some predictive capability, the predicted number of lightning caused fires exceeded the actual reported fires. This overestimation could be due to the lack of differentiation between an ignition and reported fire and errors in fire occurrence databases. Being able to predict whether lightning resulted from a 'wet' or 'dry' storm could improve predictive ability. More refined and spatially accurate fuel maps have become available and are planned to be incorporated into future models.

Online Links
Citation: Sopko, Paul; Latham, Don; Grenfell, Isaac. 2007. Verification of the WFAS lightning efficiency map. Pages 539-551 In: Butler, Bret W.; Cook, Wayne (comps.). The fire environment-innovations, management, and policy; conference proceedings. 26-30 March 2007; Destin, FL. Proceedings RMRS-P-46CD. Fort Collins, CO: USDA Forest Service, Rocky Mountain Research Station.

Cataloging Information

  • fire management
  • Lightning Ignition Efficiency map
  • probability of ignition
  • WFAS - Wildland Fire Assessment System
Record Last Modified:
Record Maintained By: FRAMES Staff (
FRAMES Record Number: 7554