Establishing Relationships between Drought Indices and Wildfire Danger Outputs: A Test Case for the California-Nevada Drought Early Warning System

Authors

Daniel J. McEvoy, Desert Research Institute & Western Regional Climate CenterFollow
Mike Hobbins, University of Colorado Boulder & NOAA/Earth System Research Laboratory/Physical Sciences DivisionFollow
Timothy J. Brown, Desert Research Institute & Western Regional Climate CenterFollow
Kristin Vander Molen, Desert Research Institute & Western Regional Climate CenterFollow
Tamara Wall, Desert Research Institute & Western Regional Climate CenterFollow
Justin L. Huntington, Western Regional Climate Center & Desert Research InstituteFollow
Mark D. Svoboda, National Drought Mitigation Center/University of Nebraska-LincolnFollow

ORCID IDs

https://orcid.org/0000-0002-0001-8265

https://orcid.org/0000-0001-7926-0742

Date of this Version

4-5-2019

Citation

2019 by the authors

Comments

Climate 2019, 7, 52; doi:10.3390/cli7040052 www.mdpi.com/journal/climate

Abstract

Relationships between drought indices and fire danger outputs are examined to (1) incorporate fire risk information into the National Integrated Drought Information System California–Nevada Drought EarlyWarning System and (2) provide a baseline analysis for application of drought indices into a fire risk management framework. We analyzed four drought indices that incorporate precipitation and evaporative demand (E0) and three fire indices that reflect fuel moisture and potential fire intensity. Seasonally averaged fire danger outputs were most strongly correlated to multi-scalar drought indices that use E0 (the Evaporative Demand Drought Index (EDDI) and the Standardized Precipitation Evapotranspiration Index (SPEI)) at approximately annual time scales that reflect buildup of antecedent drought conditions. Results indicate that EDDI and SPEI can inform seasonal fire potential outlooks at the beginning of summer. An E0 decomposition case study of conditions prior to the Tubbs Fire in Northern California indicate high E0 (97th percentile) driven predominantly by low humidity signaled increased fire potential several days before the start of the fire. Initial use of EDDI by fire management groups during summer and fall 2018 highlights several value-added applications, including seasonal fire potential outlooks, funding fire severity level requests, and assessing set-up conditions prior to large, explosive fire cases.