The Application of Southwest Monsoon Data and Forecasts to Wildland Fire Management Program for Climate, Ecosystem and Fire Applications Timothy Brown CEFA, Desert Research Institute Gregg Garfin CLIMAS, University of Arizona 21 Apr 2004

Fire Management Perspective Suppression resources –Monsoon does not necessarily reduce number of fires… –but likely reduces fire behavior severity (i.e., large fires) Prescribed fire –Intentionally lit fires to meet a planned management objective Prescribed natural fire use –Use of natural started fire to meet a planned management objective

AZ/NM Fire Occurrence

Changes in atmospheric conditions stemming from the monsoon result in both fire producing and fire mitigating effects The Southwest Monsoon and Wildland Fire USDA-FS

Human- and Lightning-Caused Fires in the Southwest Monsoon Region

Key Monsoon-Fire Physical Elements Relative humidity Wet versus dry thunderstorms –precipitation

Key Monsoon-Fire Attributes Onset date Strength –magnitude of RH –number of wet T-storms Intraseasonal consistency –no long dry periods

Monsoon Forecast Uses for Fire Management Temperature, RH, wind speed –Rx fire prescription parameters –Fire danger calculations Wet/dry thunderstorms –Ignition potential –Suppression resource demands –Fire crew safety Precipitation –Fire danger calculations –Ignition potential

Relevance to Fire Weather Meteorologist Provide fire weather watches and red flag warnings –Firefighter safety –Tactical planning Provide value added information –Fire danger –Fire behavior –Fire potential Provide medium-range forecasts –Strategic planning

Monsoon Research Issues of Interest to Fire Agencies Improving seasonal and medium-range forecasts of onset Assessing accuracy of GFS RH forecasts –Perception: RH values typically too high during monsoon season Improving ability to predict strength and consistency of monsoon Improving ability to predict wet versus dry thunderstorms

Monsoon Research Issues of Interest to Fire Agencies What factors lead to monsoon false-start or double onsets? What atmospheric patterns should be utilized for monsoon monitoring and prediction?

Monsoon Research Issues of Interest to Fire Agencies Establishing monsoon definition relevant to fire management –Current dew point definition is not applicable –Could be function of atmospheric circulation or a meteorological variable, but… –Might better be a fire danger or fire potential index – closely linked to fire business Cost Resources Management actions

BI FM RH Timber fuel prescription matrix - Zone 2 Day 1 forecast T WS Burn assessment FM: 1000 hr time lag fuel moisture BI: Burning index