The Application of Southwest Monsoon Data and Forecasts to Wildland Fire

Management

Program for Climate, Ecosystemand Fire Applications

Timothy BrownCEFA, Desert Research Institute

Gregg GarfinCLIMAS, 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

20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

BI

05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

1000-FM

RH

Timber fuel prescription matrix - Zone 2

Day 1 forecast

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

T

WS

Burn assessment

FM: 1000 hr time lag fuel moistureBI: Burning index