Presentation on theme: "LPF DRAFT 04/29/02 Los Padres National Forest Pocket Cards Fire Season 2002."— Presentation transcript:
LPF DRAFT 04/29/02 Los Padres National Forest Pocket Cards Fire Season 2002
LPF DRAFT 04/29/02 Why a Pocket Card? Its in response to the 30-Mile Accident Prevention Plan, the Chief of the Forest Service directed that each fireline supervisor will be issued a pocket card for fuel types on their home unit. All fireline supervisors will be issued a pocket card before deployment on assignments by the receiving unit.
LPF DRAFT 04/29/02 Why a Pocket Card? (continued) Pocket Cards are intended to enhance firefighter Situational Awareness. Distribution and utilization should lead to a greater Situational Awareness of potential fire danger and subsequently increase firefighter safety. Forests are responsible for briefing all incoming off-Forest resources and cooperators with the units pocket card information prior to deploying them on assignments.
LPF DRAFT 04/29/02 The Pocket Card – What is it? The Pocket Card is a visual aid for firefighters. It makes a general assessment of fire potential based on local weather conditions and historical fire occurrence. It is a tool for interpreting fire danger ratings for an area – local or non-local. -When a firefighter hears a fire danger value (such a BI of 89) from Dispatch, they can relate it to an areas potential for fire activity (i.e. Dispatch calls for a BI of 124, the pocket card shows that a BI of 89 is normal for this time of year. This means that the fire danger is higher than normal for this time of year.
LPF DRAFT 04/29/02 The Pocket Card – What is it? (continued) The Card should also communicate thresholds of concern for large fires. It identifies local factors that effect local fire danger and large fire potential (i.e. sundowner winds, etc).
LPF DRAFT 04/29/02 The Pocket Card – Basic guidelines for building a pocket card. Determine an area of applicability, such as a fire danger rating area, or combine fire danger rating areas, or a protection unit, or administrative unit, etc. Find weather station(s) that best represent that area. Must have at least 10 years of data or more (more is preferable) with weather observations from 1972 through 2001 or as close as possible. Minimum months used are May through October (5/1 – 10/30). Utilize a fire danger index and a fuel model that is used in daily operations. The Los Padres NF uses Burning Index and Fuel Model B – California Chaparral.
LPF DRAFT 04/29/02 The Pocket Card – Basic guidelines for building a pocket card. (continued) Years to remember – use recent historical years for comparison of fire danger conditions. Develop critical thresholds – identify local thresholds and local factors affecting fire behavior, such as relative humidity levels, or critical fuel moisture levels. Past experience – Include current fire season conditions, past fire events that are significant, local factors that influence fire danger (i.e. sundowners) etc.
LPF DRAFT 04/29/02 Example pocket card
LPF DRAFT 04/29/02 Unit name that the pocket card is designed to cover Upper left corner of the pocket card. Fire danger index used – this card uses Burning Index (BI) Red dashed line indicates a percentile – an index level that historically represents at what threshold large fires occur. Months of May – Oct were selected The black line is the maximum B.I. by day from years used to develop the pocket card – for this card. Average daily B.I. from years used to develop the pocket card – 2001 for this card. High point shows peak fire season
LPF DRAFT 04/29/02 Upper right corner of the pocket card. Unit name and NFDRS Areas – 2 NFDRS areas (SIG) were used for this card due to inconsistency in the weather data Describes the fire danger found in the upper left corner of the pocket card. The thresholds are designed to alert firefighters that fire behavior is expected to increase when combinations of any of these factors occur.
LPF DRAFT 04/29/02 Lower left corner of the pocket card. Fire danger index used again Years that stand out from past fire seasons in the NFDRS areas. Blue line is 1985 and the Red line is NFDRS Fuel Model assigned to the NFDRS Weather Stations Names of large fires in the NFDRS area Red dashed line indicates a percentile – an index level that historically represents at what threshold large fires occur.
LPF DRAFT 04/29/02 Lower right corner of the pocket card. Explains the index used – in this case B.I. This area describes significant past fire events, current conditions, local conditions that contribute to large fire growth, and/or other information pertinent to current and past fire danger. Also, the date the card was developed.
LPF DRAFT 04/29/02 Fire Danger Indices that can be used for the development of Pocket Cards: Energy Release Component (ERC) – an estimate of the potential energy release in the flaming zone of a fire. The higher the ERC, the harder a fire will be to suppress. The ERC traces the seasonal trends in fire danger, rather than short term fluctuations. As live fuels cure and dead fuels dry, the ERC values get higher, which provides a good idea of drought conditions. Wind is not a component of ERC. Burning Index (BI) – attempts to estimate how a fire will burn once started. If a fire occurs in the worst fuel, weather, and topography conditions in the rating area, these numbers indicate the expected fireline intensities and flame length. It is calculated by combining Spread Component and ERC. It is expressed as a numeric value closely related to flame length in feet divided by 10. (i.e. B.I. Of 124 = 12.4 foot flame lengths.) Wind is a component. BI fluctuates more than ERC.
LPF DRAFT 04/29/02 Fire Danger Indices that can be used for the development of Pocket Cards: (continued) Spread Component (SC) – predicts the rate of spread based on predicted wind, slope, and fuel. Since this component uses wind and fuel moisture in its calculations, it is much more sensitive to short-term changes in conditions. Ignition Component (IC) – an estimate of the likelihood of spot fires developing. Most sensitive to changing conditions. Uses air and fuel temperatures, relative humidity, and cloudiness to estimate the percent of firebrands that may start a spot fire. (i.e. IC of 45 indicates that 45 out of 100 firebrands are likely to start new fires.