Eldorado National Forest

Current Conditions: Daily Status

Indices, Activity Levels, and Burn Day Status

Updated after 5:00 PM by Camino Interagency Emergency Command Center during the appropriate seasons.

Actual Date: September 24, 2008
Predicted Date: September 25, 2008

Burn Day Information

Descriptions

The following are descriptions or links to descriptions of different Indices and Levels:

• Sale Activity Level (pdf) Old system.
• Project Activity Level - PAL is a scientifically-based “decision support process” to provide a fire precautionary system for industrial operations on National Forest lands in California. It’s goal is to balance the reduction in the ignition risk of large damaging wildfires with the accomplishment of resource (forest projects) management activities.
  • PAL is a danger-rating climatology-based system. It considers the effects of weather conditions for the last 30-45 days and overall seasonality.
    SAL is a fire-behavior-based system. It only considers the previous 24 hours and does not consider the moisture levels of live and large dead fuels.
    
  • The Project Activity Level is derived from a matrix using the Energy Release Component (ERC) and Ignition Component (IC) outputs from the National Fire Danger Rating System (NFDRS) processor within the Weather Information Management System (WIMS). WIMS receives weather observations from Remote Automated Weather Stations (RAWS) which are used to calculate ERC and IC. PAL uses ERC to better represent large fuel moistures and weather from the previous 30-45 days to reduce significant fluctuations in activity levels on a daily basis.
• Burning Index - The Burning Index (BI) is an NFDRS index relating to the flame length at the head of the fire. BI is an estimate of the potential difficulty of fire control as a function of how fast and how hot a fire could burn. It has been scaled so that the BI value divided by 10 predicts the flame length at the head of a fire. For example, a BI of 75 would predict a flame length of 7.5 feet. BI is a function of the Spread Component and the Energy Release Component, and has moderate variability. It is sensitive to fuel models, and can trace seasonal trends reasonably well for models with heavy dead or live components. Because it uses wind and relative humidity, it is also very sensitive to weather observation errors.
• Adjetive Rating (R) - A public information component of the NFDRS specific to the rating of fire danger. Adjective ratings are: low(L), moderate(M), high(H), very high(VH) and extreme(E).
• Energy Release Component - The Energy Release Component (ERC) is an NFDRS index (National Fire Danger Rating System) related to how hot a fire could burn. It is directly related to the 24-hour, potential worst case, total available energy (BTUs) per unit area (in square feet) within the flaming front at the head of a fire. The ERC can serve as a good characterization of a fire season as it tracks seasonal fire danger trends well. The ERC is a function of the fuel model and live and dead fuel moistures. Fuel loading, woody fuel moistures, and larger fuel moistures all have an influence on the ERC, while the lighter fuels have less influence and wind speed has none. ERC has low variability, and is the best fire danger component for indicating the effects of intermediate to long-term drying on fire behavior (if it is a significant factor) although it is not intended for use as a drought index.
• Ignition Component (IC) - Related to the probability of a firebrand producing a fire that will require suppression action. It is mainly a function of the 1 hour time lag (fine fuels) fuel moisture content and the temperature of the receptive fine fuels. IC has no units. A percentage of probability from 1-100.
• Lightning Activity Level (pdf)