Wildland Fire Behavior Alert
July 31, 2007
THE POTENTIAL FOR EXTREME FIRE BEHAVIOR EXISTS THIS SEASON FOR
ALL CAL FIRE UNITS AND CONTRACT COUNTIES
The large number of early season shelter deployments and other fire behavior related incidents warrant a review of the conditions that contribute to extreme fire behavior. All of California is experiencing prolonged, record breaking drought and critical fuels conditions. Situational awareness is more than a buzz word – assess the big picture;
Situation factors to consider:
• Assess/scout the fire
• Always include SAFETY in your actions; making it your number one priority!
• Know the Weather
• Know Previous & Predicted Fire Behavior
• Have the Communications Plan & use it
• Look for & understand Local Factors relating to fire behavior
Concerns for Firefighters to Consider
• Live fuel moisture samples across the state, and especially in Southern California, have been the lowest sampled in history. Critical fuel moisture will be reached at least two months early in most areas. The heat sink properties that live fuel moisture usually provide will be absent this season. Assume live fuels are fully available to burn. Low live fuel moistures and heavier than normal dead fuel accumulations under stressed vegetation will cause explosive fire behavior.
• Weather conditions were unusually dry this spring with historically low rainfall and mountain snow pack over the entire state. Soil moisture is exceedingly low and large dead fuels are fully cured. Fuel beds will support rapid ignition, heavy spotting, & high intensity fire spread.
• Energy Release Component (ERC) values are above the 90th percentile in all areas, and above the 97th percentile in the most critical areas of the state. The 97th percentile indicates that only 3% of observations have ever been recorded above that level; in other words, the ERC values currently being recorded in most areas of the state are at historical highs. Remember, the ERC calculation is dominated by fuels and does not consider wind or topography and typically trends better than other NFDRS Indices.
• Topography plays a significant role in fire intensity through slope, aspect, and channeling. Watch for the daily changes in sun exposure over the various aspects and consider topographic channeling or alignment when evaluating your position.
Gather intelligence and remember the fundamentals – emphasize and implement LCES prior to engagement! Develop situational awareness of the critical conditions described above. Use your experience or ask the locals what situations cause the greatest difficulty.
How’s it burning? If your gut makes you anxious, there is probably a good reason! Re-evaluate your situation and act accordingly. Clear and concise communication must be maintained.
Evaluate conditions continuously. Monitor fire weather conditions throughout your commitment. Pay attention to how internal and external distractions affect your risk-decisions. Focus on the Big Picture, not the narrow view immediately in front of you.
You are empowered to make risk-decisions based on current and expected conditions and your evaluation of probability of success. When considering structure protection, ask yourself, "Is the structure defendable and would you be there if the structure was not?" Do not attempt a frontal assault on a fast moving fire. Existing conditions warrant a "back to the basics" approach to safely mitigate incidents; anchor and flank, one foot in the black, valid safety zones and escape routes. Once you figure all these things out, communicate them to all concerned and make sure someone is acting as a knowledgeable and capable lookout. DO NOT OVER COMMIT!
THE FIRST PRIORITY FOR ALL DECISIONS IS FIREFIGHTER SURVIVAL.
As of 9 a.m. on July 31 there are no major state or local incidents. CAL FIRE is assisting federal firefighting agencies throughout California.
15 miles northeast of Buellton
Santa Barbara County
This fire has burned 33,500 acres and is now 60 percent contained. The Zaca Fire started on July 4 and is burning in steep and rocky terrain. Low humidity and winds resulted in extreme fire behavior yesterday within the Los Padres National Forest wilderness area. Weather conditions are predicted to be relatively the same throughout the week. An evacuation order has been issued for the Community of Peachtree. For the most current evacuation information contact the Zaca Fire Information Center at (805) 961-5770. Over 1,000 firefighters are assigned to this fire. The fire is under a unified command with Santa Barbara County Fire and the US Forest Service. The full containment date is estimated to be September 7.
Elk Complex Fire
Near Happy Camp
This fire has burned 12,656 acres and is 77 percent contained. Of the 30 identified fires in the Elk Complex, 25 are now 100 percent contained. The fires will continue to be monitored, patrolled and staffed as safety, resources and access permit. Over 900 firefighters are assigned to the complex. The complex is expected to be fully contained on August 5.
Abundant monsoonal moisture across Nevada will slowly edge westwards towards California today. A weak upper level low off the Central Coast will help shift southwest winds to a more southeast direction by this evening into Wednesday. This should be enough for thunderstorms to form along the Sierra Crest and move further north and northwest into the Northern Sierra area. Isolated thunderstorms, mainly dry are possible this evening near the Tahoe Basin. On Wednesday, a larger scale monsoonal push of moisture will let up with a more widespread thunderstorm threat both wet and dry. Thunderstorm activity could linger into Thursday across the area, but would be mainly wet with locally heavy rain in some spots.
A ridge of high pressure centered over the Four Corners Area will maintain near normal temperatures over the region through Friday. A Pacific trough will move over the West Coast bringing cooler temperatures Saturday through early next week. Humidity will be low across most of the region through early next week. Isolated to scattered showers and thunderstorms will continue over the Eastern Deserts through early next week.