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California Fuels and Fire Behavior Advisory

BillJune 24, 2008July 30, 2019Uncategorizedfire behavior advisory

Issued June 21. Better late than never.
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Subject: Low live and dead fuel moistures, along with persistent drought, have created the potential for active to extreme fire behavior in many low to mid-elevation parts of the state.

Discussion: With the exception of the northwest corner of the state, most of California is experiencing drought conditions. Effects of lower than normal live and dead fuel moistures and localized sudden oak death are the focus of this advisory.

Concerns to Firefighters:
• Energy Release Components (ERC) at numerous weather stations in the affected Predictive Service Areas (PSA) are setting record highs; this is an indication of very dry fuels. Expect increased fire intensity and spread rates in these areas. Already this year several burnover situations have occurred. The fuels in these PSA’s are primarily grass and brush. A common denominator of fire behavior on tragedy and near-miss fires: Flare-ups generally occur in deceptively light fuels, such as grass and light brush.
• The combination of persistent drought in the South and record setting low March-May precipitation totals in the North has led to low live and dead fuel moistures. Expect fires to ignite easier and spread faster. During mobile attack in light fuels engine crews have found that it takes more time using additional water to knock down fire under these current conditions.
• Both live and dead fuel moistures are 3-6 weeks ahead of last year’s drying rates. Low 1000 hour fuel moistures have been evidenced by complete consumption on recent fires. Anticipate increased spread rates, spotting, and active nighttime burning. Link to extreme fire behavior video on the Indians fire in the Central Coast Mountains:
http://gacc.nifc.gov/oncc/predictive/fuels_fire-danger/LP_FIRE_BEHAVIOR_08.wmv
• Localized sudden oak death (SOD) has affected a number of oak species in southern California.
Fire behavior in areas affected with SOD is often more intense due to increased fuel loadings.

Mitigation Measures:
• Local and inbound fire personnel need to develop situational awareness of the conditions represented in this advisory. Details on site specific conditions regarding ERC’s, live and dead fuel moistures, and/or disease should be covered during briefings.
• Ensure firefighters have good anchor points, escape routes, and safety zones. Remember LCES.
• Consult the latest Fire Weather Forecasts, Monthly Fire Weather / Fire Danger Outlooks, Pocket Cards, and the recently updated California Fire Season Assessment (July-October) posted at:
http://gacc.nifc.gov/oncc/predictive/index.htm
http://gacc.nifc.gov/oscc/predictive/index.htm

Area of Concern: The area of concern covers the following 6 PSA’s in California: Bay Area, Central Coast Mountains and Valleys, Mid Coast to Mendocino, Sierra Foothills, Sacramento Valley Foothills and the portion of the Northern Sierras below 3,000 feet elevation. A map showing the areas of concern described in this advisory can be found at:
http://www.nifc.gov/nicc/predictive/fuels_fire-danger/fuels_advisories.htm

Issued: June 21, 2008 Valid Until Further Notice
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HERE is a link to the document that includes a map.

(From FireNet)

Arizona: Fuels and fire behavior advisory

BillMay 8, 2008November 19, 2020UncategorizedArizona, fire behavior advisory

Posted at the Southwest Coordination Center web site:

Subject: Heavy Fine Fuel Loads Have Created the Potential for More Active Fire Behavior

Discussion: Above-average rains during the summers of 2006 and 2007 have created heavier than normal fine fuel loads in southern Arizona, especially in desert areas infested with Buffelgrass (Pennisetum ciliare).

Many grassland areas in southeastern Arizona (above 3,500’) have had above average precipitation the past two summers, creating a heavy crop of grass. Historically, this situation has been followed by a year with large fires.

In addition, buffelgrass continues to increase in desert areas. Buffelgrass is a noxious, non-native grass that is roughly doubling each year in Pima County. Fuel loads can be 5-20 times greater than annual grasses like red brome. Because it is increasing so rapidly, firefighters may find thick grass in places that traditionally had little. Because the fuel load is so heavy, it can generate fireline intensity and flame length much more extreme than usual for the desert. Strategies and tactics normally used on desert fires may not succeed on buffelgrass fires.

Common denominators of tragedy fires are potentially present in deserts and grasslands: relatively small fires or deceptively quiet areas of large fires; relatively light fuels, such as grass, herbs, and light brush; unexpected shift in wind direction or in wind speed; fire responds to topographic conditions and runs uphill.

Concerns to Firefighters and the Public:

• Flame length in grass can exceed 4 feet at almost any time of year, exceeding capability of hand tools. Flame lengths can exceed 8 feet during fire season, exceeding the capability of light engines.

• Grass fuels can be continuous, creating wide flaming fronts.

• Greater fireline intensity can lead to increased torching of shrubs and increased spot fires.

• Anticipate fire whirls because of a combination of fuel loading, terrain, and unstable atmosphere.

• Heavier fuel load raises moisture of extinction, and active burning may occur throughout the night.

• Normally bare, rocky areas and steep, south-facing slopes may have enough grass to carry a fire.

• Washes and trails that formerly served as fuel breaks may no longer be effective.

• Retardant may be less effective at stopping fires where grass is thick.

• Greater fireline intensity and flame length increase threat to structures, power poles, and other improvements.

• Some Wildland Urban Interface areas are infested with buffelgrass. Increased fire behavior increases risk to structures, improvements, and public safety, and there is potential for more human-caused fires.

• Increased fuel loading increases radiant heat output, therefore increasing the risk of thermal burns.

• The outlook for April-June is for above average temperatures and below average rainfall, exacerbating the problem.

Mitigation Measures:

• Indirect tactics may have to be used more often.

• Maintain situational awareness of fuel conditions and fire behavior.

• Safety zone size may need to be larger than usual for the desert. Safety zones may be harder to find.

• Use of Nomex face shrouds helps protect the face and airways.

Area of Concern: Desert