A firestorm is a conflagration which attains such intensity that it creates and sustains its own wind system. It is most commonly a natural phenomenon, created during some of the largest bushfires and wildfires. Although the term has been used to describe certain large fires, the phenomenon's determining characteristic is a fire with its own storm-force winds from every point of the compass towards the storm's center, where the air is heated and then ascends.
The Oakland firestorm of 1991 was a large suburban wildland–urban interface conflagration that occurred on the hillsides of northern Oakland, California, and southeastern Berkeley over the weekend of October 19–20, 1991, before being brought under full control on October 23. The official name of this incident by Cal Fire is the Tunnel Fire. However, it is also commonly referred to as the Oakland Hills firestorm or the East Bay Hills fire. The fire ultimately killed 25 people and injured 150 others. The 1,520 acres destroyed included 2,843 single-family dwellings and 437 apartment and condominium units. The economic loss from the fire was estimated at $1.5 billion.
A controlled or prescribed (Rx) burn, which can include hazard reduction burning, backfire, swailing or a burn-off, is a fire set intentionally for purposes of forest management, fire suppression, farming, prairie restoration or greenhouse gas abatement. A controlled burn may also refer to the intentional burning of slash and fuels through burn piles. Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters.
A fuel ladder or ladder fuel is a firefighting term for live or dead vegetation that allows a fire to climb up from the landscape or forest floor into the tree canopy. Common ladder fuels include tall grasses, shrubs, and tree branches, both living and dead. The removal of fuel ladders is part of defensible space 'firescaping' practices.
This glossary of wildfire terms is a list of definitions of terms and concepts relevant to wildfires and wildland firefighting. Except where noted, terms have largely been sourced from a 1998 Fireline Handbook transcribed for a Conflict 21 counter-terrorism studies website by the Air National Guard.
A fire retardant is a substance that is used to slow down or stop the spread of fire or reduce its intensity. This is commonly accomplished by chemical reactions that reduce the flammability of fuels or delay their combustion. Fire retardants may also cool the fuel through physical action or endothermic chemical reactions. Fire retardants are available as powder, to be mixed with water, as fire-fighting foams and fire-retardant gels. Fire retardants are also available as coatings or sprays to be applied to an object.
Smouldering or smoldering is the slow, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase fuel. Many solid materials can sustain a smouldering reaction, including coal, cellulose, wood, cotton, tobacco, cannabis, peat, plant litter, humus, synthetic foams, charring polymers including polyurethane foam and some types of dust. Common examples of smouldering phenomena are the initiation of residential fires on upholstered furniture by weak heat sources, and the persistent combustion of biomass behind the flaming front of wildfires.
Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts depend on many factors such as the available fuel, the local atmospheric conditions, the features of the terrain, and the size of the wildfire. Because of this wildfire suppression in wild land areas usually requires different techniques, equipment, and training from the more familiar structure fire fighting found in populated areas. Working in conjunction with specially designed aerial firefighting aircraft, fire engines, tools, firefighting foams, fire retardants, and using various firefighting techniques, wildfire-trained crews work to suppress flames, construct fire lines, and extinguish flames and areas of heat in order to protect resources and natural wilderness. Wildfire suppression also addresses the issues of the wildland–urban interface, where populated areas border with wild land areas.
The Yellowstone fires of 1988 collectively formed the largest wildfire in the recorded history of Yellowstone National Park in the United States. Starting as many smaller individual fires, the flames quickly spread out of control due to drought conditions and increasing winds, combining into several large conflagrations which burned for several months. The fires almost destroyed two major visitor destinations and, on September 8, 1988, the entire park was closed to all non-emergency personnel for the first time in its history. Only the arrival of cool and moist weather in the late autumn brought the fires to an end. A total of 793,880 acres (3,213 km2), or 36 percent of the park, burned at varying levels of severity.
Fire-retardant gels are superabsorbent polymer slurries with a "consistency almost like petroleum jelly." Fire-retardant gels can also be slurries that are composed of a combination of water, starch, and clay. Used as fire retardants, they can be used for structure protection and in direct-attack applications against wildfires.
A defensible space, in the context of fire control, is a natural and/or landscaped area around a structure that has been maintained and designed to reduce fire danger. The practice is sometimes called firescaping. "Defensible space" is also used in the context of wildfires, especially in the wildland-urban interface (WUI). This defensible space reduces the risk that fire will spread from one area to another, or to a structure, and provides firefighters access and a safer area from which to defend a threatened area. Firefighters sometimes do not attempt to protect structures without adequate defensible space, as it is less safe and less likely to succeed.
Wildfire suppression in the United States has had a long and varied history. For most of the 20th century, any form of wildland fire, whether it was naturally caused or otherwise, was quickly suppressed for fear of uncontrollable and destructive conflagrations such as the Peshtigo Fire in 1871 and the Great Fire of 1910. In the 1960s, policies governing wildfire suppression changed due to ecological studies that recognized fire as a natural process necessary for new growth. Today, policies advocating complete fire suppression have been exchanged for those who encourage wildland fire use, or the allowing of fire to act as a tool, such as the case with controlled burns.
The wildland–urban interface (WUI) is a zone of transition between wilderness and land developed by human activity – an area where a built environment meets or intermingles with a natural environment. Human settlements in the WUI are at a greater risk of catastrophic wildfire.
Wildfires are outdoor fires that occur in the wilderness or other vast spaces. Other common names associated with wildfires are brushfire and forest fire. Since wildfires can occur anywhere on the planet, except for Antarctica, they pose a threat to civilizations and wildlife alike. In terms of emergency management, wildfires can be particularly devastating. Given their ability to destroy large areas of entire ecosystems, there must be a contingency plan in effect to be as prepared as possible in case of a wildfire and to be adequately prepared to handle the aftermath of one as well.
The Waldo Canyon fire was a forest fire that started approximately 4 miles (6.4 km) northwest of Colorado Springs, Colorado on June 23, 2012, and was declared 100 percent contained on July 10, 2012, after no smoke plumes were visible on a small portion of the containment line on Blodgett Peak. The fire was active in the Pike National Forest and adjoining areas, covering a total of 18,247 acres. The fire had caused the evacuation of over 32,000 residents of Colorado Springs, Manitou Springs and Woodland Park, several small mountain communities along the southwestern side of U.S. Highway 24, and partial evacuation of the United States Air Force Academy. There were 346 homes destroyed by the fire. U.S. Highway 24, a major east–west road, was closed in both directions. The Waldo Canyon Fire resulted in insurance claims totaling more than US $453.7 million. It was the most destructive fire in Colorado state history, as measured by the number of homes destroyed, until the Black Forest Fire surpassed it almost a year later when it consumed 486 homes and damaged 28 others.
Forestry mulching is a land clearing method that uses a single machine to cut, grind, and clear vegetation.
The Ikes Fire was a 2019 wildfire that burned 16,416 acres (6,643 ha) in Grand Canyon National Park and Kaibab National Forest in Arizona. A lightning strike on July 25, 2019, was determined to be the cause. The Ikes Fire was also being utilized to fulfill its natural role within a fire-dependent ecosystem while providing for point protection of identified sensitive natural and cultural resources. Resource objectives included reducing hazardous fuels, promoting forest regeneration, improving wildlife habitat, and restoring more open forest understory. These objectives will lead to a healthier and more resilient landscape.
The 1998 Florida wildfires, sometimes referred to as the Florida Firestorm, was a wildfire event involving several thousand separate woodland and mixed urban-rural wildfires which wrought severe damage during the summer months of 1998. Wildfires sparked mainly by lightning threatened to converge into single, vast blazes, crossed natural firebreaks such as rivers and interstate highways, and demanded an unprecedented suppression response of firefighting resources from across the country. Regular activities such as Fourth of July celebrations, sporting events, tourism, and daily life were profoundly interrupted for millions of residents and visitors in the northeastern part of the state.
The Mill Fire was a fast-moving, deadly and destructive wildfire that burned during the 2022 California wildfire season, destroying parts of the communities of Weed, Lake Shastina and Edgewood in Siskiyou County in the U.S. state of California. Igniting during hot, dry & windy conditions on September 2, 2022, amid a record-breaking heat wave that spanned much of the state, the Mill Fire moved rapidly to the north. Most of the fire's acreage burned and structures destroyed occurred on the first day, due to its predominantly wind-driven nature. The Mill Fire burned 3,935 acres, destroyed 118 structures, and damaged 26 more. The fire also caused 2 fatalities when two residents of Weed were unable to escape the quick-moving blaze in its first hours. The fire was fully contained on September 13, 2022.
The Silver Fire was a 1987 wildfire in the Siskiyou National Forest in Oregon. It burned 96,240 acres (389 km2), of which 42,350 acres (171 km2) was located in the Kalmiopsis Wilderness. Parts of its burned area were re-burned in the Biscuit Fire and the Chetco Bar Fire. It was started by a lightning strike near Silver Creek on August 30, and was contained on November 2 after a dry summer in the area, with relative humidity as low as 4% at times in certain places, was ended by heavy rain. Firefighters from across the country, as far away as Virginia, went to Oregon to fight the fire. Nearly 4,000 people were involved in the effort.
