Forest Fires in the United States

10 October 2000


Forest managers were forewarned of high fire risk
TUCSON, Arizona, 9 October 2000 (ENS) - Two wildfires that began this year as prescribed burns would not have been lit if forest managers had listened to experts who warned in February that 2000 would be a year of high fire risk. Fire history expert Thomas Swetnam, director of the University of Arizona Laboratory of Tree-Ring Research, hopes this summer's experience will encourage forest managers to consider the climate prognosis before using such volatile preventive medicine in the future. Wildfires have consumed about 6.5 million acres of western U.S. forests this year, including the 47,000 acres burned around Los Alamos, New Mexico after a prescribed burn raged out of control.
Swetnam recommends prescribed burns to reduce the small trees and dead wood that fuel wildfires. But he is also among the climatologists, meteorologists and regional fire managers who in February warned of high fire hazards this summer in the Southwest and Florida. At their annual meeting in Tucson, the experts warned it would not be a good year for prescribed burns. "The fire season we're seeing this year is in large part related to a climatic event: a large scale La Niņa," Swetnam explained at a University seminar last week. "We should do more prescribed burning in the southwest and southeast during El Niņo years, and then build up fire fighting forces during La Niņa years so we can better fight these big conflagrations. Somehow this message hasn't quite gotten down to all management levels." El Niņo brings a warming pattern in the Eastern Tropical Pacific and wet winters to the southwest and southeast where vegetation thrives. When La Niņa arrives to cool the Eastern Tropical Pacific, it brings drying effects to the southern states and the El Niņo brush turns to tinder. The summer of 2000 was the second year of La Niņa circulation patterns.

 

From the Society of American Foresters

 

The Wildland Fire Assessment System (WFAS) is a contribution of "The Fire Behavior Research Work Unit", Missoula (Montana USA). The broad area component of the Wildland Fire Assessment System (WFAS) generates maps of selected fire weather and fire danger components.

Fire Danger (Potential) is a normalized adjective rating class across different fuel models and station locations. It is based on information provided by local station managers about the primary fuel model, fire danger index selected to reflect staffing level, and climatological class breakpoints. Low danger (class 1) is green and extreme potential (class 5) is red.

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Fire danger maps for the United States for 8 October 2000 (observation time) and 9 October 2000 (forecast)
(Source: Fire Behavior Research Work Unit, Missoula)

Dead fuel moisture responds solely to ambient environmental conditions and is critical in determining fire potential. Dead fuel moistures are classed by timelag. A fuel's timelag is proportional to its diameter and is loosely defined as the time it takes a fuel particle to reach 2/3's of its way to equilibrium with its local environment. Dead fuels in NFDRS have four timelag classes:
1-hr: Fine flashy fuels, less than 1/4" (< 0.63 cm) diameter. Responds quickly to weather changes. Computed from observation time temperature, humidity and cloudiness.
10-hr: 1/4 to 1" (0.63 to 2.54 cm) diameters. Computed from observation time temperature, humidty, and cloudiness, or may be a standard set of "10-Hr Fuel Sticks" that are weighed as part of the fire weather observation.
100-hr: 1 to 3" (2.54 to 7.62 cm) diameter. Computed from 24 hour average boundary condition composed of day length, hours of rain, and daily temperature/humidity ranges.
1000-hr: 3 to 6" (7.62 to 15.24 cm) diameter. Computed from a 7-day average boundary condition composed of day length, hours of rain, and daily temperature/humidity ranges.

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10-HR Fuel Moisture

100-HR Fuel Moisture

1000-HR Fuel Moisture

Fuel moisture maps for conterminous US, 8 October 2000
(Source: Fire Behavior Research Work Unit, Missoula)

The Keetch-Byram Drought Index (KBDI) is a soil/duff drought index that ranges from 0 (no drought) to 800 (extreme drought) and is based on a soil capacity of 8 inches of water. Factors in the index are maximum daily temperature, daily precipitation, antecedent precipitation, and annual precipitation. KBDI = 0 - 200: Soil moisture and large class fuel moistures are high and do not contribute much to fire intensity. Typical of spring dormant season following winter precipitation. KBDI = 200 - 400: Typical of late spring, early growing season. Lower litter and duff layers are drying and beginning to contribute to fire intensity. KBDI = 400 - 600: Typical of late summer, early fall. Lower litter and duff layers actively contribute to fire intensity and will burn actively. KBDI = 600 - 800: Often associated with more severe drought with increased wildfire occurrence. Intense, deep burning fires with significant downwind spotting can be expected. Live fuels can also be expected to burn actively at these levels.
For further information on the Keetch-Byram Drought Index (KBDI) by Florida's Division of Forestry / Forest Protection Bureau please refer to Keetch-Byram Drought Index Revisited: Prescribed Fire Applications.

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Keetch-Byram Drought Index Maps for conterminous US, 8 October 2000
(Source: Fire Behavior Research Work Unit, Missoula)

 

GeoMAC Wildland Fire Support
The GeoMAC (Geospatial Multi-Agency Coordination Group) team has produced an internet based mapping application which allows firefighting coordination centers and incident command teams to access online maps of current fire locations and perimeters. Fire perimeter data is updated daily based upon input from incident intelligence sources, GPS data, IR imagery from fixed wing and satellite platforms. The fire maps also have relational databases in which the user can display information on individual fires such as name of the fire, current acreage and other fire status information. Additional data layers including fuel types, aircraft hazard maps, links to remote weather station data and other critical fire analysis information are currently being added to the GeoMAC application.

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An example of GeoMAC Wildfire Information on forest fires in Idaho and Montana.
The right image shows a screen shot about the fire size at the Clear Creek Complex, the biggest wildfire in Idaho.
(Source: GeoMAC)

The Clear Creek Complex in Idaho (USFS Fire News 10 October 2000)
At day 87 and still counting, the Clear Creek Fire is now 90 percent contained, and fire managers estimate that by November 1 the fire should be fully controlled. Carr's Type II team turned the fire over to local Forest management this week, and most resources are being demobed. The Clear fire camp has been vacated, and things are winding down at a rapid pace. Four crews will remain on the fire to complete mop-up and rehabilitation. They will be housed at the Care Center in Salmon and at the Moyer Housing site in Cobalt. Suppression rehab work is continuing after being put on hold for a day waiting for the soils to dry from the rain showers last weekend. Rehab is about 75 percent completed, and cataloging of additional rehab sites is ongoing. This work will continue until late fall, with an emphasis on preparing the land to withstand the effects of spring runoff. Some of the work that has been occurring or that will start soon includes the planting of riparian species along lower Panther Creek, spreading grass and forb seeds, cross-slope felling and placing of trees in steep areas, laying straw wattles to intercept silt and fine debris, and clearing culverts and ditches.

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Clear Creek Fire Progression
(Source: USFS Fire News)

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A view from the helicopter over parts of the burned area from the Clear Creek Complex.
The fire base camp one month ago.
(Source: GFMC)

The Clear Creek Fire burned in a mosaic pattern, and the varying intensity of the fire is obvious. About 5 percent of the area, much of it in watersheds and elk winter range, shows high intensity burn. About 25 percent of the area burned with moderate intensity, and another 70 percent of the 216,000 acres burned either at low intensity or not at all.

The objective of fire rehabilitation is to mitigate suppression damage of wildfire and restore disturbed areas to as near pre-fire conditions as possible. Damaged meadows and riparian areas and steep slopes with high erosion potential should be prioritized to receive immediate rehabilitation. Several medium-sized track-mounted or rubber-tired excavators and hand crews will be needed to accomplish the rehabilitation work.
General rehabilitation includes: clearing drainage ditches and lead-out ditches of slash and debris, reshaping damaged segments of road near log decks, and watering and grading the road to repair the surface damaged by heavy equipment and excessive traffic.
Standard treatment for rehabilitation of safety zones includes: pulling in topsoil from berms around the perimeter of the safety zone; spreading the recovered topsoil over the disturbed area; distributing slash and limbs and tops from felled and culled trees over the topsoil; and piling and burning excess slash.
As part of fire protection efforts during the Clear Creek fire, a fuel break was constructed along the Salmon River Ridge road above the municipal watershed for the City of Salmon. The work created a large amount of felled trees and high stumps that hamper the effectiveness of the fuel break and impede suppression rehabilitation efforts. Therefore, the high stumps will be crushed or cut flush to the ground and most of the felled trees will be removed from along the fuel break by the equipment performing suppression rehabilitation work.

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Left: Hydrologists, geologists and forester discuss the procedure of a creek rehabilitation.
Bulldozer went through the stream and destroyed the natural stream.
Right: On a very steep slope a bulldozer built a fireline. This area is very sensitive, due to the very high erosion risk.

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Left: The topsoil from berms around the perimeter of a safety zone have to be pulled back.
Right: A former forest road, which was rebuilt and re-seeded (front: green and brown), was again destroyed by a dozerline (back: white).
(Source: GFMC)

Dozerline rehabilitation may be delayed in some areas until salvageable timber is removed under the authority of a timber sale contract. Many areas impacted by dozerline have not yet been inventoried because fire is still actively burning. Specialized equipment and techniques may be necessary to rehabilitate some dozerline. A site-specific plan for each area, similar to the one written for the Mackinaw Creek restoration, will be completed and agreed upon prior to rehabilitation. Due to the number of miles of dozer and hand line that may require suppression rehabilitation and impending winter weather, the Incident Management Team and the Forest may not be able to complete rehabilitation measures this year, except on the highest priority areas.

 

Fire and Aviation Management Morning Report (8 October 2000) [conversion table]
National Overview:
Preparedness Level II
Currently, there is 1 fire over 1,000 acres. The total number of acres burned this year is 219% of the ten-year average. Little activity is being reported on the Clear Creek Fire and it will likely be dropped from the reporting process within a week. Initial attack activity was minimal throughout most of the United States, with some increase in activity in the Eastern Great Basin and Northern California areas. No new large fires were reported. Very high to extreme fire indices were reported in Oregon, California, Idaho, Utah, Arizona, Kansas, and Nebraska.

Summary of Fire Activity Across The United States [conversion table]:

  Yesterday Year to Date Ten Year Average
Fires 42 82,376 67,765
Acres Burned 509 6,897,016 3,153,769
Estimated Daily Cost unavailable    

Regional Summary [conversion table]:

Burned Area Emergency Rehabilitation Summary as of 6 October 2000

281,500 Acres Severely Burned 82 Rehabilitation Plans
Costs: $36 million 4,550 acres mulched
21,500 acres weed treated Over 78,000 acres seeded
Over 1000 miles of road drainage protection 80 miles of stream protection
Over 19,000 acres of intensive erosion control 110 miles of fence construction and reconstruction

Note: Access summary information for individual fires from the NIFC Incident Management Situation Report.

Resources and Statistics:
Resources committed on 7 October 2000:
14 – 20 person crews, 11 helicopters, 50 engines, 10 air tankers (7 in the Southern Area and 3 in California), and 746 total personnel.

Weather Outlook (8 October 2000) [conversion table]
A RED FLAG WARNING IS POSTED FOR NORTHWEST ALABAMA FOR STRONG WINDS.
A RED FLAG WARNING IS POSTED FOR THE PANHANDLE OF FLORIDA FOR STRONG WINDS AND LOW RELATIVE HUMIDITIES.
A RED FLAG WARNING IS POSTED FOR ALL OF MISSISSIPPI FOR LOW FUEL MOISTURE AND LOW RELATIVE HUMIDITIES.
A weak low pressure offshore will keep the coastal areas of California and Southern Oregon under fog. Otherwise a ridge over the western states will slowly shift eastward as a weakening cold front moves into the Pacific Northwest into Canada. High temperatures will be in the 60's to 70's along the coast, 70's and 80's inland and in the 90's to lower 100's in the desert areas and lowest valleys. Winds will be northeast to southeast at 10 to 15 mph across southern Oregon and northern California. South, southwest or onshore winds at 5 to 15 mph elsewhere. Minimum relative humidities will range 10 to 20 percent in the driest areas, 15 to 35 percent inland and higher along and near the coast.
Temperatures in Texas and Oklahoma will be quite cool. Moisture from the Gulf of Mexico will ride over the cold air at the surface helping to bring a slight chance of rain or snow showers across portions of west and central Texas. There will be widespread showers across far south Texas. High temperatures will be in the 40's across north and west Texas and Oklahoma, and in the 50's to 60's east. Winds will be north to northeast at 15 to 25 mph. Minimum relative humidities will range 30 to 40 percent in north and central Texas and Oklahoma, and 60 to 80 percent to the south and west.

 

National Interagency Fire Center (NIFC)
NIFC Wildland Fire Update (6 October 2000) [conversion table]
Initial attack activity was moderate in the Eastern Great Basin, Southern and Southwest areas while the rest of the country was relatively quiet. No new large fires were reported. Texas and Oklahoma will see a cold frontal passage which should bring cooler weather and a good chance of thunderstorms in southeast Texas.

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Large Fire Activity in the United States, 8 October 2000.
(Source: US Forest Service)

NIFC Wildland Fire Potential Assessment (7 September 2000 - 5 October 2000):
ALASKA - Potential: Below normal. Temperatures have been below normal and precipitation has been above normal for the last four to six weeks. August temperatures were the coolest ever recorded for most of the Interior. The Fire Potential Index is low and Fine Fuel Moisture Code is being measured as low and very low throughout the Interior. Shorter days and colder temperatures will continue the below normal fire activity in September.
NORTHWEST – Potential: Normal to above normal. Temperatures have been normal and precipitation has been below normal in the area for the past month. Live fuel moistures are close to average in areas and have been measured at 79% in northeastern Oregon to 161% in northwestern Washington. 1000-hour dead fuel moistures have also been mostly average for this time of the year. Measurements range from 21% in northwestern Washington to 8% in southeastern Oregon. The Energy Release Component (ERC) is being measured at or above average in the west and above average in the eastern portions of the area. PDI (Palmer Drought Index) indicates severe drought conditions in eastern Oregon and extreme drought in central Washington. The long-range weather forecast calls for above normal temperatures and below average precipitation for most of the area.
CALIFORNIA - Potential: Above normal. Temperatures have been normal in the north and above normal in the south. Precipitation has been below normal for the last 4 to 6 weeks and the recent rains could provide only short-term relief. Live fuel moistures in the north are still at critical levels at about 70% in the north. Live fuel moistures are being measured at around 50% to 70% in the south and east and up to 100% in the west. 1000-hour fuel moisture in most of the state is around 6% to 10%, which is below average. Predicted Santa Ana winds could be a factor in the next month. PDI indicates normal conditions in the north and severe and extreme drought in the central and southern areas. Long range forecasts calls for above normal temperatures.
NORTHERN ROCKIES - Potential: Above normal. Precipitation has been below normal in much of the area and temperatures have been above normal. Live fuel moistures are being measured from the 50% to 120% and 1000 hour fuel moistures are generally between 10% to 20 % in the area. Though recent storms in northern Idaho and western Montana have brought some relief to large fire growth, the PDI indicates extreme and severe drought conditions exists in much of the area. Long-range weather forecasts call for above normal temperatures and below normal precipitation in northwestern Idaho.
GREAT BASIN - Potential: Normal to above normal. Temperatures have been above normal during the past month while precipitation has been below normal through the area. Live fuel moisture is ranging from 47% to 113% in Nevada and 51 to 170% in the Eastern Great Basin. 1000-hour fuel moisture is averaging 6% in Nevada and from 5% to 15% in the Eastern Great Basin. Cloudy skies, higher humidities and cooler temperatures have moderated fire conditions for the present. The PDI indicates that most of the region is in severe and extreme drought conditions except for southern Nevada. Long-range weather predicts normal to above normal temperatures and near normal precipitation.
SOUTHWEST - Potential: Normal. Temperatures have been normal and precipitation has been normal to above normal. Live fuel moisture readings are normal in much of the area at 95% to 120%. 1000-hour fuel moisture levels are normal to above normal at 10% to 14% in Arizona and 10% to 18% in New Mexico. Palmer Drought Index (PDI) shows extreme drought conditions in Arizona and severe drought in central and western New Mexico. The long-range outlook indicates above normal temperatures and above normal precipitation for the next 30 days.
ROCKY MOUNTAIN - Potential: Normal to above normal. Temperatures were below normal to above normal and precipitation was normal to above normal for the last four to six weeks. Live fuel samples are below normal for much of the area, ranging from 95% in ponderosa pine to 70% to 90% in pinyon pine and juniper fuels. 1000-hour fuel moisture is around 6% to 10 % in the west and 11% to 15% in the east, which is slightly below normal. Normal monsoon moisture did not move far enough north to provide relief from the dry conditions in Wyoming and eastern South Dakota so large fire growth is anticipated in those areas. PDI indicates severe and moderate drought in most of the area. The long-range forecast calls for normal precipitation for Colorado.
EASTERN - Potential: Normal. Temperatures and precipitation have been normal through much of the area for the last month. The 1000-hour fuels are currently ranging from 18% to 25% which is average for this time of year. Potential for any significant activity should be limited to the southern tier states. The PDI indicates that most areas are near normal or wetter than normal. Long-range climate forecasts call for normal temperatures. Below normal precipitation is predicted for the Great Lakes and above normal for the Eastern Seaboard.
SOUTHERN - Potential: Normal to above normal. Temperatures have been below normal in Kentucky and Virginia and normal elsewhere. Precipitation has been below normal in most of the southern tier states. Live fuel moisture is being measured as low as 30% to 50% in Texas and Louisiana and at 120% to 180% elsewhere. 1000 hour dead fuel moisture is at 12% in Louisiana and is averaging 18% through much of the rest of the area. The PDI shows large portions of Texas, Louisiana, Arkansas, Mississippi, Georgia, and Florida and all of Alabama to be in drought conditions. The long-range outlook is calling for normal temperatures and precipitation for most of the area.

Temperatures and Precipitation reflect conditions over the past four to six weeks. The long-range forecast is for the next 30 days. Above and below normal is indicated above in the narrative, areas not mentioned fall in the climatological category which means there are equal chances of being below normal (33.3%), normal (33.3%) or above normal (33.3%).

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Map describing the wildland fire potential, 7 September - 5 October 2000
(Source: NIFC)

 

National Weather Service
Long-range, 30-day weather forecasts are predicting above-normal temperatures for the southern tier of states from southern California to Florida and throughout the Midwest (see 30 and 90-day forecast maps).

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30 and 90-day temperature and precipitation forecast maps (September and September to November 2000)
(Source: National Weather Service)

 

Remarks on Prescribed Burning
Fire is an important natural tool for ecosystem management. It can reduce dense vegetation improving wildlife habitat and lessening the potential for large, wildfire disasters. Land managers are directed to prepare a prescribed fire/burn plan for every area of public land that can burn. Some areas require total suppression while others will benefit from a wildland fire. Those areas that will benefit from a fire can be treated by a prescribed fire.
Especially, for the moment, in the southern and southeastern regions of the United States prescribed fire activities will be carried out in the following weeks and months. In this case, fire signals on satellite images can be traced back to this kind of land management activities.

In the Prescribed Fire Position Paper of the Forest Protection Bureau by the Division of Forestry in Florida, prescribed fire activity is described as a land management application that is essential to the practice of forestry, management of wildlife, preservation of endangered plant and animal species, improvement of range conditions and reduction of wildfire damage in the wildland/urban interface areas. While there is general public and landowner concern with increased smoke, reduced air quality, and liability; the general public and landowners benefit significantly from the reduction of devastating wildfire, improved wildlife habitat and forage, preservation of endangered and threatened plant and animal species, and improved management of forest resources. The prospect of severe reductions in the utilization of this management tool is of major concern to Florida's natural resource managers and conservationists due to the subsequent loss of derived public and private benefits. They suggest the need for legislative attention.

Another report on nation-wide prescribed burning in the U.S.A. was published in  International Forest Fire News No.19 (September 1998).
A set of photographic documents on prescribed burning techniques and objectives in the Southeast can be visited in our photo archive.


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