Forest Fires in the United States

24 October 2000


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 23 October 2000 (observation time) and 24 October 2000 (forecast)
(Source: WAFS)

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, 23 October 2000
(Source: WAFS)

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, 23 October 2000
(Source: WAFS)

 

The BLM - Alaska Fire Service Initial Attack Management System (IAMS) is suite of computer applications developed by BLM/Fire to aid dispatchers and fire managers. IAMS Maps is one of these applications and provides graphical representation of various kinds of geographic data. Maps has been modified to produce output to a Web site to allow internet access to the data that IAMS stores. Dynamic data such as lightning (available May - September), fires, etc. are updated at the homepage of the BLM - Alaska Fire Service  (select Maps / AFS IAMS Maps Viewer) every 15 minutes during the fire season.

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IAMS image of active fires in Alaska, 23 October 2000
(Source: BLM - Alaska Fire Service)

 

Operational Significant Event Imagery (OSEI) (22 October 2000)
The following significant events were identified by Satellite Analysis Branch meteorologists and reviewed by the OSEI support team:

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NESDIS/OSEI NOAA-14 AVHRR HRPT satellite images, 22 October 2000 
Heat signatures are visible from fires burning in British Columbia and the Northwest U.S.
(Source: NESDIS/OSEI)

 

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 (see below), the biggest wildfire in Idaho.
(Source: GeoMAC)

 

USFS Fire and Aviation Management Morning Report (23 October 2000) [conversion table]
National Overview:
Preparedness Level I
One new large fire was reported in Northern California. Initial attack activity was light throughout the nation. One large fire reached containment in the Eastern Area. Very high to extreme fire indices were reported in Minnesota and California.

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

  Yesterday Year to Date Ten Year Average
Fires 113 85,140 67,765
Acres Burned 4,321 6,987,815 3,153,769
Estimated Daily Cost $504,000    

Burned Area Emergency Rehabilitation Summary as of 18 October 2000

311,340 Acres Severely Burned 82 Rehabilitation Plans
Costs: $36 million 4,550 acres mulched
25,498 acres weed treated Over 78,000 acres seeded
Over 1200 miles of road drainage protection 85 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 22 October 2000:
60 – 20 person crews, 21 helicopter, 185 engines, and 2,528 total personnel. 1 air tanker was committed, however, 31 remain available across the country.

Weather Outlook (23 October 2000) [conversion table]:
A FIRE WEATHER WATCH IS POSTED IN THE PANHANDLE AND PORTIONS OF NORTHWEST FLORIDA FOR LOW RELATIVE HUMIDITY AND STRONG WINDS.
A RED FLAG WARNING IS POSTED IN NORTHERN CALIFORNIA FOR LOW RELATIVE HUMIDITY AND STRONG WINDS IN THE SACRAMENTO VALLEY AND SURROUNDING FOOTHILLS SOUTH OF RED BLUFF. HIGHER ELEVATIONS OF NORTH AND EASTERN ASPECTS IN THE MENDOCINO NATIONAL FOREST WILL ALSO BE AFFECTED.
Southern California will be mostly cloudy with a chance of showers and thunderstorms mainly south and east of Los Angeles. Temperatures will be in the 50's to 70's in the mountains and coastal areas, and in the 80's in the southern and eastern deserts. Afternoon relative humidity will be 20 to 40 percent, except for the areas of wetting rains. Winds will be east to southeast at 10 to 20 mph. Minnesota will be mostly cloudy with a few showers. High temperatures will be in the upper 50's to 60's. Winds will be northwest at 10 to 15 mph and the relative humidity will be 40 to 55 percent.

USFS Fire News (23 October 2000):
Minnesota fire still smoldering
Overnight rain reliefed firefighters on the 8600-acre Carlos Edge Fire north of the Twin Cities; about a third of an inch of rain saturated ground fuels, but the fire is still burning underground in peat. Crews are digging up the peat and forcing water into the ground. The fire was about 70 percent contained yesterday. An infrared overflight to locate hotspots was planned for yesterday; about 300 firefighters are still on the fire. Though most of the flames were extinguished Saturday night, the area is still smoldering. The burned area of the refuge will remain closed to the public until at least Wednesday, and because of problems with sightseers, the area is restricted to residents only. Losses have not been totaled, but three houses, one garage, and a trailer were completely destroyed. The fire zone has been declared an emergency area by FEMA, so federal money will help with up to 70 percent of the state's suppression costs.
California fire update
The 3970-acre Hidden Fire near Middletown was reported at 75 percent containment. Crews have put in 13 miles of line, and more than 1000 personnel are on the fire, along with five helicopters, two lead planes, and an air attack. Existing line is holding, even with the strong winds, and crews expect to complete the fireline yesterday. Some demobilization is also expected for 23 October 2000.
Another fire yesterday in San Jose started when a powerline fell into a pine tree. Firefighters were worried that the gusting winds could spread embers and re-ignite the fire.
(Information Sources: )

 

National Interagency Fire Center (NIFC)
Although the US fire season is not over yet, there is available a Wildland Fire Season Overview from January through October 2000.

NIFC Wildland Fire Potential Assessment (5 October - 2 November 2000):
ALASKA - Potential: Below normal. Temperatures have been below normal and precipitation has been above normal for the last four to six weeks. Nighttime temperatures are routinely falling below freezing in the Interior. The 1000 hour and live fuel moisture levels are normal for this time of year. Typical October fire occurrence is five fires for .1 acre.
NORTHWESTPotential: 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 below average in all areas and have been measured at 59% to 148% in Washington and 53% to 124% in Oregon. 1000-hour dead fuel moistures are also below average for this time of the year. Measurements range from 8% to 19% in Washington and 5% to 16 % in Oregon. The Energy Release Component (ERC) is showing well above average for southeastern Oregon, average for northwestern Washington and above average for the rest of the area. Palmer Drought Index (PDI) indicates extreme to severe drought conditions in eastern Washington and Oregon. The long-range weather forecast calls for average to above normal temperatures and below average precipitation for most of the area.
CALIFORNIA - Potential: Normal to above normal. Temperatures and precipitation have been normal for Northern California. Live fuel moistures have reached their critical levels and are now mostly dormant. 1000-hour fuel moisture in most of the state is around 8% to 15%, which is slightly below average. PDI indicates normal conditions in the north except east of the Sierra range where severe drought conditions persist. Long range forecast calls for normal temperatures and slightly below normal precipitation for Northern California.
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 continuing to experience drought induced stress. Rainfall was received at the first of the month, but the area still lags behind in the year to date precipitation. The PDI indicates extreme and severe drought conditions continue to exist in most of Montana and Idaho. Long-range weather forecasts call for slightly above normal precipitation for southeast Montana and normal conditions for the rest of the area.
GREAT BASIN - Potential: 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 73% to 143% in Nevada and 30% to 120% in the Eastern Great Basin. 1000-hour fuel moisture is averaging 5% to 9% in Nevada and from 6% to 18% in the Eastern Great Basin. Due to precipitation early in the month, shorter days and increased nighttime relative humidity has moderated the fire danger. The PDI indicates that most of the region is still in severe and extreme drought conditions except for southern Nevada. Long-range weather predicts normal to above normal temperatures and below normal precipitation.
SOUTHWEST - Potential: Normal. Temperatures have been normal and precipitation has been normal to a little below normal in eastern New Mexico. PDI shows drought conditions continuing though recent precipitation has lessened the fire danger. The long-range outlook indicates above normal temperatures and slightly below normal precipitation.
ROCKY MOUNTAIN - Potential: Normal to above normal. Temperatures were normal to above normal and precipitation was normal to below normal for the last four to six weeks. Live fuel samples are well below normal for much of the area in the conifer and oakbrush fuels due to lack of long duration precipitation. 1000-hour fuel moisture is around 6% to 10 % in the north-central portions of Wyoming and 11% to 15% in the rest of the area. The potential for short duration large fire occurrence remains high for the period. PDI indicates severe and moderate drought in most of the area. The long-range forecast calls for above normal temperatures and below normal precipitation for most of the area.
EASTERN - Potential: Normal. Temperatures have been below normal in Indiana, Minnesota and the Lower Peninsula of Michigan. Above normal temperatures were observed for the rest of the area. Precipitation has been above normal through much of the area for the last month. The 1000-hour fuels are currently ranging from 18% to 30% which is slightly below average for this time of year. The PDI indicates that most areas are near normal or wetter than normal. Potential still exists for large fire growth in the southern part of the area due to continuing drought conditions. Long-range climate forecasts call for normal temperatures except for the Great Lakes, which is predicted to be below normal. The Eastern Seaboard is predicted to have above normal precipitation this month and normal rainfall for the rest of the area.
SOUTHERN - Potential: Normal to above normal. Temperatures have been below normal in Kentucky and Virginia and normal elsewhere. Precipitation has been below normal in Texas, Oklahoma and Louisiana. The PDI shows large portions of Texas, Mississippi, and Alabama to be in severe to extreme drought conditions. The long-range outlook is calling for above normal temperatures and normal precipitation for 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, 5 October - 2 November 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 (October and October to December 2000)
(Source: National Weather Service)

 

The Clear Creek Complex in Idaho (Salmon-Challis National Forest, 13 October 2000)
CLEAR CREEK FIRE 100 % CONTAINED!!
The Clear Creek fire was declared 100 % contained today at 1:13 PM, almost three months to the day that it blew up and changed the summer for many people. There are still 36 people involved with the fire in the form of overhead, monitoring and rehabilitation of the suppression activities.
The recent rain and snow on the burned area helped to declare it contained, but is also hampering the rehabilitation efforts. There’s very little left to do out there, but it may not get finished if it stays wet until we’re snowed out.
The fire area will still be monitored by air and ground until it is declared controlled.

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Clear Creek Fire Progression
(Source: Salmon-Challis National Forest)

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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.

Satellite movie of Clear creek fire 7/23 (1.150 MB; AVI-format): Clear creek fire is at 2nd arrow from bottom-a little to the right.

 

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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