Forest Fires in the United States

11 July 2000


Colorado fire under control [conversion table]
Fire crews brought on Sunday a 4,960-acre wildfire under control. The fire south of Gateway, Colorado, was controlled at 6 p.m. Sunday, a week after it was reported. The fire was caused by lightning and it cost approx. $1.3 million to extinguish. About 125 miles to the north, the Buster Flats Fire remained 65 percent contained for a second day after burning 11,033 acres in and around Dinosaur National Park. The forecast called for cooler temperatures and higher humidity. Officials projected the fire would be 100 percent contained, or completely encircled by fire lines, by Tuesday. Four helicopters and 221 firefighters, including three hot shot crews.
(information source: Environmental News Network)

 

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 10 July (observation time) and a forecast for 11 July 2000.
(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 the United States, 10 July 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, 10 July 2000
(Source: Fire Behavior Research Work Unit, Missoula)

 

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, 10 July 2000
(Source: BLM - Alaska Fire Service)

 

Fire and Aviation Management Morning Report (10 July 2000) [conversion table]
Colorado
BUSTER FLATS: This 11,033 acre fire is burning on public lands administered by the National Park Service in the Dinosaur National Monument, 75 miles west of Craig. This fire is burning in pinyon pine and juniper. Parts of the fire have received rain and higher humidities are helping with containment efforts. 85% of the work necessary to contain this fire has been completed. 217 people are assigned to this fire.
Wyoming
WILD HORSE BASIN: This 36,700- acre fire is burning near Rock Springs on public lands administered by the Bureau of Land Management, Rock Springs District. This fire is burning in pinyon pine, juniper and sagebrush. Parts of the fire have received some rain, helping with containment. 90% of the work has been done toward containment. 620 people are working on the fire.
DRY FORK: This 650 acre fire is burning 14 miles northeast of Bill on public lands administered by the Medicine Bow National Forest. All of the work necessary to contain this fire has been completed. 10 people are assigned to this fire. This will be the last report on the fire unless conditions change.
Northwest
OASIS: This 800 acre fire is burning on land protected by Washington State Forestry 15 miles south of Anatone, Washington, on the bank of the Grande Ronde River. Steep terrain, strong wind, and poor access are deterring containment efforts. There is no estimate of containment. 215 persons are assigned to this fire.
Utah
BORROW PIT: This 3,900 acre fire is burning 20 miles southwest of Salt Lake City near Lake Point, on public land administered by the Bureau of Land Management, Salmon-Clearwater District. All of the work necessary to contain this fire has been completed and this will be the last report unless conditions change. 298 people are assigned to this fire.
New Mexico
VERDE: This 650 acre fire is burning on land administered by the Bureau of Land Management 20 miles south of Laguna, New Mexico. 100% of the work has been completed to contain the fire and this will be the last report unless conditions change. 35 people are assigned to this fire.
Alaska
BEARPAW MOUNTAIN: The 34,602 acre fire is burning 100 miles southwest of Fairbanks on public lands administered by the Bureau of Land Management, Tanana Zone. Cabin protection operations are continuing at several locations. 16 people are assigned to this fire.
ZITZIANA: This lightning ignited 165,377 acre fire is burning 85 miles west of Fairbanks on public lands administered by the Bureau of Land Management, Tanana Zone. Parts of the fire have received rain. 69 people are assigned to this fire.
BERING CREEK: This 107,110 acre fire is burning 35 miles southwest of Tanana on public lands administered by the Bureau of Land Management, Tanana Zone. Thick smoke prevented aerial operations yesterday. 73 people are assigned to this fire.

 

National Interagency Fire Center (NIFC) Wildland Fire Update (10 July 2000) [conversion table]
Wildland fire activity was moderate throughout the weekend and firefighters were successful in reaching containment on many large fires in several western states. There are currently eight large fires burning in Alaska, Colorado, Nevada, Oregon, Washington and Wyoming for a total of 356,772 acres. Showers and thunderstorms are expected over Utah, Colorado, Wyoming and southeast Idaho today, with dry lightning storms predicted for Nevada. Winds will be light at 10 to 20 mph with gusts of 25 to 30 mph in the afternoon. The BLM Smokejumpers resumed normal operations after a moratorium was instituted on April 30th, the day after a smokejumper died during a practice jump. The moratorium affected about 130 smokejumpers in Fairbanks, Alaska, and Boise, Idaho.

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Large Wildland Fires in the United States, 10 July 2000.
(Source: National Interagency Fire Center)

 

Five-Year Wildland Fire Comparison Statistics Year-to-Date for the United States (10 July 2000)
(Source: National Interagency Fire Center (NIFC)
[conversion table]

As of 10 July 2000 Number of Wildland Fires Area burnt
Acres
2000 51,519 2,232,874
1999 51,181 1,852,125
1998 38,971 1,351,188
1997 35,422 1,385,294
1996 71,276 2,788,692

 

NIFC Incident Management Situation Report (9 July 2000) [conversion table]
Current Situation:
The Western Great Basin, Northwest, Southern California, and Southern Areas reported new large fire activity. Initial attack activity was light to moderate nationwide. Monsoon moisture is forecast to accompany thunderstorms in the Great Basin, which should moderate new fire activity and assist with containment of existing fires. The National Interagency Coordination Center processed orders for helicopters, an airtanker, infrared aircraft, radio equipment, supplies, a caterer, and miscellaneous overhead. Very high to extreme fire danger indices were reported in Oregon, Washington, Alaska, California, Idaho, Utah, Nevada, Colorado, Wyoming, and Arizona.
Outlook:
Monsoon moisture will again produce scattered wet thunderstorms across Utah, Colorado and Wyoming. Thunderstorms are also anticipated in southeast Idaho as the moisture moves farther north and west. These thunderstorms are expected to produce rain but the rest of Idaho will be dry. Winds will be southwest at 10 to 20 mph with gusts of 25 to 30 mph during the afternoon. Stronger gusts will occur in Wyoming, especially near thunderstorms. Temperatures will range from the 70's in the mountains to the mid 90's in the deserts of southern Utah and Nevada. Minimum humidities will range from 10 to 20 percent in southwest Idaho and the Utah deserts and 20 to 30 percent elsewhere in the Great Basin.

 

Long-range, 30-day weather forecasts are predicting above-normal temperatures and below-normal precipitation 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 (July and July to September 2000)
(Source: National Weather Service, Boise, Idaho)

 

NIFC Wildland Fire Potential Assessment (8 July to 10 August 2000):
ALASKA - Potential: normal.
Temperatures and precipitation have been normal for the last four weeks. Conditions in the interior of the state continue to support fire activity. The Fire Weather Index (FWI), which represents the intensity of a spreading fire in tundra and forest fuels, is currently high in the central interior in many places. Long-range forecasts call for above normal temperatures and normal rainfall.
NORTHWEST - Potential: Normal to above normal.
Temperatures have been above normal and precipitation has been below normal for the area for the past month. Live fuel moistures are average or slightly below average in most areas and have been measured at 80% in central Oregon to 100% in eastern Washington. 1000 hour dead fuel moistures have been normal in the west and slightly below normal in the eastern portions. Measurements range from 13% in eastern Washington to 25% in northwestern Oregon. The central portions of the area are showing moderate drought conditions as measured by the Palmer Drought Index (PDI). Long-range weather forecasts call for normal warm and dry conditions for the month.
CALIFORNIA - Potential: Normal.
Precipitation has been below normal in the south and normal in the north. Temperatures have been above normal in the south and normal in the north. Live fuel moistures are in decline in both zones with timber fuels at around 90% and between 60 to 100% in southern forests. Some moderate drought conditions still exist in southern California and in eastern portions of the Sierra Nevada in the north as measured by the PDI. 1000 hour fuel moisture is below normal for this time of year with measurements of 12%. Actual fire occurrence numbers are near normal and acres are slightly above in the north and below in the south as compared to the 5 year averages. Long-range climate prediction calls for above normal temperatures and normal rainfall for the month.
NORTHERN ROCKIES - Potential: Normal to above normal.
Precipitation has been below normal in much of the area and temperatures have been mostly normal. Live fuel moisture is ranging from 50 to 200% and 1000 hour dead fuel moisture is measured between 9 to 25%. North Dakota is expected to see below normal fire activity due to above average precipitation received during last month. Long-range climate prediction calls for normal temperature and rainfall to occur for the month. PDI indicates moderate to severe drought conditions exist in mainly eastern and central Montana. Fire occurrence and acres reported burned are well above the 5 year averages.
GREAT BASIN - Potential: Above normal.
Temperatures have been above normal during the past month while precipitation has been below normal through the area. Live fuel moisture are around 100% in the north and 65 to 100% in the south which is below the average values for the area. 1000 fuel moisture is being measured at 10% in the West Great Basin and 5 to 20% in the East Great Basin, which is below normal and normal. PDI indicates moderate and severe drought for most of the area. Long-range forecasts call for above normal temperatures and normal precipitation for Nevada and above normal precipitation for southern Utah. Overall, weather conditions are being reported as two to three weeks ahead of normal. Lightning activity in the past two weeks indicates that the northern edge of the monsoonal flow pattern has arrived.
SOUTHWEST - Potential: Normal to above normal.
Precipitation has been normal to above normal everywhere except in northern New Mexico, where it has been below normal. Temperatures have been normal in most parts of the region except northern Arizona, where they were above normal. Live fuel moisture has been measured at 60 to 120% which is normal for most of the area. 1000 hour fuel moisture is 9 to 14% in Arizona and 8 to 20% in New Mexico which is normal for this time of year. The PDI indicates that a large part of New Mexico and all of Arizona is in moderate to severe drought. The exception is south central New Mexico, which is near normal. Fire occurrence is up slightly from the five year average and acreage for the year is up 355% this year. Some significant precipitation has been received since mid June and fire danger has lessened considerably. With the arrival of the monsoon season, it is reasonable to expect this trend to continue.
ROCKY MOUNTAIN - Potential: Normal to above normal.
Temperatures and precipitation have been normal to below normal for the last four weeks. Live fuel moistures have been normal in the north and below normal in the south and west portions of the area with measurements of 95 to 130% in ponderosa pine, pinyon pine and juniper at 80 to 90% and sagebrush at 95%. 1000 hour fuel moistures are measured at 6 to 10% in the west and 11 to 15% east of the Continental Divide which is a little below average for this time of year. Fire activity is expected to be normal with the arrival of the monsoon pattern and above normal if the monsoon is weaker than average and does not move up into the area.
EASTERN - Potential: Normal to below normal.
Temperatures and precipitation have been normal in most of the Eastern Area. Live fuel moisture is at the seasonal normal for this time of year. 1000 hr fuels are being measured in the 20 to 25% ranges for this time of year and are mostly normal. PDI indicates some moderate drought in the western and central portions of the area. Increased precipitation over the past month has contributed to lessening the fire danger situation in the area. The Boundary Waters Canoe Area Wilderness blow down area continues to be of concern.
SOUTHERN -Potential: Normal.
Temperatures have been normal to above normal and precipitation has been normal to below normal through most of the area last month. Live fuel moisture is averaging 150% which is slightly below normal. 1000 hr fuels are being measured from 16 to 35% and are mostly average. PDI indicates moderate and severe drought conditions continuing through much of the area. July historically has a low occurrence of fire activity and the long-range climate prediction calls for above normal temperatures and normal precipitation, except for portions of the Carolinas and Tennessee, which is forecast for below normal.
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 (6 July - 10 August 2000) for areas throughout the country.
(Source: National Interagency Fire Center)

 

Remarks on Prescribed Burning
At this time of the year prescribed burning operations are conducted routinely.
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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