Forest Fires in the United States

13 June 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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Fig. 1. and 2. Fire Danger Forecast Maps of the United States and Alaska for 12 June (observation time) and 13 June 2000 (forecast).
(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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Fig. 3. Keetch-Byram Drought Index Map of the United States, 12 June 2000
(Source: Fire Behavior Research Work Unit, Missoula)

 

According to the Fire and Aviation Management Morning Report (12 June 2000), current wildfires are burning in:
New Mexico:
VIVEASH: This 28,283 acre (11,445 hectars)  fire is burning on the Santa Fe National Forest five miles northwest of Pecos, New Mexico. 80% of the work has been done to contain the fire. There are 292 people working on the fire.
CHANCE: This 32,860 acre (13,298 hectars) fire is burning on Bureau of Land Management administered land 30 miles southwest of Datil, New Mexico. 100% of the work hasbeen done for containment and this will be the last report unless conditions change. There are 392 people working on the fire.
Arizona:
OUTLET: This 14,118 acre (5,713 hectars) fire is burning at Grand Canyon National Park lands, 25 miles south of Jacob Lake, Arizona. 90% of the work has been completed to contain this fire. There are 234 people working on the fire.
Florida:
BRIGHT HOUR: This 1,100 acre (445 hectars) fire is burning on Florida State Division of Forestry administered land in Desoto County, Florida. 80% of the work to contain the fire is completed. There are 9 people working on the fire.
MICROWAVE: This 5,000 acre (2,023 hectars) fire is burning on lands protected by the Florida State Division of Forestry in Osceola County. 90% of the work has been done toward containment. There are 14 people working on the fire.
CYPRESS #2: This 1,000 acre (404 hectars) fire is burning on Florida State Division of Forestry managed land near Gainesville, Florida. 100% of the work has been
completed to contain this fire and this will be the last report unless conditions change. There are 70 people working on the fire.
DC COMMAND: This 1,000 acre (404 hectars) fire is burning on Florida State Division of Forestry managed land near Homestead, Florida. There are 5 people working on the fire. 50% of the work has been completed for containment.
SHIP COMMAND: This 625 acre (253 hectars)  fire is burning on Florida State Division of Forestry managed lands in Hillsborough County. There are 37 people working on this fire and 80% of the work has been completed for containment.
LOUISE: This 4,000 acre (1,618 hectars) fire is burning on Florida State Division of Forestry administered land in Alachua County near Gainesville, Florida. 60 people are working on this fire. 90% of the work has been done toward containment.
Colorado:
BOOTH: This 550 acre (223 hectars) fire is burning on Department of Defense lands on the Fort Carson military installation south of Colorado Springs, Colorado. 100% of the work has been completed for containment of this fire and this will be the last report unless conditions change. 47 people are working on the fire
Utah:
BROWN SPRINGS: This 3,500 acre (1,416 hectars) fire is burning southeast of Tooele, Utah, on the west side of the Cedar Mountains. 100% of the work has been completed for containment of the fire and this will be the last report unless the situation changes. 15 people are working on the fire.
WING: This 700 acre (283 hectars) human caused fire is burning on the Uinta National Forest near the city of Springville, Utah. 20% of the work has been completed to contain of this fire. 198 people are working on the fire.

 

The National Interagency Fire Center (NIFC) Wildland Fire Update (12 June 2000) shows, that wildland fire activity was moderate during the weekend with less than 120 new fires reported from throughout the country. Firefighters made good progress the past two days reaching containment on numerous large fires in several states. Currently 13 large fires are burning in Arizona, California, Florida, New Mexico and Utah for a total of 55,966 acres (22,648 hectars).
Arizona and New Mexico are expected to receive scattered thunderstorms and locally heavy precipitation. The Great Basin area will have mostly sunny skies with temperatures ranging from the 70s (21-26°C) in the mountains to 105 degrees (40°C) in the deserts. Florida will be partly sunny with scattered showers and thunderstorms. Very high to extreme fire conditions were reported from Arizona, New Mexico, Utah, Nevada, California, Colorado, Texas, Kansas, Minnesota, and Mississippi.

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Fig. 4. Large Wildland Fires in the United States, 12 June 2000.
(National Interagency Fire Center)

 

NIFC Incident Management Situation Report (12 June 2000)
Current Situation:
Initial attack activity was minimal throughout the country and firefighters achieved containment goals on fires in the Southwest, Eastern Great Basin, Rocky Mountain, and Southern Areas. Alaska has 13 fires burning in limited protection areas for 1,570 acres (635 hectars). Very high to extreme fire indices were reported in Arizona, New Mexico, Utah, Nevada, California, Colorado, Texas, Kansas, Minnesota, and Mississippi.
Outlook:
The mountains of New Mexico and southeast Arizona will have scattered thunderstorms and locally heavy precipitation. The rest of the Great Basin area will have mostly sunny skies. Temperatures will range from the 70's (21- 26°C)in the mountains to near 105 (40°C) in the deserts. Winds will be south to southwest at 10 to 20 mph (16-32km/h). Minimum relative humidities will be 5 to 15 percent in desert areas and 15 to 30 percent elsewhere.
Florida will be partly sunny with scattered showers and thunderstorms, most likely in the south. High temperatures will be in the mid 80's (29°C) to the lower 90's (33°C). Winds will be east to south at 10 mph (16 km/h). Minimum relative humidities will be 40 to 50 percent in the north and up to 60 percent in south Florida.

 

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).

Tab.1. Five-Year Wildland Fire Comparison Statistics Year-to-Date for the United States (12 June 2000)
(Source: National Interagency Fire Center (NIFC)

As of 12 June 2000 Number of Wildland Fires Area burnt
Acres Hectars
2000 44,318 1,210,368 489,818
1999 43,583 854,206 345,684
1998 25,873 596,365 241,340
1997 29,772 475,258 192,330
1996 61,008 1,848,917 748,230

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Fig. 5. 30 and 90-day temperature and precipitation forecast maps (June and June to August 2000)
(Source: National Weather Service, Boise, Idaho)

 

NIFC Wildland Fire Potential Assessment (8 June to 6 July 2000):
ALASKA - Potential: normal. Temperatures have been below normal and precipitation has been above normal for the last six weeks. May was the second coolest in the past 35 years, and green-up was a week or more later than usual. Currently south-central Alaska has the greatest fire potential. Thunderstorm activity should increase later this month and cause a normal amount of fire activity in the interior.
NORTHWEST - Potential: Below normal to normal. Temperatures and precipitation have been normal for the past month. Live fuel moistures are above average and have been measured at 121% in central Oregon to 131% in eastern Washington. 1000 hour dead fuel moistures have been above normal in most of the area and generally are being measured from 28% in the west to 17% in the eastern regions. Low potential for fire occurrence and severity is expected for most of the area. In the lower elevations of eastern Washington and Oregon, predicted warmer and drier than normal weather conditions will lead to a normal potential for fires.
CALIFORNIA - Potential: Normal to above normal. Precipitation has been below normal and temperatures have been above normal in southern California. In the north both temperature and precipitation have been normal. Some moderate drought conditions still exist in southern California. 1000 hour fuel moistures are normal for this time of year throughout the area. Precipitation received in June will be critical to determining the rest of the season for northern California. The May pattern of less marine influence on southern California will likely continue through June, promoting the likeliness of above average temperatures and low humidities.
NORTHERN ROCKIES - Potential: Normal. Precipitation has been below normal and temperatures have been above normal during the last month in most of the area except for northern Idaho, where both have been normal. Live fuel moisture is below normal east of the Continental Divide. 1000 hour dead fuel moisture is running 9 to 12 percent below normal and is measured at 13 to 21%. Eastern and central Montana are experiencing moderate to severe drought conditions, but wetting rains at the end of May have brought some relief. If normal June rains occur, fire occurrence will be average.
GREAT BASIN - Potential: Normal to above normal. Temperatures have been above normal during the past month while precipitation has been normal to below normal through the area. Snowpack is 45 to 80 percent of normal in the higher elevations, and most areas are reporting that they are two to three weeks ahead of normal fire season, because of the mild winter. Frost-killed fuels are a concern in eastern Utah. Fine fuel carryover from the past several years is contributing to increased risk of fire activity in Nevada. 1000 hr fuel moistures were measured at 10 to 25% throughout the Great Basin and are 10% below normal in Nevada. Moderate to severe drought conditions are being reported in both southern Nevada and southern Utah.
SOUTHWEST - Potential: Above normal. Precipitation has been below normal everywhere except in southeastern Arizona, where it has been normal. Temperatures have been above normal in all parts of the region, as much as 5 to 8 degrees Fahrenheit. Long range forecasts call for above normal temperatures to persist during this month. Long range outlook indicates above normal precipitation for Arizona and New Mexico. 1000 hour fuel moistures are below normal in the central and southern regions and normal in the north. Live fuel moisture is in the 50 to 90 percent range everywhere except the northern portions of both state where live fuel moistures are measured in the 70 to 110 percent ranges. PDI indicates that moderate to severe drought conditions continue throughout all of Arizona and all except the northeast part of New Mexico.
ROCKY MOUNTAIN - Potential: Normal to above normal. Precipitation has been normal to below normal and temperatures have been normal to above normal in the past month. Live fuel moistures have been normal except in southern and western Colorado, where they have been up to 40 percent below normal. 1000 hour fuel moistures are below normal for this time of year at 7 to 12% in the west and 10 to 14% in the east. Fire activity is expected to be above normal in southwestern Colorado and in southwestern Wyoming. Due to the anticipated weather pattern where waves of moisture move through about once a week, fire events should be of high intensity but relatively short duration.
EASTERN - Potential: Normal to above normal. Temperatures and precipitation have been normal in most of the Eastern Area, except in the Upper Great Lakes region, where precipitation has been below normal. 1000 hr fuels are being measured in the 19 to 25% ranges, approximately 3% below normal for this time of year. Moderate to severe drought conditions exist in the central Midwest and the upper Great Lakes region. Green-up and increased precipitation over the past two weeks have significantly reduced fire danger everywhere except in the Upper Great Lakes area.
SOUTHERN -Potential: Normal to above normal. Temperatures have been above normal and precipitation has been normal to below normal through most of the area last month. Approximately one third of the area has a soil moisture deficit of six inches or more. Long-term precipitation anomalies are substantial over most of the region. Southern Louisiana, Georgia, western South Carolina, and central Florida all report extreme drought conditions. 1000 hour fuel moistures are being measured at 7% in parts of Florida and around 20% in the rest 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 climatology 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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Fig.6. Map describing the wildland fire potential (8 June - 6 July 2000) for areas throughout the country.
(Source: National Interagency Fire Center)

 

An article, titeled Park Service to change prescribed burn policy which was posted yesterday (12 June 2000) by ENN World Wire gives a brief overview of the currently ongoing discussion on brescribed burning.

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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