Forest Fires in the United States: 20 March 2000
Forest Fires in the United States
20 March 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.
Fig. 1. & 2. Fire Danger Forecast Maps of the United States for 19 March (observation time) and 20 March (forecast) 2000
(Source: Fire Behavior Research Work Unit, Missoula)
Wildland Fire Update (17 March 2000)
The National Interagency Fire Center (NIFC) provides new data of the current wildland fire season in the United States. These data were analysed after different geographic regions. Further, a five-year wildland fire comparison statistic shows the number and the area of wildland fires from 1996 to 2000.
Although wildland fire activity decreased during the past week, extreme fire conditions remain in California, Arizona, New Mexico, Texas, Illinois, and Virginia. In the first 77 days of 2000, over 0.5 million acres ( 202,343 ha) have been affected by wildland fires. This figure is nearly three times greater than the four-year average of 185,000 acres (74,867 ha) burned by this time of the year.
While burning conditions in some states are severe, other states throughout the country are experiencing ideal conditions for prescribed fires. As of today, nearly 400,000 acres (161,874 ha) of wildlands have been treated by prescription fires. Prescribed fires are planned under specified conditions intended to improve the health of the natural landscape and/or reduce hazardous build-up of vegetation that lead to devastating wildland fires.
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 Fig.3. 30 and 90-day forecast maps).
Tab.1. Five-Year Wildland Fire Comparison Statistics Year-to-Date for the United States (17 March 2000)
(Source: National Interagency Fire Center (NIFC))
As of 03/17/00 Number of Wildland Fires Area burnt Acres ha 2000 18,270 530,556 214,708 1999 12,821 155,567 46,171 1998 3,229 114,652 12,068 1997 6,956 154,670 39,314 1996 18,936 318,644 111,936
Fig.3. 30 and 90-day temperature and precipitation forecast maps (April and April to June 2000)
(Source: National Weather Service, Boise, Idaho)
Keetch-Byram Drought Index (KBDI) by Florida’s Division of Forestry / Forest Protection Bureau
John Keetch and George Byram developed the K/B index at the Southern Forest Fire Laboratory to evaluate the effects of long-term drying on litter and duff and subsequently, on fire activity (1968). The index is based on a measurement of 8 inches (20 cm) of available moisture in the upper soil layers that can be used by vegetation for evapotranspiration. The index measure is in hundredths (0.01) of an inch of water and has a range of 0 through 800, with 0 being saturated and 800 representing the worst drought condition. The index indicates deficit inches of available water in the soil. A K/B reading of 250 means there is a deficit of 2.5 inches (64 mm) of ground water available to the vegetation. As drought progresses, there is more available fuel that can contribute to fire intensity.
For further information on the KBDI please refer to Keetch-Byram Drought Index Revisited: Prescribed Fire Applications.
Fig.4. Keetch-Byram Drought Index Map of Florida, 19 March
(Source: Florida Division of Forestry)
The Florida Forest Fire Weather Index (FWI) System consists of six components that account for the effects of fuel moisture and wind on fire behavior. The first three components are fuel moisture codes that follow daily changes in the moisture contents of three classes of forest fuel with different drying rates. The last three components are fire behavior indexes, representing rate of spread, amount of available fuel, and fire intensity; their values increase as fire weather severity increases. For detailed information on the Florida Fire Management Information System (FFMIS) the GFMC would like to refer to the original website.
According to the FFMIS for 19 March these parameters show various fire weather conditions for Florida.
Fine Fuel Moisture Code
Duff Moisture Code
Drought Code
Initial Spread Index
Buildup Index
Fire Weather Index
Fig.5.-10. Output maps of the FFMIS, 19 March 2000
(Source: Florida Forest Fire Weather Index (FWI) System)
The Southern Area Coordination Center Morning Report (19 March 2000) is a narrative summary of fire activity within the Southern Area including number of fires, wildfires as well as prescribed burns, and area. (For detailed numbers of wildfires and prescribed burns, please refer to the original website of the report.)
SOUTHERN AREA:
Southern Area Coordination Center (GA-SAC): THE KANSAS CITY COMPUTER IS UP NOW. DUE TO IT BEING DOWN YESTERDAY (03/19/2000), THERE IS NO CURRENT SIT REPORT. AGAIN, INFORMATION IS LIMITED DUE TO THAT REASON.
The crews from the southwest and Oklahoma arrived at their home destinations. The fires are demobing some overehead. All transportation was demobed and the Staging Areas shutdown. The forecast for the coastal areas of the Carolinas are to expect severe thunderstorms with winds 58 mph or greater, ¾ (19mm) or larger hail, or tornadoes. Eastern Florida and the coast of Georgia are to expect thunderstorms today. There was lightening along the border of Georgia and South Carolina. Highs will be in the 60-80s (15-31°C) and the lows will be 40 to 50 degrees (4-10°C).
FLORIDA:
Florida Interagency Coordination Center (FL-FIC): The burn ban is still in effect.
KENTUCKY:
Kentucky Interagency Coordination Center (KY-KIC): The Center reported no fire activity for the area. The rains across much of the Commonwealth which lowered the fire danger and resulted in flash flood watches for portions of western and central Kentucky.
TENNESSEE:
Tennessee Interagency Coordination Center (TN-TNC): The Staging Area is shut down due to all crews demobed to their home units.
According to the Incident Management Situation Report three categories of fires are distinguished, such as:
1. Fires*
2. Prescribed Fires
3. Wildland Fire Use Fires**
* This classification corresponds to the category “wildland fires” as defined by the National Interagency Fire Center (NIFC)
** A brief excursion to wildland fire terminology:
Wildland Fires: Fires occurring on any tpye of vegetation, regardless of ignition sources, damages or benefits.
Wildfire: Any uncontrolled wildland fire which (1) may require suppression response, or (2) any uncontrolled wildland fire which meets management objectives and is declared as a Wildland Fire Use Fire (see below) or syn. Prescribed Natural Fire or Prescribed Fire.
Prescribed Fire: Occasionally also called management-ignited fire, or prescribed burning, is a controlled application of fire to vegetation in either their natural or modified state, under specified environmental conditions which allow the fire to be confined to a predetermined area and at the same time to produce the intensity of heat and rate of spread required to attain planned resource management objectives.
Wildland Fire Use Fire: Naturally ignited fire which is managed to achieve resource benefits under close supervision (syn. Prescribed Natural Fire)
Incident Management Situation Report (17 March 2000):
Current Situation:
Initial attack and large fire activity in the Southwest, Southern, and Eastern Areas has been light to moderate since Monday. Demobilization of resources from the Southern Area is continuing. Very high to extreme fire indices were reported in Mew Mexico, Arizona, Texas, Virginia, California, and Illinois.
Outlook:
New Mexico – variable cloudiness will move into the state Monday and Tuesday. Conditions will be breezy and a little cooler, with a chance of showers and mountain snow showers. Wednesday and Thursday will continue cooler with a chance of showers.
Northwest Arizona will be breezy. High temperatures will range from the low 50’s (10°C) in the mountains to the 90’s (30°C) in desert areas. There is a chance of showers in central and northeast Arizona on Monday and Tuesday, with cooler temperatures. On Wednesday and Thursday, the southwest and south-central parts of the states will have below normal temperatures and a chance of showers.
Southern California coastal areas will be mostly clear to partly cloudy except for overnight low clouds and fog, with high temperatures in the mid 70’s (24°C). The desert areas will be mostly clear and breezy over the weekend, with highs from the mid 60’s (20°C) to the upper 70’s (26°C). Monday through Thursday will be partly cloudy with increasing winds and below normal temperatures. Southern California mountainous areas will be mostly clear and windy, with high temperatures in the 50’s and 60’s (10-20°C). Partly cloudy conditions will move in on Monday.
Indiana: Monday through Thursday will be partly cloudy and warmer, with highs from the mid 50’s to lower 60’s (10-20°C).
Missouri: Monday through Thursday, conditions will be clear to partly cloudy and warmer, with highs to the mid 60’s (25°C).
Tab.2. Fires and area burnt year-to-date (17 March 2000)
(Source: Incident Management Situation Report)
Geographic Area Number of Fires Area Burnt acre ha Alaska 0 0 0 Northwest 1 0 0 California 228 114 46 Northern Rockies 0 0 0 Eastern Great Basin 3 54 22 Western Great Basin 1 1 0,4 Southwest 423 189,062 76,511 Rocky Mountain 54 2,720 1,101 Eastern 1,675 28,798 11,654 Southern 15,885 309,807 125,374
Total United States
18,270 530,556 214,708
Tab.3. Prescribed fires and area burnt year-to-date (17 March 2000)
(Source: Incident Management Situation Report)
Geographic Area Number of Prescribed Fires Area Burnt acre ha Alaska 0 0 0 Northwest 20 2,618 1,059 California 65 2,433 984 Northern Rockies 0 0 0 Eastern Great Basin 4 49 20 Western Great Basin 0 0 0 Southwest 357 28,257 11,435 Rocky Mountain 0 0 0 Eastern 29 4,919 1,991 Southern 586 305,733 123,726
Total United States
1,061 344,009 139,215
Tab.4. Wildland Fire Use (WFU) Fires area burnt year-to-date (17 March 2000)
(Source: Incident Management Situation Report)
Geographic Area Number of WFU Fires Area Burnt acre ha Alaska 0 0 0 Northwest 0 0 0 California 1 0 0 Northern Rockies 0 0 0 Eastern Great Basin 0 0 0 Western Great Basin 0 0 0 Southwest 1 300 121 Rocky Mountain 0 0 0 Eastern 0 0 0 Southern 0 0 0
Total United States
2 300 121
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.
