Forest Fires in the United States: 20 April 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 April (observation time) and 20 April (forecast) 2000
(Source: Fire Behavior Research Work Unit, Missoula)

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.

The Forest Fire Weather Index (FWI) System is part of the Florida Fire Management Information System (FFMIS) and consists of six components that account for the effects of fuel moisture and wind on fire behavior. The first three components (FFMC, DMC and DC) 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 (ISI, BUI,FWI) 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 forecast for 19 April 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

The Southern Area Coordination Center Morning Report (19 April 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: Fire activity yesterday was fairly minimal. SACC continues to fill miscellaneous overhead orders for severity requests and presuppression operations.
Red Flag Watches predicted for most of Florida this afternoon, particularly within the interior, as humidities are predicted to drop below 35 percent. Warmer and sunny over most of the area, though there is a possibility of afternoon thunderstorms in parts of Oklahoma.
ARKANSAS/OKLAHOMA:
Arkansas/Oklahoma Interagency Coordination Center: A warm front will move northward over the area today. A cold front will be developing from a low in south-central Nebraska to west Texas. Thunderstorms will develop in advance of the cold front.
Buffalo National River: Buffalo National River’s prescribed burn module is still committed to work at Wind Cave National Park in South Dakota.
MISSISSIPPI:
Mississippi Interagency Coordination Center: The forecast calls for mostly sunny skies, highs in the mid 80s, north winds at 5-10 mph, and humidity about 40 percent.
TENNESSEE:
Great Smoky Mountains NP: The seven-member Fire Use Module, plus five members from the Park, are using fire at the Congaree Swamp National Monument for wildlife habitat management. During the next few days these twelve people will conduct prescribed burns to restore habitat for endangered red-cockaded woodpeckers.
VIRGINIA:
Virginia Interagency Coordination Center: Reported no activity. It rained in Virginia on Tuesday.

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)

Current Situation:
The Southwest, Rocky Mountain, and Southern Areas reported new large fires. The National Interagency Coordination Center processed orders for crews, a caterer, a shower unit and miscellaneous overhead requests. Very high to extreme fire indices were reported in Arizona, New Mexico, Texas, Colorado and Kansas.
Outlook:
A RED FLAG WARNING IS ISSUED IN NORTHERN FLORIDA FOR LOW RELATIVE HUMIDITIES.
A FIRE WEATHER WATCH IS POSTED IN CENTRAL AND SOUTHERN FLORIDA FOR LOW HUMIDITIES.
Florida will be sunny with minimum relative humidities in the 25 to 35 percent range. Winds are forecast to be out of the northwest and northeast at 5 to 15 mph.
A FIRE WEATHER WATCH IS POSTED TODAY FOR LOW RELATIVE HUMIDITIES AND STRONG SOUTH WINDS IN NORTHEAST NEW MEXICO.
The southwest will be mostly sunny and not as windy as yesterday. Temperatures will range from the 40's (5°C) in the mountains to the 70's (20°c) in the lower valleys. Winds will be 15 to 30 mph out of the northwest and southwest.

Detailed information and data about fires, prescribed fires, wildland fire use fire and burned areas (19 April 2000) for all geographic areas of the United States can begathered from the Incident Management Situation Report.

Wildland Fire Update (19 April 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.

Fire suppression forces have battled hundreds of fires during the past 10 days including several large fires in Arizona, New Mexico, Florida, Missouri, Colorado, Kentucky and North Carolina. Severe fire conditions exist in several states throughout the Southwest, Southern Area and the Midwest as unseasonably warm, dry weather persists. Several wildland fires have either destroyed or threatened homes in these areas. Land managers encourage homeowners near the wildlands to take precautions in protecting their homes from wildfires.
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.5. 30 and 90-day forecast maps).

Tab.1. Five-Year Wildland Fire Comparison Statistics Year-to-Date for the United States (19 April 2000)
(Source: National Interagency Fire Center (NIFC))

As of 04/19/00	Number of Wildland Fires	Area burnt
As of 04/19/00	Number of Wildland Fires	Acres	Hectars
2000	25,909	664,995	269,114
1999	27,051	422,798	171,100
1998	13,213	229,251	92,775
1997	17,947	312,329	126,395
1996	43,030	1,097,711	444,228

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.

A set of photographic documents on prescribed burning techniques and objectives in the Southeast can be visited in our photo archive.