Forest Fires in the United States: 6 April 2000

Forest Fires in the United States

6 April 2000

Smoke enveloped areas of western Miami-Dade County on Wednesday as wind worked against firefighters battling a 3,500-acre (1,414 hectares [ha]) blaze at the edge of the Everglades. The fire broke out Saturday, according to the Florida Division of Forestry, and a strong northwesterly wind pushed it through an undeveloped, swampy area on Wednesday. No residences or businesses were threatened by fire, but smoke hampered visibility for drivers on nearby Tamiami Trail, Okeechobee Road and Florida’s Turnpike.

According to the United States Department of Agriculture Forest Service (USDAFS) Fire News another early-season brushfire in Northern California burned on 4 April 2000. The Robinson Fire (see also location map below) started on private land about 2½ miles south of Doyle, California, and burned 250 acres (101 ha). Three airtankers, four helicopters, 22 engines, and about 70 personnel were on the fire, which was burning mostly on private land adjoining the Plumas National Forest. Heavy winds pushed the fire through dry brush; 20 homes and 10 outbuildings were threatened. The lack of green vegetation and high winds contributed to aggressive fire behavior. The fire was acting like one during the summer. Flamelengths ran to eight feet, with spotting a half mile ahead of the fire.

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Fig.1. Location map of the current forest fires in northern California (Source: USDAFS Fire News)

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Fig.2. The satellite image shows heat signatures (red) from the avove mentioned fires in northern California.

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. 3. & 4. Fire Danger Forecast Maps of the United States for 5 April (observation time) and 6 April (forecast) 2000
(Source: Fire Behavior Research Work Unit, Missoula)

Several active fire signals were recorded by NOAA/OSEI with the NOAA-14  AVHRR HRPT satellite on 5 April 2000 in the United States plains.

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Fig.5. Heat signatures (red) from numerous fires burning in Oklahoma, Kansas, Iowa and Missouri.
(Source: NOAA/OSEI)

Wildland Fire Update (5 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.

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Fig.6. Geographic areas and coordination centers
(modified map from National Interagency Fire Center (NIFC)).

Nearly 600 small and large fires were reported during the past five days burning more than 14,000 acres (5,656 ha). This brings the year-to-date total for the number of acres burned to 589,300 (238,077 ha); the four-year average for the number of acres burned for this time of year is 390,000 (157,560 ha). There are currently four large fires burning in northern California and New Mexico. Keeping pace with the number of acres burned in wildland fires is the number of acres treated by prescribed fires. While burning conditions in some states are severe, other states throughout the country are experiencing ideal conditions for prescribed fires. As of 5 April 2000, more than 500,000 acres (202,000 ha) of wildlands have been treated by prescribed 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.6. 30 and 90-day forecast maps).

Tab.1. Five-Year Wildland Fire Comparison Statistics Year-to-Date for the United States (5 April 2000)
(Source: National Interagency Fire Center (NIFC))

As of 03/27/00 Number of Wildland Fires Area burnt Acres Hectars 2000 21,557 589,301 238,077 1999 20,659 240,712 97,248 1998 8,505 147,095 59,527 1997 15,281 292,269 118,077 1996 32,805 880,620 355,770

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Fig.7. 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.

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Fig.8. Keetch-Byram Drought Index Map of Florida, 5 April 2000
(Source: Florida Division of Forestry)

The Florida 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 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 4 April these parameters show various fire weather conditions for Florida.

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Fine Fuel Moisture Code

Duff Moisture Code

Drought Code

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Initial Spread Index

Buildup Index

Fire Weather Index

Fig.9.-14.  Output maps of the FFMIS, 4 April 2000
(Source: Florida Forest Fire Weather Index (FWI) System)

The Southern Area Coordination Center Morning Report (5 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:  RED FLAG WARNING issued for all of Florida due to 15+ mile per hour gusty winds and relative humidities under 30%. Fire danger continues to be low in most of the Area. Some prescribed fire activity was reported where conditions allowed. Winter like conditions and frost occurred over night with unseasonably low temperatures across the Area. High winds are forecast Texas, Oklahoma and Arkansas today moving eastward tonight. Fire danger in Florida will continue to be high this week, particularly with the windy and dry air following the passage of the cold front.
Alabama Interagency Coordination Center: Rainfall totals ranging from 6” in the north to 0.43” in the south have been received since Saturday. Temperatures are forecast to return to the mid 80’s by the weekend.
Arkansas/Oklahoma Interagency Coordination Center: Today’s temperatures will be in the 70’s, with winds 15-20 miles per hour and humidities in the low 30’s. No wildfires reported.
Ozark & St Francis NF’s: One prescribed fire for 26 acres (10 ha) completed yesterday.
Ouachita NF: 4 prescribed fires for 1,268 acres (512 ha) completed yesterday.
Florida Interagency Coordination Center: The Red Flag Warning for Florida will extend through tonight.
Kentucky Interagency Coordination Center: Fire danger is low. Since Sunday, rainfall amounts range from 1.5” to 3” with southeastern Kentucky receiving the heaviest amounts. Additional rainfall is forecast for Thursday.
Mississippi Interagency Coordination Center: No reported fire activity.
South Carolina Interagency Coordination Center: The coastal area has not received any precipitation since 29 March and fire occurrence is increasing. Weather for the next few days will be sunny with temperatures above normal. Next chance of rain is forecast for Saturday.
Virginia Interagency Coordination Center: No new fire activity reported. High winds expected the next few days with temperatures reaching the high 70’s by Friday.

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 (5 April 2000):

Current Situation:
New large fire activity was reported in Northern California and Southwest Areas. The National Interagency Coordination Center mobilized infrared aircraft, a shower unit, a caterer and miscellaneous overhead. Very high fire danger indices were reported in New Mexico and Missouri.
Northern California will be mostly sunny except for some low clouds and fog along the coast. High temperatures will be in the 50’s (10-15°C) on the coast and in the mountains and in the 70’s (21-26°C) in the valleys. Winds will be north to northwest at 10 to 20 mph.
Eastern New Mexico and West Texas will be windy, sunny and warm. High temperatures will be in the upper 80’s with relative humidities forecast for the teens. Winds will be southwest at 15 to 25 mph.
Minnesota and Wisconsin will be warm with gusty winds at 15 to 25 mph. Scattered showers are forecast for the northern portions with relative humidities around 25 to 35 percent in the south. High temperatures will mainly be in the high 50’s (10-15°C) except near 70 degrees (21-26°C) in southwest Minnesota.

Detailed information and data about fires, prescribed fires, wildland fire use fire and burned areas (5 April 2000) for all geographic areas of the United States can begathered from the Incident Management Situation Report.

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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