Forest Fires in the United States: 24 May 2000

Los Alamos National Laboratory re-opened on Monday after New Mexico's worst wildfire shut the sprawling lab for two weeks but left dangerous nuclear materials untouched. 1,000 to 2,000 employees were expected back at work the first day but would need the rest of the week to clean soot and ash and repair such items as power lines before everybody of the 12,000 employees can return back. Lab officials backed by air testing results from federal and state environmental regulators said no radiation was released by the fire. The fire, started by National Park Service brush burning on May 4 which got out of control due to high winds, was 90 percent contained on Monday and firefighters expected to have it fully contained by Wednesday. The fire burnt nearly 8,000 acres (3,238 hectares) on the lab's 111 square km on a plateau cut through by canyons in the Jemez Mountains. It scorched the grass covering half-buried storage bunkers for explosives. The fire, which has scorched 47,650 acres (19,280 hectares), also left the lab and Los Alamos town facing a new danger from flash flooding by burning off vegetation that slows water running downhill and hardening the soil so it sheds water. The lab's safety division said there were concerns that flash floods in the rainy season in late June or July could wash away ground contaminated by radiation in the lab's earlier years. But he said radiation levels were too low to pose a health threat and the contaminated ground may even be buried deeper by floods rather than washed downstream to the Rio Grande.

Scientists say that prescribed burns are necessary and aimed at cleaning up the debris on the forest floor to avoid more disastrous fires. A prescribed burn, undertaken under carefully controlled and monitored conditions, is aimed at removing the brush and other undergrowth that typically provides fuel for bigger fires that are often sparked in the West by lightning. However, fire doesn´t always follow plans. Alternative to remove underbrush could be a mechanically system, but that is too expensive. For instance, it is safer to order a controlled burn in the winter when there is more moisture. But more smoke will be produced in such conditions and that means health problems. On the other side spring and summer burns with less smoke pollution for the inhabitants are carried out under unstable conditions. Last year 1.4 million acres were put under controlled burn on U.S. Forest Service land, compared with 250,000 acres 10 years ago. In the past five years the U.S. Forest Service set 23,000 fires and 230 of them turned into wildfires. The article Scientists say prescribed burns are needed by Judith Crosson, published by Environmental News Network on 19 May 2000, deals with the above mentioned questions.

Florida
A heat signature (red) and smoke plume (light blue) are visible from a fire burning to the west of Orland, Florida.

Fig. 1. NOAA-14 POES AVHRR HRPT multichannel color composite for Florida, 23 May 2000.
(Source: NOAA/OSEI).

Wildland Fire Update for the United States on 23 May 2000 (National Interagency Fire Center (NIFC))
Only two large fires continue to burn in New Mexico after a series of wildland fires last week that required resources from several regions of the United States to help battle numerous blazes throughout the Southwest. Two large fire were contained and two large fires continue to burn in Florida where fire conditions remain extreme. Texas and Oregon also reported new large fires today.
More than one million acres have been burned by wildland fires so far this year, which is about 300,000 acres above the four-year average.
Fire Weather
A fire weather watch is posted in the Florida panhandle for high winds aloft and unstable air.
Arizona, New Mexico and west Texas will be partly cloudy with temperatures ranging form 75 to 85 in the mountains and 95 to 115 in the southern deserts.

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. 2.-4. Fire Danger Forecast Maps of the United States and Alaska for 23 May (observation time) and 24 May 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.

Incident Management Situation Report (23 May 2000)
Current Situation:
New large fires were reported in the Southern and Northwest Areas. Initial attack activity was light throughout the nation. The National Interagency Coordination Center processed orders for helicopters, engines, radio equipment, and miscellaneous overhead. Very high to extreme fire indices were reported in New Mexico, Arizona, Texas, Utah, California, and Oklahoma.
Outlook:
A fire weather watch is posted in the Florida panhandle for high winds aloft and unstable air.
Florida will be partly cloudy with a slight chance of afternoon thunderstorms. High temperatures will be 85 to 95. Winds will be west to southwest at 10 to 15 mph. Minimum afternoon relative humidities will be 40 to 45 percent.
Arizona, New Mexico and west Texas will be partly cloudy and very warm. High temperatures will be 75 to 85 in the mountains and 95 to 115 in the southern deserts. Winds will be west to southwest at 10 to 15 mph. Minimum relative humidities will be 10 to 20 percent in the mountainous areas and 5 to 15 percent in the deserts.
South Carolina will be partly cloudy with a chance of showers or thunderstorms. Winds will be southwest at 10 mph. Temperatures will be 85 to 90.
Georgia will be mostly cloudy with scattered thunderstorms. High temperatures will be 75 to 85. Winds will be west at 10 mph

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 (22 May 2000)
(Source: National Interagency Fire Center (NIFC)

As of 05/22/00	Number of Wildland Fires	Area burnt
As of 05/22/00	Number of Wildland Fires	Acres	Hectars
2000	39,865	1,027,072	415,641
1999	38,769	715,714	289,639
1998	20,550	383,148	155,054
1997	25,747	415,500	168,146
1996	54,611	1,419,290	574,366

The four month period of January through April this year was the warmest such period on record in the United States, the National Oceanic and Atmospheric Administration (NOAA) said Friday. This was the warmest January through April in 106 years of record keeping, according to statistics calculated by NOAA's scientists working from the world's largest statistical weather database. The American southwest has been struck by a rash of wildfires in recent weeks, with one blaze sweeping the north rim of the Grand Canyon and another threatening the nation’s largest nuclear weapons lab in Los Alamos, New Mexico. Set deliberately to clear underbrush, the fires spread quickly through the ultra-dry forests.
(Year to Date: Hot and Dry - Forecast: Hot and Dry by ENVIRONMENT NEWS SERVICE (ENS)).

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.

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