Double trouble is the phrase for the 2005 fire season in the western United States and Alaska, according to the third National Seasonal Assessment Workshop, held March 28 — April 1 in Boulder, Colo. At the workshop, fire behavior analysts, fuels specialists, intelligence personnel, fire meteorologists and climate forecasters examined recent weather and fuels conditions, as well as climate projections for the late spring and early summer.
Continuous and heavy fine fuel growth, a result of abundant autumn and winter precipitation, is the main concern for the southwestern states. Forest ecosystem desiccation, a result of low winter precipitation and long-term drought, is the main concern in the Pacific Northwest and Northern Rockies. Thus, there is a higher than normal potential for Southwest rangeland fires, and a higher than normal potential for Northwest timber fires.
Tree mortality throughout the western United States and southern Alaska also poses a threat for increased fire potential, especially where interspersed with abundant fine fuels. In addition, Southern California and Eastern Great Basin representatives expressed concerns that initial response to fires could be slowed in some areas because roads have been covered by landslides or washed out by floods.
ALASKA, PACIFIC NORTHWEST
In Alaska, the 2005 fire season is expected to be normal, with the exception of the western Kenai Peninsula, where low snowpack amid large areas of bug-killed spruce create increased fire potential. The climate outlook is for a warmer-than-average spring, which is likely to mean an earlier start to the fire season.
In the Pacific Northwest, above-average fire potential is expected for based on ongoing drought, low snowpack, and the likelihood that El Niño — type conditions will continue steering storms away from the area. Snow is expected to melt earlier than usual in May. If this is the case, then logs and other large fuels will reach critical dryness in late June or early July. This would increase the possibility of large timber fires, even at high elevations. Forests west of the Cascades could burn well into October unless the region receives abundant spring precipitation.
The combination of long-term drought and low snowpack will lead to above-average fire potential in the Northern Rockies, especially in northern Idaho and western Montana. Spring rains are expected to limit fire potential early in the season but boost fine fuels that contribute to grassland fires by early summer. High fire potential is expected between July and September.
In the Rocky Mountains, above-average fire potential is predicted for drought-stricken northern Wyoming and South Dakota's Black Hills. In some areas, including the Black Hills and Wyoming's Shoshone National Forest, insect outbreaks have reached epidemic proportions, causing widespread tree mortality. Below-average fire potential is expected for portions of southern Colorado, thanks to substantial winter and spring precipitation.
GREAT BASIN, CALIFORNIA
In the southern Great Basin, near-record high precipitation in southern Nevada and southwestern Utah has contributed to abundant grass growth. Once these fine fuels cure, rangeland fire potential will greatly increase. In the northern Great Basin, extremely low precipitation amid ongoing drought will likely lead to a timber fire problem in Idaho.
Above-normal fire potential is expected for southern California desert and grassland areas and the northeastern corner of California based on current and forecast weather and fuel conditions. Elsewhere in the Golden State, near-normal fire potential is expected. Fire season is expected to begin a few weeks earlier than normal in the southern California desert areas and a little later than normal in the higher elevations.
Below-normal fire potential is expected for most high-elevation forests in the Southwest. In contrast, above-normal fire potential is projected for lower-elevation areas. This is due to near-record high precipitation during autumn and winter, which has resulted in fine fuel growth and increased fuel continuity. Although above-average precipitation is expected to continue through the late spring, pre-monsoon dryness will cure grasses and intensify fire potential.
— Gregg Garfin & Melanie Lenart
University of Arizona in Tucson.
Tim Brown, Director
Program for Climate, Ecosystem and Fire Applications Desert Research Institute, Reno, Nev.
Rick Ochoa, Vice Chair
National Predictive Services Group
BLM National Fire Weather Program
National Interagency Coordination
Center, Boise, Idaho
BLM National Assistant Fire Weather
Program Leader, NICC, Boise.