Lightning has officially entered Alaska’s wildfire equation. Over the past two weeks, almost 5,000 lightning strikes have been recorded across Alaska, according to the Alaska Interagency Coordination Center in Fairbanks, which tracks daily lightning activity in Alaska. That number includes approximately 2,400 lightning strikes recorded on Monday, the highest single-day total of the season.
There have been five lightning-caused fires reported since May 10, including two on Tuesday, according to AICC records.
- The McArthur Creek Fire (#133) was reported at approximately 4 p.m. on Tuesday, May 21 by Federal Aviation Administration personnel east of Northway shortly after a thunderstorm moved through the area. The fire is located about two miles west of the Canada border and 28 miles east of Northway. Alaska Division of Forestry personnel from the Tok Area forestry office responded to the fire by helicopter and air attack personnel from Fairbanks responded. The initial size-up was a 7-acre fire but it had grown to 50 acres by the time helitack arrived. There are structures and gold mining sites approximately 3 miles from the fire. The fire, which is burning in a Limited protection area, had grown to approximately 150 acres at last report. The fire is being monitored and personnel are discussing taking possible structure protection measures.
- The Melozitna Fire (#132) was reported by local commercial aircraft on Tuesday, May 21 approximately 75 miles northwest of Tanana. It was estimated to be approximately 5 acres and burning in tundra with no structures threatened. A helicopter from the BLM Alaska Fire Service Tanana Zone flew over the fire a short time later and it was estimated to have grown to 150 acres. The fire is in a Limited protection area and will be monitored.
A lightning strike on May 16 ignited a spruce tree near Harding Lake southeast of Fairbanks. Firefighters from Salcha Fire & Rescue responded and suppressed two hot spots associated with the Friendly Fire (#122) while state forestry personnel cut down the tree and cold trailed the fire area, which was estimated at one-tenth of an acre.
- The lightning-caused Lynx Fire (#125) was discovered on May 16 by air attack personnel returning from work on the Oregon Lakes Fire near Delta Junction. The fire was reported at one-quarter of an acre on a ridge top on military land in the Yukon Training Area with low spread potential. Three personnel from the BLM Alaska Fire Service responded and contained the fire on Friday.
- The 24-acre Bear Lake Fire (#104) on May 10 about 9 miles south of Manley Hot Springs. The fire was detected by passing aircraft and a load of eight BLM Alaska Fire Service smokejumpers responded and suppressed the fire, which was burning in grass, tundra and black spruce.
While this is not necessarily early for lightning-caused fires to occur in Alaska, it is unusual to see daily tallies of more than 1,000 lightning strikes this early in the season. Typically, lightning-caused fires don’t occur in Alaska until late May or early June. Last year, for example, the first lightning-caused fire was on June 3 just south of Fairbanks.
The recent uptick in lightning activity coincides with warmer temperatures in the Interior of Alaska as a result of a high-pressure system that has been parked over northeast Alaska and western Canada for the past week. The warmer temperatures create instability in the atmosphere, which leads to convective activity.
Fire caused by lightning is a natural part of Alaska’s boreal forest and tundra ecosystems. It plays a role in maintaining the diverse mosaic of vegetation on the landscape, reduces the risk of more intense fires by breaking up the continuity of fuels, rejuvenates habitat, returns nutrients to the soil, and enables the growth of new plants. Lightning-caused fires also are responsible for the bulk of the land burned each summer in Alaska.
Alaska generally receives somewhere between 40,000 and 100,000 lightning strikes per year. Over the past 15 years, lightning has accounted for 39 percent of wildfires in Alaska while humans have been responsible for starting the remaining 61 percent. However, lightning-caused fires account for 96 percent of the acreage burned each summer in Alaska while human-caused fires account for only 4 percent of acres burned.
As of Tuesday, there had been 117 wildfires reported in Alaska so far this season and they have burned a total of 15,626 acres. While there have been five lightning-caused fires that have burned 325 acres, those numbers will undoubtedly increase with warmer temperatures and more lightning activity as summer progresses.