Prolonged heat wave to bake Alaska, keep fire danger high into early next week

For residents in southern Alaska that have been dealing with dense smoke and poor air quality from the Swan Lake Fire, more bad news is on the way as a rare, long-lasting heat wave overspreads the state.

The Swan Lake Fire, which was ignited by lightning on June 5, has already charred over 84,000 acres and continues to burn south of Anchorage on the Kenai Peninsula of Alaska.

As of Wednesday night, the fire was still only 14 percent contained, according to Inciweb.

The National Weather Service office in Anchorage issued the first ever Dense Smoke Advisory for the region on Saturday afternoon, and the city’s international airport reported smoke for 74 straight hours ending 3 p.m. local time Sunday.

“The city is likely to face more smoke into this weekend,” AccuWeather Senior Meteorologist Kristina Pydynowski said.

After high temperatures in the middle 70s to near 80 Fahrenheit on Wednesday, temperatures are forecast to generally peak in the 80s from Thursday through at least Monday.

High temperatures in Fairbanks will trend upward from the lower 70s on Independence Day to the middle 80s this weekend and the upper 80s to near 90 early next week.

"However, the all-time record high in Fairbanks is 99 set on July 28, 1919," according to AccuWeather Senior Meteorologist Alex Sosnowski.

"The period from July 26 to August 3, 1919 in Fairbanks was very hot with many daily record highs set and still in in the books, including the all-time mark," Sosnowski said.

Anchorage, Alaska, set a new all-time record high on Thursday, topping out at 89F. This shattered the old record of 85F set in 1969.

In general, high temperatures across the state will be 10-20 degrees above normal for early July.

The above normal temperatures and extremely dry weather have led the Anchorage Fire Department to cancel all fireworks shows in Anchorage, Eagle River and surrounding areas, the Associated Press (AP) reports. Independence Day celebration fireworks were originally planned in Eagle River for Wednesday night and in Anchorage on Thursday.

A burn ban also remains in effect, banning the use of bonfires, campfires and the burning of debris. However, barbecue grills are still allowed. Due to fire danger last week, the Alaska fire marshal banned the use of fireworks in most populated areas, AP reports.

A large ridge of high pressure building northward over Alaska will be the culprit for the unusual heat.

An atmospheric traffic jam will prevent this high pressure system from moving much, leading to the extended stretch of hot and dry weather.

In addition to fueling a high fire danger, the heat dome will create poor air quality as a result of air stagnation.

Air stagnation results when little, if any, wind is present for a period of at least a few days.

West-to-northwesterly winds pushed the smoke from the Swan Lake Fire south of Anchorage late on Sunday and kept it south of the city through early Wednesday morning.

“However, fluctuating winds can spread smoke back into Anchorage at times into this weekend, which would lead to another period of poor air quality,” AccuWeather Senior Meteorologist Brett Anderson warned.

Meanwhile, smoke from the Shovel Creek Fire can occasionally create smoky conditions around Fairbanks. The Shovel Creek Fire has consumed 10,000 acres so far and was only 8 percent contained as of Thursday morning.

Residents, especially those with respiratory issues, the elderly and young children, should be prepared to take steps to protect against smoke inhalation, including staying indoors and keeping windows and doors closed.

With vegetation continuing to dry out through the weekend, campers and hikers should be sure to thoroughly extinguish fires and cigarette butts to minimize the risk of sparking a wildfire.

Anybody spending prolonged periods of time outdoors should be sure to drink plenty of fluids in order to stay properly hydrated.

Even though humidity levels will remain relatively low through early next week, light winds and abundant sunshine accompanying the heat may be enough to increase the risk of heat exhaustion or heatstroke for anyone engaging in strenuous, outdoor activities.

For areas not impacted by wildfire smoke, the weather should turn out ideal for outdoor picnics and barbecues on the Fourth of July with no rain expected across the majority of the state.

By the middle to latter part of next week, temperatures should fall back to near normal for July as the high pressure lifts farther to the north and west into the Bering Sea and northeastern Russia.

Download the free AccuWeather app to find out how high temperatures will climb in your community. Keep checking back for updates on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.