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ALASKA and NORTHWESTERN CANADA 

Weather and Climate Highlights and Impacts, June-August 2018; Climate Outlook Oct.– Dec. 2018
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Temperature & Precipitation, June-August 2018

Source: NOAA and ECCC 

Source: NOAA and ECCC 

Between June and August 2018, the western portion of Alaska, the southernmost part of the

Yukon, and northern British Columbia experienced warmer than average conditions. The portion

of Alaska and the Yukon along the coast of the Beaufort Sea, along with most of central

Northwest Territories (NWT) saw below normal temperatures, while the central parts of Alaska

and the Yukon, along with the south-western part of the NWT experienced near normal

temperatures during that same time period. Total precipitation between June and August 2018

was above average over the majority of Alaska, the Yukon and the western part of the NWT,

while below normal precipitation was observed over small regions around the southern

Yukon/NWT border, and the northern coast of British Columbia.

A warm and dry summer in the southeastern Yukon caused several wildfires. The photo above

shows the Watson Lake, Yukon, wildfire on August 21st, 2018. Photo courtesy of the Yukon

Wildland Fire Management.

Photo of flooding near Tetlin, Alaska, in late June 2018. Photo

Credit: National Weather Service. 

For the second summer in a row, high water on the Tanana River during June accelerated the

ongoing process of the cutting of a new channel alignment due to erosion. The new channel

flooded the access road from Tetlin to Alaska Highway. Area residents improved a secondary

access road that had been started the previous summer, and so were able to get in and out of the

community by car and truck. This proved important in late July when the Taixtsalda Hill wildfire

started not far south of Tetlin.
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Fire season in the Yukon and northern British Columbia

The photo shows the South Stikine River fire on August 6th, 2018. Handout photo provided 

by the BC Wildfire Service.

A series of upper-level ridges (high pressures) from July through the

end of August brought above normal temperatures and little

precipitation to much of the southern Yukon and northern British

Columbia (BC). These persistent warm and dry conditions over the

region caused the wildfire season to extend one month longer than

normal. The situation was severe as several large wildfires burned in

close proximity to towns and highways.

Strong westerly winds on August 13th caused explosive growth of

fires in the Watson Lake, Yukon and Lower post, BC areas. These

fires forced the closure of the Robert Campbell and Alaska highways

and caused an evacuation order for Lower Post, BC on August 21st.

The relatively strong westerly winds continued for the next week,

severely impacting firefighting efforts.

The Alkali Lake and South Stikine River fires in northwestern BC caused evacuation orders of the town of Telegraph Creek, BC

and the Tahltan Nation Lands, BC. A total of 44 primary residences, 69 outbuildings, 7 cultural historical buildings, a Church,

and a Headstart/day care were lost in the fires.

Wildfires in the area also caused the Air Quality Health Index to climb to Very High Health Risk for two to three weeks

throughout northwestern BC and the Yukon, including Fort St. John, Prince George, Burns Lake, and Watson Lake.

In contrast, this same weather pattern that brought large fires in northern BC and the Yukon lead to less than average fire

activity in Alaska.

An L188 Electra air tanker fights wildfires in the vicinity of

Watson Lake, Yukon on August 21st, 2018. Photo courtesy

of the Yukon Wildland Fire Management.

El Niño–Southern Oscillation forecast

The figure to the left shows the quarterly forecast of the status of El Niño, La Niña, and neutral

conditions between August 2018 and July 2019 based on the official El Niño–Southern Oscillation

(ENSO) probability forecast from the Climate Prediction Centre (CPC – NOAA)/International

Research Institute (IRI) dated early-September 2018. Letters on the x-axis denote the first letter

of each month. For example, ASO represents August-September-October. The prediction is

based on the NINO3.4 index (120-170W, 5S-5N) sea surface temperature (SST) anomaly. This

forecast has slightly less chances of an El Niño this winter than the earlier summer forecast.

Although El Niño is a meteorological phenomenon taking place in the southern Pacific Ocean, its

occurrence can affect the cold season climate of Alaska and northwestern Canada. During an El

Niño event, a higher number of storms than average travel northward from the mid-latitudes into

the Gulf of Alaska and adjacent British Columbia, bringing warm air into the region. Given that El

Niño conditions are likely to develop this winter, northwest Canada and much of Alaska have

increased chances for above normal temperatures this upcoming winter.
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Sea Ice Conditions at the end of August 2018 in the Beaufort and Chukchi Seas

After an extremely early start to the melt season in the southern Chukchi

Sea, summer ice melt near Alaska was much slower than recent years.

June featured persistent cloudy and cool weather, slowing melt. July was

milder with more storminess which increases ice melting, but it was not

until August that melt really accelerated. Nonetheless, there was still

considerable ice in the Beaufort Sea near the Alaskan coast east of Cape

Halkett by late August. The ice was sufficiently consolidated that non icehardened vessels had to wait for open channels to develop. The ice was

well north of the Alaska coast in the Chukchi Sea at the end of August.

Overall, ice conditions in the Beaufort Sea area are currently about 3-4

weeks ahead of normal in terms of ice melt; on the other hand, the area

along the Alaskan Coast represents conditions that are 1-2 weeks later

than normal. Nearing the minimum ice extent for the 2018 ice season,

large areas of ice that have melted during the summer season are

represented by areas in red on the top right figure. However, we also see

areas of ice that have lingered longer than normal, notably north of the

Alaskan coast, as represented by areas in blue on the top right figure.

Temperature Outlook: Oct.-Dec. 2018 Precipitation Outlook: Oct.-Dec. 2018

A combined Canada-USA climate forecast model is used to provide

temperature and precipitation outlook for October-December 2018.

The temperature outlook for October through December 2018 shows that

the majority of Alaska and northwest Canada have a 40-90% chance of

above average temperature (warm colors). Banks Island in the NWT, as

well as the portion of Victoria Island showing on the map, on the other

hand, shows a 40-50% chance of below normal temperatures (blue

areas).

The precipitation outlook for October through December 2018 shows that

most of Alaska, the Yukon, and the northwest part of the NWT have a 40-

60% chance of above normal precipitation (green areas). Isolated pockets

along the coast of the Beaufort Sea, the southern Yukon/Alaska border,

and the Great Slave Lake area have a 40-50% likelihood of below normal

precipitation (brown areas).

Content and graphics prepared in partnership with the Alaska Center for Climate Assessment and Policy, NOAA National Weather 

Service Alaska Region, and Environment and Climate Change Canada. 

ALASKA REGION PARTNERS: Alaska Climate Research Center, Alaska Climate Science Center, National Snow and Ice Data Center 

(NSIDC), NOAA / NWS Weather Forecast Offices, NOAA / NESDIS / NCEI, Scenarios Network for Alaska + Arctic Planning. 

NOAA ALASKA REGION CONTACTS: 

RICK THOMAN richard.thoman@noaa.gov

ncei.noaa.gov • #regionalclimateoutlooks

BRIAN BRETTSCHNEIDER: ACCAP 

brbrettschneider@alaska.edu

ENVIRONMENT AND CLIMATE CHANGE 

CANADA WESTERN CONTACTS: 

GABRIELLE GASCON 

gabrielle.gascon@canada.ca