Alaska Climate Research Center

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2018 May Monthly Report


Highlights

May 11th was this year’s greenup date in Fairbanks. Greenup has been tracked since 1974 and “is the rapid transformation of the landscape from brown to spring green as the leaves of deciduous trees burst forth”, according to Ted Fathauer of the NWS.

The Nenana Ice Classic recorded the 2018 breakup date as May 1st. The Ice Classic has been going on for nearly a century and provides a valuable record of how breakup dates on the Tanana River have changed over time. May 1st is close to the recent average but about a week earlier than was typical during the first half of the 20th century.

Strong winds caused widespread power outages in the interior on May 11, with more than 2300 people affected, mainly in the area between Fairbanks and Delta Junction.

During the same wind event, a power line downed by a falling tree caused the first significant wild fire of the season in Delta Junction. About 250 acres burned before the fire was brought under control on May 12th. Several smaller grass fires caused by wind damaged power lines in Delta Junction and Tok were quickly put out.

A fire on the Kenai Peninsula that is believed to have been human caused was largely under control by May 14. Ahead of the Memorial Day weekend, the BLM issued a fire prohibition for fire prone federal lands near the Steese Highway. On May 31st, a fire started in a tidal flat north of Juneau due to as yet unknown causes.

Arctic sea ice extent remained at record or near record level low levels throughout May, with the Bering Sea reaching only about 5% of normal mid-month, the lowest value of the satellite record. The entire 2018 Arctic sea ice season has been characterized by very low ice extent, remaining below 2 standard deviations of normal for almost all of the year to date.

Responding to changing sea ice conditions in the Arctic and increasing shipping traffic, the International Maritime Organization, the United Nations regulatory body for international shipping, has recently approved two-way shipping routes into the Arctic Ocean through the Bering Strait. This measure is designed to keep vessels on the safest available course and reduce risk of accidents and interference with subsistence hunting.

During the first weeks of May, residents of Port Heiden on the Alaska Peninsula reported an unusually large herd young male walruses gathered in an area near the village. The herd was estimated to consist of up to 1000 animals. The cause for their sudden appearance has not been determined yet but is likely related to shifts in food sources. Unlike the large herds of female walruses and their offspring that have been reported on Arctic beaches such as Point Lay, the appearance of the herd at Port Heiden has not been directly linked to sea ice conditions.