Highlights

January: Freezing rain during warm spells in January caused hazardous road conditions and traffic problems in the Anchorage area, as well as in Fairbanks and surroundings. High winds knocked down power lines in areas between Palmer and Wasilla during a storm at the end of the month, causing widespread power outages. Blowing snow alerts were issued for parts of the Glen and Parks highways.

February: A winter storm with wind gusts of about 100 mph and open water caused damages and power outages on Little Diomede located 150 miles north of Saint Lawrence in the Bering Strait on February 20, 2018. Flood warnings and open waters never happened before in the middle of the winter. The event was a result of all-time record minimum ice coverage in the Bering Sea.

A large winter storm system caused traffic problems throughout the state during the last week of the month. In the southcentral region, drivers experienced delays as workers rushed to clear snow from the roads. Whiteout conditions in Fairbanks led to an accident involving a fuel truck on the Richardson highway. The highway was temporarily closed. Another closure of the Richardson was caused by a 100ft wide avalanche at mile 195 near Summit Lake on Feb. 27.

March: A snowy March in the southern regions of the state led to a number of winter storm warnings, snow-related traffic issues, and hazardous avalanche conditions. On March 19, two avalanches reached the road to Hatcher Pass and the road was subsequently closed, stranding 10 people for part of the week.

April: Wind gusts of up to 80mph felled trees and caused power outages and damage to roofs around Anchorage and the rest of southcentral Alaska during a storm system that affected the state during the last week of April. Two parties recreating in the Alaska Range required rescue after the strong winds and severe weather associated with the same storm system destroyed their supplies.

May: A combination of snow fall and warmer temperatures led to hazardous avalanche conditions during the first week of May. Two avalanche incidents – a close call and a fatal accident – in the Hatcher Pass area highlighted the difficult conditions. Spring break-up at many Alaska rivers occurred around mid-May. An ice jam on the Susitna near Talkeetna caused flooding in some areas and temporarily shut down the Alaska Railroad service.

June: A cold front brought late season frost to the Interior and significant snowfall along the Glenn Highway during the second week of June. Winter weather and icy conditions were also reported on the Tok Highway and the Dalton Highway. The Mooseheart and Zitziana River fires were the most noteworthy wildfires of the month with estimates of over 53,000 and 34,000 acres burned, respectively. The Southeast experienced a dry spring season and this pattern continued into June. Several communities experienced problems with their hydroelectric power generation due to low water levels.

July: The largely warm and dry weather combined with occasional lighting strikes produced an uptick in wildfires in July and the highest fire danger of the year to date. During the last week of July, firefighters were working at four staffed fires: the Zitziana River Fire south of Manley hot springs, the Dome Creek Fire in the Yukon-Charley Rivers National Park, the Hughes Mountain Fire near Hughes and the Taixtsalda Hill Fire between Northway and Tok. Dry conditions in the Southeast continued throughout July. Moderate drought status as de-fined by the US Drought Monitor was declared in parts of the panhandle.

August: A major storm system hit the Southcentral region mid-month and caused wind damage as well as flooding. The second half of August was characterized by wet weather in much of the state with a series of storms that included remnants of Hurricane Hector. Mud-slides and minor flooding caused significant delays on the Taylor Highway and the road to McCarthy. In the southeast, conditions remained unusually dry.

September: In contrast to the previous month, a persistent high pressure ridge dominated the weather in much of the state in September, leading to record breaking warmth, particu-larly in the southeast and southcentral regions, and lots of sunshine. Drought conditions in the panhandle persisted and the southern regions reached “severe drought” conditions.

Following damaging storms in August, the North Slope Borough filed a disaster emergency declaration in early September. This gave the Borough access to 22,000 sandbags from the US Army Corps of Engineers to temporarily protect the area behind a damaged seawall. De-clining sea ice has exacerbated storm damage in the fall season along the Utqiaġvik coast-line.

October: While October started dry in Ketchikan, by the end of the month it had rained enough to restart the community’s hydropower facility, allowing the electric utility to switch off the diesel generators they had been using to compensate for the lack of rain. Tempera-tures remained unusually high, leading to a number of unusually late dates of first frost, first snow, first consistent snow cover and a late end of the growing season throughout the state.

November: Drought conditions persisted in the Southeast. Precipitation was close to normal during October and November, but this was not enough to compensate for the dry previous months and the southern part of the panhandle remained in D2/severe drought conditions. Ash emissions from Veniaminof volcano prompted aviation warnings and air quality adviso-ries on November 21 for the Aleutians. According to the USGS, the ash plume rose up to 15 000 feet and spread about 150 miles to the Southeast.

On November 30th, a magnitude 7 earthquake struck Alaska. The epicenter was about 7 miles from Anchorage and slope failures caused substantial infrastructure damage, primarily to roads such as the Glenn Highway. It is interesting to note that earthquakes can affect weather observations and data quality control needs to be performed on station data accord-ingly. Figure 5 shows the data recorded at a precipitation gauge in Kenai during the earth-quake. The earthquake signal can be seen clearly as an anomalous peak shortly before 9am on November 30th (Figure 17).

December: High winds associated with a storm in the Gulf of Alaska caused some damage in parts of the panhandle on December 10th and 11th. Gusts of up to 61mph felled trees, which temporarily blocked a road in Craig. High winds also affected the Aleutians and Alaska Pen-insula on December 30th and 31st.