Alaska Statewide Climate Summary
October temperatures were above normal across the state throughout the month with all 20 first order stations reporting positive deviations. The only day with a negative divergence occurred October 1. The month’s peak deviation was 15.5 degrees Fahrenheit, which coincided with a storm impacting Southcentral and the Interior on the 28th. This is an astounding departure for an area as large as Alaska. The monthly mean temperature for all 20 first order stations was 39.8 degrees, a significant 7.4 degrees above the normal of 32.4 degrees. McGrath held the highest positive deviation from normal with 13.6 degrees over its long-term mean of 25.1 degrees Fahrenheit. Following McGrath with positive deviations exceeding 10 degrees were: Delta Junction at 13.1 degrees, Bettles at 12.4 degrees, Fairbanks at 11.9 degrees, Gulkana at 11 degrees and Kotzebue at 10.2 degrees. Most of the stations with the highest positive deviations were located in the Interior.
The warmest temperature reported for the 20 first order stations was 62 degrees Fahrenheit at Delta Junction on the 28th. This event was the result of Chinook winds from a storm that impacted Southcentral. The month’s coldest temperature was minus 2 degrees Fahrenheit and took place on the 31st in Barrow. Annette reported the highest mean temperature for the month at 48.2 degrees. Barrow reported the coldest temperature for the state with 24.7 degrees.
A number of record temperature events happened in October and, unsurprisingly, were all new record high temperatures. There were no new low temperatures noted. The record highs occurred October 15 to 20 and October 25 to 29. Delta Junction set five new records and tied another. Homer and Bettles had five records events each. Three of the records broken had been in place since 1936. Delta Junction's new record of 62 degrees Fahrenheit on the 28th shattered the 1962 record by 19 degrees.
It was the warmest October on record for Anchorage that saw a mean temperature of 43 degrees Fahrenheit. This temperature broke the 1936 record of 42.1 degrees. Cold Bay had the warmest October on record at 46 degrees. This broke the 2002 record of 44 degrees for the community. Similarly, McGrath broke a 2006 record by reaching a mean temperature of 38.7 degrees for the month. Delta Junction broke the 1969 record with its month’s mean temperature of 37.2 degrees. Fairbanks experienced the third warmest October in 109 years. The month’s lowest temperature in the community was 16 degrees, tying 2002 for the warmest low temperature for the month.
Precipitation for October was significantly above normal for the state at 165 percent of normal. Sixteen of the 20 stations reported above normal values. Four stations reported values below normal, most of which were located in the Interior. These are, in ascending order, Delta Junction with 38 percent of the expected value of precipitation, Annette with 63 percent, Gulkana with 70 percent and Fairbanks with 71 percent.
McGrath had the greatest positive deviation from normal, with 4.64 inches or 222 percent above the expected amount of precipitation. Following McGrath was Talkeetna with 196 percent, Bettles with 191 percent, Bethel with 156 percent, King Salmon with 123 percent, Nome with 120 percent and Valdez with 116 percent. The 16 stations that reported snowfall, all reported below normal values for October. In Fairbanks, October 2013 saw hardly any snow. In fact, there are only three other Octobers on record where the community had less snow. Barrow recorded trace or more amounts of snow on 28 days of the month.
Numerous daily record precipitation events were set for October. The majority of the record events were set October 27 to 28. This was due to a storm slamming into Southcentral. October 2013 was the wettest on record for Valdez, which had 17.83 inches of precipitation. This amount just topped the 2006 record of 17.31 inches for the community.
The month started out with high wind warnings for Southcentral and the Interior on October 6. Winds caused power outages in Anchorage and pushed north to the Interior where winds up to 80 mph were experienced in the Alaska Range. The Denali Highway was closed due to heavy snow on the 9th, but minimal effort was put into clearing it as the highway closed for the winter October 13. High winds, again, hit portions of the Interior close to the Alaska Range on the 27th. Unseasonable rainfall made driving in the Fairbanks area treacherous toward the end of the month. In addition, storm warnings for high winds and flooding were issued for Southcentral on the 27th. In the storms aftermath, Amber Lake totaled 3.04 inches of precipitation October 28, while Bear Valley had winds up to 106 mph. The Ted Stevens Anchorage International Airport measured winds up to 40 mph, gusts up to 60 mph were measured at Tanacross and Delta Junction experienced 60 mph winds during the storm. Disaster declarations were issued for the Seward Peninsula areas due to localized flooding. For Fairbanks, the precipitation resulted in hazardous driving conditions due to ice on the roads. The storm impacted driving on the Elliott, Dalton and Alaska Highways.
The unseasonably warm weather and high winds of October, especially in the Interior, resulted in the reemergence of the Mississippi fire near Delta Junction on the 30th. The fire began in May and was smoldering. Fire fighters were dispatched to the fire in October and this was the latest date the Alaska Fire Service could remember actively fighting a wildfire. A last minute snowfall on the 31st made sure that it was a white Halloween in Fairbanks. The only time Fairbanks ever experienced a Halloween with no snow on the ground was in 1938. For Fairbanks, the late onset of winter was paired with a late start to spring back in May.
This information consists of preliminary climatological data compiled by the Alaska Climate Research Center, Geophysical Institute, University of Alaska Fairbanks. This summary is based on the 20 first order stations in Alaska operated by the National Weather Service. Extreme events of other stations are also mentioned. It should be noted that the new climate normals for the time period of 1981-2010 are applied for the calculations of the deviations, and they can be slightly different from the old normals (1971-2000), which were in use up until end of August 2011.
IMAGE CAPTION/CREDIT: This infrared satellite image from the National Weather Service shows the storm system affecting Southcentral and Interior Alaska on Oct. 28, 2013. The storm drove record high temperatures, rainfall and localized flooding across the region.