While many locations east of the Rockies have been shivering this January, it's been a completely different story from the West Coast northward into Alaska, where above-average warmth has dominated.
This warmth is being caused by a persistent and expansive ridge of high pressure anchored across these regions this month. To the east of this ridge is a dramatic jet stream dip, or trough, that has kept the eastern states frigid at times. While it's not unusual for an upper-level ridge to park near or over Alaska in winter, the persistence and magnitude of this feature in January has been staggering.
During the final week of January, the warmth in Alaska reached its peak.
According to the National Weather Service, the state tied its all-time January record high of 62 degrees near Port Alsworth on Monday, Jan. 27. The temperature in January has only been this high in Alaska on two other occasions in recorded history. The first time was Jan. 30, 1940 in Craig and the second was Jan. 16, 1981 in Petersburg.
The average January high temperature in Port Alsworth is about 23 degrees, so the high on Jan. 27 was nearly 40 degrees above average. Port Alsworth is located in southwest Alaska, well to the southwest of Anchorage.
That same day, Nome, Alaska set an all-time January record high of 51 degrees, beating the old record by five degrees. Records in Nome go back to 1906.
While Alaska was basking in the mild temperatures on Jan. 27, Chicago recorded a low temperature of 7 degrees below zero. In Duluth, Minn., the wind chill that morning fell as low as 50 degrees below zero.
Normally frigid interior sections of Alaska have also seen well above-average temperatures in January. Fairbanks is near 16 degrees above average for the entire month through Jan. 28. Outside of a stretch of very cold temperatures for about four days in early January, mild temperatures have dominated.
(MORE: Current Conditions in Alaska)
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Mendhall Glacier, Alaska: Undated Photo
This undated photo shows the Nugget Creek power house near the Mendenhall Glacier, which was believed to be part of 19th Century mining operations in the area. (Alaska State Library Historical Collections)