The ongoing spate of warmth is tied to a sprawling dome of stagnant high pressure banked southeast of the Aleutians in the northeastern Pacific. Reinforced by unusually warm ocean waters north of Hawaii, that high-pressure “heat dome” is inducing sinking air. That brings about additional warming.
This latest bout of record-shattering warmth caps off a year that has brought a number of high-end climate extremes to North America, including a withering late June heat wave that heated Seattle up to 108 degrees.
On Sunday, the Kodiak tide gauge station hit 67 degrees at 2:17 p.m. In addition to being a local record, it set a monthly record for the entire state for December.
Nearby, Kodiak Airport recorded 65 degrees and beat its previous daily record by 20 degrees, surpassing the 45-degree record reading last set on Dec. 26, 1984, by leaps and bounds.
Even more remarkable is that the same 65-degree reading would have set a record for November, January, February and March, too; those months haven’t seen readings above 59, 54, 56 and 57 degrees, respectively. The previous December record was 56 degrees, set on Dec. 22, 1984.
Sunday also brought records in Cold Bay, Alaska, where the community hit a high of 62 degrees. The previous record, set in 1990, was 44. St. Paul tied its record at 42 degrees.
Unalaska, Alaska, spiked to 57.3 degrees by noon Monday after bottoming out at 50 degrees overnight. According to Rick Thoman, an Alaska-based climatologist, that morning low was warmer than the average low at any point in the year — even the heart of summer.
For every degree the air warms, it can hold about 4 percent more water. That is also lending to high-end rainfall extremes.