November 2012 Synoptic Summary

Statewide Extremes
Highest Temperature 54°F at Adak in the central Aleutian Islands on the 25th and at Annette Island and Metlakatla in southern Southeast Alaska on the 4th
Lowest Temperature -52°F at Chicken on the 29th and at Tok #2 on the 30th in the southeastern Interior on the 30th
Highest Average 41.5°F at Metlakatla in southern Southeast Alaska
Lowest Average -23.9°F southwest of Fort Yukon in the eastern Interior
Most Precipitation 25.80 inches at Little Port Walther in southern Southeast Alaska
Most snowfall reported 44.4 inches at Annex Creek in northern Southeast Alaska
Most snow on the ground 33 inches at the top of the Eaglecrest Ski Resort at elevation 2,600 feet near Juneau on the 26th

A series of strong low pressure systems remained over the Gulf of Alaska for nearly all of November. High pressure over the Arctic and the Interior combined with the low pressure systems. Persistent northeast flow over the mainland ensued. The onshore flow over the Arctic coast brought well above normal precipitation and above normal temperatures to the region, and well below normal precipitation in the lee of the Brooks Range, especially northwest Alaska. The influx of frigid air from the Arctic held temperatures over nearly all of the Alaska mainland well below normal, in the eastern Interior most of all. In general, the coastal areas of Alaska had temperatures fairly close to normal. The Interior regions, far removed from the moderating effect of proximity to the ocean, displayed the largest departures of temperatures from normal. This pattern often appears in Alaska, particularly in the winter. Although the weather in Southeast Alaska was often stormy, both temperatures and precipitation in that region were close to normal, particularly in the southern portion of that region. Frequently clear skies over the Interior strengthened temperature inversions, sometimes to an uncomfortable extent. Several air quality advisories, most in effect for several days, were issued in Fairbanks during November. Concentrations of fine particulate matter sometimes reached 200 micrograms per cubic meter. Brisk northeast winds in the Interior highlands occasionally broke the temperature inversions and brought pristine air down into valleys. On November 18, northeast winds of 15 to 25 miles per hour blew in Fort Yukon, where winds in the winter rarely reach 10 miles per hour. The winds in the high country were sometimes strong enough to cause blowing snow and large snow drifts, occasionally resulting in road closures. Many residents lamented that the snowfall over nearly all the Alaska mainland was not enough to form a snow pack sufficient for winter sports such as skiing or dog sledding. Snow making equipment at Birch Hill in Fairbanks and at the Hilltop Ski Area in Anchorage salvaged the runs at the end of November. Without the insulation of a normal snow pack, combined with the cold throughout November, the frost layer in the eastern Interior advanced rapidly downward. Many residents busily shoveled snow to insulate the ground above water well pipes and the base of exterior walls. The winter ice on lakes and rivers was affected by the cold. By the end of November, the thickness of lake and river ice around Fairbanks increased to two to four times what it was at the beginning of November. This was fine for ice fishing, but areas of heavy overflow of ground water, constricted by the deep frost layer, made travel over some rivers, streams and lakes difficult. Freeze up on large rivers such as the Yukon occurred sooner than normal, and some stretches of rivers had rough, jumbled ice. The weather at sea was typical for November – frequently rough and often hazardous, even for large oceangoing ships. A large tugboat ran aground in strong winds and rough seas about 40 miles northeast of Cold Bay on November 12. The ship had not moved, and was still aground at the end of November. From November 12 onward, a series of several large freight ships were taking cover in protected waters to avoid storms in the Gulf of Alaska and the Aleutians. On November 23, adverse weather and seas swamped and sank an 18-foot skiff near Tenakee Springs in northern Southeast Alaska. None of the three aboard survived the frigid waters. The day before, the propulsion mechanisms on a large drill ship were damaged in heavy weather about 30 miles east of Dutch Harbor in the eastern Aleutians. The captain's cautious tactics paid well; no members of the crew were lost or injured. As in recent years, the advance of the winter ice pack was rapid. On November 1, the Beaufort Sea was ice free up to 200 miles offshore. The Chukchi Sea, including Barrow, was mostly iced in north of Icy Cape. Norton Sound, Kotzebue Sound and near shore waters down to Pilot Point on the Alaska Peninsula were mostly ice covered on November 9. By November 19 all waters north of Bering Strait were ice covered. Compared to 2011, freeze up in November was a little slower in the waters in the northern Bering Sea, and more rapid in waters south of Saint Lawrence Island. Ice formation in uppermost Cook Inlet was in progress on November 1 and on November 28, had reached Cape Kasilof and Tuxedni Bay. Half of Kamishak Bay and upper Kachemak Bay were ice covered. Freeze up in Cook Inlet during November in 2012 progressed more slowly than in November 2011. Sea surface water temperatures were from 1° F to 3° F below normal in Gulf of Alaska waters on November 1, and rose to as much as 2°F above normal in the northeastern Gulf waters by the end of November. Surface water temperatures above the continental shelf in the southeastern Bering Sea were from 3°F to 9°F colder than normal. Waters along the Arctic coast cooled from as much as 5°F above normal to 1°F colder than normal during November. Five earthquakes of magnitude 4.0 or larger were reported in November. People in Anchorage and Kenai felt the quake on November 1. On November 12, a tremor of magnitude 6.4 – the largest under the Gulf if Alaska in 25 years – was felt by people from Anchorage to Sitka. On November 15, a quake of magnitude 5.6 was reported at the far end of the Aleutians. Two others occurred on the west shore of Cook Inlet on November 30. As with earthquakes in November, there was some return of mild activity in Alaska volcanoes. Seismic activity was slightly elevated on the Little Sitkin volcano in the western Aleutians and on Iliamna volcano on the west side of Cook Inlet. There were a couple of small ash clouds emitted from the Cleveland volcano. The lengthening night hours afforded improving opportunities for observing auroras, especially one in the Interior on the evening of November 24.