Winter Storm — Upper Koyukuk Valley, Alaska

2004-12-22 to 2004-12-23 · Upper Koyukuk Valley, Alaska

Wider weather episode

A low pressure center in Bristol Bay on the morning of the 22nd moved north into the interior near Fairbanks that evening. The low then moved northeast and dissipated by 9pm on the 23rd, but high pressure which had resided over eastern Russia moved east over western Alaska and into the Interior on the 23rd. On the 22nd, a weather front associated with the low brought strong winds and local blizzards to the Alaska Range, and the low itself created strong winds and blizzards over Cape Romanzof on the west coast. Heavy snows were generated over the western and northern interior, and in the Alaska Range. Ahead of the front over the interior southeast of Fairbanks, freezing rain fell over zone 226 and parts of zone 224. Winter Storm/Avalanche:Zone 225 - Parks Highway mile 218 near Panorama Peak, just north of Cantwell and south of Denali National Park. Unofficial reports noted that the avalanche covered the highway for up to a quarter of a mile to a depth of 16 feet. The highway was closed for nearly 2 days. There were no deaths or injuries from this avalanche, though one truck with an empty propane trailer encountered the edge of the moving snow mass. Snow fall amounts in the area of the avalanche were reported to be 12-16 inches by the D.O.T. At the Denali Park Co-operative observing station, 7.5 inches of snow was recorded by 0800AST on the 23rd, with snow beginning around 0800 on the 22nd. The avalanche knocked out power to the community of Cantwell for 6 to 8 hours on the 23rd, and in the Denali Park Entrance on the 23rd and into the 24th. The Parks Highway was closed at Panorama Peak most of the 23rd and the 24th. Land transportation of mail and goods was halted between Fairbanks and Anchorage, as the Richardson Highway from Delta Junction through Isabel Pass was noted to have treacherous driving conditions from the sleet, freezing rain, and blowing snow. Blizzard conditions followed the heavy snowfall as north winds developed due to the high pressure over western Alaska moving into the interior. This hampered quick removal of the snow on the Parks Highway.Zone 226 - The Richardson Highway between Delta Junction and Paxson was closed on the 23rd and not reopened until the 26th due to large snow drifts from blowing snow. An avalanche occurred during this time at some point on the Richardson highway (inferred from a State of AK D.O.T. report on the 27th), though no injuries or damage occurred.Freezing Rain was reported:Zone 224 - 0.5 inches by the Tok Maintenance Station of the Alaska D.O.T, a combination of freezing rain, sleet, and snow. The Alaska Highway was closed for a period of time. Freezing Rain was reported by the D.O.T. in zone 226 along the Richardson Highway at Donnelly Dome, and along the Tok Cutoff, although amounts are unknown. Blizzard conditions reported:Zone 214 - likely at Cape Romanzof AWOS.Zone 220 - The Steese Highway at Eagle Summit and 12 Mile Summit were reported closed on the afternoon and evening of the 23rd due to strong winds and poor visibility in blowing snow. Zone 226 - Alaska State D.O.T. reported low visibility in blowing snow in the pass on the morning of the 23rd, and closed the section in this zone due to high winds and poor visibility, and unknown, but reported, amounts of freezing rain and sleet.High winds reported:Zone 214 - Cape Romanzof AWOS gust 56 knots (64 mph)Zone 225: Amateur Radio operator noted winds of 55 knots (63 mph) at Otto Lake.Zone 226: State of Alaska D.O.T. Trims Camp 55 knots (63 mph). Fort Greeley MesoNet: Texas Condo 54 knots (62 mph). Winter Storm Conditions reported at:Zone 218: State of Alaska D.O.T. reported heavy snow, high winds, and poor visibility the morning of the 23rd. Chandalar State of Alaska D.O.T. camp reported 8.0 inches ending 0600 AST 23rd; snow began approximately 0600 AST 22nd. Wiseman Co-operative Observer reported 10.0 inches ending 2100 AST 22nd. Snow began approximately 0100 AST 22nd.Zone 219 - Jim River State of Alaska D.O.T. camp reported 7.0 inches at 0900 am on the 22nd, and another 8.1 inches ending on 0600 AST 23rd. Snow began approximately 0300 AST 22nd. Also reported by the D.O.T. were high winds, poor visibility in blowing snow from Milepost 90 to 112. Heavy Snow reported at:Zone 216 - Galena Co-operative Observer: Total of 8.0 inches through 1700 AST on the 22nd. Snow began around 0800 AST on the 22nd.

Source: NOAA Storm Events Database, event_id 5432423. Narrative written by the NWS forecast office that issued the report.