Southwest flow and a weakening trough brought warm air to the northern Susitna Valley. This created an overrunning event that led to heavy snowfall.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS AFC wrote it up.
Southwest flow and a weakening trough brought warm air to the northern Susitna Valley. This created an overrunning event that led to heavy snowfall.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Anchorage, AK wrote its last area forecast discussion before the first event at Jan 31, 4:20 PM AKST, 7 hours 40 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 420 PM AKST Tue Jan 31 2017 .ANALYSIS AND UPPER LEVELS... There is a sharp trough with its axis stretching from southwest of Kodiak Island north to Norton Sound. This trough is moving very slowly eastward and weakening. An associated front on the eastern side of the trough is oriented north-south and is pushing moisture and precipitation into south central Alaska. There is a large vertically stacked upper low centered to the southwest of the western Aleutians with a 958 mb surface low. A storm force front from this low is moving from the western Aleutians into the central Aleutians. An upper level ridge is building ahead (to the east) of this low/front over the eastern Bering and eastern Aleutians as well as the Alaska Peninsula and the west coast of the mainland. && .MODEL DISCUSSION... The numerical models are in good agreement for the short term portion of the forecast (through Thursday afternoon). The one area they are struggling with a bit is with how they handle the precipitation over Southcentral into Thursday evening. Therefore the forecast confidence is near to slightly above normal. && .AVIATION... PANC...VFR conditions and light winds will persist. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)... The frontal system currently extending from the Gulf northward into the Susitna Valley will remain fairly stationary through Wednesday morning, while gradually weakening. Rain and snow associated with this system will persist along the Northern Gulf coast and Cook Inlet region through this evening, then becoming more showery overnight tonight as the system weakens. The Winter Storm Warning for heavy snow remains in effect over parts of the Susitna Valley through tonight, with persistent southerly upslope flow and ample moisture feeding in from the Cook Inlet region. A strong ridge will begin to build over Southcentral from the north Wednesday afternoon, leading to development of a weak outflow wind event along the coast. As a result, showery conditions will taper off over Southcentral by Wednesday afternoon, with cooler and drier weather settling in across the region by Wednesday evening. && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)... Fog and low stratus will be the main concern in the short term. Lingering low-level moisture, diminishing winds, and a building ridge overhead will promote fog/stratus development and thickening of areas already in place. Visibility will likely drop to a quarter-mile or less in places with the Kuskokwim Delta being the most likely. The Bristol Bay area will also see fog, less widespread though as weak offshore flow will develop overnight. Offshore flow will continue to strengthen through the day tomorrow into Thursday further reducing the fog threat. High pressure will control the forecast for the next couple days with no chance of precipitation and relatively light winds. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)... The storm force front will continue eastward overnight before stalling over the central Bering/Aleutians on Wednesday. The front slowly weakens in place through Thursday. High pressure and offshore flow will stay in place over the eastern Bering while another gale force front approaches the western Aleutians on Thursday. && .LONG TERM FORECAST (Days 3 through 7)... There remains good agreement that a blocking pattern setting up over the mainland late this week will bring a period of quiet weather to much of the Mainland through this weekend. A weak ridge associated with this blocking pattern has shifted a little further to the east due to a stronger shortwave trough rotating around the western edge of it. The result of this is a slightly warmer forecast from Southcentral into the Copper River Basin, along with weaker outflow winds than initially expected. This setup will also put Cook Inlet closer to the ridge axis, which would be more favorable for fog/low stratus development. This was left out of the forecast however as the down inlet flow (while a bit weaker) should be enough to limit significant fog development, but this will need to be monitored in the coming days. Over the Western Bering little has changed as stationary frontal boundary will bring nearly persistent gale force winds with rain to much of the area from late this week into the weekend. Forecast confidence then quickly diminishes by early next week as significant model disagreement in the track and intensity of both an upper low moving developing over the Mainland and a polar low over the Beaufort Sea. The exact track of these features will has a significant impact in the forecast looking into early-mid next week, especially with regards to temperature. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...Winter Storm Warning 145. MARINE...Storm 175 176 177 178 Gale 170 172 173 174 179 185. && SYNOPSIS AND MODEL DISCUSSION...BL SOUTHCENTRAL ALASKA...PEPE SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ML LONG TERM...DK
1 heavy snow. Local standard time, as filed.
Bentalit Lodge reported 10-11 storm total snowfall. Gate Creek Lodge reported 14 storm total snowfall. Safari Lake reported 24 storm total snowfall.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2017Every state in 2017This day in weather historyWarnings in Alaska, February 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 679864.