A 978mb low in the Gulf of Alaska and cold air in the Copper River Basin combined to bring strong winds through Thompson Pass.
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.
A 978mb low in the Gulf of Alaska and cold air in the Copper River Basin combined to bring strong winds through Thompson Pass.
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 Feb 12, 5:07 AM AKST, 5 hours 32 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 507 AM AKST Wed Feb 12 2020 .ANALYSIS AND UPPER LEVELS... There is a mature system with a front that spans from Southcentral to the North Pacific. The occlusion was over the Alaska Peninsula early this morning. There is a developing low south of the Western Aleutians. Gales have been detected with both systems using ASCAT (advanced scatterometer) data. There is a 130+ knot jet core south of Kodiak and a 160+ knot jet core south of the Western Aleutians. Lightning strikes were detected early this morning with the system south of the Western Aleutians. The radars at King Salmon (PAKC), Kenai (PAHG) and Middleton Island (PAIH) have all been active this morning. && .MODEL DISCUSSION... For initialization purposes compared the 9z radars at Kenai and Middleton Island to the QPF at 9z on the models (GFS/NAM/ECMWF/Canadian/HRRR). The HRRR, Canadian and the ECMWF were the only models that had precipitation near Hope at 9z while the GFS and NAM were bone dry. Meanwhile on the Middleton Island radar there were some minor differences with the precipitation band near Valdez but all 5 models did reasonably well over the northern Gulf Of Alaska. The GFS ensemble members are tightly grouped through 60 hrs. The GFS ensemble mean is in lock step with the operational run of the ECMWF in the Bering and the North Pacific through F60. Temperatures in the boundary layer associated with the low continue to show some variance even in the first 24 hrs of the forecast package. The models all show warm air advecting into Southwest and nudging the arctic air mass eastward. && .AVIATION... PANC...Active TAF package. Low ceilings will persist as the frontal boundary moves inland. At 11z Wednesday the cig at PANC was 4,400 ft which rapidly deteriorated to 1,200 ft by 13z. Snow has fallen on the tarmac this morning and more is expected this morning. The visibility was reduced to 1 sm at 13z. Degraded vsby anticipated as the precipitation moves through. The models show moisture getting wrapped around the back side of this low and near the aerodrome until 9z Thursday and VFR conditions may not return until after that. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)... The low in the Gulf will slide eastward today. There is plenty of moisture with this low and snow is spreading inland, especially over the Copper River Basin. Winds will be fairly gusty over the Kenai Peninsula, with some areas of blowing snow. The strongest winds will be from Portage through Turnagain Pass, and along Cook Inlet. Conditions will slowly dry out from west to east tonight through Thursday as the low pushes into Canada. Offshore winds and cold advection will return to the area as a sharp ridge builds over the area. Most of Southcentral will be cold and dry Thursday and Thursday night. For Kodiak, another system will push into the Island Thursday night bringing snow, but winds will be lighter than they were last night (Tuesday night). && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)... Northeasterly winds have developed over much of southwest Alaska as anticipated, with the southern Bristol Bay area continues to see snow and blowing snow. Snow and blowing snow exists in southern Bristol Bay and along the Alaska Range due to a decaying front that remains nearly stationary. Its parent low (that moved through the eastern aleutians yesterday) is still moving east into the Gulf of Alaska. After this low exits later today the front will become a non factor. However, it does look like weather will linger a little longer than expected, so extended blowing snow along the AKPEN through this afternoon. Northeasterly winds will continue through the day today and slowly diminish overnight tonight. This flow is still expected to usher in colder temperatures and wind chills pushing -45F. As a result issued wind chill advisory starting midnight. Dropped temperatures a few degrees tonight for interior southwest AK with cold air barreling from the interior. Winds also look to stay elevated coming down the Kuskokwim River Valley tonight and tomorrow, so reflected this in the forecast. Be advised it will be cold for the next few days. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)... The weather story for the Bering continues to the be storm force low pressure system that will move north through the Bering and will enter our forecast area later today. This storm is rapidly deepening as it approaches. It is now close enough to our forecast area that is can be seen on satellite and so far it appears to be on track. The latest model runs have the storm taking a bit more of an easterly track, so adjusted the storm track slightly tonight. This storm is also sizable and will encompass much of the Bering Sea. Therefore, even with an adjustment to storm track, many locations will still see at least gale force winds. Also of note this morning, a stretched out decaying front is still sitting over the eastern Bering/Aleutians and providing some snow showers and elevated winds with blowing snow. This front will be a non-factor after today. && .MARINE (Days 3 through 5)... Bering/Aleutians: A gale force low in the central Bering will weaken Friday into Saturday. Another strong low will approach the western Aleutians late Sunday, likely bringing another round of gales. Gulf of Alaska: Winds will generally remain below gale force through Sunday. However, model agreement is poor so confidence in the forecast is below normal. && .LONG TERM FORECAST (Days 3 through 7)... Beginning the extended period forecast on Thursday afternoon, there will be a large and deep upper level cyclone with a stacked surface low over the Western Aleutians with the occluded front moving into the eastern Bering Sea. Cold northwest offshore flow will be keeping the mainland dry at this time. As the front shifts east, the zonal flow will result in a developing triple point low around Kodiak Island. Snow will move into the AKPEN and parts of interior Bristol Bay, but this will not make much northward progress as the arctic high will be in place, so much of the energy will move into the Gulf of Alaska and fall apart as it moves east Friday. This pattern means most of Southern Alaska will remain drier and colder, although Southwest Ak will be open to brief bouts of clouds and snow through the weekend as the Alaska Range will keep Southcentral much drier given the fast westerly flow aloft. The upper level flow reamplifies sometime Sunday night, and this will likely bring in more stormy weather for the Southern Mainland, with a myriad of impacts including inland snow and stormy seas. It looks to get colder thereafter as another arctic trough digs in. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...Wind Chill Advisory 155. WSW Blowing Snow 121 125. WSW Snow 141. MARINE...Storm 119 130 132 138 411 413 178 177 176 175 174. Gale 352 120 131 139 414 412 150 155 170 171 172 173 179 180 185. Heavy Freezing Spray 139 414 412 150 160 165 185 150 160 165 185. FIRE WEATHER...NONE. && SYNOPSIS AND MODEL DISCUSSION...PJS SOUTHCENTRAL ALASKA...BL SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BJB MARINE/LONG TERM...MM
1 blizzard. Local standard time, as filed.
Thompson Pass RWIS station reported 12 hrs of winds above 35 mph. Avalanche control in Thompson Pass also reported visibility less than one quarter mile and difficult driving conditions.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2020Every state in 2020This day in weather historyWarnings in Alaska, February 2020
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: 879427.