A low pressure system developed south of the Aleutian Chain and then moved northward along the Alaska Peninsula and up Cook Inlet. A strong high pressure system behind it brought a large amount of cold air behind the low.
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 low pressure system developed south of the Aleutian Chain and then moved northward along the Alaska Peninsula and up Cook Inlet. A strong high pressure system behind it brought a large amount of cold air behind the low. This created the perfect scenario for snow and high winds along the Alaska Peninsula and northward through the Cook Inlet area. Snow and blizzard conditions began in December 2019 and continued into January 2020.
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 Dec 31, 4:23 PM AKST, 7 hours 37 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 423 PM AKST Tue Dec 31 2019 .ANALYSIS AND UPPER LEVELS... A major upper level Arctic trough remains over southwest Alaska and the eastern Bering Sea bringing very cold temperatures to areas under it. South central Alaska is in the warm southerly flow aloft ahead of this trough, but that will change over the next day as a cut off low develops from this trough over Southwest and Southcentral Alaska. At the surface, the main low is tracking up Cook Inlet this evening and will move into the western Copper River Basin overnight. Satellite imagery shows cold air cumulus clouds streaming off the ice edge over the northern Bering Sea and tracking over the central and eastern Bering Sea. These clouds are bringing snow squalls to the eastern Bering to the eastern Aleutians and Alaska Peninsula. Very cold air is also moving north up Cook Inlet today and will move into the rest of south central Alaska by Wednesday morning. && .MODEL DISCUSSION... Models are all in good alignment with the synoptic pattern as well as the system moving through southwest and south central Alaska through tomorrow. The differences mainly are due to model resolution and ability to resolve small details. The NAM has been doing a very good job with this storm and both it and the GFS seem to have good timing on the cold front as it moves up Cook Inlet this afternoon. After this system passes, models look to be locked in good agreement through the weekend before some more notable discrepancies creep in for early next week. && .AVIATION... PANC...The strong southeasterly winds will abruptly shift to the southwest this evening as much colder air moves up Cook Inlet and rapidly switches rain to snow sometime between 4Z to 6Z this evening. Snow will likely be moderate-to-heavy in intensity for a while with gusty winds producing IFR conditions. The biggest challenge is forecasting the duration of this heavy snow, though it should become light or end no later than 15Z. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Tuesday night through Friday)... Low pressure currently located over Kodiak Island is continuing to produce strong southerly flow and warm temperatures for much of south central AK. However, cold air can be seen on satellite streaming into the western Gulf of Alaska and surface observations are indicating snow and cold air are now moving up Cook Inlet. Blizzard conditions arrived as expected for the Homer area as well. This means the forecast is on track for a sharp drop in temperatures and 4-8 inches of snow for the Anchorage area tonight. The Mat-Su Valley will also see snow tonight with highest totals just under 6 inches in areas near Skwentna. Both the Blizzard Warning and Winter Weather Advisory remain in effect due to these conditions into tomorrow morning. After the initial push of cold weather, light snow will linger through the morning as temperatures continue to fall. The low pressure system will then exit, but cloud cover is expected to linger keeping temperatures steady in the single digits for much of south central Alaska and Kodiak for the next couple of days. The exception is the Copper River Basin where temperatures will continue to drop to around 10 below zero by Friday. && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)... A deep upper level trough combined with an elongated low centered near Kodiak Island is continuing to enhance snowfall over the Middle Kuskokwim Valley. An additional 4 inches is likely over this area through New Year's morning. Gusty northwesterly winds will lead to periods of blowing snow as well. Farther west, a Wind Chill Advisory remains in effect for the Kuskokwim Delta. Lows near -15 combined with the aforementioned winds will lead to wind chills near -40. Snow will taper off and winds will gradually diminish through the day Wednesday as a broad upper level low stalls over Bristol Bay. Precipitation chances will be minimal on Thursday, however temperatures will remain below zero across much of the region. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)... Northwesterly flow will persist across the central and eastern Bering/Aleutians bringing widespread snow showers. Heavy freezing spray is likely given the gusty winds combined with the very cold airmass. A weak ridge will bring more settled weather across the western Aleutians through Thursday. && .MARINE (Days 3 through 5: Friday through Sunday)... A relatively quiet weather pattern sets up for this time of year all across Southern Alaska and the Bering. A low over the southern Gulf of Alaska may get winds to gale force along the North Gulf coast, southern Cook Inlet, the Barren Islands, and Shelikof Strait on Friday. The low moves into the eastern Gulf of Alaska Saturday, with a chance of some northwesterly gales through the Barren Islands. A new North Pacific low may move into the southern Gulf of Alaska on Sunday, but there is substantial model disagreement, and confidence in that is low. For the Bering, high pressure will keep all winds below gale force all across the Bering Sea, with a possible exception of a dying front over the western Aleutians early on Friday. Winds may approach gale force in the western Aleutians Sunday night as a strong low approaches. && .LONG TERM FORECAST (Days 3 through 7: Friday through Tuesday)... A much quieter weather pattern is setting up for much of Southern Alaska in the long-term period as a cold air mass becomes firmly entrenched across the area. This will divert the storm track from being over us to instead staying south over the North Pacific with any lows impacting the Panhandle. This is generally well-agreed upon in the models. With that said, there will still be a few storm systems that will be worth watching. On Friday, a weak low will be centered off the coast of Kodiak, over the southwestern Gulf. It will slowly move eastward across the southern Gulf and into the eastern Gulf on Saturday. Snow may impact Kodiak into Friday morning, though a repeat of the near blizzard conditions of a few days ago does not appear likely. On Sunday, a new North Pacific low may approach the AK Pen and Kodiak, but there is poor model agreement on this. There is much better agreement on the leading front of a strong North Pacific low moving into the western Aleutians on Monday. The front should slowly track across the southern Bering into Tuesday. Elsewhere, cold and dry will be the name of the game over mainland Alaska, which means the main weather hazards will be strong gap winds, particularly through Thompson Pass, but also possibly through the Matanuska Valley. These winds coupled with the cold air may lead to wind chill concerns, which unlike previous days, will focus more on Southcentral, rather than Southwest Alaska. Continued polar air pouring southward across the Bering on Friday looks to diminish this weekend, to more light and variable winds. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...Blizzard Warning 181 and 121. Snow Advisory 101. Flood Advisory 145. Heavy Snow Warning 152. Wind Chill Advisory 155. MARINE...Storm Warning 130 Gale Warning 131 132 138 139 150 155 160 165 172 179 180 181 185. Heavy Freezing Spray Warning 130 131 132 136 137 138 139 140 141 150 160 165 179 180 181 185. FIRE WEATHER...DONE. && SYNOPSIS AND MODEL DISCUSSION...EZ SOUTHCENTRAL ALASKA...BB SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...AP MARINE/LONG TERM...JW/CK
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1130 PM AKST TUE DEC 31 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1125 PM SNOW EAGLE RIVER 61.32N 149.54W
12/31/2019 M3.5 INCH ANCHORAGE AK NWS EMPLOYEE
&&
MSOPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1153 PM AKST TUE DEC 31 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1152 PM HEAVY SNOW 2 SW CAMPBELL 61.16N 149.94W
12/31/2019 M4.0 INCH ANCHORAGE AK MESONET
1151 PM HEAVY SNOW 8 MILES SSE EAGLE RIVER 61.24N 149.44W
12/31/2019 M4.4 INCH ANCHORAGE AK NWS EMPLOYEE
&&6 blizzard. Local standard time, as filed.
Alaska DOT closed the Seward Highway from Indian to Turnagain Pass due to blizzard conditions.
Blizzard conditions at Pilot Point began on December 31st and continued into January.
Blizzard conditions began in Port Heiden on December 31st and continued into January.
Blizzard conditions at Toksook Bay began December 31st and continued into January.
Homer ASOS reported 8 hours of blizzard conditions. Near-whiteout conditions were reported near Anchor Point on social media.
Visibility less than one quarter mile in blowing snow observed for 17 hours at Saint Paul airport.
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, January 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: 864131, 864132, 864133, 864134, 864130, 870879.