A North Pacific Low approaching the South Mainland of Alaska brought early season heavy snowfall to the Susitna Valley. While this area is known for good snowpack and is popular winter recreation, heavy snowfall like this in the first week of November is not common.
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 North Pacific Low approaching the South Mainland of Alaska brought early season heavy snowfall to the Susitna Valley. While this area is known for good snowpack and is popular winter recreation, heavy snowfall like this in the first week of November is not common.
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 Nov 8, 5:32 AM AKST, 31 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 532 AM AKST Sun Nov 8 2020 .ANALYSIS AND UPPER LEVELS... A negatively tilted upper level trough shows up well on satellite extending from Southwest Alaska through the AKPEN. A minor shortwave is moving across the southern Bering moving towards the eastern Aleutians and AKPEN. A surface low has moved inland near Dillingham with the front extending east towards the southern Kenai Peninsula. Radar is showing a wide swath of precipitation from Prince William Sound and west towards Anchorage and Kenai area and across most of Southwest Alaska. Temperatures continue to climb all over Southcentral with the upper 20s and 30s across Anchorage and the MAT valley, and 30s across northern Kenai and 40s for the southern part of the Kenai. Temperatures across the Copper River Basin have warmed to upper teens to 30s from Gulkana southward. Most coastal locations are above freezing except Valdez which is holding in the upper 20s. While Southwest Alaska is in the low 30s across the Kuskokwim Delta and upper 30s to 40s across the Bristol Bay region. Snow is occurring from just north of Kenai up into Anchorage and the MAT- SU valleys, with a few pockets of rain or mix where temperatures have gone above freezing. Most coastal locations are rain except for Valdez which is still reporting snow. Snow is also reported across the Kuskokwim Delta and rain across the Bristol Bay area. && .MODEL DISCUSSION... Models are still in good agreement with the low moving into southwestern Alaska with a developing triple point low in the Shelikof Strait this morning. With this warmer track much of the snow will change over to rain today as the warm air pushes north into the Anchorage and MAT Valley. Models remain in good agreement with another low moving through the western to northern part of the Bering Sea Sunday through Monday night. The next complex low that approaches the southern Bering Sea by Tuesday is seeing considerable spread in model track and strength which is causing increased uncertainty for the Aleutians through southwest mainland Alaska for the middle of next week. && .AVIATION... PANC...Transition from snow to rain is still expected this morning with all rain likely at the terminal by the afternoon. IFR ceilings with Intermittent IFR visibilities could continue until the changeover occurs, after which expect visibility to quickly become MVFR or better in the rain with ceilings remaining IFR to MVFR. Additionally, winds will pick up from the south out of the Turnagain Arm around the time of precip transition with gusts up to 20 kts possible until the early evening when winds decrease and become more westerly through Monday morning. For this evening into early tonight, a few snow showers are possible as colder air advects in from the west with occasional IFR conditions not out of the question during any brief periods of snow. Any snow showers will end late tonight, and ceilings should lift to VFR as colder, drier air advects in from the west early Monday morning. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2: Today through Monday Night)... So far the storm is on track as forecasted. The snow changed over to rain overnight along the Kenai Peninsula, and also changed over in Palmer. A few reports of rain mixing in across portions of Anchorage have also come in. The rain/snow line will continue moving north and west across Anchorage and the rest of the Mat Valley today, such that most everywhere should be all rain around midday. A Winter Storm Warning remains in effect for the Susitna Valley from Talkeetna north and west, with up to a foot and a half of additional snow, mainly along the Alaska Range expected. The Winter Weather Advisory for the Copper River Basin north of Glennallen also remains in effect, with over a foot of snow expected in the Paxson area and along the Denali Highway. Temperatures have rapidly risen on strong southeasterly winds in Glennallen, resulting in rain mixing in with the snow there, so accumulations from Glennallen south and east will be very light, if there are any at all. On the wind front, the High Wind Warning verified on the Hillside this morning with gusts up to 90 mph reported. Fortunately, those levels of gusts were relatively isolated, with the average peak gust on the Hillside and Turnagain Arm holding in the 60 to 65 mph range. As the center of the low causing all of this wintry and windy weather moves into Prince William Sound later this morning, that will cause the winds through Turnagain Arm to rapidly diminish, then flip to a westerly or northwesterly direction tonight. After the sun sets tonight and the low begins to drift eastward across Prince William Sound and into the northern Gulf, somewhat cooler air will begin to move back into the Cook Inlet region. This should allow any remaining precipitation to change back over to snow. If any snow occurs at all, it will be brief in duration and not last very long for most low elevation areas. However, with northwesterly flow causing upslope along the Hillside, snow showers will persist through midnight, which could result in several inches of accumulation before ending. See the Special Weather Statement for more details. As an upper level wave moves across the area on Monday, the upper level flow will enhance the strong outflow winds in Whittier and Thompson Pass behind the departing low. Gusts to 60 mph are possible in Whittier. For Thompson Pass, winds of similar magnitude are expected out of the north starting late Sunday night and continuing through the day on Monday. The snow falling now through the Pass is falling on southeasterly winds. When the winds flip to northerly on Monday, it is likely much of that snow will redrift back over the Richardson Highway, causing hazardous travel conditions. Elsewhere, much quieter conditions are expected for the rest of Southcentral with some sunshine expected. && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)... The much anticipated low is moving ashore into Southwest Alaska, with the low center now on land northeast of Bristol Bay. Rain has been falling in coastal areas, though coastal Southwest Alaska in now on the backside of the low. Winds have switched to the Northwest in the Kuskokwim Valley and cooled temperatures, with rain switching to snow at Bethel overnight. This trend will continue, however with most precipitation now inland, coastal areas will not see much accumulation. Higher snowfall totals are still expected inland and in the AK Range, where upslope flow will help enhance snowfall. Some brief clearing will occur overnight with a short wave ridge moving in. However, low level cloud cover is still expected along the coast with moist, on-shore flow continuing. Some fog may be possible as well with recent precipitation falling. Further analysis was done on the next low in regards to coastal flooding. While its a bit early to completely rule it out, as of now there will not be a fetch of winds strong enough and for long enough duration to be of much concern. The storm just making landfall looked more favorable for coastal flooding and did not cause any impacts, so this is factored into reasoning as well. We will certainly keep an eye on this situation though. While the concern is low at this time, do stay tuned as a precaution. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)... The large low pressure system that has been progressing through the Bering is currently moving ashore in Bristol Bay. Behind this low in the Eastern Bering Sea are gale force winds. In the Central Bering, there is a brief break in the weather with a short wave ridge moving through. The next low in the series of lows is already entering the Western Aleutians. It will take a northwesterly track through the Central Bering, bringing largely gale force winds, with a few areas of storm force winds. A third low moves in Tuesday, keeping the pattern active. Although the pattern is active, none of these lows are very powerful or will stick around long enough to create any sustained impacts. && .MARINE (Days 3 through 5: Monday through Wednesday)... Gulf of Alaska: A frontal system from the North Pacific will usher gales southeast of Kodiak and offshore starting Tuesday night. As this front moves east-northeast, the gales will be following closely too along the frontal axis and west of the frontal boundary across the Gulf through Wednesday morning. A long period fetch from south of the Aleutians will approach the southwestern Gulf by late Wednesday afternoon into Wednesday night. This will generate hazardous wave heights peaking to near 27 ft late Wednesday night. Wave heights near the frontal boundary are expected to remain near 12 to 15 ft with higher sets. Bering Sea: A couple of lows connected to a frontal boundary from the Northwest Pacific will bring gales and storm force winds across the Aleutians, central and eastern Bering starting Tuesday morning through Wednesday afternoon. One of the lows will break away and trek eastward toward Bristol Bay on Wednesday morning. Meanwhile, a parent low linked to the frontal zone moves northward then curves south of Saint Lawrence Island before descending southward Friday night. Dangerous wave heights between 25 to 35 feet with potentially higher sets will stay south of the Aleutians and the central Bering through at least Wednesday afternoon. Gales from the low over the eastern Bering will gradually wane by Thursday night to small craft conditions. && .LONG TERM FORECAST (Days 4 through 7: Wednesday through Saturday)... Synoptically, a broad longwave trough will exist from the Kamchatka Peninsula to the west coast of Alaska with ridging over the Gulf and Alaska mainland. The dominate feature to watch in the first half of the forecast period is a negatively tilted trough over the AKPEN on Wednesday. Given the broad southerly flow and tropical moisture feed within the warm conveyor belt of the system, warm temperatures and rain are expected over southern Alaska on Tuesday and Wednesday. Snow is likely over Southwest Alaska at elevations above approximately 3000 feet. For Southcentral the rain/snow line will be a difficult forecast once again do to when, where, and if a triple point low sets up in the northern Gulf along the warm front. However, at this time lower elevations along the Gulf coast will likely be rain due to little cold air in place as the front moves in. Over the Bering, strong cold air advection is expected out of eastern Russia, which will be reinforced by a nearly stationary low over the Bering Strait. Most models now show gale to storm force winds over the central Aleutian Chain on Wednesday. On Thursday the main shortwave trough mentioned earlier is expected to move into the eastern Gulf, which should allow for clearer and colder conditions over the southern mainland through Saturday. Over the AKPEN, Bering, and Aleutian Chain, strong west to northwest winds and rain are expected through Saturday. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...NONE. MARINE...NONE. FIRE WEATHER...NONE. && SYNOPSIS AND MODEL DISCUSSION...RC SOUTHCENTRAL ALASKA...JPW SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BJB MARINE/LONG TERM...CB/CJ
SPECIAL WEATHER STATEMENT National Weather Service ANCHORAGE AK 453 AM AKST Sun Nov 8 2020 AKZ101-111-082100- Anchorage-Matanuska Valley- Including the cities of Anchorage, Eagle River, Indian, Eklutna, Palmer, Wasilla, Sutton, and Chickaloon 453 AM AKST Sun Nov 8 2020 ...SNOW CHANGING TO RAIN WITH GUSTY WINDS DIMINISHING TODAY... Snow occurring this morning in Anchorage will mix with rain this morning, then change entirely over to rain by this afternoon. Across the Matanuska Valley and far southern Susitna Valley, the precipitation has already changed over to rain in eastern areas, including Palmer and the Knik River Valley. Rain is mixing in across Wasilla, and will change over entirely to rain later this morning. For the far southern Susitna Valley, rain will mix in later this morning and may change over entirely in some areas this afternoon. As the storm departs, there is a slight chance the rain may change back over to snow before ending Sunday night at lower elevations. Any accumulations will hold to 1 inch or less. At higher elevations along the Hillside, upslope flow on westerly winds will keep accumulating snow going well into Sunday night once any rain changes back over to snow. An additional 2 to 4 inches of snow are possible Sunday night. In the areas where the snow changes over to rain, icy conditions are likely for several hours following the changeover as the rain falls on frozen ground due to the recent cold temperatures. As temperatures warm into the upper 30s to around 40 late this morning into the afternoon, the icy conditions will improve. The second impactful element with this strong storm is wind. The High Wind Warning remains in effect until 9am this morning for Turnagain Arm and higher elevations, where gusts to 90 mph have been reported on the Hillside earlier this morning. Meanwhile gusty winds of 20 to 30 mph with occasional gusts to 40 mph are possible in the Matanuska Valley this morning. The winds everywhere will rapidly diminish later this morning. Please visit weather.gov/Anchorage for the latest forecasts for your area and for any updates. AKZ125-131-082100- Western Prince William Sound-Northeast Prince William Sound- Including the cities of Whittier, Seward, Girdwood, Moose Pass, Valdez, and Thompson Pass 453 AM AKST Sun Nov 8 2020 ...PERIODS OF HEAVY SNOW, BLOWING SNOW, LOW-ELEVATION RAIN, AND GUSTY WINDS CONTINUE AROUND PRINCE WILLIAM SOUND... Periods of heavy snow associated with a strong storm system are occurring in Turnagain and Thompson Passes this morning. Snowfall amounts will be measured in feet at higher elevations by the time the snow ends Sunday night. Gusty winds and warmer temperatures have resulted in the snow changing over to rain at lower elevations, including Portage Valley. Snow levels will rise to around 1,500 feet later today, allowing rain to mix in to road level through the Passes. Winds are gusting over 50 mph through Portage Valley. Areas of blowing snow combined with the falling snow will reduce visibility in the windier areas through Thompson and Turnagain Passes today where the precipitation remains all snow. Travelers should expect rapid changes in visibility. With the departure of the storm Sunday night into Monday, strong westerly winds are expected in Whittier. Gusts to 60 mph are possible during the day on Monday. Gusty winds through Thompson Pass Monday may cause localized severe reductions in visibility from blowing snow. This will be due to the large wind direction shift from southeasterly now to northerly on Monday. Please visit weather.gov/Anchorage for the latest forecasts for your area.
1 heavy snow. Local standard time, as filed.
Trained spotters near Talkeetna and Petersville, AK reported 10-15 inches of snowfall from this event. Further south and Eagle Song Lodge 17 inches of snow was reported in a roughly 18 hour period.
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, November 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: 930549.