A large trough of low pressures in the Gulf of Alaska brought precipitation to Southeast Alaska. This was the second in a series of storms in an active period, as a jet streak allowed for enhanced precipitation rates over much of the northern Alaska Panhandle.
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 AJK wrote it up.
A large trough of low pressures in the Gulf of Alaska brought precipitation to Southeast Alaska. This was the second in a series of storms in an active period, as a jet streak allowed for enhanced precipitation rates over much of the northern Alaska Panhandle.
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 Juneau, AK wrote its last area forecast discussion before the first event at Nov 17, 4:36 PM AKST, 5 hours 24 minutes earlier.
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
436 PM AKST Wed Nov 17 2021
.SHORT TERM.../Through Thursday night/Temperatures have warmed
throughout the panhandle to the upper 30s to low 40s this
afternoon, with the exception of Hyder and White Pass. Tonight,
strong cold air advection is expected to move in from the west
changing rain showers to snow showers. Yakutat will see the change
in precip type first this evening followed by the Northern
Panhandle and then the Central Panhandle. By Thursday morning even
parts of the Southern Panhandle will get to play as temperatures
will be near freezing leading to a rain/snow mix possible through
the day. Shower activity will increase through late tonight into
early Thursday morning. This forecast is challenging due to the
showery nature of the snow which will lead to highly variable
snowfall rates and accumulations. Confidence is higher that heavy
snow will fall under the strongest showers leading to moderate
snow accumulations. With this in mind, greatest accumulations look
to be focused across the NW Gulf Coast and through the Icy Strait
Corridor.
As for the posted winter weather products, the Winter Weather
Advisories for Yakutat, Pelican, Elfin Cove, and Juneau have been
upgraded to Warnings. For Sitka, a Winter Weather Advisory remains
in effect. Heavy snow continues to fall in Hyder, so a Winter
Storm Warning remains in effect for them until 5AM Thursday.
Snowfall accumulations of 5 to 8 inches are expected through the
warning areas with lesser amounts for the advisory area. As
mentioned earlier, snow showers will be highly variable leading to
amounts varying greatly over short distances.
Winds have been on the decline through today has pressure
gradients have decrease. Through upper Lynn Canal, High end small
crafts remain and strong winds (gusts to 40 mph) for Skagway and
Haines will persist through the evening. Through tonight and
Thursday afternoon winds will be largely un-impactful. By
Thursday night, an arctic air mass surges south out of the Yukon.
This will lead to strong northerly outflow winds Thursday night
into Friday. With the colder air mass sliding south, temperatures
will be on a downhill slide through the day Thursday and Friday
with temperatures reaching the teens and single digits by Friday
night.
.LONG TERM.../Friday through mid next week/ Very active period
continues through the week and into the weekend as winter takes
hold of Southeast Alaska. Continued chances for accumulating snow
and Much Colder temperatures are in the forecast.
The period begins with a deep trough over Southern Alaska with a
strong jet streak rounding the base over the gulf. The jet streak
pushes right into the Panhandle placing the northern half of the
region in an area of enhanced lift under the left exit region. At
the same time, very cold arctic air will be ushered into the region
with 850mb temps falling to around -8C to -15C! As a low in the NE
gulf weakens and an arctic high pushes south in the region, snow
shower activity will end across the northern half of the Panhandle
through the day.
Precipitation will likely continue for the Southern half of the
region through Friday night as a weak area of low pressure passes
through. The combination of very cold air surging southward from
the arctic high to the north and this weak low pushing in from the
southwest will set the stage for accumulating snow at sea level
across the South. The main challenges with this system will be how
much snow is possible at sea level and if the arctic high to the
north will be strong enough to dry out the atmosphere and limit
accumulations. Current forecast is for minor accumulations across
the Southern Panhandle Friday morning before a transition to rain.
Areas that could remain all snow are northern Prince of Wales
Island, and along and north of Sumner Strait. Confidence remains
marginal in the Friday forecast with regards to snowfall
accumulations. Winter weather products may be needed if this low
looks to come in a bit stronger with more moisture. This will be
watched closely over the next couple days.
**Saturday Drying Trend and Sunday Potential Winter Storm**
As the aforementioned arctic high drops south into the region,
expect a drying and clearing trend from north to south into
Friday night. Some of the coldest temperatures of the season are
possible Saturday morning as lows could drop into the single
digits across the north! Highs may not make it out of the 20s for
many areas Saturday afternoon. With such cold air in place, the
next system expected to move in Sunday into Monday could bring
another round of accumulating snow before a changeover to rain.
Ensemble member low locations have been all over the Gulf with
potential tracks for this system. A likely path for the low will
be coming out of the N pacific and moving NE towards the Northern
Gulf Coast with a warm frontal feature extending eastward toward
the Panhandle. This solution agrees well with WPC, so will be
keeping with them until deterministic guidance comes into better
agreement. Nonetheless, this pattern is favorable for potentially
heavy snow before a changeover to rain. The arctic high to the
north is expected to have deep enough cold air for precipitation
to begin as snow Saturday evening and through Sunday.
Precipitation is expected to change to rain from south to north;
however confidence remains low in how quickly that changeover will
occur. Highest confidence in significant snow amounts exists
along and north of the Icy Strait Corridor. This will be monitored
very closely over the next few days.
Next week looks to be very active with multiple lows moving into
the Gulf from the south. With continued southerly flow, expect a
warm up at sea level and a changeover to rain for most areas. Too
early to get into exact details regarding the storm systems for
next week due to low model and ensemble agreement. Confidence is
low for the exact details but high that the pattern will remain
quite active.
Used a blend of EC/NAM/GFS for Friday then transitioned to mainly
using the EC/WPC Sunday through next week.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning from midnight tonight to midnight AKST
Thursday night for AKZ022-025.
Winter Weather Advisory from midnight tonight to 9 PM AKST
Thursday for AKZ023.
Strong Wind until 6 PM AKST this evening for AKZ018-019.
Winter Storm Warning from 6 PM this evening to 4 PM AKST
Thursday for AKZ017.
MARINE...Small Craft Advisory for PKZ012-013-022-031-032-041>043-051>053.
&&
CC/CM
Visit us at http://www.weather.gov/JuneauPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
524 PM AKST WED NOV 17 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM SNOW SKAGWAY 59.46N 135.31W
11/17/2021 M4.7 INCH SKAGWAY AK CO-OP OBSERVER
4.7 INCHES 24 HOUR TOTAL SNOW AT SKAGWAY
POWER COOP.
0700 AM SNOW HYDER 55.92N 130.03W
11/17/2021 M8.1 INCH PRINCE OF WALES-HYDAK CO-OP OBSERVER
8.1 INCHES OF SNOW AT HYDER COOP.
0700 AM SNOW HAINES CUSTOMS 59.45N 136.36W
11/17/2021 M7.0 INCH HAINES AK CO-OP OBSERVER
7.0 INCHES OF NEW SNOW AT HAINES CUSTOM
STATION.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
528 PM AKST WED NOV 17 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 AM SNOW WHITE PASS 59.63N 135.16W
11/17/2021 M10.0 INCH SKAGWAY AK DEPT OF HIGHWAYS
AKDOT REPORTS UP TO 10 INCHES OF NEW SNOW ON
THE KLONDIKE HIGHWAY NEAR WHITE PASS. SOME
BLOWING SNOW AND LIGHT DRIFTING (0-1 FT)
ALSO OBSERVED.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
640 PM AKST WED NOV 17 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0637 PM HEAVY SNOW HYDER 55.92N 130.03W
11/17/2021 E15.0 INCH PRINCE OF WALES-HYDAK TRAINED SPOTTER
POWER IS OUT IN HYDER (SNOW LADEN TREE FELL
ON LINES). ROUGHLY 15 INCHES OF NEW SNOW.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
651 PM AKST WED NOV 17 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0635 PM HEAVY SNOW HYDER 55.92N 130.03W
11/17/2021 U1.0 INCH PRINCE OF WALES-HYDAK DEPT OF HIGHWAYS
POWER LINES DOWN ON THE ONLY ROAD BETWEEN
HYDER, ALASKA AND STEWART, CANADA. ROAD IS
CLOSED.
&&3 heavy snow. Local standard time, as filed.
A member of the general public estimated 6 inches of snow overnight in Yakutat. 10 inches was reported by 1330 akst.
A total of 8.0 inches of snow midnight to 9 pm at the Juneau National Weather Service Forecast Office.
A trained spotter in Gustavus reported 8.1 inches of new snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2021Every state in 2021This day in weather historyWarnings in Alaska, November 2021
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: 994859, 994863, 994862.