Storm Warning 1, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
635 AM AKST Sat Jan 1 2022

.SHORT TERM.../Through Saturday night/...The main front has passed
through the panhandle and it delivered quite the snowy night.
Early morning reports have been impressive. A spotter in Haines
reported 15 inches and it was still snowing at the time of the
report. A spotter in Petersburg reported 10.5 inches. Here at the
WFO in the back of the Mendenhall Valley, we have received around
10 inches as of 6AM.

Going forward, we'll transition into a more showery pattern with
those getting stuck under the showers still receiving some decent
snowfall amounts today. We have highlighted Yakutat and Juneau as
two of those areas that could see heavy snow through today. In
Yakutat's case, we did extend the winter storm warning through 3
PM today to account for heavy snow showers persisting, at least
through the morning. In Juneau's case, we may recommend that when
the Winter Storm Warning expires at noon today, that we may
replace it with an advisory through midnight.

With the center of the low sitting and spinning so close to
Yakutat, repeated snow showers are likely. For the rest of the
panhandle, continued onshore winds, driving showers through SE AK
is likely. But there is evidence of a pocket of warmer air being
pushed in. So some rain and snow mixing is possible along the
coast, and in the southern half of the panhandle. Juneau is more
likely to stay with just snow so continued heavy snow is more
likely.

That being said, temperatures were generally kept warmest in the
early parts of the day and allowed to cool this evening. But
temperatures will play a big role today. As of 6AM, 33 to 34
degrees is the transition zone where snow switches to rain. Temps
warmer than 34 are producing rain and temps colder 33 are
producing snow. But temps around 33 to 34 are producing snow in
some cities and rain in other cities. So a difference of 1 or 2
degrees makes all the difference.

As the low tracks south today through tonight, winds will increase
from the north. Lynn Canal is forecasted to see winds increasing
to 30 to 40 knots tonight and continue to increase Sunday. And as
those northerly winds kick in, temperatures will really drop
tonight with lows dipping into the single digits to teens for the
north while the south sees lows in the upper 20s to low 30s.

LONG TERM.../Sunday through Wednesday Night/ Lingering showers
from the weekend storm will continue to move out of the region on
Sunday as high pressure begins to establish itself in the Yukon.
This high pressure will be the main feature of the forecast
period. As it builds, a very strong pressure gradient will kick up
the winds, mainly for northern portions of the panhandle. To
account for this, the High Wind Watch issued for Downtown Juneau
and Skagway was upgraded to a High Wind Warning. While Taku
signals are not the strongest, the cross-barrier flow coupled with
the strong model indicated cold air advection was difficult to
pass, as this will help a Taku wind initiate in a big way, but nor
are we completely confident. Strong winds are also expected in
Haines but confidence in reaching "High Wind" criteria is lacking
at this time (we define strong wind as gusts from 40 mph through
57 mph, and high wind as gusts from 58 mph and higher). As
further guidance becomes available, will be better prepared to
issue any headlines for there and other locations if needed.
Expect that this will also translate to storm force winds through
Lynn Canal with Gales and high end small craft winds, mainly
through N-S aligned channels, as you travel further south. Arctic
outflow around the high will also cause a massive dip in the
temperatures. Well below normal temperatures are currently in the
forecast for the entirety of next week with several daily records
potentially in Jeopardy. Extreme low temperatures for the month of
January appear to be safe at this point (among observation sites
with long established periods of record) but the chance of setting
such a benchmark somewhere is not zero. Little to no PoP in the
forecast means that the cold and the wind are the forecast
challenges. Since the snowfall will be ending at approximately the
beginning of the strongest winds, blowing snow may become a
travel concern for some locations. Another potential hazard will
be the combination of wind and frigid temperatures will likely
lead to wind chill concerns. As of now, the higher elevations
along the Klondike Hwy appear to be the most likely place to see
such issues, but regardless of weather or not advisory or warning
criteria are met, many locations will likely feel very
uncomfortable if outside for too long.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning until noon AKST today for AKZ025-026.
     Winter Storm Warning until 9 AM AKST this morning for AKZ018>022-
     024.
     High Wind Warning from midnight tonight to 6 AM AKST Monday for
     AKZ018-025.
     Winter Storm Warning until 6 AM AKST early this morning for
     AKZ028.
     Winter Storm Warning until 3 PM AKST this afternoon for AKZ017-
     029.
     Strong Wind from this evening through late Sunday night for
     AKZ019.
MARINE...Heavy Freezing Spray Warning for PKZ012.
     Gale Warning for PKZ011>013-022-036-043-051>053-310.
     Small Craft Advisory for PKZ021-031>035-041-042.

&&

GJS/JDR

Visit us at http://www.weather.gov/Juneau

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
1059 AM AKST SAT JAN 1 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     HEAVY SNOW       PELICAN                 57.96N 136.23W
01/01/2022  M15.6 INCH       HOONAH-ANGOON      AK   TRAINED SPOTTER

            A TRAINED SPOTTER RECORDED 15.6 INCHES OF
            SNOW IN PELICAN OVER THE PAST 24 HOURS.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
1121 AM AKST SAT JAN 1 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1115 AM     HEAVY SNOW       TENAKEE SPRINGS         57.78N 135.22W
01/01/2022  E12.0 INCH       PKZ032             AK   TRAINED SPOTTER

            A TRAINED SPOTTER ESTIMATED A FULL FOOT OF
            SNOW FELL IN TENAKEE SPRINGS WITH THE
            CURRENT SYSTEM.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
1135 AM AKST SAT JAN 1 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 AM     HEAVY SNOW       2 ESE KETCHIKAN         55.34N 131.65W
01/01/2022  E8.0 INCH        KETCHIKAN GATEWAY  AK   TRAINED SPOTTER

            A TRAINED SPOTTER ESTIMATED THAT 8 INCHES OF
            SNOW FELL BEFORE A CONVERSION TO RAIN
            OCCURRED. PRECISE MEASUREMENTS WERE
            CHALLENGING AS RAIN MELTED SOME SNOW AND
            WINDY CONDITIONS HELPED LEAD TO DRIFTING
            SNOW.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
1208 PM AKST SAT JAN 1 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1050 AM     HEAVY SNOW       2 SE PETERSBURG         56.79N 132.91W
01/01/2022  M15.5 INCH       PETERSBURG CENSUS AAK   PUBLIC

            A MEASUREMENT INDICATES THAT APPROXIMATELY
            15.5 INCHES OF SNOW HAS FALLEN NEAR
            PETERSBURG. PETERSBURG AIRPORT HAS SINCE
            SWITCHED OVER TO RAIN.

&&