Gale Warning 28, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
710 AM AKST Sun Jan 9 2022

.SHORT TERM...Sunday...Winter Storm in progress across SE AK...

The well advertised winter storm is underway across Southeast
Alaska this morning. A deep low continues to churn in the southern gulf
of Alaska with a warm front extending eastward towards the Central
Panhandle. One thing to note, the low is much further east than
what guidance continues to depict. Models are in agreement the low
should move north along 150 W and then towards Kodiak Island.
However, current satellite imagery shows the low moving NNE along
142 W. The much further east position of the low explains the
stronger warm air advection from the south and the rapid northerly
movement of the rain/snow line. As of the writing of this
discussion, the rain snow line extends from Sitka to Kake to
Petersburg and Wrangell. Up to a foot of snow fell in Wrangell
before the transition to rain. Reports of around 5 inches in
Petersburg and on POW Island and up to 10 inches around Ketchikan
before everything changed to rain. Despite snowfall amounts on the
lower end of the spectrum, still expecting an impactful winter
storm through the day. Heavy rainfall will increase in coverage
and intensity through the day today across the southern half of
the Panhandle. A Flood Watch remains in effect for Ketchikan and
Metlakatla as 3-4 inches of rain on top of deep snow pack may lead
to flooding issues.

Despite the rapid movement of the rain/snow line, the arctic
airmass to the north of the warm front is still holding strong
across the northern Panhandle. The Juneau forecast office has only
risen to 8 degrees so far this morning while the rest of Juneau
is in the teens. Upper Lynn Canal remains around zero as of 6 AM.
Heavy snow will continue for the Icy Strait corridor and northward
through the day. With the low further east and the warm front
moving north faster than anticipated, expect snowfall amounts
across the north to remain on the lower end of the range. As of 6
AM around 4 to 6 inches of very dry, fine snow has fallen across
the Icy Strait corridor including Juneau. The forecast calls for
another 8 to 15 inches possible for the Icy Strait Corridor
through 3 AM Monday; however with snow likely to change to rain
early, the final snowfall amounts may be a little lower. Current
forecast still reflects the larger snowfall totals. This will need
to be monitored very closely. Another important thing to note is
the likelihood of freezing rain. Before a full transition to plain
rain, there is likely to be a 1-3 hour period of freezing rain
which could add a glaze of ice over frozen surfaces. Even after
temperatures rise above freezing, rainfall on top of a deep snow
pack and frozen ground will make for very slick/icy conditions. Very
slick conditions still expected no matter the outcome of the snow
totals.

Highest confidence remains for Upper Lynn Canal where the cold air
will remain through tomorrow. Still expecting up to 2 feet of snow
for this area; however if warmer air continues to intrude
northward, totals may also be a tad lower due to lower snow to
liquid ratios.

This storm is also packing a punch when it comes to wind. Gale
force conditions persist through the Southern Inner Channels and
Outer Coast through the day. With the main low much further east,
expect winds to be stronger than forecasted regionwide. A High
Wind Warning was issued for the western coast of Prince of Wales
Island and Hydaburg for winds up to 60 mph through the day. Will
need to watch Sitka and possibly other communities for high wind
potential later this morning and afternoon as a 65-75 kt low level
jet pushes in with the cold/occluded front.

Overall confidence remains on the low side for this system as
guidance does not have a good handle on its position and strength.
Minor changes and updates made to the forecast with the early
morning package. Current forecast remains as is but will be
closely monitored through the day in case big changes need to be
made.

.LONG TERM.../Monday morning through Thursday/...Bottom line, this
week is going to be wet and warmer. Models show an upper level
trough over the gulf with multiple disturbances, about one per
day, moving up towards the panhandle from the south along the
east flank of the trough. Model details (track and timing) are
fuzzy at best with each wave so changes to the forecast were
focused on the first wave approaching the southern panhandle
Monday morning, which also appears to be the strongest of the
series in this time frame.

For the Monday system, winds will be elevated and gusty across the
southern zones. Strong winds, 50 mph or higher, are likely for
areas around Craig, Hydaburg, Annette Island, and Ketchikan
Monday during the day. In addition to the wind continuing, 1-2
inches of rain are expected Monday for the same areas. Obviously,
this is on top of whatever falls out of the sky between now and
then. For this reason, Special Weather Statements and a Flood
Watch (Ketchikan area) continue into Monday afternoon for
expected impacts (ponding, street flooding). Increased the winds
and QPF in the forecast as part of today's package.

Beyond Monday, the general trend is to keep the relatively high
snow levels through Wednesday before they start to creep down
slowly. Forecast snow levels are 2000-3000 feet south, 500-1000
feet north. This will keep precipitation mostly rain, except some
snow at high elevations and possibly at night for the northern
areas. High temperatures are expected to be above freezing at sea
level for all of the panhandle through Thursday. Forecaster
confidence in the general warm, wet pattern is high.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning until 6 PM AKST this evening for AKZ026.
     High Wind Warning until 4 PM AKST this afternoon for AKZ027.
     Strong Wind from 3 PM AKST this afternoon through this evening
     for AKZ027.
     Winter Storm Warning until 9 PM AKST this evening for AKZ020>022-
     024-025.
     Winter Storm Warning until noon AKST today for AKZ023.
     Strong Wind through this evening for AKZ023-028.
     Flood Watch through Monday afternoon for AKZ028.
     Winter Storm Warning until 6 AM AKST Monday for AKZ017>019-029.
     Strong Wind from 3 PM AKST this afternoon through late tonight
     for AKZ017.
MARINE...Heavy Freezing Spray Warning for PKZ012.
     Storm Warning for PKZ043-051-052.
     Gale Warning for PKZ012-013-021-022-033-036-041-042-310.
     Small Craft Advisory for PKZ011-031-032-034-035-053.

&&

CM/BFL

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