Gale Warning 301, NWS Juneau, AK

Southeast Alaska Forecast Discussion...CORRECTED
National Weather Service Juneau AK
554 AM AKST Thu Dec 13 2018

.SHORT TERM...Active weather Thursday as a strong low moves east
across the panhandle and to Canada. Expect the low to move through
the panhandle and pull away by Thursday night. A small trailing
wave/trough will move across the northern gulf Thursday night while
a ridge of high pressure is built up over the gulf and pacific ahead
of the next large and strong low south of the Aleutians.

The low today has some stronger shower activity which had
continued some lightning with the bigger cells. That should be going
away as cooler air moves into the lower levels around the low. The
line of bigger shower cells is expected to lift north to the north
central panhandle. The rain snow line should be just north of that
area as the northern inner channels stay northerly and try to filter
some cooler air in. Although when the rain increases could see that
pull snow down to the surface with snow melt cooling too. The back
side of the low complex should move into the panhandle through the
day with a strong westerly punch of surface wind. Rain or snow
should continue through the day.

On Friday most of the precipitation will have tapered off over the
land areas. The small exception being of west of Yakutat, and that
area dries out by Friday night too. This will be in response to the
powerful low moving into the gulf by Saturday, more on that in the
long term period.

.LONG TERM.../Saturday through Thursday as of 10 pm Wednesday/
Long range period will start out stormy with a very large low over
the gulf and NE PAC Sat that moves N and weakens Sun. Model
agreement begins to break down after Sun, but they show potential
for more strong systems affecting the area during Mon-Thu with
long wave trof setting up between 150 and 160W. Ended up using
the 18z GFS to handle Sat, then went with mainly latest WPC from
Sun onward.

Increased winds somewhat with the Sat-Sun system. Raised the max
wind band ahead of the occluded front to 55 kt (with the GFS model
suggesting 60-65 kt but it was strongest model) for Sat into Sat
night. Raised POPS to categorical for most areas ahead of the
front for Sat into Sun. May still see some snow over mainly the N
half of the area as some colder air will be in place as initial
precip arrives Sat, but a warm up from the S should occur Sat
night into Sun, diminishing the snow threat over the central area.
Still looks fairly mild with above average temps continuing into
at least early next week, and active pattern will keep precip
threat on the higher side as well, although the main precip threat
may end up over the S half of the area during early to middle of
next week. Wind will be the main hazard that will need to be
monitored with these systems, with a threat for accumulating snow
Sat into Sat night over the N half.

&&

.AVIATION...Wind sheer is prevalent in the forecast today as a
strong low moves inland with gusty winds in the lower levels and
across the ridge tops. A brisk westerly wind will be moving in
behind the low to the coast through the morning. Cloud ceilings are
1000 to 3000 feet over the southern two thirds do to showers pushing
into the panhandle as well.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Strong Wind until 3 PM AKST this afternoon for AKZ026.
     Strong Wind until noon AKST today for AKZ027.
     Strong Wind from noon AKST today through this afternoon for
     AKZ022.
     Strong Wind from noon today to 3 PM AKST this afternoon for
     AKZ023.
     Strong Wind from 3 PM AKST this afternoon through this afternoon
     for AKZ020.
MARINE...Storm Warning for PKZ042.
     Gale Warning for PKZ021-022-033-035-041-043-051.
     Small Craft Advisory for PKZ013-031-032-034-036-052.
     Small Craft Advisory due to Seas for PKZ053.

&&

Bezenek/RWT

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