Gale Warning 143, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
227 PM AKDT Wed Apr 11 2018

.SHORT TERM.../through Friday night/ A broad cyclonic flow will
remain over the gulf through Fri night. Several smaller lows and
trofs will move N into the area through Fri night. Models still
struggling on the details especially with a system moving into
the area Fri, so most forecast adjustments were localized in
nature.

First trof will move N through the southern area tonight, then
weaken over the N late tonight. There will likely be a burst of
wind with the trof over the S early this evening over the inside
channels, so bumped winds up in zone 28 and Clarence Strait for
the 00-03z time frame. Could potentially reach strong wind level
for a very short time, but went with gusts to 35 mph to handle the
wind burst in zone 28 and SCA for Clarence Strait. Further N,
winds will pick up some tonight as trof approaches and the
northerly pressure gradient increases. Left in the SCA for Lynn
Canal, mainly for the 06-12z time frame. After trof passes by late
tonight and early Thu morning, winds over the N should shift to
southerly.

A band of showers with the trof will pass through the southern
area this evening, then weaken as it reaches the central area
later tonight. Highest POPs with this trof were kept over the S
tonight.

A small low will move N into the SE gulf tonight, then curve W
into the central gulf Thu. Think most wind and precip with this
feature will stay over the gulf. However, another trof will move
into the area Thu, and this will bring in more wind and better
threat for precip, especially to the S area, by late Thu morning.

The system that has best potential for stronger winds and more
organized precip will move in for late Thu night and Fri. Looks
like a low will move NE into the SE gulf late Thu night, then turn
more N then NW through the eastern gulf Fri. Still some important
model differences to resolve with this low however, so did not
make much change to winds over the area Fri. Later shifts will
likely need to adjust winds for Fri, with trend toward higher
winds most likely. Could potentially see gale force winds over the
eastern gulf and possibly some of the inner channels Fri.

.LONG TERM.../ Saturday to Wednesday / Broad upper level low over
the Central Gulf of Alaska will persist and then be forced
southeast to the pacific Northwest by a low in the Bering moving
to the western gulf Monday, and this low will continue to track
to the southeast. At the surface the low in the gulf has multiple
centers rotating about that are continuing to lift fronts/troughs
into the southern half of the panhandle into early Saturday
however with the low begin to be forced out of the gulf a drying
trend through Saturday and Saturday night which should lead to a
dry 24 to 48 hours over the panhandle. Into the early part of next
week precipitation may start trying to work its way across the
gulf.

None of the individual waves are looking particularly strong so
think most of the winds will stay under 20 kt except when a
trough is sweeping through the region, small craft winds would be
possible then.

Overall Temperatures returning closer to norms for this time of
year based on the ensemble means from a slightly below normal
trend. ECMWF solution and the WPC solution served as base for the
small changes the extended got. Forecast confidence in the long
range is average.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-013-036-041-042-051-052.
     Small Craft Advisory due to Seas for PKZ022-043-053.

&&

RWT/Bezenek

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