Storm Warning 47, NWS Juneau, AK

087 
FZAK67 PAJK 071235
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 AM AKST MON NOV 7 2016 

OFFSHORE WATERS FORECAST FOR GULF OF ALASKA EAST OF 144W

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT THE AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WINDWAVE AND SWELL HEIGHT.

PKZ398-080100-
400 AM AKST MON NOV 7 2016 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A VIGOROUS FRONT WILL MOVE NORTH ACROSS THE EASTERN GULF EARLY
MONDAY. AT LEAST TWO TRAILING TROUGHS WILL MOVE NORTH OVER THE
SAME REGION THROUGH TUESDAY. THE LARGE LOW OVER THE WESTERN GULF
WILL BE REPLACED WITH A 950 MB LOW LATE TUESDAY WHILE THE
ASSOCIATED GALE FORCE FRONT WILL MOVE INTO THE EASTERN GULF
WEDNESDAY. 

$$

PKZ310-080100-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 AM AKST MON NOV 7 2016 

...GALE WARNING TODAY...

.TODAY...SE WIND 45 KT DIMINISHING TO 25 KT IN THE AFTERNOON.
SEAS 25 FT SUBSIDING IN THE AFTERNOON. SW SWELL IN THE AFTERNOON.
RAIN EARLY IN THE MORNING. SLIGHT CHANCE OF THUNDERSTORMS. 
.TONIGHT...SE WIND 30 KT. SEAS 16 FT. RAIN SHOWERS AND SLIGHT
CHANCE OF THUNDERSTORMS. 
.TUE...SE WIND 30 KT. SEAS 16 FT. RAIN SHOWERS IN THE MORNING.
SLIGHT CHANCE OF THUNDERSTORMS. 
.TUE NIGHT...S WIND 25 KT. SEAS 16 FT. S SWELL. SLIGHT CHANCE OF
THUNDERSTORMS IN THE EVENING. 
.WED...SE GALE TO 45 KT. SEAS 21 FT. 
.THU...SE WIND 30 KT. SEAS 22 FT. 
.FRI...SW WIND 30 KT. SEAS 18 FT. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
242 PM AKST Sun Nov 6 2016

.SHORT TERM...Sunday afternoon WV imagery shows a large upper low
centered 600 miles south of Kodiak. A potent shortwave trough
associated with the exit region of a 120+ kt upper jet was
ejecting NE along the periphery of the low, and is forecast to
reach Haida Gwaii late tonight. This will cause a triple point
frontal zone to advance NNW to the SERN gulf by 12Z Monday...at
which point the front will pivot W across the gulf during the
remainder of Monday. Storm force ELY winds will develop in the
immediate vicinity of the front tonight across the SRN half of the
gulf, while strong wind gusts to 40-50 mph occur inland for
AKZ023...027...028, and also 025 (downtown Juneau/Douglas). Winds
will subside significantly across the region by Monday afternoon
as the front exits west across the northern gulf.

A strong zone of 850 mb warm air advection will spread north with
the front tonight through Monday. This will favor moderate
rainfall rates across the southern panhandle late tonight...the
central panhandle Monday morning...and the northern panhandle by
midday Monday. In addition...surface winds are forecast to
maintain a northerly component over the Haines and Klondike
Highways...which will aid in locking in temperatures near
freezing. The cold temperatures combined with increasing
precipitation rates will favor snowfall accumulations near
advisory levels during Monday afternoon. Future shifts will need
to further evaluate for potential snow headlines.

Finally, strong differential thermal/moisture advection will occur
tonight into Monday as 500 mb temperatures from -24 to -28 C
spread north across a relatively warm/moist boundary layer
airmass. This will yield MUCAPE values near 400 J/kg, and support
isolated post frontal thunderstorm development...with the highest
probability for thunderstorms occurring in the vicinity of
midlevel impulses progressing NE across the gulf.

.LONG TERM...Complex low pressure area will drift N through the
gulf Mon night and Tue, then turn W and weaken Tue night. A strong
occluded front will move NE into the gulf Wed, then it should be
through the area by Thu morning. Models differ somewhat on
whether a significant low pressure wave will develop on the front
and affect the area Wed night. Parent low of the front will move
NE into the gulf Thu then slowly weaken over the gulf through Fri.
Looking like another strong system will move into the gulf for the
weekend, but details on timing of any lows/fronts differ amongst
the models. Ended up keeping much of the Mon night-Wed forecast as
is except did tweak winds over the inner channels. For Wed night
onward, used latest WPC.

With several shortwaves aloft passing through the area and fairly
unstable atmosphere, kept mention of TSTMS in for much of the gulf
and southern coastal area into Tue evening. Did bring them to the
S inner channels later Mon night and Tue as more unstable air
reaches that area then. There will likely be several bands of
enhanced wind with surface trofs/small lows moving around the low
pressure complex. One of the more pronounced bands will be Tue as
a stronger trof/small low move through the E gulf. Models differ
some on how strong the wind will be but gales are most likely for
the E gulf Tue.

Not much break expected between systems with next strong front
moving in Wed. Should be widespread gales over the gulf with storm
force a possibility depending on whether any low pressure waves
develop along the front. The front will be well away from the
parent low, and flow aloft will become more parallel to it, which
will make for a slow frontal passage Wed night into Thu morning.
Precip will continue over the area into Fri with onshore flow and
several trofs moving through the area.

Wet/windy weather should continue into the weekend with yet
another system moving in. All in all, the active pattern should
continue during the entire week, with models suggesting it
lasting into next week.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...STRONG WIND from 6 PM AKST this evening through late tonight for
     AKZ027.
     STRONG WIND from midnight AKST tonight through Monday morning
     for AKZ025.
     STRONG WIND from 9 PM AKST this evening through Monday morning
     for AKZ023.
     STRONG WIND from 9 PM AKST this evening through late tonight for
     AKZ028.
MARINE...Storm Warning for PKZ041>043.
     Gale Warning for PKZ022-034>036-051-052.
     Small Craft Advisory for PKZ012-013-021-031>033.
     Small Craft Advisory due to Seas for PKZ053.
&&

Garner/RWT

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