Gale Warning 93, NWS Juneau, AK

287 
FZAK67 PAJK 261116
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
316 AM AKDT Mon Mar 26 2018

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.

PKZ398-270530-
316 AM AKDT Mon Mar 26 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A gale force front will track northeast across the  gulf passing
over the Panhandle through Monday night.  

$$

PKZ310-270530-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
316 AM AKDT Mon Mar 26 2018

...GALE WARNING THROUGH TONIGHT...

.TODAY...E wind 35 kt becoming SW in the afternoon. Seas 11 ft. 
Rain.
.TONIGHT...W wind 35 kt. Seas 14 ft. 
.TUE...W wind 30 kt. Seas 15 ft. 
.TUE NIGHT...W wind 25 kt. Seas 11 ft. SW swell. 
.WED...S wind 15 kt. Seas 8 ft. 
.THU...N wind 20 kt. Seas 7 ft. 
.FRI...NW wind 20 kt. Seas 7 ft. 

$$

965 
FZAK67 PAJK 262311
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
311 PM AKDT Mon Mar 26 2018

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.

PKZ398-271715-
311 PM AKDT Mon Mar 26 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A gale force front will track northeast across the gulf stalling 
and weakening over the northern Panhandle tonight and Tuesday. 

$$

PKZ310-271715-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
311 PM AKDT Mon Mar 26 2018

...GALE WARNING TUESDAY...

.TONIGHT...W wind 30 kt. Seas 10 ft. Rain early in the evening. 
.TUE...W wind 35 kt. Seas 11 ft. 
.TUE NIGHT...W wind 25 kt. Seas 9 ft subsiding to 6 ft late.
W swell. 
.WED...W wind 15 kt. Seas 7 ft. W swell. 
.WED NIGHT...S wind 15 kt. Seas 6 ft. W swell. 
.THU...N wind 20 kt. Seas 6 ft. 
.FRI...NW wind 20 kt. Seas 7 ft. 
.SAT...NE wind 15 kt. Seas 6 ft. 

$$

597 
FZAK67 PAJK 271217
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
417 AM AKDT Tue Mar 27 2018

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.

PKZ398-280630-
417 AM AKDT Tue Mar 27 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A low over the NE Gulf will weaken Tuesday. The associated front
over the panhandle will dissipate through Tuesday night. A ridge
of high pressure will begin to build over the gulf late Tuesday
into early Wednesday. 

$$

PKZ310-280630-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
417 AM AKDT Tue Mar 27 2018

...GALE WARNING TODAY...

.TODAY...W wind 35 kt diminishing in the afternoon. Seas 15 ft. 
.TONIGHT...W wind 25 kt. Seas 11 ft. SW swell. 
.WED...W wind 15 kt. Seas 9 ft. SW swell. 
.WED NIGHT...Winds light increasing to NW 15 kt late. Seas
6 ft. 
.THU...NW wind 20 kt. Seas 6 ft. 
.FRI...NW wind 20 kt. Seas 6 ft. 
.SAT...E wind 15 kt. Seas 6 ft or less. 

$$

534 
FZAK67 PAJK 272305
OFFAJK

Offshore Waters Forecast
National Weather Service Juneau AK
305 PM AKDT Tue Mar 27 2018

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.

PKZ398-281715-
305 PM AKDT Tue Mar 27 2018
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A weak front over the northern Panhandle will dissipate through 
tonight. A second area of low pressure will develop over the North
Pacific and track eastward south of the Panhandle Wednesday night
and Thursday. 

$$

PKZ310-281715-
Gulf of Alaska North of 55 Degrees North and East of 144 Degrees
West-
305 PM AKDT Tue Mar 27 2018

.TONIGHT...W wind 25 kt. Seas 11 ft. SW swell. 
.WED...W wind 15 kt. Seas 8 ft. W swell. 
.WED NIGHT...Winds light increasing to NW 15 kt late. Seas
6 ft. 
.THU...NW wind 20 kt. Seas 6 ft or less. 
.THU NIGHT...NW wind 20 kt. Seas 6 ft or less. 
.FRI...NW wind 20 kt. Seas 6 ft. 
.SAT...E wind 15 kt. Seas 6 ft or less. 
.SUN...Wind variable less than 15 kt. Seas 6 ft. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
226 PM AKDT Sun Mar 25 2018

.SHORT TERM...Complex early spring storm will affect SE AK over
the next 24 to 36 hours. Arctic boundary marking the dividing line
between cool and very dry continental air to the north and a more
moist marine airmass to the south lies draped across the southern
Panhandle early this afternoon. Strong shortwave trough along the
Aleutian chain will track NE towards the northern Gulf by late
Monday. A northern stream shortwave will continue sinking south
into the Yukon tonight and will act to suppress the Gulf system
Monday and Monday night. Occluded front will move from S to N
through the Gulf Monday before stalling somewhere over the
northern Panhandle Monday evening as the weakening shortwave over
the Gulf shears out to the east. This front and the interaction of
the northern and southern stream shortwaves will be the key in
determining precip types and amounts across especially the
northern one third of the Panhandle through early Tuesday.

As the front lifts north and merges with the weak Arctic boundary
over the southern Panhandle Monday morning, moist Gulf air will
begin overrunning the cool, dry continental airmass over the
northern channels. Enough dry air will be in place for the
precipitation to begin as snow from roughly Petersburg to Port
Alexander and points north. With the cold stable air near the
surface and the tendency for high pressure to be maintained
somewhat over NW Canada, expect the rain/snow line to have a hard
time creeping north. A period of moderate snowfall is likely
Monday evening especially for areas from Pelican to Juneau. Models
are in good agreement showing strong overrunning with lift aided
by some upper jet dynamics from a departing jet entrance region
over the Yukon. The tricky part of the forecast comes into play
Monday night. As the upper wave over the NE Gulf shears out to the
east, a surface trough will lie east/west across some portion of
the northern channels. Continued pieces of weak mid level energy
will run along parallel to this surface boundary. Models all
indicate decent lapse rates of around 7 C/Km in the dendritic
growth zone which coupled with dry air above 500 mb may set the
stage for a training snow shower event along and just north of the
weakening surface trough. The question is, where does this trough
set up? The Canadian model is bullish on keeping it just south of
the Icy Strait corridor, placing the Juneau area under the gun
for likely warning amounts of snow while the GFS and EC continue
slowly moving the surface trough north into the central Lynn Canal
area. For now, went with a Winter Weather Advisory for widespread
3 to 6 inches for Juneau northward which would be a top 10 late
March snow for many areas. Later shifts will have to monitor the
positioning of the surface trough to determine if any upgrade
might be necessary later on.

Gale force easterly winds associated with the front will develop
over the eastern gulf by monday morning with outflow gales out of
Cross Sound. Post frontal wind shift to the southwest spreading
from southwest to northeast across the eastern gulf through the
day Monday with a reduction small craft intensity. On the inside,
northerly winds will shift southerly with the progression from
south to north, beginning with Clarence Strait. Transition to
southerly winds will be complete with northern Lynn Canal by
Tuesday morning as the front stalls over the northern panhandle.
Some small craft winds on the inside, except for gales over Lynn
Canal and Cross Sound. With the low pressure trough associated
with the front and high pressure over northwest Canada, small
craft northerlies over the Canal will increase to gale force by
tomorrow morning over the northern half. Currently, only have 30
kt northerlies over the southern half, but higher winds may be
necessary. After all...its Lynn Canal. Northern inner channels
gales should should diminish to small craft intensity by Monday
evening. Southwest flow over the eastern gulf and southerly winds
over the inner channels should remain through the end of the short
range forecast period.

.LONG TERM...Tuesday through Saturday as of 9 PM Saturday...Model
solutions continue to diverge and ensemble spreads remain high
beginning Tues. There is fair agreement in the synoptic pattern
being highly zonal through mid next week but even 500mb spreads
increase significantly heading into next weekend. Models indicate
another low will move over the gulf for the latter half of the
week but differ significantly on track and timing. Elected to
trend inherited forecast towards WPC solution after coordinating
with neighboring office. This solutions tracks a closed low
across the gulf Thu and is in the middle of the EC/GEM solutions.
Adjusted mass fields towards 24/12Z WPC to represent this updated
track with continued low confidence in the exact solution and
track.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Winter Weather Advisory from 1 PM Monday to 7 AM AKDT Tuesday
     for AKZ017-019>022-025.
     Strong Wind from Monday morning through Monday afternoon for
     AKZ018.
MARINE...Gale Warning for PKZ012-022-043-051-052.
     Small Craft Advisory for PKZ013-021-031>033-036-041-042.

&&

DEL//Fritsch/BC

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