Gale Warning 337, NWS Juneau, AK

868 
FZAK67 PAJK 301246
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
346 AM AKST FRI DEC 30 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.

PKZ398-310700-
346 AM AKST FRI DEC 30 2016
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A QUICK MOVING FRONT WILL MOVE SOUTHEAST ACROSS THE NORTHERN
PANHANDLE THROUGH THE AFTERNOON THEN THROUGH THE SOUTHERN
PANHANDLE BY SATURDAY MORNING. WINDS WILL SHIFT TO THE NORTH
BEHIND THE FRONT. 

$$

PKZ310-310700-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
346 AM AKST FRI DEC 30 2016

...GALE WARNING TODAY THROUGH TONIGHT...

.TODAY...SW WIND 25 KT BECOMING W 35 KT IN THE AFTERNOON. SEAS 
10 FT BUILDING TO 13 FT IN THE AFTERNOON.
.TONIGHT...NW WIND 45 KT. SEAS 18 FT.
.SAT...NW WIND 30 KT. SEAS 15 FT. 
.SAT NIGHT...NW WIND 25 KT. SEAS 10 FT. W SWELL. 
.SUN...NW WIND 20 KT. SEAS 7 FT. 
.MON...NW WIND 20 KT. SEAS 8 FT. 
.TUE...NW WIND 25 KT. SEAS 7 FT. 

$$

427 
FZAK67 PAJK 310019
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
319 PM AKST FRI DEC 30 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.

PKZ398-311830-
319 PM AKST FRI DEC 30 2016
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A FRONT IS QUICKLY MOVING SOUTHEAST ACROSS THE NORTHERN
PANHANDLE THROUGH THE AFTERNOON THEN THROUGH THE SOUTHERN
PANHANDLE BY SATURDAY MORNING. WINDS WILL SHIFT TO THE NORTH
BEHIND THE FRONT. 

$$

PKZ310-311830-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
319 PM AKST FRI DEC 30 2016

...GALE WARNING THROUGH SATURDAY...

.TONIGHT...W WIND 35 KT BECOMING NW 45 KT. SEAS 13 FT BUILDING TO
18 FT. 
.SAT...NW WIND 35 KT DIMINISHING TO 30 KT. SEAS 15 FT.
.SAT NIGHT...NW WIND 25 KT. SEAS 10 FT. W SWELL. 
.SUN...NW WIND 20 KT. SEAS 7 FT. W SWELL. 
.SUN NIGHT...W WIND 20 KT. SEAS 7 FT. W SWELL. 
.MON...NW WIND 20 KT. SEAS 7 FT. 
.TUE...NW WIND 20 KT. SEAS 7 FT. 
.WED...NW WIND 20 KT. SEAS 7 FT. 

$$

613 
FZAK67 PAJK 311236
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
336 AM AKST SAT DEC 31 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.

PKZ398-010645-
336 AM AKST SAT DEC 31 2016
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
STRONG HIGH PRESSURE WILL REMAIN OVER THE GULF AND SOUTHERN
YUKON TERRITORY THROUGH MON. 

$$

PKZ310-010645-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
336 AM AKST SAT DEC 31 2016

...GALE WARNING THROUGH TODAY...

.TODAY...NW WIND 40 KT DIMINISHING TO 30 KT BY AFTERNOON. SEAS
23 FT SUBSIDING TO 13 FT IN THE AFTERNOON.
.TONIGHT...NW WIND 25 KT. SEAS 10 FT.
.SUN...NW WIND 20 KT. SEAS 8 FT. W SWELL. 
.SUN NIGHT...NW WIND 20 KT. SEAS 7 FT. W SWELL. AREAS OF FOG
LATE. 
.MON...N WIND 20 KT. SEAS 7 FT. 
.TUE...NW WIND 20 KT. SEAS 6 FT. 
.WED...NW WIND 20 KT. SEAS 6 FT OR LESS. 

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
541 AM AKST Thu Dec 29 2016

.SHORT TERM...Significantly less shower activity this morning then
yesterday at this time across the area with most of it north of
Frederick Sound. An area of mid level vorticity and some low
level convergence are concentrating the showers in bands lining up
from between Cross Sound and Sitka to Lynn Canal. Temperatures
have been warm enough that most of the precip has been rain but
some snow has mixed in from time to time with little accumulation.
Meanwhile the southern half of the panhandle has cleared out for
the most part thanks to the offshore flow from a storm heading
into the BC coast farther south. There are some areas of low
clouds and fog around Petersburg and Wrangell but obs at
Petersburg have shown it to be very variable on visibility and
ceiling.

Diminishing showers are the main rule for the short range as a
surface ridge begins to build in from the SW. The band of showers
over the northern panhandle will start a drift to the SE this
morning but will be diminishing as it goes. Ptype will primarily be
rain but a mix of snow at times is not out of the question with
little in the way of accumulation expected. By late this afternoon
or evening showers should have dissipated completely with most of
the clouds diminishing. Winds will also be on the diminishing
trend as pressure gradients relax this afternoon.

The clearer skies for tonight ahead of the next front will allow
for some radiational cooling with temps dipping below freezing in
a few places before the winds start to increase again. Some fog is
also not out of the question around Petersburg again tonight so
decided to put some patchy fog into the forecast for that area.

Focus then shifts to a new front that will just be entering the
northwestern part of the area late tonight. Onshore flow will be
increasing ahead of the front with increasing chances of precip
and increasing clouds for late tonight for many areas as a result.
Kept pops at chance tonight for most areas as the main moisture
and forcing has yet to make it in to the area by that point. Winds
will also be increasing across the north as southerly pressure
gradients begin to tighten up again. Lynn Canal in particular
should increase to 25 kt by late tonight so have a small craft
advisory posted there for late tonight.

.LONG TERM...Strong upper shortwave trof will move SE across the
area Fri and Fri night. Cold front will move SE through the area
just ahead of the shortwave. Strong upper ridge will build into
the area for the weekend and early next week. The ridge will
likely weaken over our area but reform over W AK and E Bering Sea
late next week.

Expect increasing precip over the N Fri morning then over the S
Fri afternoon as shortwave and cold front move in. System is
fairly energetic and will likely produce a burst of moderate to
locally heavy precip for several hours just ahead of the front.
Temps will be generally in the 35-40 range during much of the
precip event, but during the heavier burst temps may fall several
degrees due to snowmelt cooling. Moderate to strong S-SW low level
flow will try to counteract that by bringing in marine airmass
from the gulf, so ptype will be in flux during the day especially
over the N and E areas. Think snowfall would not amount to more
than a couple inches in most of this area, but a few spots that
are more sheltered in S-SW low level flow could see more
consistent snow and could get close to advisory levels. Think
best chance of this near sea level will be around Petersburg.
Higher elevations should get decent shot of snow with above 1000
feet getting at least 6 inches over the central and S area. The N
higher elevations should see a bit less but still could get 4-5
inches, and a winter weather advisory could be needed for White
Pass area Fri. Sly winds of 15-25 mph will be common over the
area Fri, with even stronger Nly winds likely beginning Fri night
over the N after cold front and shortwave trof move past the
area. Some of these stronger winds will move S across the area
later Fri night and Sat morning.

Should see decent amount of clearing Sat although some higher
level clouds could brush the NE area. Cooler air should also move
in but not looking like a significant cold blast at this point.
Still, with some leftover snow cover in some areas, nighttime
temps may be able to drop into the teens Sat night over the N and
far E areas.

One thing that will have to be monitored for Sun night into early
next week is potential for fog to develop and not dissipate during
the daytime. Upper ridge building in will warm temps aloft with
925 mb temps possibly rising above freezing by Sun night. Winds
will likely die off as well with high pressure in control over the
area, setting up potential for a strong inversion to form in lower
1-2K ft. This would trap moisture in lowest levels and with some
snowmelt in warmer layer aloft, add even more moisture to the
lower levels. There are differences in the models on how warm the
elevated warm layer will get, but setup is one that has caused
multi-day fog episodes in the past. Want models to sort out their
differences with warm layer above the surface before adding in
mention of fog however.

A weak shortwave trof could move in toward midweek, which might
bring in a little precip but also weaken any inversion that has
formed and decrease the fog threat. After upper ridge rebuilds
further W and strong Nly flow aloft develops over the area, much
colder air will be able to move in for late next week.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012.
     Small Craft Advisory due to Seas for PKZ022-041>043-051-052.
&&

EAL/RWT

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