Gale Warning 15, NWS Anchorage, AK

472 
FZAK62 PAFC 240025
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
325 PM AKST MON JAN 23 2017

OFFSHORE WATERS FORECAST FOR THE BERING SEA

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

PKZ499-241345-
325 PM AKST MON JAN 23 2017
.SYNOPSIS FOR CENTRAL BERING SEA...

BOGOSLOF VOLCANO AT 54N 168W REMAINS ACTIVE. A 964 MB LOW AT 53N
167W WILL BECOME A TROUGH OF LOW PRESSURE OVER THE EASTERN BERING
AND ALASKA PENINSULA WATERS BY TUE AFTERNOON. A 980 MB LOW AT 46N
179W WILL MOVE TO 51N 158W AT 968 MB WED AFTERNOON.

$$

PKZ411-241345-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
325 PM AKST MON JAN 23 2017

.TONIGHT...N WIND 25 KT. SEAS 14 TO 18 FT. FREEZING SPRAY.
.TUE...N WIND 25 KT. SEAS 12 FT. FREEZING SPRAY.
.TUE NIGHT...N WIND 25 KT. SEAS 10 FT. FREEZING SPRAY.
.WED...N WIND 10 TO 25 KT. SEAS 8 TO 11 FT.
.WED NIGHT...NW WIND 15 TO 25 KT. SEAS 8 TO 12 FT.
.THU THROUGH FRI...NW WIND 15 TO 30 KT. SEAS 8 TO 12 FT.
.SAT...SW WIND 15 TO 30 KT. SEAS 8 TO 16 FT.

$$

PKZ412-241345-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
325 PM AKST MON JAN 23 2017

...GALE WARNING TONIGHT...

.TONIGHT...N WIND 35 KT. SEAS 13 TO 19 FT. FREEZING SPRAY.
.TUE...N WIND 20 TO 30 KT. SEAS 10 TO 13 FT. FREEZING SPRAY.
.TUE NIGHT...N WIND 20 TO 30 KT. SEAS 9 FT. FREEZING SPRAY.
.WED...N WIND 20 TO 30 KT. SEAS 8 TO 12 FT.
.WED NIGHT...NW WIND 20 TO 35 KT. SEAS 10 TO 18 FT.
.THU THROUGH FRI...NW WIND 20 TO 35 KT. SEAS 9 TO 15 FT.
.SAT...W WIND 15 TO 25 KT. SEAS 7 TO 11 FT.

$$

PKZ413-241345-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
325 PM AKST MON JAN 23 2017

...GALE WARNING TONIGHT...

.TONIGHT...N WIND 25 TO 35 KT. SEAS 13 TO 19 FT. FREEZING SPRAY.
SNOW SHOWERS.
.TUE...N WIND 15 TO 25 KT. SEAS 10 TO 13 FT. FREEZING SPRAY.
.TUE NIGHT...N WIND 15 TO 25 KT. SEAS 9 FT. FREEZING SPRAY.
.WED...NW WIND 20 TO 30 KT. SEAS 8 TO 12 FT.
.WED NIGHT...NW WIND 25 TO 35 KT. SEAS 10 TO 17 FT.
.THU THROUGH FRI...NW WIND 20 TO 35 KT. SEAS 9 TO 17 FT.
.SAT...W WIND 25 KT. SEAS 9 TO 12 FT.

$$

PKZ414-241345-
BERING SEA OFFSHORE EAST OF 171W-
325 PM AKST MON JAN 23 2017

...GALE WARNING TONIGHT...
...HEAVY FREEZING SPRAY WARNING TONIGHT...

.TONIGHT...NE WIND 20 TO 35 KT. SEAS 9 TO 14 FT. HEAVY FREEZING
SPRAY. SNOW.
.TUE...N WIND 10 TO 25 KT. SEAS 5 TO 10 FT. FREEZING SPRAY.
.TUE NIGHT...NW WIND 10 TO 20 KT. SEAS 3 TO 7 FT. FREEZING SPRAY.
.WED...NW WIND UP TO 20 KT. SEAS 3 TO 7 FT.
.WED NIGHT...NW WIND 15 TO 30 KT. SEAS 6 TO 11 FT.
.THU THROUGH SAT...W WIND 15 TO 30 KT. SEAS 8 TO 13 FT.

$$

930 
FZAK62 PAFC 241251
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
351 AM AKST TUE JAN 24 2017

OFFSHORE WATERS FORECAST FOR THE BERING SEA

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

PKZ499-250130-
351 AM AKST TUE JAN 24 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
BOGOSLOF VOLCANO AT 54N 168W REMAINS ACTIVE. A 972 MB LOW NEAR
55N 164W WILL MOVE TO 57N 165W WED MORNING AT 974 MB AND STEADILY
WEAKEN AND DISSIPATE THROUGH WED NIGHT. A 980 MB LOW NEAR 47N 178W
WILL MOVE TO 50N 166W WED MORNING AND INTO THE WESTERN GULF OF
ALASKA BY THU MORNING.

$$

PKZ411-250130-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
351 AM AKST TUE JAN 24 2017

.TODAY...N WIND 25 KT. SEAS 11 TO 14 FT. FREEZING SPRAY.
.TONIGHT...N WIND 15 TO 25 KT. SEAS 8 TO 11 FT. FREEZING SPRAY.
.WED...NW WIND 10 TO 25 KT. SEAS 7 TO 11 FT. FREEZING SPRAY.
.WED NIGHT...NW WIND 10 TO 25 KT. SEAS 8 TO 11 FT.
.THU THROUGH FRI...NW WIND 15 TO 30 KT. SEAS 8 TO 13 FT.
.SAT...SW WIND 10 TO 25 KT. SEAS 5 TO 10 FT.

$$

PKZ412-250130-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
351 AM AKST TUE JAN 24 2017

.TODAY...N WIND 25 KT. SEAS 11 FT. FREEZING SPRAY.
.TONIGHT...N WIND 25 KT. SEAS 10 FT. FREEZING SPRAY. SNOW SHOWERS.
.WED...N WIND 30 KT. SEAS 8 TO 11 FT. FREEZING SPRAY.
.WED NIGHT...NW WIND 20 TO 30 KT. SEAS 10 TO 14 FT.
.THU THROUGH SAT...NW WIND 15 TO 30 KT. SEAS 8 TO 13 FT.

$$

PKZ413-250130-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
351 AM AKST TUE JAN 24 2017

.TODAY...N WIND 15 TO 25 KT. SEAS 11 TO 14 FT. FREEZING SPRAY.
.TONIGHT...N WIND 25 KT. SEAS 10 FT. FREEZING SPRAY.
.WED...NW WIND 20 TO 30 KT. SEAS 9 TO 12 FT. FREEZING SPRAY.
.WED NIGHT...NW WIND 20 TO 30 KT. SEAS 11 TO 15 FT.
.THU THROUGH SAT...W WIND 15 TO 30 KT. SEAS 9 TO 14 FT.

$$

PKZ414-250130-
BERING SEA OFFSHORE EAST OF 171W-
351 AM AKST TUE JAN 24 2017

.TODAY...N WIND 15 TO 30 KT. SEAS 6 TO 11 FT. FREEZING SPRAY.
SNOW.
.TONIGHT...N WIND 10 TO 25 KT. SEAS 4 TO 8 FT. FREEZING SPRAY.
SNOW.
.WED...NW WIND 10 TO 25 KT. SEAS 4 TO 9 FT. FREEZING SPRAY.
.WED NIGHT...NW WIND 15 TO 30 KT. SEAS 7 TO 12 FT.
.THU THROUGH SAT...W WIND 20 TO 35 KT. SEAS 8 TO 13 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
437 PM AKST Sun Jan 22 2017

.ANALYSIS AND UPPER LEVELS...
There is a large upper low centered over the central Aleutians.
The leading front is pushing into the Alaska Peninsula, bending
back westwards across the southern and central Bering Sea. High
winds and even some Blizzard conditions area associated with this
system. There is a weak short-wave ridge over southwest Alaska
where very cold temperatures persist. A negatively tilted upper
level trough is pushing northeast across south central Alaska,
with some associated snow showers.

&&

.MODEL DISCUSSION...
The numerical models are in good agreement today. There are some
differences in how they handle the precipitation amounts and
types. Thus the forecast confidence is just a bit above normal.

&&

.AVIATION...
PANC...MVFR conditions in snow showers are likely into the early
evening, then transitioning to mostly VFR.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Light snow showers will taper off by early evening over the
Anchorage area and western Prince William Sound. Any lingering
showers will begin to shift eastward this evening, as the upper
level trough providing support tracks inland over the Northern
Gulf Coast. However, due to less available moisture and weakening
upper level forcing, showers should remain light as they track
through central and eastern Prince William Sound tonight.

By Monday a strong front will push into the Gulf of Alaska
supporting another round of precipitation and gusty winds.
Recent models have trended stronger along the northern Gulf Coast,
with storm force gusts expected along the coast. The most
uncertain aspect of this system is the amount of warm air it will
pull northward. If enough cold air remains in place, moderate to
heavy snow would occur again across the eastern Kenai Peninsula
Monday night into Tuesday. However, it is also possible that
enough warm air will be present to limit snowfall totals and
result in heavy wet snow. The current forecast is leaning toward
the bulk of precipitation being snow from the onset of the system
through later Monday night, then transitioning to rain Tuesday
morning. On the other hand, most areas west of the Chugach and
Kenai mountains are expected to see snow Monday night through
Tuesday morning.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Frigid temperatures will persist for one more night across the
southwest mainland before beginning to moderate with the arrival
of the strong Bering front along the coast on Monday. Increasing
winds in advance of the front will produce very low wind chill
values over the Kuskokwim Delta through early Monday morning. The
front will then bring blowing snow to western portions of Bristol
Bay during the morning, with the worst conditions expected to last
into late Monday night before snow begins to diminish. Blowing snow
will also be possible along the delta, but visibilities are
expected to remain above advisory criteria as snow amounts and
intensity will be lower than in Bristol Bay.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The powerful North Pacific low and associated front will continue
to impact the southern Bering Sea with strong winds and heavy
precipitation through Monday as the front continues to push
eastward towards the southwest coastline. Hurricane force winds
will continue over the waters of the southwest Bering through
tonight in cold advection on the backside of the low, with
blizzard conditions continuing to impact Shemya through around
midnight. Meanwhile, conditions will improve through the evening
hours across the Eastern Aleutians as the front moves to the east
and warmer air changes lingering precipitation to rain. The Winter
Weather Advisory has been upgraded to a Blizzard Warning for the
Alaska Peninsula with the issuance of the afternoon package as
visibilities have deteriorated to 1/4 mile near Cold Bay.
Conditions will then improve from west to east during the late
evening with the eastward advance of the front. Blizzard
conditions will be most persistent over the Pribilof Islands as
colder air remains in place to the north of the front, with
conditions finally beginning to improve by Monday afternoon as
snow diminishes in intensity.

&&

.LONG TERM FORECAST (Days 3 through 7)...
The longwave trough continues to remain over the Bering Sea and extending
southward into the North Pacific Ocean through midweek. This
synoptic feature moves eastward, becomes negatively tilted before
moving into the Gulf by Friday. This coincides with the strong
southeast to northwest jet streak tracking into the Southeast
Panhandle by Wednesday. This pattern remains intact through next
weekend. Southcentral Alaska, and the Gulf will have a warming
trend heading with temperatures to rise above freezing by the
midweek time-frame through the weekend. This results in abundant
moisture streaming into the Southcentral region resulting in a
wintry mix along the coastal communities. While the interior sets
up with a better scenario for moderate snowfall in favored
mountain regions. Meanwhile, the majority of the Bering Sea
temperatures remains cold with the northerly flow through Friday
before a warming trend begins from the Western Aleutian/Bering by
Saturday spreading eastward. This coincides with a storm force low
tracking over the Kamchatka Peninsula with associated front
draping through the Western Aleutians. Looking at the models, they
continue to struggling with the complex low in the North Pacific
Ocean as it tracks eastward along the Eastern Aleutians by
Wednesday before moving into the Southwest Alaska region. The next
model issue pertains to a North Pacific low tracking into the Gulf
by Friday. The GFS takes this system over the eastern Gulf, and
the ECMWF tracks this low near Kodiak Island. These storm tracks
will bring warmer temperatures to the Southcentral region.
Therefore, the forecast confidence is below average with these
discrepancies with the storm track.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 120 125
Storm 119
Heavy Freezing Spray 121

&&

SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...TP
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
LONG TERM...PD