Storm Warning 169, NWS Anchorage, AK

046 
FZAK52 PAFC 180053
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
353 PM AKST Mon Dec 17 2018

Coastal Waters Forecast for Southwest Alaska+Bristol Bay+The
Alaska Peninsula Waters and the Aleutian Islands up to 100 nm out.

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.

PKZ199-181345-
353 PM AKST Mon Dec 17 2018
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA 
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
A front over the eastern Aleutians will dissipate Tue morning. 
A low will move over the western Aleutians Tue morning then it will 
move over the central Aleutians and weaken Wed morning.

$$

PKZ150-181345-
South of the AK Peninsula Sitkinak to Castle Cape-
353 PM AKST Mon Dec 17 2018

...GALE WARNING TUESDAY AND TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Gusts to 45 kt out of bays and passes. 
Seas 13 ft. Freezing spray.
.TUE...NW wind 35 kt. Gusts to 50 kt out of bays and passes. 
Seas 14 ft. Freezing spray.
.TUE NIGHT...NW wind 35 kt. Seas 14 ft. Freezing spray.
.WED...NW wind 30 kt. Seas 13 ft.
.WED NIGHT...NW wind 25 kt. Seas 10 ft.
.THU THROUGH SAT...N wind 25 kt. Seas 13 ft.

$$

PKZ155-181345-
South of the AK Peninsula Castle Cape to Cape Sarichef-
353 PM AKST Mon Dec 17 2018

...GALE WARNING TUESDAY...

.TONIGHT...NW wind 30 kt. Gusts to 45 kt out of bays and passes. 
Seas 13 ft. Freezing spray. Snow showers.
.TUE...NW wind 35 kt. Seas 12 ft. Freezing spray. Snow showers.
.TUE NIGHT...NW wind 30 kt. Seas 14 ft. Freezing spray.
.WED...W wind 25 kt. Seas 13 ft.
.WED NIGHT...S wind 25 kt. Seas 10 ft.
.THU THROUGH FRI...NE wind 25 kt. Seas 15 ft.
.SAT...NE wind 20 kt. Seas 9 ft.

$$

PKZ160-181345-
Bristol Bay-
353 PM AKST Mon Dec 17 2018

...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY NIGHT...
...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas in ice free waters 9 ft. Heavy
freezing spray.
.TUE...NW wind 30 kt. Gusts to 40 kt. Seas in ice free waters 10 ft.
Heavy freezing spray.
.TUE NIGHT...NW wind 30 kt. Seas in ice free waters 8 ft. Heavy
freezing spray.
.WED...N wind 25 kt. Seas in ice free waters 7 ft.
.WED NIGHT...NE wind 15 kt. Seas in ice free waters 5 ft.
.THU THROUGH FRI...NE wind 20 kt. Seas in ice free waters 5 ft.
.SAT...N wind 15 kt. Seas in ice free waters 3 ft.

$$

PKZ165-181345-
Port Heiden to Cape Sarichef-
353 PM AKST Mon Dec 17 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas 13 ft. Freezing spray. Widespread
snow showers.
.TUE...NW wind 30 kt. Seas 13 ft. Freezing spray. Widespread snow
showers.
.TUE NIGHT...NW wind 25 kt. Seas 11 ft. Freezing spray. Snow
showers.
.WED...N wind 25 kt. Seas 8 ft.
.WED NIGHT...E wind 20 kt. Seas 8 ft.
.THU THROUGH FRI...NE wind 20 kt. Seas 8 ft.
.SAT...NE wind 15 kt. Seas 5 ft.

$$

PKZ170-181345-
Cape Sarichef to Nikolski Bering Side-
353 PM AKST Mon Dec 17 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas building to 13 ft. Freezing spray. 
Widespread snow showers.
.TUE...NW wind 30 kt. Seas 13 ft. Freezing spray.
.TUE NIGHT...W wind 30 kt. Seas 12 ft.
.WED...S wind 30 kt. Seas 12 ft.
.WED NIGHT...SE wind 25 kt. Seas 10 ft.
.THU...NE wind 25 kt. Seas 10 ft.
.FRI...E wind 20 kt. Seas 8 ft.
.SAT...E wind 15 kt. Seas 6 ft.

$$

PKZ171-181345-
Unalaska Bay-
353 PM AKST Mon Dec 17 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas 10 ft. Freezing spray. Widespread
snow showers.
.TUE...NW wind 30 kt. Seas 13 ft subsiding to 4 ft in the
afternoon. Snow showers.
.TUE NIGHT...W wind 25 kt. Seas 3 ft. Snow.
.WED...S wind 20 kt. Seas 3 ft.
.WED NIGHT...SE wind 20 kt. Seas 2 ft.
.THU...NE wind 20 kt. Seas 7 ft.
.FRI...E wind 15 kt. Seas 2 ft.
.SAT...E wind 10 kt. Seas 2 ft.

$$

PKZ172-181345-
Cape Sarichef to Nikolski Pacific Side-
353 PM AKST Mon Dec 17 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas 12 ft. Snow showers.
.TUE...NW wind 30 kt. Seas 10 ft.
.TUE NIGHT...W wind 30 kt. Seas 10 ft.
.WED...SW wind 30 kt. Seas 13 ft.
.WED NIGHT...SE wind 25 kt. Seas 14 ft.
.THU...NE wind 25 kt. Seas 15 ft.
.FRI THROUGH SAT...E wind 20 kt. Seas 12 ft.

$$

PKZ173-181345-
Nikolski to Seguam Island Bering Side-
353 PM AKST Mon Dec 17 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas 11 ft.
.TUE...W wind 25 kt. Seas 11 ft.
.TUE NIGHT...S wind 30 kt. Seas 9 ft building to 14 ft after
midnight. Snow.
.WED...SW wind 30 kt. Seas 13 ft.
.WED NIGHT...NE wind 20 kt. Seas 10 ft.
.THU THROUGH SAT...E wind 20 kt. Seas 9 ft.

$$

PKZ174-181345-
Nikolski to Seguam Island Pacific Side-
353 PM AKST Mon Dec 17 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...N wind 30 kt. Seas 11 ft.
.TUE...W wind 25 kt. Seas 9 ft.
.TUE NIGHT...S wind 30 kt. Seas 11 ft building to 17 ft after
midnight. Snow and rain.
.WED...S wind 30 kt. Seas 17 ft.
.WED NIGHT...NE wind 25 kt. Seas 14 ft.
.THU...NE wind 25 kt. Seas 14 ft.
.FRI...E wind 20 kt. Seas 13 ft.
.SAT...SE wind 15 kt. Seas 12 ft.

$$

PKZ175-181345-
Seguam Island to Adak Bering Side-
353 PM AKST Mon Dec 17 2018

...GALE WARNING TUESDAY NIGHT...

.TONIGHT...NW wind 20 kt. Seas 8 ft.
.TUE...W wind 15 kt in the morning becoming S wind 30 kt. Seas 9 ft.
.TUE NIGHT...S wind 35 kt. Seas 12 ft. Snow and rain.
.WED...W wind 20 kt. Seas 9 ft.
.WED NIGHT...NW wind 20 kt. Seas 9 ft.
.THU...E wind 20 kt. Seas 9 ft.
.FRI THROUGH SAT...E wind 25 kt. Seas 10 ft.

$$

PKZ176-181345-
Seguam Island to Adak Pacific Side-
353 PM AKST Mon Dec 17 2018

...GALE WARNING TUESDAY NIGHT...

.TONIGHT...NW wind 25 kt becoming W 15 kt after midnight. 
Seas 10 ft.
.TUE...SW wind 15 in the morning increasing to 30 kt. 
Seas building to 12 ft.
.TUE NIGHT...S wind 40 kt. Seas 18 ft. Snow and rain.
.WED...NW wind 25 kt. Seas 15 ft.
.WED NIGHT...N wind 20 kt. Seas 13 ft.
.THU...E wind 20 kt. Seas 13 ft.
.FRI THROUGH SAT...SE wind 20 kt. Seas 15 ft.

$$

PKZ177-181345-
Adak to Kiska-
353 PM AKST Mon Dec 17 2018

...GALE WARNING TUESDAY AND TUESDAY NIGHT...

.TONIGHT...S wind increasing to 20 kt. Seas 8 ft.
.TUE...S wind 40 kt. Seas 10 ft building to 15 ft in the
afternoon. Snow and rain.
.TUE NIGHT...SW wind 35 kt becoming W 20 kt after midnight. 
Seas 16 ft. Rain.
.WED...W wind 25 kt. Seas 15 ft.
.WED NIGHT...W wind 20 kt. Seas 15 ft.
.THU THROUGH FRI...SE wind 30 kt. Seas 17 ft.
.SAT...E wind 20 kt. Seas 14 ft.

$$

PKZ178-181345-
Kiska to Attu-
353 PM AKST Mon Dec 17 2018

...GALE WARNING THROUGH TUESDAY...

.TONIGHT...SW wind 20 kt becoming SE 40 kt after midnight. 
Seas building to 10 ft. Snow.
.TUE...SE wind 45 kt. Seas 19 ft. Snow and rain.
.TUE NIGHT...W wind 30 kt. Seas 20 ft.
.WED AND WED NIGHT...S wind 25 kt. Seas 18 ft.
.THU THROUGH FRI...SE wind 30 kt. Seas 18 ft.
.SAT...E wind 20 kt. Seas 14 ft.

$$

PKZ179-181345-
Pribilof Islands Near Shore Waters-
353 PM AKST Mon Dec 17 2018

...SMALL CRAFT ADVISORY THROUGH TUESDAY...

.TONIGHT...NW wind 30 kt. Seas 10 ft. Freezing spray. 
Snow showers.
.TUE...NW wind 25 kt. Seas 9 ft. Freezing spray. Snow showers.
.TUE NIGHT...N wind 15 kt becoming E after midnight. Seas 7 ft.
Freezing spray.
.WED...SE wind 30 kt. Seas 11 ft.
.WED NIGHT...SE wind 25 kt. Seas 12 ft.
.THU...E wind 25 kt. Seas 12 ft.
.FRI...E wind 20 kt. Seas 8 ft.
.SAT...E wind 15 kt. Seas 6 ft.

$$

PKZ180-181345-
Kuskokwim Delta and Etolin Strait-
353 PM AKST Mon Dec 17 2018

...HEAVY FREEZING SPRAY WARNING TONIGHT AND TUESDAY NIGHT...
...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...NW wind 30 kt. Seas in ice free waters 9 ft. Heavy
freezing spray.
.TUE...NW wind 30 kt becoming N 20 kt in the afternoon. Seas in
ice free waters 9 ft. Freezing spray.
.TUE NIGHT...N wind 25 kt. Seas in ice free waters 6 ft. Heavy
freezing spray.
.WED...NE wind 20 kt. Seas in ice free waters 6 ft.
.WED NIGHT...NE wind 25 kt. Seas in ice free waters 6 ft.
.THU...NE wind 25 kt. Seas in ice free waters 7 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas in ice free waters 5 ft.

$$

PKZ181-181345-
North and West of Nunivak Island-
353 PM AKST Mon Dec 17 2018

...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY NIGHT...
...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NW wind 25 kt. Seas 9 ft. Heavy freezing spray.
.TUE...NW wind 20 kt. Seas 6 ft. Heavy freezing spray.
.TUE NIGHT...N wind 20 kt. Seas 5 ft. Heavy freezing spray.
.WED...E wind 20 kt. Seas 4 ft.
.WED NIGHT...E wind 25 kt. Seas 6 ft.
.THU...NE wind 20 kt. Seas 6 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 5 ft.

$$

PKZ185-181345-
Saint Matthew Island Waters-
353 PM AKST Mon Dec 17 2018

...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY...
...SMALL CRAFT ADVISORY TUESDAY NIGHT...

.TONIGHT...NW wind 20 kt. Seas 7 ft. Heavy freezing spray.
.TUE...N wind 20 kt. Seas 6 ft. Heavy freezing spray.
.TUE NIGHT...N wind 15 kt E of Saint Matthew Island...E 30 kt 
W of Saint Matthew Island. Seas 6 ft. Freezing spray.
.WED...E wind 35 kt. Seas 14 ft.
.WED NIGHT...E wind 30 kt. Seas 15 ft.
.THU...E wind 30 kt. Seas 14 ft.
.FRI THROUGH SAT...NE wind 20 kt. Seas 9 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
508 PM AKST Sun Dec 16 2018

.ANALYSIS AND UPPER LEVELS...

An upper level low stationed over the Lower Kuskokwim Delta is
extending a long wave trough over the eastern Bering into the
Gulf. This low is advecting cold and dry air over the eastern
Bering and the Kuskokwim Delta on the backside of the low. Within
the flow around the trough, a northwesterly oriented short wave
pushes over the AK-PEN and into the Gulf. Coupled with this
shortwave is a band of increased vorticity encompassing the
western mainland, the AK-PEN and spreading over Kodiak Island. A
surface front which is aligned with these two features is
tracking northward towards this low. A meso low is spinning in the
near the Kenai Peninsula this afternoon. This low, is bringing
heavy precipitation to the Kenai Peninsula, northern Gulf Coast,
into Anchorage and the Mat-Su Valleys.

&&

.MODEL DISCUSSION...

The models are doing decent with the main synoptic features into
the mid-term but are struggling with the mesoscale. One area
where the differences in guidance have been an issue is with the
continuously changing snow forecasts around Southcentral Alaska
today. Guidance has shifted placement of the main band of
precipitation anywhere from near Homer to around Palmer. Run to
run consistency has also been a problem for most models with the
individual runs shifting each run. However, the GFS has
initialized better than most and was preferred.

&&

.AVIATION...
PANC...Winds look to stay light through the forecast period but
ceilings and visibilities will be primarily down through the
much of the night. There will be some breaks between bands of
snow where conditions will rise to near VFR but overall lower
conditions are expected. Conditions will improve in the early
morning and should raise to VFR around noon.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2...Mon and
Tue)...
The day will start with the remnants of the big snow event
pushing through Southcentral. After the moisture drifts west over
Cook Inlet, a strong shortwave will push it back through the
Anchorage Bowl in the morning hours. This will make for another
period of heavy snow in very early morning (3am) hours. This
shortwave wave will also usher in some serious cold air advection
dropping 850 mb (5,000') temperatures tumbling from -5C to -11C.
This could allow the event to come to an end with some light,
fluffy snow which may blow around a fair bit during the morning
commute. It could also allow for some gusty winds to blast across
Cook Inlet and Shelikof Strait from the W-NW. Besides a few
lingering snow showers (especially along the mountains), the rest
of the day Mon should bring a drying trend across the entire area.

Cold air moves in after the snow and will keep temperatures across
the region below freezing. So plan for the freshly fallen snow to
stick around.

The break in the action won't last long. Another storm system will
track towards Prince William Sound Tue afternoon into Wed. This
could bring yet another shot of heavy snow to just about all of
Southcentral, to include the Anchorage Bowl. This storm track has
proven notoriously tricky for exact low placement and timing over
the past month. So stay tuned as we refine the details with this
next event.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Sunday
through Tuesday night)...

Not much change to the forecast for the next few days, as the
upper level trough is still on track to bring a blast of Arctic
air through the Southwest mainland. Over land, winds will remain
light, which should limit concerns for winds chills in that area.
The western portions of the Kuskokwim Delta are seeing and will
continue to see strong northerly winds. For tonight, the limiting
factor will be that low-level cloud cover currently over the
K-Delta, which is keeping temperatures a little higher to start
with. However, by tomorrow, flow will switch to be a little more
offshore, which should cause temperatures to drop, and wind chills
below -40F may be a concern for Monday and Tuesday night.
Meanwhile, a little bit of moisture will continue to sneak over
the Aleutian Range into the Bristol Bay region, which will bring
periods of light snow overnight, but no accumulation to speak of.
This will dissipate by tomorrow, bringing clearing skies and
sub 0F temperatures to Bristol Bay as well.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3/Sunday
through Tuesday night)...

Northerly winds and snow showers continue to be the regime for the
eastern Aleutians, Bering Sea, and AK Pen as the upper level low
moves over the mainland. These showers are not expected to bring a
large amount of precipitation but should be fairly consistent over
the next three days. By Tuesday, a stronger system will approach
from the western Aleutians, with the front moving into the central
Aleutians Tuesday night. Right now the winds associated with this
front are expected to barely reach storm force, but not much
higher. Warming temperatures are expected with this front, which
will bring rain to the western Aleutians through Tuesday night.

&&

.LONG TERM FORECAST (Days 3 through 7)...
By Wednesday, the cold upper level low will be centered over the
Barren Islands with an upper level trough and accompanying deep
cold air mass persisting over western Alaska and the eastern
Bering. Additional cold air over Kodiak Island and the western
Gulf will rotate east and north to spread across the Gulf and into
Southcentral Alaska as well, with troughs rotating around the
broader low continuing to bring additional periods of snow with
them. On Thursday, the upper low will stretch out to a trough and
lift north to be centered over Prince William Sound and northern
Gulf with precipitation becoming more limited to these areas and
then tapering off Thursday night as the trough dissipates.

Over mainland Alaska, a cold, elongated upper level low will
stretch across much of the state through Thursday night as a deep
north Pacific low tracks well south of the western Gulf. As the
north Pacific low and an accompany frontal system turns to the
northeast and tracks towards the southern Gulf Friday and
Saturday, the mainland upper trough will retrograde back to the
west to become centered over western Alaska and the eastern
Bering. Further to the west, a couple of developing lows will
track over the western Aleutians Thursday through Friday morning,
followed by a third low tracking north and then west through the
central Aleutians Friday night and Saturday.

For Sunday through the first half of next week, the large arctic
low will persist centered over the northern Bering with cold upper
troughing extending into western Alaska. Low pressure systems will
continue to rotate through the central and western Aleutians.
While the main jet and stronger storm track will remain well south
of the Gulf and directed at the Pacific Northwest, additional
troughs and weaker low pressure systems breaking off from this
will track north and rotate through the Gulf as well through early
next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 101 121 125 131 145.
MARINE...Heavy Freezing Spray 160 180 181 185
         Gale 119 130 131 178.

&&

SYNOPSIS AND MODEL DISCUSSION...DK/RA
SOUTHCENTRAL ALASKA...MSO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...LF
LONG TERM...JR

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
1135 PM AKST Sun Dec 16 2018

AKZ181-180900-
Alaska Peninsula-
Including the cities of Cold Bay and Sand Point
1135 PM AKST Sun Dec 16 2018

...Veniaminof Volcano Remains Active...

Veniaminof Volcano, located 22 miles northwest of Perryville is
currently active. Indications are that occasional low level
emissions of ash are occurring. The current northerly transport
winds will carry any ash to the south which may bring a trace to
a dusting of ash at Perryville.