Gale Warning 492, NWS Anchorage, AK

088 
FZAK62 PAFC 171152
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
352 AM AKDT SAT SEP 17 2016

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.

PKZ499-180030-
352 AM AKDT SAT SEP 17 2016
.SYNOPSIS FOR CENTRAL BERING SEA...HIGH PRESSURE MOVES OVER THE
CENTRAL AND EASTERN BERING SEA THROUGH SUN NIGHT. A 997 MB LOW AT
55N 164E MOVES TO 58N 173E AND DEEPENS TO 976 MB BY MON MORNING.
THE ASSOCIATED FRONT PUSHES OVER THE ALEUTIANS THROUGH MON
MORNING.


$$

PKZ411-180030-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
352 AM AKDT SAT SEP 17 2016

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...S WIND 15 TO 30 KT. SEAS 6 TO 11 FT. PATCHY FOG. RAIN.
.TONIGHT...S WIND 25 TO 40 KT. SEAS 8 TO 16 FT. PATCHY FOG. RAIN.
.SUN...SW WIND 20 TO 35 KT. SEAS 12 TO 16 FT. PATCHY FOG. RAIN.
.SUN NIGHT...SW WIND 25 TO 40 KT. SEAS 12 TO 20 FT.
.MON...W WIND 20 TO 35 KT. SEAS 11 TO 19 FT.
.TUE THROUGH WED...NW WIND 15 TO 25 KT. SEAS 7 TO 12 FT.

$$

PKZ412-180030-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
352 AM AKDT SAT SEP 17 2016

...GALE WARNING SUNDAY...

.TODAY...SW WIND 10 TO 25 KT. SEAS 4 TO 8 FT.
.TONIGHT...S WIND 10 TO 25 KT INCREASING TO 20 TO 30 KT AFTER
MIDNIGHT. SEAS 5 TO 10 FT. PATCHY FOG.
.SUN...S WIND 25 TO 35 KT. SEAS 9 TO 16 FT. PATCHY FOG. RAIN.
.SUN NIGHT...S WIND 20 TO 35 KT. SEAS 13 TO 17 FT.
.MON...SW WIND 15 TO 30 KT. SEAS 11 TO 19 FT.
.TUE THROUGH WED...W WIND 10 TO 25 KT. SEAS 9 TO 14 FT.

$$

PKZ413-180030-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
352 AM AKDT SAT SEP 17 2016

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...SW WIND 20 TO 30 KT. SEAS 6 TO 10 FT. PATCHY FOG.
.TONIGHT...SW WIND 20 TO 35 KT. SEAS 8 TO 13 FT. PATCHY FOG.
.SUN...S WIND 25 TO 35 KT. SEAS 9 TO 17 FT. PATCHY FOG. RAIN.
.SUN NIGHT...SW WIND 20 TO 35 KT. SEAS 9 TO 16 FT.
.MON THROUGH WED...W WIND 15 TO 30 KT. SEAS 9 TO 17 FT.

$$

PKZ414-180030-
BERING SEA OFFSHORE EAST OF 171W-
352 AM AKDT SAT SEP 17 2016

.TODAY...W WIND 20 TO 30 KT. SEAS 7 TO 10 FT.
.TONIGHT...W WIND 15 TO 30 KT BECOMING SW 10 TO 20 KT AFTER
MIDNIGHT. SEAS 5 TO 10 FT.
.SUN...SW WIND 15 TO 30 KT. SEAS 5 TO 10 FT. PATCHY FOG.
.SUN NIGHT...S WIND 25 TO 40 KT. SEAS 9 TO 14 FT.
.MON THROUGH WED...SW WIND 20 TO 35 KT. SEAS 9 TO 14 FT.

$$

171 
FZAK62 PAFC 172323
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
323 PM AKDT SAT SEP 17 2016

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.

PKZ499-181345-
323 PM AKDT SAT SEP 17 2016
.SYNOPSIS FOR CENTRAL BERING SEA...
HIGH PRESSURE OVER THE CENTRAL BERING SEA MOVES OVER THE ALASKA
PENINSULA AND BRISTOL BAY SUNDAY. A 983 MB LOW AT 55N 165E TONIGHT
MOVES TO 58N 176E AND DEEPENS TO 977 MB BY MONDAY AFTERNOON.

$$

PKZ411-181345-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
323 PM AKDT SAT SEP 17 2016

...GALE WARNING THROUGH SUNDAY NIGHT...

.TONIGHT...S WIND 25 TO 40 KT. SEAS 10 TO 16 FT. PATCHY FOG. RAIN
SHOWERS.
.SUN...S WIND 25 TO 40 KT BECOMING SW 20 TO 30 KT IN THE
AFTERNOON. SEAS 13 TO 17 FT. PATCHY FOG. RAIN SHOWERS.
.SUN NIGHT...SW WIND 20 TO 35 KT. SEAS 12 TO 16 FT BUILDING TO 13
TO 20 FT AFTER MIDNIGHT.
.MON...SW WIND 25 TO 40 KT. SEAS 13 TO 20 FT.
.MON NIGHT...W WIND 20 TO 30 KT. SEAS 10 TO 18 FT.
.TUE THROUGH THU...NW WIND 15 TO 30 KT. SEAS 8 TO 13 FT.

$$

PKZ412-181345-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
323 PM AKDT SAT SEP 17 2016

...GALE WARNING SUNDAY AND SUNDAY NIGHT...

.TONIGHT...S WIND 15 TO 30 KT. SEAS 5 TO 8 FT BUILDING TO 7 TO 13
FT AFTER MIDNIGHT. PATCHY FOG.
.SUN...S WIND 30 KT BECOMING 25 TO 40 KT IN THE AFTERNOON. SEAS 10
TO 18 FT. PATCHY FOG.
.SUN NIGHT...S WIND 20 TO 35 KT. SEAS 12 TO 17 FT. PATCHY FOG.
RAIN.
.MON...SW WIND 15 TO 30 KT. SEAS 11 TO 15 FT.
.MON NIGHT...SW WIND 20 TO 30 KT. SEAS 11 TO 18 FT.
.TUE THROUGH THU...NW WIND 15 TO 25 KT. SEAS 9 TO 14 FT.

$$

PKZ413-181345-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
323 PM AKDT SAT SEP 17 2016

...GALE WARNING SUNDAY AND SUNDAY NIGHT...

.TONIGHT...SW WIND 20 TO 30 KT. SEAS 8 TO 13 FT. PATCHY FOG.
.SUN...S WIND 25 TO 40 KT. SEAS 10 TO 18 FT. PATCHY FOG.
.SUN NIGHT...S WIND 25 TO 40 KT BECOMING SW 10 TO 20 KT AFTER
MIDNIGHT. SEAS 12 TO 17 FT. PATCHY FOG. RAIN.
.MON...SW WIND 20 TO 30 KT. SEAS 9 TO 14 FT.
.MON NIGHT...SW WIND 30 KT. SEAS 10 TO 16 FT.
.TUE THROUGH THU...NW WIND 20 TO 30 KT. SEAS 9 TO 15 FT.

$$

PKZ414-181345-
BERING SEA OFFSHORE EAST OF 171W-
323 PM AKDT SAT SEP 17 2016

...GALE WARNING SUNDAY NIGHT...

.TONIGHT...W WIND 15 TO 30 KT BECOMING SW 10 TO 20 KT AFTER
MIDNIGHT. SEAS 5 TO 11 FT.
.SUN...SW WIND 10 TO 20 KT INCREASING TO 15 TO 30 KT IN THE
AFTERNOON. SEAS 5 TO 10 FT.
.SUN NIGHT...S WIND 25 TO 40 KT. SEAS 10 TO 18 FT. PATCHY FOG.
RAIN.
.MON...S WIND 30 TO 45 KT. SEAS 13 TO 17 FT.
.MON NIGHT...SW WIND 15 TO 25 KT. SEAS 8 TO 13 FT.
.TUE THROUGH WED...SW WIND 10 TO 25 KT. SEAS 7 TO 12 FT.
.THU...NW WIND 10 TO 20 KT. SEAS 6 TO 9 FT.

$$

585 
FZAK62 PAFC 181158
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
358 AM AKDT SUN SEP 18 2016

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.

PKZ499-190045-
358 AM AKDT SUN SEP 18 2016
.SYNOPSIS FOR CENTRAL BERING SEA...A 981 MB LOW AT 56N 165W MOVES
TO 59N 178W AT 978 MB BY TUE MORNING. THE ASSOCIATED FRONTS PUSH
THROUGH THE BERING SEA AND ACROSS ALASKA PENINSULA AND THE WESTERN
AND CENTRAL ALEUTIANS THROUGH TUE MORNING.

$$

PKZ411-190045-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
358 AM AKDT SUN SEP 18 2016

...GALE WARNING THROUGH MONDAY...

.TODAY...S WIND 25 TO 40 KT. SEAS 12 TO 17 FT. PATCHY FOG. RAIN.
.TONIGHT...SW WIND 20 TO 35 KT. SEAS 12 TO 18 FT. SLIGHT CHANCE OF
THUNDERSTORMS AFTER MIDNIGHT.
.MON...SW WIND 25 TO 40 KT. SEAS 13 TO 19 FT. SLIGHT CHANCE OF
THUNDERSTORMS.
.MON NIGHT...W WIND 20 TO 35 KT. SEAS 11 TO 19 FT. SLIGHT CHANCE
OF THUNDERSTORMS.
.TUE THROUGH THU...NW WIND 15 TO 25 KT. SEAS 8 TO 13 FT.

$$

PKZ412-190045-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
358 AM AKDT SUN SEP 18 2016

...GALE WARNING THROUGH TONIGHT...

.TODAY...S WIND 30 KT BECOMING 25 TO 40 KT IN THE AFTERNOON. SEAS
9 TO 17 FT. PATCHY FOG.
.TONIGHT...S WIND 20 TO 35 KT. SEAS 12 TO 17 FT. PATCHY FOG. RAIN.
.MON...SW WIND 15 TO 30 KT. SEAS 11 TO 16 FT. SLIGHT CHANCE OF
THUNDERSTORMS IN THE AFTERNOON.
.MON NIGHT...SW WIND 25 TO 35 KT. SEAS 12 TO 18 FT. SLIGHT CHANCE
OF THUNDERSTORMS.
.TUE THROUGH THU...NW WIND 15 TO 30 KT. SEAS 8 TO 16 FT.

$$

PKZ413-190045-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
358 AM AKDT SUN SEP 18 2016

...GALE WARNING THROUGH TONIGHT...

.TODAY...S WIND 25 TO 40 KT. SEAS 9 TO 17 FT. PATCHY FOG. RAIN.
.TONIGHT...SW WIND 25 TO 40 KT. SEAS 10 TO 17 FT. PATCHY FOG.
RAIN.
.MON...SW WIND 20 TO 30 KT. SEAS 10 TO 16 FT. SLIGHT CHANCE OF
THUNDERSTORMS IN THE AFTERNOON.
.MON NIGHT...SW WIND 30 KT. SEAS 11 TO 17 FT. SLIGHT CHANCE OF
THUNDERSTORMS.
.TUE THROUGH THU...NW WIND 15 TO 30 KT. SEAS 9 TO 14 FT.

$$

PKZ414-190045-
BERING SEA OFFSHORE EAST OF 171W-
358 AM AKDT SUN SEP 18 2016

...GALE WARNING TONIGHT AND MONDAY...

.TODAY...SW WIND 15 TO 30 KT. SEAS 5 TO 10 FT. PATCHY FOG.
.TONIGHT...S WIND 25 TO 40 KT. SEAS 9 TO 14 FT. PATCHY FOG.
.MON...SW WIND 30 TO 45 KT. SEAS 11 TO 17 FT. PATCHY FOG. RAIN.
.MON NIGHT...SW WIND 15 TO 25 KT. SEAS 8 TO 13 FT.
.TUE THROUGH WED...W WIND 10 TO 25 KT. SEAS 7 TO 12 FT.
.THU...NW WIND 10 TO 20 KT. SEAS 5 TO 9 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
509 AM AKDT FRI SEP 16 2016

.ANALYSIS AND UPPER LEVELS...
Satellite imagery this morning reveals a longwave trough over
the eastern Bering Sea and western Alaskan mainland, with the
trough axis situated roughly along the west coast of AK. This
trough is anchored by two distinct low pressure centers, one
moving eastward along the AK Peninsula and the other dropping
south from the Bering Strait, with the longwave beginning to take
on a slightly negative tilt as the northern low becomes the
dominant feature. This pattern is keeping widespread shower
activity over the eastern Bering and southwest mainland beneath
broad cyclonic flow and relatively cold air aloft. Showers also
prevail over much of Southcentral AK with deep southerly flow
focused along the northern gulf coast between the trough and an
upper level ridge extending from western Canada to the vicinity
of the Brooks Range. Farther west, showers are diminishing in
coverage from west to east across the Bering in increasing
northwest flow and the backside of the trough.

&&

.MODEL DISCUSSION...
Models are in excellent agreement through the weekend as the
Akpen low shifts eastward into the gulf and high pressure builds
into the central and eastern Bering Sea. Primarily utilized the
GFS for the morning forecast, along with some NAM to better
capture some of the smaller scale details.

&&

.AVIATION...
PANC...A shortwave moving up Cook Inlet looks to bring light rain
to PANC around 18Z. Guidance is varying somewhat on exact timing
of the start and stop of this band, but most of the HIRES data is
around 18Z for a start and 03Z for when the band pushes off to the
north. The other question is how far ceilings will drop during
this period. There is higher than average confidence it will stay
above 3,000 FT but there is a good chance ceilings will drop below
5,000 FT.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The next upper level wave in the series of upper disturbances is
making its way up Cook Inlet this morning and will be the catalyst
for yet more showers today throughout Southcentral Alaska. This
pattern will persist through Saturday and then a transitory ridge
will begin to build into the area Sunday which will bring an end
to the showers.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2...Fri and Sat)...
A vertically stacked low is just east of Sand Point and will
continue its trek to the east through the day. This will still
create the opportunity for some isolated thunderstorms out over
the coastal waters southwest of Kodiak during the day. Morning
fog, mainly near Bethel, could hold on through at least the
morning as that area is in somewhat of a col of lighter winds. A
narrow band of energy will then work its way south from the Bering
Strait and should help to dissipate the fog. This energy is due in
part to some colder air from the Arctic clashing with the warm air
the current system brought to the area. As this energy digs in to
the backside of the trough, it will help to provide the lift for a
few bands of more widespread precipitation today stretching from
Bristol Bay through the YK Delta. But the entire area will be
vulnerable to showers with plenty of cold air aloft helping to
create modest lapse rates.

The energy will start to form a closed upper level low by
Saturday. This will open the door for some of that colder air to
work its way toward the Alaska Peninsula. This should be enough to
keep some potent showers popping up and bring some gusty northwest
winds. This colder air will be modified quite a bit by the warm
waters over the Eastern Bering. But it will still bring a
definitive fall chill to the air by Sat afternoon and Sun morning
as it filters inland.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2...Fri and
Sat)...
A transient shortwave ridge over the Western Aleutians coupled
with a closed low over the Alaska Peninsula is leaving most of the
Bering under northerly flow. This will result in some cold air
showers and gusty north to northwest winds dominating the sensible
weather from Atka east. A new, fairly weak low from the Kamchatka
area will then start to track into the extreme Western Aleutians
by this evening. This will help to push the transient ridge
towards the Central Bering and should allow a relatively drier
westerly flow to set up on Saturday. The low over the Western
Aleutians will bring an initial round of rain and small craft
winds through the area late this evening into Sat morning. The
bigger story will be the second low that moves into that area and
phases with the first low somewhat on Sat. It will bring at least
gale-force winds with the possibility of some storm-force gusts.
It will also have a much better moisture tap back into the North
Pacific, so rain could be moderate at times. This rain and wind
will then move into the Central Bering along an elongated warm
occlusion by Sun.

&&

.LONG TERM FORECAST (Days 3 through 7)...

Beginning the long term period on Sunday, the main trough of
interest will be  moving into the southeast Gulf of Alaska
Sunday, allowing for the Bering ridge axis to slide east by
Sunday evening. This will allow for drying and partly clearing
skies as another large trough across the far western Bering Sea
tracks a rather impressive warm front toward the Bering Strait.

This is the point in the extended forecast where things get rather
interesting. Both the GFS and ECMWF deterministic and ensembles
are depicting a rather impressive amplification of the northeast
Pacific ridge Monday and into the late portions of the week. In
conjunction with this will be a series of very low amplitude
tropical/subtropical low level diabatic anomalies progressing east
along the Pacific jet stream which will be pushing 150+ knots by
midweek. Standardized anomalies in some model runs are pushing 2-3
sigmas with respect to precipitable waters whereas the GFS
ensemble mean depicts 30-50% chance of PW values pushing +1 sigma.
The combination of impressive baroclinic dynamics, strong
polar/subtropical jet streams, and high latent energy in the form
of moisture condensation *may* set the stage for a very active
pattern for southern Alaska Tuesday through Thursday. What is
known is a moderate gale force front will quickly move across the
Bering into southwest Alaska by Monday night, but what is less
known is what happens with that front by midweek. The details are
subtle but important, but it should be noted that the amount of
energy available means the potential exists for strong lows to
impact southern Alaska, and there is such high moisture values
that coastal flooding is also a possibility. Once again, there is
much uncertainty with the details, but the large scale pattern is
becoming more favorable for the potential for significant weather
by midweek.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gales...178 180 181.

&&

SYNOPSIS AND MODEL DISCUSSION...CB
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MSO
LONG TERM...JA