Gale Warning 637, NWS Anchorage, AK

037 
FZAK62 PAFC 131246
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
346 AM AKST Tue Nov 13 2018

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.

PKZ499-140145-
346 AM AKST Tue Nov 13 2018
.SYNOPSIS FOR CENTRAL BERING SEA...A 978 mb low at 57N 158W Tue
morning moves to 55N 155W at 993 mb by Wed morning and then 
dissipates. A new 999 mb low forms at 56N 165W Wed morning then moves
to 58N 170W at 1004 mb by Thu morning.

$$

PKZ411-140145-
Bering Sea Offshore West of 180 and East of the International
Dateline-
346 AM AKST Tue Nov 13 2018

.TODAY...N wind 15 to 25 kt. Seas 15 ft.
.TONIGHT...N wind 15 to 25 kt. Seas 10 to 13 ft.
.WED...NE wind 20 kt. Seas 11 ft.
.WED NIGHT...NE wind 10 to 20 kt. Seas 9 ft.
.THU THROUGH FRI...NE wind 15 to 30 kt. Seas 7 to 12 ft.
.SAT...N wind 20 kt. Seas 7 to 10 ft.

$$

PKZ412-140145-
Bering Sea Offshore 171W to 180 and North of 56N-
346 AM AKST Tue Nov 13 2018

.TODAY...N wind 20 to 30 kt. Seas 15 ft.
.TONIGHT...N wind 20 to 30 kt. Seas 14 ft.
.WED...N wind 15 to 25 kt. Seas 12 ft.
.WED NIGHT...N wind 10 to 25 kt. Seas 7 to 11 ft.
.THU THROUGH FRI...NE wind 10 to 25 kt. Seas 5 to 9 ft.
.SAT...N wind 20 kt. Seas 6 to 9 ft.

$$

PKZ413-140145-
Bering Sea Offshore 171W to 180 and South of 56N-
346 AM AKST Tue Nov 13 2018

.TODAY...N wind 25 kt. Seas 13 to 17 ft.
.TONIGHT...N wind 20 kt. Seas 13 ft.
.WED...N wind 20 kt. Seas 11 ft.
.WED NIGHT...NW wind 10 to 20 kt. Seas 9 ft.
.THU...N wind up to 20 kt. Seas 5 to 10 ft.
.FRI...E wind up to 20 kt. Seas 5 to 10 ft.
.SAT...N wind 20 kt. Seas 8 ft.

$$

PKZ414-140145-
Bering Sea Offshore East of 171W-
346 AM AKST Tue Nov 13 2018

...GALE WARNING TODAY...

.TODAY...N wind 20 to 35 kt. Seas 10 to 15 ft.
.TONIGHT...N wind 10 to 25 kt. Seas 7 to 12 ft.
.WED...N wind 10 to 20 kt. Seas 5 to 10 ft.
.WED NIGHT...NE wind up to 15 kt. Seas 3 to 8 ft.
.THU THROUGH SAT...NE wind up to 20 kt. Seas 3 to 7 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
532 AM AKST Mon Nov 12 2018

.ANALYSIS AND UPPER LEVELS...

In the upper levels, a deep low spinning south of Cold Bay is
anchoring a deep longwave trough, that is currently negatively
tilted across the northeast Pacific. This pattern is supporting
strong divergence aloft, with an area of diffluence across
Southwest Alaska. Meanwhile, ridging across the Panhandle is
helping invigorate the jet stream winds between these two
features, and supporting the ongoing atmospheric river moving into
the north Gulf Coast, with numerous showers of variable
precipitation types continuing inland across Southcentral and
Southwest Alaska.

A surface low centered just east of Dutch Harbor is driving much
of the active weather across Southwest Alaska and the eastern
Bering. Widespread gales are ongoing across much of the eastern
and central Bering, including Bristol Bay under strong north to
northeast winds as noted by a series of ASCAT satellite passes
last evening. Gusts to 50 knots have been occurring along the
Bering coast of the Kuskokwim Delta and at St. George as well.
Gales were also noted through southern Cook Inlet, Shelikof
Strait, and out in the Gulf southeast of Kodiak. The copious
moisture moving into the coast has kept conditions wet across the
southern parts of Southcentral after this morning's bout with
winter. The airport in Gulkana got above freezing just before
midnight last night for the first time in 2 weeks. Anchorage
more than doubled their daily precipitation record yesterday. The
cold air was incredibly stubborn as well today, with Palmer
reporting a quarter inch of ice accumulation from this morning's
freezing rain. Needless to say, this has been a very notable storm
over southern Alaska.

&&

.MODEL DISCUSSION...

Disagreement in the models is diminishing this morning, and
forecast confidence is improving in part because of an expected
general quieting down of the weather from Tuesday afternoon going
forward. In the meantime, the models are in good agreement on a
deepening low developing over the southern Gulf during the day
today and tracking northwestward into the Alaska Peninsula
tonight. The models begin to disagree first on whether or not the
center of the low tracks into Bristol Bay before turning southward
and recrossing the Alaska Peninsula or if it simply stays on the
Pacific side. The impact for most of southern Alaska will be the
same regardless of the exact track of the low. A front moving over
Southwest Alaska today will bring a renewed round of mixed
precipitation to the Kuskokwim Valley. It is likely to weaken this
afternoon as it moves north and out of the area. Then the next low
moves in, briefly bringing more warm air to the area, along with
another round of precipitation. The timing of that precipitation
is well agreed upon, but precipitation type remains a point of
considerable uncertainty due to the transient nature of any warm
air aloft over Southwest Alaska. Once the low shifts into the Gulf
and weakens, quiet weather looks likely to return to all of
southern mainland Alaska. Forecast confidence is about average.

&&

.AVIATION...

PANC...Quieter conditions are expected over the next day in
general. Wind shear will continue through the day as light
northerly winds at the surface move under stronger east to
southeast winds at 2,000 feet. Another round of rain showers is
expected this afternoon into this evening, though there's some
uncertainty if they will only be in the vicinity or actually over
the airport. If the latter occurs, will likely result in
intermittently reduced ceilings. The rain ends this evening with
VFR conditions expected to return for much of the rest of the
workweek.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Southerly flow will continue through much of Tuesday due to the
low near the Alaska Peninsula and a second low that will move
into the same area tonight as the previous one exits to the south.
This setup is still bringing a long fetch of warm air to
Southcentral Alaska resulting in more rain for the north Gulf
coast that will last into Tuesday. Precip will also make it past
the coastal mountains today and bring light rain to many
locations. Some areas of the Susitna Valley that are staying below
freezing will see some light freezing rain mixed with snow this
morning before turning to rain by late morning. Tuesday will see
precip diminish throughout Southcentral Alaska, but some showers
will remain and Tuesday night temps will start to drop back down
again.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2...Mon and Tue)...
After freezing precipitation overnight at many locations, expect
things to dry out later this morning before another round of
freezing precipitation moves in. First, the band of heaviest
precipitation is stretching from Bethel up through Aniak.
Temperatures at the surface are only in the low-mid 20s. But there
is plenty of warm air aloft (up to 3000'), as evidenced by the
Bethel sounding showing temperatures all the way up to 4C. As snow
is falling into this layer, it is melting and becoming liquid rain
drops. Then, as it falls through the final layer before
reaching the surface, it is becoming supercooled and freezing on
contact. The winter weather advisories will continue through the
morning hours as the bands pull quickly off to the north and west.

Take note however that another very similar storm system will set
up near Kodiak Island this afternoon. This system will start to
push another area of mixed precipitation across the AK Range and
through Bristol Bay this evening. It will continue to track from
southeast to northwest. Gusty northeast to east flow at the
surface during the day today will allow more cold air to filter
back into the area. This system will usher in another round of
warm air (though not quite as warm as right now) aloft. This could
spell another round of freezing precipitation across many of the
same areas. Stay tuned to the forecast as this is a rather dynamic
weather pattern.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2...Mon and
Tue)...
Two more potent lows will drive through the Eastern Aleutians
before quieter weather returns by the middle of the week. The
first storm is currently moving over Dutch Harbor. To the west of
this system, you have storm-force northerly winds bringing plenty
of cold air down. The end result is seas climbing to near 30 ft
and snow/rain showers. To the east of the system are
southeasterly winds. These winds are helping to usher in some
warmer air and allowing for most of the precipitation to fall as
rain.

The next system will pivot through Bristol Bay overnight into Tue.
This system will be a fair amount weaker than the current low and
it will remain farther to the east. The net effect is that it will
pull cold air down across just about all of the Bering (through
Cold Bay). This should allow all of the precipitation to mix (turn
to) snow showers and make for gusty conditions. However, because
the gradient is weaker and the low farther to the east, sustained
winds will not be as strong and waves will continue to subside
into the middle of the week.

&&

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

The long-term forecast begins Tuesday night with a double-barrel
surface low situated in the Gulf with one center of circulation
south of the AKPEN and the second drifting slowly northeast toward
the Alaska Panhandle. As has been the theme, there are subtle
differences in placement and strength of these features; however,
the various guidance (NAM, EC, GFS, and Canadian) show the double-
barrel system and indicate a weakening trend with said features.
Support for these features is also lacking in the upper levels,
with the jet is well south of the surface lows and little if any
thermal gradient or advection in the mid-levels.

Guidance begins to breakdown further heading into the late
Wednesday/early Thursday time frame. The GFS and EC both indicate
an upper-level shortwave digging south across the Aleutians,
helping amplify the pattern over the north Pacific. This, in turn,
strengthens and steers another strong north Pacific low northward.
The GFS and Canadian are the more bullish solutions, with a low
approaching Kodiak Island late Thursday. The EC, however, slows
the track of the low, stalling it in the southern Gulf until
Friday before a low upstream finally pushes the Gulf low toward
the southcentral coast.

Upstream, guidance is holding tight to the building of a ridge
over eastern Russia and keeping it in place through the long term.
This will keep the jet, and surface low track, south of the
Aleutians. Here, the GFS, Canadian, and EC all develop a low
southwest of Shemya Wednesday with a front across the western half
of the Aleutians. Solutions then diverge greatly with the forward
progression of not only the low, but the front and development of
a subsequent triple point low Thursday into Friday. Again, the GFS
and Canadian are more similar than the EC.

By the weekend, guidance is all over the place with the upper-
level and surface features. However, the common denominator
between each solution is the continuation of the broad low
centered over the eastern Aleutians. This setup would keep a
moist, southerly flow over the Gulf and across southcentral and
southwest Alaska with clouds and precipitation wrapping around
the low over the Bering and Aleutians.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 145 152 155 161.
MARINE...Gales 120 125 130 131 132 136 137 138 139 140
			155 160 170 173 174 175 176 185 351 352.
		 Storm 119 179 180 181 412 413 414.

&&

SYNOPSIS AND MODEL DISCUSSION...JPW
SOUTHCENTRAL ALASKA...DWK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MSO
LONG TERM...TM