Gale Warning 570, NWS Anchorage, AK

537 
FZAK62 PAFC 120011
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
311 PM AKST Sat Nov 11 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.

PKZ499-121430-
311 PM AKST Sat Nov 11 2017
.SYNOPSIS FOR CENTRAL BERING SEA...

A front enters the western Bering Sea Sun morning moving into the
central Bering Sea by Sun evening. High pressure in the central 
Bering Sea will move into the southwestern Gulf of Alaska by Mon 
evening.

$$

PKZ411-121430-
Bering Sea Offshore West of 180 and East of the International
Dateline-
311 PM AKST Sat Nov 11 2017

.TONIGHT...E wind 10 to 25 kt. Seas 8 ft. Rain.
.SUN...SE wind 20 to 30 kt. Seas 9 ft. Rain.
.SUN NIGHT...SE wind 20 to 30 kt. Seas 8 to 12 ft. Areas of fog.
Rain.
.MON...SE wind 15 to 30 kt. Seas 10 ft.
.MON NIGHT...SW wind 20 to 30 kt. Seas 11 ft.
.TUE THROUGH THU...SW wind 15 to 30 kt. Seas 10 to 17 ft.

$$

PKZ412-121430-
Bering Sea Offshore 171W to 180 and North of 56N-
311 PM AKST Sat Nov 11 2017

.TONIGHT...S wind 10 to 20 kt. Seas 6 to 11 ft. Patchy fog.
.SUN...SE wind 10 to 25 kt. Seas 5 to 9 ft. Rain.
.SUN NIGHT...SE wind 25 kt. Seas 6 to 10 ft. Patchy fog. Rain.
.MON...SE wind 15 to 30 kt. Seas 8 to 11 ft.
.MON NIGHT...S wind 20 to 30 kt. Seas 9 to 12 ft.
.TUE THROUGH THU...SW wind 15 to 25 kt. Seas 9 to 14 ft.

$$

PKZ413-121430-
Bering Sea Offshore 171W to 180 and South of 56N-
311 PM AKST Sat Nov 11 2017

.TONIGHT...SE wind 15 to 25 kt. Seas 5 to 8 ft. Patchy fog. Rain.
.SUN...SE wind 20 to 30 kt. Seas 6 to 11 ft. Rain.
.SUN NIGHT...S wind 30 kt. Seas 11 ft. Areas of fog.
.MON...SE wind 30 kt. Seas 9 to 12 ft.
.MON NIGHT...S wind 20 to 30 kt. Seas 9 to 12 ft.
.TUE THROUGH THU...W wind 15 to 25 kt. Seas 7 to 12 ft.

$$

PKZ414-121430-
Bering Sea Offshore East of 171W-
311 PM AKST Sat Nov 11 2017

.TONIGHT...SW wind 10 to 20 kt. Seas 4 to 8 ft. Patchy fog.
.SUN...SW wind 10 to 20 kt. Seas 4 to 7 ft. Patchy fog.
.SUN NIGHT...S wind 10 to 20 kt. Seas 3 to 7 ft. Patchy fog.
.MON...SE wind up to 20 kt. Seas 3 to 7 ft.
.MON NIGHT...SE wind 10 to 25 kt. Seas 4 to 9 ft.
.TUE...S wind 10 to 25 kt. Seas 4 to 9 ft.
.WED THROUGH THU...NW wind 15 to 25 kt. Seas 6 to 10 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
419 PM AKST Fri Nov 10 2017

.ANALYSIS AND UPPER LEVELS...

The main synoptic features aloft are an amplifying ridge over the
Bering Sea and a long wave trough extending south from the Arctic
to over the Gulf of Alaska. A weak upper wave dropping down the
forward side of the Bering ridge is bringing a little rain and
snow to the Delta. At the surface, a low pressure trough extends
west across the northern Gulf with high pressure inland. The pinch
in the pressure gradients between these two features, aided by
cold advection, are generating gale-storm force gusts over the
western Gulf and strong and gusty outflow winds along the northern
Gulf/eastern Kenai Peninsula. Subsidence under the Bering Sea is
producing widespread stratus and some fog across the Aleutians and
Bering. Strong southeasterly winds were observed over the far
western Aleutians with a frontal trough just to the west.

&&

.MODEL DISCUSSION...

The models are in good synoptic agreement through the short term.
The focus today will be on minor adjustments to published grids.

&&

.AVIATION...
PANC...VFR conditions with gusty north winds developing this evening.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
High pressure will remain over the Bering Sea through Sunday with
low pressure over the Yukon. Northerly flow aloft and strong
offshore flow at the surface will continue through Saturday night.
On Sunday, a trough will drop southeastward through central and
eastern Alaska. This will allow the flow aloft to become more
westerly, and will bring a chance of precipitation to the Copper
River basin and the northern Susitna valley. At the same time, the
surface offshore gradient will weaken, but not end. Temperatures
will remain a bit below normal with the northerly flow, moderated
somewhat by the near to above normal 500 mb heights.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The large ridge of high pressure from the 1034 mb high near Adak
north into the Bering Sea continues to be the main driver of the
weather over the Bering Sea to southwest Alaska. Moisture from a
trough that is riding over the top of the ridge is shooting south
across the Kuskokwim Delta triggering showers today. Warm air is
pushing in today resulting in the snow mixing with rain. With this
influx of warm air aloft and subsidence under this ridge, we will
see strong low level inversions across the southwest mainland and
eastern Bering Sea. Therefore the main forecast challenge for
this weekend will be fog.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The subsidence and low level inversion under the ridge over the
eastern Bering Sea and the resulting stratus and fog will remain
the issue through the weekend for the eastern Bering Sea. The
ridge will slide to the east allowing the Pribilofs to realize
increased southerly flow and mixing of the lower atmosphere by
late Sunday. The warm moist advection along the west side of the
ridge will bring +8 C 850 mb temperatures across the Aleutians
tonight and eventually to the Pribilofs Monday. West of the ridge strong
winds remain the main concern. At this time it looks like the
current minimal gales are all we expect across the western
Aleutians.

&&

.LONG TERM FORECAST (Days 3 through 7)...
From Sunday evening onward, the extended forecast will be
a steady state continuation of the current conditions, mainly dry
and colder across the southern mainland. The dominant feature in
the models is an upper level ridge centered over the Bering Sea.
The next downstream longwave trough is well into the Canadian
Arctic, leaving much of Alaska in northerly jet scenario between
these two features. Several shortwave troughs will come through
the flow within the jet, but any precipitation associated with
them should stay on the windward side of the Alaska Range.
Generally this pattern is a cold and dry one for southcentral
Alaska with gusty gap winds along the coast. Expect high
temperatures in the 20s inland and 30s along the coast with lows
in the single digits and teens. Over the southwest mainland,
fronts coming through the ridge will bring periods of snow and
northwesterly winds.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 121, 126-128, 130-132, 150.

&&

SYNOPSIS AND MODEL DISCUSSION...RMC
SOUTHCENTRAL ALASKA...BL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...SA
LONG TERM...ML