Gale Warning 593, NWS Anchorage, AK

426 
FZAK61 PAFC 071248
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
348 AM AKST Sat Nov 7 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-080200-
348 AM AKST Sat Nov 7 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 987 mb low forms near 59N 153W Sun morning, moves to 60N 147W 
at 983 mb Sun afternoon, then moves to 60N 144W at 993 mb by Mon 
morning.

$$

PKZ351-080200-
Gulf of Alaska Offshore North of 57N and West of 144W-
348 AM AKST Sat Nov 7 2020

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...S wind 10 to 20 kt. Seas 7 ft. Rain.
.TONIGHT...S wind 20 to 35 kt increasing to 30 to 40 kt after
midnight. Seas 7 to 10 ft building to 9 to 16 ft after midnight.
Rain.
.SUN...SW wind 25 to 35 kt. Seas 14 to 18 ft.
.SUN NIGHT...W wind 30 to 45 kt. Seas 19 to 27 ft.
.MON...W wind 30 to 45 kt. Seas 16 to 24 ft.
.TUE...SW wind 15 to 30 kt. Seas 10 ft.
.WED...W wind 20 to 30 kt. Seas 13 to 16 ft.

$$

PKZ352-080200-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
348 AM AKST Sat Nov 7 2020

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...SW wind 10 to 20 kt becoming S 15 to 30 kt in the
afternoon. Seas 8 to 12 ft. Rain.
.TONIGHT...S wind 25 to 40 kt. Seas 10 to 18 ft. Rain.
.SUN...W wind 25 to 40 kt. Seas 19 ft.
.SUN NIGHT...W wind 30 to 45 kt. Seas 17 to 25 ft.
.MON...W wind 30 to 45 kt. Seas 14 to 22 ft.
.TUE...SW wind 20 to 30 kt. Seas 9 to 12 ft.
.WED...W wind 30 to 40 kt. Seas 15 to 21 ft.

$$

754 
FZAK61 PAFC 080038
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
338 PM AKST Sat Nov 7 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-081630-
338 PM AKST Sat Nov 7 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A front associated with a low moving northward into Bristol Bay
moves northward through the Gulf of Alaska and then inland by Sat
night. A new 984 mb low forms Sun morning over northern Cook Inlet
at 61N 151W and moves to 59N 139W at 999 mb by Mon morning.

$$

PKZ351-081630-
Gulf of Alaska Offshore North of 57N and West of 144W-
338 PM AKST Sat Nov 7 2020

...STORM WARNING SUNDAY NIGHT...

.TONIGHT...S wind 20 to 35 kt increasing to 30 to 40 kt after
midnight. Seas 7 to 10 ft building to 9 to 16 ft after midnight.
Rain.
.SUN...SW wind 25 to 35 kt. Seas 14 to 18 ft.
.SUN NIGHT...W wind 35 to 50 kt. Seas 19 to 27 ft.
.MON...W wind 30 to 45 kt. Seas 14 to 28 ft.
.MON NIGHT...W wind 25 kt. Seas 10 to 18 ft.
.TUE...SW wind 15 to 30 kt. Seas 10 ft.
.WED THROUGH THU...NW wind 15 to 30 kt. Seas 11 to 18 ft.

$$

PKZ352-081630-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
338 PM AKST Sat Nov 7 2020

...GALE WARNING THROUGH SUNDAY NIGHT...

.TONIGHT...S wind 25 to 40 kt. Seas 10 to 18 ft. Rain.
.SUN...W wind 25 to 40 kt. Seas 19 ft.
.SUN NIGHT...W wind 30 to 45 kt. Seas 18 to 25 ft.
.MON...W wind 30 to 45 kt. Seas 16 to 24 ft.
.MON NIGHT...W wind 20 to 30 kt. Seas 12 to 20 ft.
.TUE...SW wind 20 to 30 kt. Seas 9 to 12 ft.
.WED THROUGH THU...NW wind 25 to 40 kt. Seas 15 to 21 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
555 AM AKST Fri Nov 6 2020

.ANALYSIS AND UPPER LEVELS...

Overall zonal upper level flow across Southcentral with a
shortwave moving across the Fairbanks area. Satellite shows high
clouds streaming eastward along the upper level jet from the Kenai
Peninsula and southward with lower clouds seen across the rest of
Southcentral. The cold airmass continues over Southcentral with
temperatures in the mid to upper teens from the Mat- Su Valleys
and Anchorage area with the Kenai in the low 20s north and upper
20s near Homer and elsewhere along the coast, to the single digits
across the Copper River Valley. While warmer air is over Kodiak
Island with upper 30s to low 40s. Occasional light snow flurries
continue from Anchorage to the MAT- SU valleys and the Copper
River Basin.

Farther west a trough east of the Kamchatka Peninsula will
continue to push warmer air into Southwest Alaska with
temperatures currently in the upper 30s with mid 40s across the
Aleutians. Currently very little precipitation is being observed
at our observation sites, however minor shortwaves embedded in
the larger upper- level trough and southwesterly flow will produce
a few showers across the Bering and Aleutians today.

&&

.MODEL DISCUSSION...

Still some model uncertainty with the low pressure moving towards
Kodiak Island Sunday morning. The GFS has been the most consistent
so we have opted to use it as the model of choice for this
forecast period. The NAM is slightly faster but takes a similar
track from near Kodiak Island to eastern Prince William Sound by
Sunday night while the preferred GFS solution puts the low in the
center of Prince William Sound by early Monday morning. The EC is
a bit of the outlier with the main low moving into Bristol Bay
with a weaker triple point forming east of the Kenai Peninsula
Sunday. The ensembles also show better agreement with GFS.

Confidence is still low, but is increasing as GFS and ensembles
are showing better agreement. However, these model differences
still pose challenges to how much precipitation, wind speeds and
precipitation type. Current thinking with the GFS solution is for
several inches of snowfall in most areas with the exception of
Cordova and Kodiak where temperatures are expected to be warm
enough for rain. Advisory to warning level snowfall is becoming a
better bet in many areas with the current track of this system.

&&

.AVIATION...

PANC...Lingering moisture in the Anchorage bowl behind a
dissipating frontal system will continue to generate periods of very
light snow that may mix with light freezing drizzle for the first
few hours of the morning. The light precip, ceilings as low as
500-1000 ft, and perhaps areas of fog will result in LIFR/IFR
conditions initially. Current thinking is for conditions to
gradually improve with lower visibility associated with
snow/drizzle abating early this morning and ceilings lifting to
MVFR then eventually VFR ceilings by late this evening. However,
confidence for timing of better conditions is low to moderate with
no obvious mechanism to fully mix out the damp low-level airmass
arriving until early Saturday morning. Ceilings should more
markedly improve on Saturday morning to VFR out ahead of the next
storm system arriving later this weekend. Winds will remain light
and North to Northeast through Saturday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Today
through Sunday Night)...

The wave that crossed the area this morning appears to have been
more bark than bite. The 12Z Anchorage sounding offers the reason
why once again most of the area got very little snow from last
night's frontal passage. Significant dry air moved in over the
area behind the front, which dried out the dendritic snow growth
layer. That is a portion of the atmosphere that needs to be fully
saturated for snowflakes to grow. When that layer dried out, the
snowflakes that fell stayed very small. Thus, when they reached
the ground, they did not result in much accumulation. For the next
day or so, the snow drought continues. The rest of today will
feature mostly cloudy conditions.

Skipping ahead to the next storm, much of the area will get a much
better chance of getting the first real accumulating snow of the
season. Unlike the last big storm, where cold air was completely
absent, this time there is no shortage of that, as we all know
from the past few days. The biggest forecast question is the track
of the storm. Most of the models keep some of the energy west of
the Aleutian/Alaska Ranges for a time, then transfer that energy
in the form of a developing triple-point low to the Gulf. The EC
solution is by far the latest with this energy transfer occurring,
taking the stronger low through the Kuskokwim Valley before
developing a much weaker low south of Seward. This solution would
bring a warm event to Southcentral, with most areas seeing lots of
rain. Fortunately, almost all of the other models depict that
transfer happening much sooner, with the stronger low in the Gulf
developing near Kodiak Island, then tracking south of Seward and
into Prince William Sound. This track would keep most of the Cook
Inlet region on the "cold" side of the low. However, regardless of
the low track, it will bring a substantial amount of warm air
north along with it. Thus, some areas, particularly along the
coast from Seward to Whittier and Valdez will be rain for a bulk
of the event. Time will tell how high snow levels rise in Thompson
Pass as well. For now most of the event in Thompson Pass is
expected to stay snow, with Sunday being the best chance of rain
mixing in there.

Regardless of track, plenty of cold air will persist in the
Susitna Valley for this event. The plentiful moisture will result
in heavy snow for much of the Valley. A Winter Storm Watch has
been issued. Special Weather Statements have been issued for
Anchorage, the Mat Valley, and the Western Kenai Peninsula.
Precipitation type will be the primary challenge, which will
depend on the track of the low and how much warm air moves in on a
period of gusty southeasterly winds ahead of the low Saturday
night. Snow will be measured in feet in Turnagain Pass, resulting
in very hazardous to impossible travel along the Sterling and
Seward Highways in the mountains. Snow will linger in the Copper
Basin into Sunday night, where several inches of snow are expected
as well.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...

Drier condition across the Southwest today with persistent
southwesterly flow through tonight, keeping temperatures above
freezing today and tomorrow. For tonight, the coasts will remain
above freezing with temperatures at or just below freezing
further inland. By Saturday, a North Pacific low approaches the
AKPEN. Models are disagreeing on the track of this low, with the
NAM/GFS giving it a more easterly track towards Shelikof Strait,
and the EC/Canadian tracking it north through Bristol Bay.
Precipitation type with this low is very path dependent and the
current forecast follows the more easterly path. Thus, rain is
expected along the coasts by Saturday afternoon, and snow further
inland across the Kuskokwim Valley Saturday evening into Sunday.
Snow accumulations, should this system stay on the current track,
may be significant enough to warrant an advisory with anywhere
from 5-8 inches expected in some areas.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 Through 3)...

Widespread small crafts and persistent southwesterly flow
dominates much of the Bering through tonight. A band of moderate
to heavy rainfall skims the southern edge of the Alaska Peninsula
before tapering off to light showers. Widespread light rain
showers are expected elsewhere through tomorrow night. A second
system approaches the Western Bering on Sunday, bringing more
rain and another round widespread gales with possible storm force
gusts.

&&

.MARINE (Days 3 through 5)...

Gulf of Alaska: A gale force low will move across the Gulf
Sunday. Wave heights at their worst Sunday will range between 15
to 18 feet. Gale force winds are expected through Monday and as
the low fills the pressure gradient will slack off.

Bering Sea: Sunday a new low will emerge from the North Pacific
with a surface low of 984 mb near Attu Island. 24 hrs later, the
models diverge on the track of the surface low, however, the
ECMWF brings takes the low north of Attu and into the Bering. By
late Monday the surface low is much stronger and in the North
Bering. The model consensus is that this system will produce gale
to storm force winds.

&&

.LONG TERM FORECAST (Days 4 through 7)...

The longwave pattern has a trough entering western Alaska, a
glimmer of a ridge axis over the Western Bering and a trough over
Kamchatka. Twelve hrs later, the leading trough is bisecting
Mainland Alaska, the ridge is over the Pribilof Islands and the
trough has made headway into the Western Aleutians. This is a very
progressive and dynamic pattern. The amount of shortwave energy
associated with each upper level trough is stunning. Both of these
lows are juiced. The primary forecast challenge will be pinging
into the precipitation types (rain vs. snow vs. rain/snow mix) and
as always...the timing of the the low tracks. Long story short,
Mainland Alaska will get back to back lows.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...RC
SOUTHCENTRAL ALASKA...JPW
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KM
MARINE/LONG TERM...PJS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
957 AM AKST FRI NOV 6 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0630 AM     SNOW             NEAR CONFLUENCE OF MOOS 60.54N 150.76W
11/06/2020  M1.0 INCH        KENAI PENINSULA    AK   TRAINED SPOTTER

            SPOTTER REPORTED 1 INCH OF SNOW.

&&

MTL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1000 AM AKST FRI NOV 6 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0959 AM     SNOW             3 S KENAI               60.52N 151.21W
11/06/2020  E0.3 INCH        KENAI PENINSULA    AK   TRAINED SPOTTER

            SPOTTER REPORTED 3/16TH INCH STORM TOTAL AS
            OF 8AM.

&&

MTL

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
316 PM AKST Fri Nov 6 2020

AKZ101-111-121-070600-
Anchorage-Matanuska Valley-Western Kenai Peninsula-
Including the cities of Anchorage, Eagle River, Indian, Eklutna,
Palmer, Wasilla, Sutton, Chickaloon, Kenai, Soldotna, Homer,
and Cooper Landing
316 PM AKST Fri Nov 6 2020

...WINTER WEATHER WITH MIXED PRECIPITATION, GUSTY WINDS, AND
ACCUMULATING SNOW EXPECTED FROM SATURDAY AFTERNOON THROUGH
SUNDAY...

A strong storm system potentially causing a variety of
precipitation types will move into Southcentral this weekend. Snow
will begin Saturday afternoon, first along the Kenai Peninsula,
then spreading north through Anchorage and the Matanuska Valley
Saturday night. Late Saturday night, a warming air mass moving
into the Kenai Peninsula and the Knik Valley wind will result in
rain mixing in with the snow. The precipitation may change over
to all rain Sunday morning over much of the area. As the storm
departs Sunday afternoon, the rain may change back over to snow
before ending Sunday night. Significant snowfall accumulations are
expected along higher elevations, including Hatcher Pass.
Accumulations through the Anchorage Bowl, Mat Valley, and Western
Kenai Peninsula will be highly dependent on how much rain mixes in
and how warm the temperatures get on Sunday.

Gusty winds of 15 to 25 mph with gusts to 35 mph are possible in
the Mat Valley from both the Mat Wind and Knik River Valley wind.
Along Turnagain Arm and higher elevations, gusts to 40 mph are
possible Saturday night. The winds will diminish Sunday morning.
Areas seeing gusty southeasterly winds Saturday night have an
increased likelihood of rain mixing in along with warmer
temperatures.

Any areas where rain falls may cause icy conditions to develop,
especially when colder temperatures return Sunday night.

Updates will be issued as the details of this storm become more
clear. Significant changes to the forecast are possible. Please
visit weather.gov/Anchorage for the latest forecasts for your area.

AKZ125-131-070600-
Western Prince William Sound-Northeast Prince William Sound-
Including the cities of Whittier, Seward, Girdwood, Moose Pass,
Valdez, and Thompson Pass
316 PM AKST Fri Nov 6 2020

...PERIODS OF HEAVY SNOW, BLOWING SNOW, LOW-ELEVATION MIXED
PRECIPITATION, AND GUSTY WINDS LIKELY THIS WEEKEND AROUND PRINCE
WILLIAM SOUND...

Periods of heavy snow associated with a strong storm system will
impact both Turnagain and Thompson Passes this weekend. While
snowfall amounts will be measured in feet at higher elevations by
the time the snow ends Sunday night; gusty winds and warmer
temperatures may result in rain mixing in at lower elevations,
including Portage Valley. Meanwhile along the coast, including
Seward and Whittier, rain is expected for most of this event.
Winds could gust to 40 mph through Portage Valley and through
Thompson Pass, but the winds are not expected to be strong enough
with the warming temperatures and wet snow to produce prolonged
blizzard conditions. However, gusty winds and blowing snow may
cause localized blizzard conditions at times in the windier areas
where snow remains the primary precipitation type.

There remains some uncertainty with the storm track, which will
determine how much warm air moves over the area. Updates will be
issued as the details of this storm become more clear. Significant
changes to the forecast are possible. Please visit
weather.gov/Anchorage for the latest forecasts for your area.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
322 PM AKST FRI NOV 6 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0320 PM     SNOW             UPPER POTTER VALLEY     61.06N 149.76W
11/06/2020  M0.5 INCH        ANCHORAGE          AK   TRAINED SPOTTER

            SPOTTER REPORTED A 0.5 INCH OF SNOW.

&&

MV