Gale Warning 583, NWS Anchorage, AK

534 
FZAK61 PAFC 181233
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
333 AM AKST Mon Nov 18 2019

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.

PKZ399-190215-
333 AM AKST Mon Nov 18 2019
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 1001 mb low near 61N 147W will dissipate in place today. A 
series of fronts move into the western Gulf and weaken through 
late Tue night.

$$

PKZ351-190215-
Gulf of Alaska Offshore North of 57N and West of 144W-
333 AM AKST Mon Nov 18 2019

...GALE WARNING TONIGHT AND TUESDAY...

.TODAY...SW wind 25 kt. Seas 9 ft.
.TONIGHT...S wind 15 to 25 kt increasing to 20 to 35 kt 
after midnight. Seas 7 to 12 ft. Rain.
.TUE...S wind 30 to 40 kt. Seas 10 to 17 ft. Rain.
.TUE NIGHT...S wind 20 to 35 kt. Seas 14 to 19 ft.
.WED THROUGH FRI...SW wind 20 to 35 kt. Seas 14 to 22 ft.

$$

PKZ352-190215-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
333 AM AKST Mon Nov 18 2019

...GALE WARNING TONIGHT AND TUESDAY...

.TODAY...SW wind 25 kt. Seas 9 ft.
.TONIGHT...S wind 25 to 40 kt. Seas 9 to 17 ft. Rain.
.TUE...S wind 25 to 40 kt. Seas 13 to 19 ft. Rain.
.TUE NIGHT...S wind 25 to 40 kt. Seas 17 to 20 ft.
.WED THROUGH FRI...SW wind 25 to 40 kt. Seas 16 to 25 ft.

$$

217 
FZAK61 PAFC 182352
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
252 PM AKST Mon Nov 18 2019

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.

PKZ399-190145-
252 PM AKST Mon Nov 18 2019
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A front moves across the southern Gulf late tonight making it to
the northern gulf by early Tuesday...then stalls along the coast
through Wednesday night. 


$$

PKZ351-190145-
Gulf of Alaska Offshore North of 57N and West of 144W-
252 PM AKST Mon Nov 18 2019

...GALE WARNING TONIGHT AND TUESDAY...

.TODAY...SW wind 25 kt. Seas 9 ft.
.TONIGHT...S wind 15 to 25 kt increasing to 20 to 35 kt after midnight.
 Seas 9 to 14 ft. Rain.
.TUE...S wind 35 kt. Seas 10 to 17 ft. Rain.
.TUE NIGHT...S wind 20 to 30 kt. Seas 14 to 19 ft.
.WED THROUGH FRI...SW wind 20 to 35 kt. Seas 14 to 22 ft.

$$

PKZ352-190145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
252 PM AKST Mon Nov 18 2019

...GALE WARNING TONIGHT AND TUESDAY...

.TODAY...SW wind 25 kt. Seas 9 ft.
.TONIGHT...S wind 25 to 40 kt. Seas 10 to 18 ft. Rain.
.TUE...S wind 25 to 40 kt. Seas 13 to 19 ft. Rain.
.TUE NIGHT...S wind 20 to 35 kt. Seas 17 to 20 ft.
.WED THROUGH FRI...SW wind 25 to 40 kt. Seas 16 to 25 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
444 AM AKST Sun Nov 17 2019

.ANALYSIS AND UPPER LEVELS...

A weakening upper level low, currently in the process of opening
up into a trough, was responsible for the record snowfall seen in
Anchorage yesterday. The low/trough is over the Talkeetna
Mountains and is quickly lifting northeastward. The associated
ridging and subsidence in the left entrance region of a jet streak
has helped cause an abrupt ending to the snow in Anchorage. Clearing
skies are evident on satellite over much of the Kenai Peninsula,
moving northeastward across Anchorage and towards the Matanuska
Valley. Ahead of the main trough axis, a few rain and snow showers
are on radar over Prince William Sound between Valdez and Cordova.
Snow continues over the Copper River Basin, including Glennallen
as well.

A second upper level trough/low is over the Y-K Delta region as
well. As this feature also weakens and moves east later today,
additional winter weather is possible. Abundant cloud cover exists
over Southwest Alaska ahead of this trough, with snow showers
ongoing in some areas, especially along coastal Bristol Bay. A col
is over the northern Bering north of the Pribilofs, with another
upper level trough extending over the western Bering.

&&

.MODEL DISCUSSION...

The models are generally handling the broad synoptic pattern well,
though by late Monday night, there are significant differences on
where a newly formed North Pacific low will be centered relative
to the Southwest Alaska coastline. There are also large
differences on how strong the low will be at that point, with the
GFS by far the strongest, and the EC by far the weakest. Outside
of those differences, other model discrepancies and forecast
challenges focus around local effects. Those local effects
include: potential snowfall from Anchorage north this afternoon
and evening, the wind and snow forecast for the southern Kenai
Peninsula at the same time, and the potential for hazardous winter
weather across portions of Southwest Alaska Monday into Tuesday.
Warmer air moving into Southern Alaska with the low Monday night
into Tuesday will also likely cause precipitation type issues with
a moving rain-snow line. With so many uncertain variables in the
short to mid-term forecast, forecast confidence is lower than
normal.

&&

.AVIATION...

PANC...VFR to MVFR conditions will persist as the cloud cover from
yesterday's snow moves northeast out of the area. The next round
of snow comes in late afternoon into the evening today. It should
not be nearly as strong or produce nearly as much snow as
yesterday, but is expected to drop ceilings and visibilities into
the MVFR to temporarily IFR category as it moves through. The
snow ends by midnight, if not sooner.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2/Today
through Monday)...

The potent upper level low and short-wave trough which brought
significant snow accumulation to Anchorage and the Matanuska
Valley yesterday will exit across the Copper River Basin this
morning. A few low level snow showers will linger in upslope
areas of south to west facing mountains. Areas of low clouds will
also linger due to the absence of winds to clear things out.

Two more short-wave troughs crossing Southwest Alaska will then
make their way into Southcentral this afternoon through tonight.
The weaker of the two short-waves will lift northward across the
Cook Inlet to Susitna Valley corridor this afternoon. A slight
increase in low level upslope flow will be more than enough to
produce snow showers thanks to the low level moisture and weak
instability in place. While there could be a few snow showers
anywhere ahead of the wave, the Susitna Valley will be in the best
location to receive some light snow accumulation.

The second stronger short-wave will follow closely behind the
first tonight, becoming negatively tilted as it reaches
Southcentral and accompanied by another round of low level cold
air advection. Expect more widespread snow showers to develop
ahead of this trough overnight, especially along the south to west
sides of mountain ranges. Farther east, eastern Prince William
Sound will see some of the highest precipitation amounts due to
upslope flow and greater instability as the arctic air mass
crosses the warm Gulf waters. Cordova will see mostly rain, mixed
with snow as the colder air arrives. Valdez and vicinity should be
just cold enough to keep precipitation as all snow.

Gusty westerly winds will develop across the western Gulf and Cook
Inlet areas today as cold air crosses the Alaska Peninsula. The
track of the upper waves will cause winds to bend northeastward
into Kachemak Bay and Homer. Expect some "lake-effect" type snow
showers to develop along Kachemak Bay, though expect any
accumulation will be light.

The upper waves will exit across the Copper River Basin Monday,
with light snow once again lingering along the mountains.

&&

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

The forecast period starts out quiet for southwest Alaska.
However, cold temperatures will be in place with overnight lows
expected to drop below zero for interior areas tonight. Monday
will see a change in the pattern with a frontal system approaching
from the Bering Sea. This will make weather interesting as cold
air and northeasterly winds will still be in place at the surface
when this front approaches.

Weather should really take a turn Monday night into Tuesday
morning as this front moves ashore. This system will warm
temperatures for the Bristol Bay area to see rain and a rain/snow
mix, while the Y-K Delta and places near Bethel will stay cold
enough to see all snow. Finding the line where this transition
will occur is always tricky, right now it looks to be around
Dillingham. Winds are also expected to increase, with the
strongest winds anticipated Tuesday morning. It is still possible
the Y-K Delta could see blizzard conditions late Monday night into
Tuesday morning with this system. It's borderline right now, with
blowing snow expected, but the question is how much visibility
will be reduced. We are still making this determination, so stay
tuned for forecast updates.

&&

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

Low pressure is currently entering the western Aleutians as a
longwave trough replaces an upper level ridge over the Bering. As
this trough moves across the Aleutians, it will transition the
Bering Sea from the relatively quiet weather it has seen the past
few days to a much more active area. Closely following the low
entering today will be a broad, stronger low. This will create
large swaths of gale force winds across most of the Bering Sea and
Aleutians Islands. A few areas of storm force winds will also be
present in the central Bering and south side of the eastern
Aleutians Monday night into Tuesday. Winds will finally start to
taper late Tuesday. Rain and low level cloud cover will also be
present through the short term for the Bering Sea.

&&

.MARINE (Days 3 through 5)...

Beginning the extended period marine forecast on Tuesday, there
will be a very large high end gale force to near storm force low
covering the entire Bering Sea and Aleutian Chain, with the
associated gale force front moving into the Gulf of Alaska. There
is some uncertainty on a dangerous and compact low moving from the
Alaska Peninsula through Bristol Bay Tuesday, with some models
(the GFS) depicting a sub-960 hpa fast moving storm force low
rapidly moving northward across Bristol Bay to the Bering Strait.
For now this forecast will not include such a deep low in the
marine forecast, but mariners should remain aware of this
potential.

Eventually, the larger scale low will weaken and move inland on
Tuesday night as the gale force front continues to move east
through the Gulf of Alaska. Broad cyclonic flow will persist over
the Bering with the next potential storm force low moving into the
southern Bering/Aleutians on Wed afternoon into Thursday, moving
east into the Gulf of Alaska by Thursday afternoon. There is quite
a bit of uncertainty with this storm, but mariners should expect
high seas and unsettled weather with this storm mid to late week.

&&

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

Beginning Monday evening, a stormy pattern over western Alaska
will move into Southcentral Monday night into Tuesday. A warm
front associated with a low in the eastern Bering, combined with
cold air remaining over the region, will create the conditions
necessary for a wintry mix of precipitation across southern
Alaska.

The first of two fronts, driven by a strong upper-level jet, will
move across Alaska bringing warm air and ample precipitation from
tapping the subtropics. The cold air will be in place for awhile
creating favorable conditions for snowfall, until the warm air
displaces the cold. This will lead to rain and possibly freezing
rain Tuesday night into Wednesday with heavier snowfall for the
higher elevations. As that front moves east, a second front looks
to move through the region Friday. While confidence is high that a
front associated with a strong low will move across southern
Alaska, uncertainty remains with the storm track of the low and
how far north or south it may end up. This track will determine if
we will see rainfall or unsettled winter weather across the
southern mainland. Heading into Saturday night, it looks like cold
air will move into the area, wrapping around an area of low
pressure and makes its way south. In summary, active weather will
continue throughout the week with impacts expected for many
precipitation types: rain, snow and freezing rain. Temperatures
look to start off cold before warming up and then ending the
extended forecast period cold again.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Storm Warning: 174.
Gale Warning: 170-173, 175-185, 411-414.

&&

SYNOPSIS AND MODEL DISCUSSION...JPW
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BB
MARINE/LONG TERM...JA/CK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
942 AM AKST SUN NOV 17 2019

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

0911 AM     SNOW             17 S KNIK               61.21N 149.78W
11/17/2019  E8.7 INCH        ANCHORAGE          AK   NWS EMPLOYEE

            SPOTTER REPORTED 8.7 INCHES OF SNOWFALL.

&&

ED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
944 AM AKST SUN NOV 17 2019

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

0915 AM     SNOW             15 NNW HOPE             61.09N 149.80W
11/17/2019  E3.0 INCH        ANCHORAGE          AK   CO-OP OBSERVER

            SPOTTER REPORTED 3 INCHES OF SNOW. REPORTED
            IT RAINING MOST OF THE DAY. TURNED TO SNOW
            AT 4:45PM ON THE 16TH, THEN STOPPED AFTER
            11:30PM.

&&

ED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1046 AM AKST SUN NOV 17 2019

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

1046 AM     SNOW             3 ESE DILLINGHAM        59.04N 158.46W
11/17/2019  E12.0 INCH       DILLINGHAM         AK   LAW ENFORCEMENT

            DILLINGHAM PD REPORTED 12 INCHES OF SNOWFALL
            THAT ENDED EARLY AM OF NOVEMBER 16TH.

&&

ED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1118 AM AKST SUN NOV 17 2019

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

1053 AM     SNOW             SUTTON                  61.72N 148.89W
11/17/2019  E4.8 INCH        MATANUSKA-SUSITNA  AK   TRAINED SPOTTER

            SPOTTER REPORTED 4.75 INCHES OF SNOW.

&&

ED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
100 PM AKST SUN NOV 17 2019

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

1113 AM     SNOW             5 SSW MEADOW LAKES      61.56N 149.66W
11/17/2019  E12.0 INCH       MATANUSKA-SUSITNA  AK   PUBLIC

            SPOTTER REPORTED 12 INCHES OF SNOW.

&&

ED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
305 PM AKST SUN NOV 17 2019

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

0254 PM     SNOW             12 NNW HOPE             61.05N 149.77W
11/17/2019  E3.9 INCH        ANCHORAGE          AK   PUBLIC

            SPOTTER REPORTED 3.9 INCHES OF SNOW IN THE
            PAST 24 HOURS.

&&

ED