Storm Warning 45, NWS Anchorage, AK

420 
FZAK62 PAFC 251223
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
323 AM AKST Mon Feb 25 2019

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.

PKZ499-260130-
323 AM AKST Mon Feb 25 2019
.SYNOPSIS FOR CENTRAL BERING SEA...
A 960 mb low at 54N 178E moves over Northern Kamchatka at 963 mb
for Tue morning. Its front pushes into Western Alaska by Tue
afternoon. A 993 mb low near 44N 169E Tue morning moves to 59N
175W at 988 mb Wed morning. Its front trails across the Central 
Aleutians to a 990 mb low at 49N 178W by Wed morning.

$$

PKZ411-260130-
Bering Sea Offshore West of 180 and East of the International
Dateline-
323 AM AKST Mon Feb 25 2019

...STORM WARNING THROUGH TONIGHT...

.TODAY...SW wind 40 to 55 kt. Seas 23 to 34 ft. Freezing spray.
Snow and rain.
.TONIGHT...SW wind 35 to 50 kt. Seas 20 to 32 ft. Freezing spray.
Snow.
.TUE...SW wind 20 to 35 kt becoming 25 kt in the afternoon. Seas
16 to 24 ft.
.TUE NIGHT...S wind 10 to 25 kt. Seas 8 to 16 ft.
.WED...W wind 10 to 25 kt. Seas 7 to 10 ft.
.THU THROUGH FRI...SW wind 10 to 25 kt. Seas 7 to 12 ft.

$$

PKZ412-260130-
Bering Sea Offshore 171W to 180 and North of 56N-
323 AM AKST Mon Feb 25 2019

...STORM WARNING THROUGH TONIGHT...

.TODAY...SE wind 35 to 50 kt. Seas 20 to 31 ft.
.TONIGHT...S wind 35 to 50 kt diminishing to 25 to 40 kt after
midnight. Seas 20 to 33 ft.
.TUE...S wind 15 to 30 kt. Seas 16 to 24 ft.
.TUE NIGHT...S wind 10 to 25 kt. Seas 11 to 17 ft.
.WED...S wind 20 to 35 kt. Seas 12 to 20 ft.
.THU...SW wind 15 to 30 kt. Seas 11 to 19 ft.
.FRI...SW wind 20 kt. Seas 9 ft.

$$

PKZ413-260130-
Bering Sea Offshore 171W to 180 and South of 56N-
323 AM AKST Mon Feb 25 2019

...STORM WARNING TODAY...

.TODAY...SW wind 35 to 50 kt. Seas 19 to 33 ft. Snow and rain.
.TONIGHT...SW wind 25 to 35 kt diminishing to 15 to 30 kt after
midnight. Seas 19 to 30 ft.
.TUE...S wind 10 to 25 kt. Seas 13 to 21 ft.
.TUE NIGHT...S wind 10 to 25 kt. Seas 9 to 16 ft.
.WED...SW wind 25 to 40 kt. Seas 11 to 19 ft.
.THU THROUGH FRI...SW wind 15 to 25 kt. Seas 9 to 14 ft.

$$

PKZ414-260130-
Bering Sea Offshore East of 171W-
323 AM AKST Mon Feb 25 2019

...GALE WARNING TODAY...

.TODAY...SE wind 25 to 40 kt. Seas 10 to 18 ft.
.TONIGHT...S wind 20 to 30 kt diminishing to 10 to 25 kt after
midnight. Seas 11 to 19 ft.
.TUE...S wind 10 to 25 kt. Seas 10 to 18 ft.
.TUE NIGHT...S wind 20 to 30 kt. Seas 10 to 18 ft.
.WED THROUGH THU...SW wind 25 to 40 kt. Seas 13 to 21 ft.
.FRI...SW wind up to 15 kt. Seas 7 ft.

$$

134 
FZAK62 PAFC 260004
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
304 PM AKST Mon Feb 25 2019

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.

PKZ499-261430-
304 PM AKST Mon Feb 25 2019
.SYNOPSIS FOR CENTRAL BERING SEA...
A 956 mb low at 57N 177E Mon afternoon moves over northern
Kamchatka by Tue morning. A 989 mb low Tue afternoon at 50N 179E 
moves into the northern Bering by Wed afternoon. A 987 mb low at 
49N 178W Wed morning moves to 56N 174W at 982 mb by Wed afternoon. 

$$

PKZ411-261430-
Bering Sea Offshore West of 180 and East of the International
Dateline-
304 PM AKST Mon Feb 25 2019

...STORM WARNING TONIGHT...

.TONIGHT...SW wind 35 to 50 kt. Seas 20 to 32 ft. 
Freezing spray west of 177W. Snow.
.TUE...SW wind 20 to 35 kt. Seas 15 to 23 ft. 
Freezing spray west of 177W.
.TUE NIGHT...SW wind 10 to 25 kt. Seas 9 to 15 ft.
.WED...NW wind up to 15 kt. Seas 7 to 10 ft.
.WED NIGHT...W wind 10 to 25 kt. Seas 7 to 11 ft.
.THU THROUGH FRI...SW wind 10 to 25 kt. Seas 7 to 11 ft.
.SAT...SE wind 25 to 40 kt. Seas 14 to 22 ft.

$$

PKZ412-261430-
Bering Sea Offshore 171W to 180 and North of 56N-
304 PM AKST Mon Feb 25 2019

...STORM WARNING TONIGHT...

.TONIGHT...S wind 35 to 50 kt diminishing to 25 to 40 kt after
midnight. Seas 20 to 33 ft.
.TUE...S wind 15 to 30 kt. Seas 16 to 24 ft.
.TUE NIGHT...SE wind 15 to 30 kt. Seas 12 to 17 ft. 
Snow with rain.
.WED...N wind 20 to 35 kt. Seas 11 to 19 ft.
.WED NIGHT...W wind 20 to 35 kt. Seas 12 to 20 ft.
.THU...SW wind 15 to 30 kt. Seas 11 to 19 ft.
.FRI THROUGH SAT...S wind 15 to 30 kt. Seas 10 to 18 ft.

$$

PKZ413-261430-
Bering Sea Offshore 171W to 180 and South of 56N-
304 PM AKST Mon Feb 25 2019

...GALE WARNING TONIGHT AND TUESDAY NIGHT...

.TONIGHT...SW wind 25 to 35 kt diminishing to 15 to 30 kt after
midnight. Seas 19 to 30 ft.
.TUE...S wind 15 to 25 kt. Seas 14 to 21 ft.
.TUE NIGHT...SE wind 20 to 35 kt becoming SW 15 to 30 kt after
midnight. Seas 11 to 19 ft. Snow with rain.
.WED...NW wind 25 to 40 kt. Seas 11 to 19 ft.
.WED NIGHT...W wind 15 to 30 kt. Seas 10 to 18 ft.
.THU THROUGH FRI...SW wind 15 to 25 kt. Seas 9 to 15 ft.
.SAT...S wind 25 to 40 kt. Seas 12 to 20 ft.

$$

PKZ414-261430-
Bering Sea Offshore East of 171W-
304 PM AKST Mon Feb 25 2019

...GALE WARNING TUESDAY NIGHT...

.TONIGHT...S wind 20 to 30 kt diminishing to 10 to 25 kt after
midnight. Seas 11 to 19 ft.
.TUE...S wind 10 to 25 kt becoming 20 kt in the afternoon. 
Seas 10 to 18 ft.
.TUE NIGHT...S wind 25 to 40 kt. Seas 11 to 19 ft. Rain.
.WED...S wind 30 to 40 kt. Seas 14 to 22 ft.
.WED NIGHT...S wind 25 to 40 kt. Seas 16 to 23 ft.
.THU...SW wind 15 to 30 kt. Seas 11 to 19 ft.
.FRI THROUGH SAT...SW wind up to 20 kt. Seas 5 to 8 ft.

$$

230 
FZAK62 PAFC 261242
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
342 AM AKST Tue Feb 26 2019

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.

PKZ499-270215-
342 AM AKST Tue Feb 26 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A front pushes into Western Alaska through Wed morning. A 996 mb
low at 44N 168E moves over the Russian Far East at 990 mb for Wed
afternoon. Its front extends across the Aleutians to a 997 mb low
near 45N 174E Tue afternoon. This low moves to 58N 175W at 972 mb
as its front slides into the Eastern Aleutians by Thu morning.

$$

PKZ411-270215-
Bering Sea Offshore West of 180 and East of the International
Dateline-
342 AM AKST Tue Feb 26 2019

...GALE WARNING TODAY...

.TODAY...SW wind 25 to 35 kt becoming S 15 to 30 kt in the
afternoon. Seas 15 to 23 ft. Snow showers.
.TONIGHT...SW wind 10 to 25 kt becoming W up to 15 kt after
midnight. Seas 9 to 15 ft.
.WED...NW wind 10 to 15 kt. Seas 9 ft.
.WED NIGHT...NW wind 10 to 25 kt. Seas 9 ft.
.THU THROUGH FRI...SW wind 10 to 25 kt. Seas 7 to 11 ft.
.SAT...SE wind 25 to 40 kt. Seas 14 to 29 ft.

$$

PKZ412-270215-
Bering Sea Offshore 171W to 180 and North of 56N-
342 AM AKST Tue Feb 26 2019

...GALE WARNING TONIGHT AND WEDNESDAY...

.TODAY...S wind 15 to 30 kt. Seas 16 to 23 ft.
.TONIGHT...S wind 20 to 30 kt becoming SE 25 to 40 kt after
midnight. Seas 12 to 18 ft. Snow and widespread rain showers.
.WED...W wind 20 to 35 kt becoming N 25 to 40 kt in the afternoon.
Seas 12 to 20 ft. Rain.
.WED NIGHT...NW wind 30 to 45 kt. Seas 15 to 23 ft.
.THU...SW wind 30 to 45 kt. Seas 12 to 20 ft.
.FRI...SW wind 20 kt. Seas 8 to 11 ft.
.SAT...S wind 25 to 40 kt. Seas 13 to 21 ft.

$$

PKZ413-270215-
Bering Sea Offshore 171W to 180 and South of 56N-
342 AM AKST Tue Feb 26 2019

...GALE WARNING TONIGHT AND WEDNESDAY...

.TODAY...S wind 15 to 25 kt. Seas 14 to 19 ft.
.TONIGHT...S wind 25 to 40 kt. Seas 11 to 19 ft. Snow and rain.
.WED...N wind 30 to 45 kt. Seas 11 to 19 ft. Rain.
.WED NIGHT...W wind 30 to 45 kt. Seas 13 to 21 ft.
.THU...SW wind 15 to 30 kt. Seas 10 to 18 ft.
.FRI...SW wind 20 kt. Seas 7 to 10 ft.
.SAT...S wind 25 to 40 kt. Seas 13 to 21 ft.

$$

PKZ414-270215-
Bering Sea Offshore East of 171W-
342 AM AKST Tue Feb 26 2019

...GALE WARNING TONIGHT AND WEDNESDAY...

.TODAY...S wind 10 to 25 kt becoming 20 kt in the afternoon. Seas
10 to 17 ft.
.TONIGHT...S wind 20 to 35 kt increasing to 30 to 45 kt after
midnight. Seas 11 to 19 ft. Rain.
.WED...S wind 35 to 45 kt. Seas 15 to 23 ft. Rain.
.WED NIGHT...SE wind 35 to 50 kt. Seas 17 to 26 ft.
.THU...SW wind 30 to 45 kt. Seas 13 to 21 ft.
.FRI...SW wind up to 15 kt. Seas 5 to 9 ft.
.SAT...S wind 10 to 25 kt. Seas 4 to 8 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
457 AM AKST Sun Feb 24 2019

.ANALYSIS AND UPPER LEVELS...
With this ridge in place over southcentral, radiational cooling
has been at its finest overnight. A number of locations hit single
digits and below zero. For much of the night, its been colder at
Ted Steven's International Airport than Deadhorse. Just before 3
AM AST a small wedge of stratus moved over the airport and the
temperature spiked a skosh at the airport, but the temperature at
the NWS Office in Anchorage remained in single digit territory
thus remaining colder than Deadhorse. To the west, there is a
surface low in the northern Bering with a mature frontal boundary
extending from it and a second low southwest of Attu Island. The
latest ASCAT/advanced scatterometer pass has detected widespread
gale fore winds with the system in the Northeastern Bering and
has detected both gale and storm force winds with the system
southwest of the chain.

&&

.MODEL DISCUSSION...
Comparing the 7z ASCAT/advanced scatterometer pass to the GFS and
NAM12 at 6Z the placement of the front in the eastern Bering and
the high over the Gulf of Alaska initialized well. The global
models are in good agreement with the synoptic features through
Tuesday morning. There are some very minor differences on the
location and intensity of the surface low moving across the
western/central Aleutians. The potential fly in the ointment will
be fog development over the Cook Inlet with that ridge in place.
There has been a lot of consistency with the longwave pattern the
past month which has had a trough over NE Russia, NW Pacific and
some portion of the Bering with a ridge over the central and
eastern Pacific and the ridge axis vacillating between the Alaskan
interior, the Yukon Territory and other Canadian provinces.
Looking at the models, expect more of the same for the next
several day.

&&

.AVIATION...
PANC...Low cigs or intermittent low cigs and light winds will
persist this morning. The Baldy Webcam has detected an area of
fog/low stratus near Knik Arm and the potential for fog or low
stratus moving over PANC is actively being monitored. At 1151Z OR
2:51 AM AST a low deck of stratus moved over the aerodrome at
PANC. The specialized satellite imagery that normally pings into
fog/low stratus hasn't detected this stratus yet, so most likely
its a microscale feature. As daytime heating occurs, the trend is
for the dewpoint and the temperature to spread farther from
eachother, and as that occurs the fog or stratus will lift and or
dissipate. &&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
(Tonight through Monday night)

An amplified upper ridge continues over the Gulf and Southcentral
Alaska through early this week. The main forecast challenge will
be the development and extent of fog. Low and mid-level warming
will tend to strengthen surface inversions and increase the
likelihood of fog develop over interior valleys, northern Cook
inlet, and across the Anchorage Bowl, during the overnight and
morning hours. Knik Arm will be the main contributor to fog across
the Anchorage Bowl. Cold air over the Copper River Basin aided by
favorable pressure gradients will continue gusty outflow winds
through Thompson Pass and the Copper River Delta into Monday. A
weak frontal boundary and southeast winds will hold the threat of
light rain or mix(overnight hours) and fog over Kodiak Island
through Monday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2...Sunday
through Monday night)...

A stout occluded front remains in place over Southwest bringing
gusty southerly winds along the coast. Snow has already begun
falling overnight across the northern Kuskokwim Delta while
temperatures over the AKPEN and coastal areas of Bristol Bay will
allow for rain today. Although this front makes an attempt to
push further inland, a blocking area of high pressure over
Southcentral prevents the advance, forcing the remnants of the
front to retrograde back to the west beginning Sunday night.
Meanwhile, the area of high pressure will have more of an
influence over areas further inland across the lower Kuskokwim
Valley and therefore may see some areas of patchy fog develop
Sunday night into early Monday morning. As the front retraces its
steps westward early Monday, lingering precipitation is expected
to become more of a rain/snow mix. Gusty southeast winds along the
coast will persist through Monday before finally tapering off
Monday evening.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2...Sunday
through Monday night)...

The main story for the Bering is a storm force low bound for the
western Aleutians today. The leading edge of the front will
move in over the western and central Aleutians, bringing
southerly gales with a large area of embedded storm force winds.
Warm air associated with this southerly flow will allow for
precipitation to fall as rain. As the low tracks northward,
westerly storm force winds will lift over the western Aleutians
tonight. With ample cold air wrapping in on the backside of the
low, precipitation will change over to snow by Monday morning.
Currently, the low center is on track to pass just east of Shemya,
keeping the Near Islands on the colder side of the low which will
allow for snow and blowing snow through Monday morning. As the low
continues to lift northward, storm force winds will diminish to
gales over the western Bering by Monday evening.

&&

.MARINE (Days 3 through 5)...

There is a bit more divergence between the numerical guidance as
compared to yesterday, especially in the strength and timing of
the low tracking through the Bering Wed/Thu. Still, a general
consensus remains that the active pattern will persist with strong
southerly winds and significant wave heights over the Bering
through midweek. Confidence remains above average that winds and
waves will slowly diminish in intensity and height as the first
low tracks toward eastern Russia late Tuesday. Confidence also
remains high that a second deepening low moving across the
central Aleutians and into the central and eastern Bering late
Tuesday through Wednesday will bring widespread southerly gales
and wave heights building to 20 feet. The discrepancy lies in
whether this system deepens enough to produce an area of storm-
force winds across the central Bering and Pribilofs on Wednesday
before lifting north. Nonetheless, expect at the very least strong
southerly gales, and areas of rain spreading north and east
across the Bering midweek with this system. Westerly winds and
waves again relax in the wake of this system as another deepening
low brings southeasterly gales across the western Aleutians by the
end of the week.

High pressure anchored over the Gulf of Alaska will allow
generally westerly, sub small-craft winds along the coast from
Kodiak Island to Cordova through the end of the week with only
a slight chance of scattered precipitation south of Kodiak Island.

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

The longwave trough/ridge pattern extending from the western
Bering to the eastern Gulf will remain in place through midweek.
After that, model guidance begins to diverge in how this pattern
evolves moving into the second half of next week. The GFS is most
bullish progressing the main trough east, splitting the ridge,
and bringing a phased shortwave into the northern Gulf. The EC and
Canadian, while showing something similar, is slower with the
movement of these features and holds the ridge over the Gulf a bit
longer. For what it is worth, the deterministic GFS and its
ensemble means have been inconsistent over the past 24 hours or so
with the timing, placement, and strength of the developing
shortwaves in the Bering. This has resulted in a forecast weighted
a bit more towards the EC/GEM solutions, with the ridge holding
on for now.

For Southcentral, expect the tranquil pattern to continue with a
few periods of higher clouds passing overhead as weakened
shortwaves crest over the ridge. This pattern will also lend to
persistent large diurnal temperature swings with average to
slightly below average overnight lows and slightly above average
daytime highs. The biggest challenge to the forecast will
continue to be fog, especially as the high drifts to the east
through next week. A southerly flow on the back side of the ridge
could advect just enough moisture to combine with the overall weak
surface flow to allow overnight/early morning fog to develop
along Cook Inlet and portions of the MAT-SU and Copper River
valleys. The southerly flow may also bring moisture to produce a
few scattered showers across Kodiak Island by the end of the week.

For the AKPEN and southwest coast, expect periods of strong
southerly winds and precipitation (mainly rain) as the occluded
fronts attached to lows tracking north across the Bering slow and
weaken as they to push inland and run up against the ridge. The
first of these will impact the coast late Monday through Wednesday
before drifting east across the southwest interior. The second
arrives overnight Wednesday and lingers through early Friday
before weakening as it, too, drifts east. Behind it, a ridge then
attempts to build in for the weekend.

For the Bering and Aleutians, one departing low will give way to a
second, gale-force low tracking north across the central Aleutians
and into the Bering beginning early Wednesday. Expect strong,
southerly gales (with areas of storm force winds possible) moving
northeast from the central Aleutians to the Pribilofs and eastern
Bering. Broad, westerly small-craft winds and areas of showers
continue across the Bering late week as this second storm lifts
north and a weaker shortwave slides underneath the main low.
Southeasterly gales redevelop along the western Aleutians by the
weekend as another deepening NOrth Pacific low tracks east toward
the chain.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 414 160 170 172 179 180 185. Storm 413 412 173 174
175 176 177 178.

&&

SYNOPSIS AND MODEL DISCUSSION...PJS
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KO/DK
MARINE/LONG TERM...KH