Storm Warning 41, NWS Anchorage, AK

472 
FZAK62 PAFC 200105
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
405 PM AKST Tue Feb 19 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.

PKZ499-201445-
405 PM AKST Tue Feb 19 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A 984 mb low at 55N 173W Tue afternoon will move into the northern
Bering at 973 mb by Wed afternoon. A 978 mb low Wed afternoon at
50N 167E will move to 57N 176E at 969 mb by Thu afternoon. 

$$

PKZ411-201445-
Bering Sea Offshore West of 180 and East of the International
Dateline-
405 PM AKST Tue Feb 19 2019

...GALE WARNING WEDNESDAY NIGHT...

.TONIGHT...NW wind 15 to 30 kt. Seas 6 to 11 ft. Freezing spray.
.WED...SW wind 15 to 30 kt. Seas 6 to 11 ft. Freezing spray.
.WED NIGHT...SE wind 30 to 45 kt. Seas 7 to 11 ft building to 11
to 19 ft after midnight. Snow and rain.
.THU...S wind 30 to 45 kt. Seas 13 to 28 ft.
.THU NIGHT...W wind 25 to 40 kt. Seas 15 to 28 ft.
.FRI THROUGH SAT...W wind 15 to 30 kt. Seas 10 to 18 ft.
.SUN...S wind 15 to 30 kt. Seas 10 to 18 ft.

$$

PKZ412-201445-
Bering Sea Offshore 171W to 180 and North of 56N-
405 PM AKST Tue Feb 19 2019

...STORM WARNING TONIGHT...

.TONIGHT...NE wind 25 to 40 kt west of 175W and 40 to 50 kt east of 
175W becoming W after midnight. Seas 9 to 17 ft. Snow and rain.
.WED...W wind 25 to 40 kt. Seas 12 to 17 ft.
.WED NIGHT...SW wind 20 to 35 kt. Seas 9 to 17 ft.
.THU...S wind 30 to 45 kt. Seas 12 to 20 ft.
.THU NIGHT...SW wind 30 to 45 kt. Seas 20 to 26 ft.
.FRI THROUGH SUN...S wind 20 to 35 kt. Seas 13 to 21 ft.

$$

PKZ413-201445-
Bering Sea Offshore 171W to 180 and South of 56N-
405 PM AKST Tue Feb 19 2019

...GALE WARNING TONIGHT AND WEDNESDAY NIGHT...

.TONIGHT...W wind 25 to 40 kt. Seas 9 to 14 ft.
.WED...W wind 20 to 30 kt. Seas 9 to 13 ft.
.WED NIGHT...SW wind 25 kt becoming S 30 to 45 kt after midnight.
Seas 9 to 14 ft. Snow.
.THU...S wind 30 to 45 kt. Seas 14 to 22 ft.
.THU NIGHT...SW wind 30 to 45 kt. Seas 14 to 26 ft.
.FRI...SE wind 20 to 35 kt. Seas 11 to 17 ft.
.SAT THROUGH SUN...S wind 20 to 35 kt. Seas 15 to 26 ft.

$$

PKZ414-201445-
Bering Sea Offshore East of 171W-
405 PM AKST Tue Feb 19 2019

...STORM WARNING TONIGHT...

.TONIGHT...S wind 40 to 50 kt W of 168W and 30 to 40 kt E of 168W. 
Seas 12 to 20 ft. Snow.
.WED...SW wind 20 to 35 kt. Seas 11 to 19 ft.
.WED NIGHT...W wind 20 to 35 kt. Seas 11 to 16 ft.
.THU...S wind 25 to 40 kt. Seas 10 to 14 ft.
.THU NIGHT...S wind 25 to 40 kt. Seas 13 to 21 ft.
.FRI THROUGH SUN...S wind 20 to 35 kt. Seas 11 to 19 ft.

$$

386 
FZAK62 PAFC 201245
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
345 AM AKST Wed Feb 20 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.

PKZ499-210215-
345 AM AKST Wed Feb 20 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A front over the central and northern Bering will move over the
eastern Bering and dissipate Wed night. A 975 mb Kamchatka low
will move to 50N 168E Tue night then it will move to 59N 176E at
974mb Fri morning. 

$$

PKZ411-210215-
Bering Sea Offshore West of 180 and East of the International
Dateline-
345 AM AKST Wed Feb 20 2019

...GALE WARNING TONIGHT AND THURSDAY...

.TODAY...SW wind 15 to 30 kt. Seas 6 to 11 ft. Freezing spray.
.TONIGHT...SE wind 30 to 45 kt. Seas 8 to 11 ft building to 11 to
19 ft after midnight. Freezing spray. Snow showers.
.THU...S wind 30 to 45 kt. Seas 15 to 29 ft.
.THU NIGHT...W wind 25 to 40 kt. Seas 16 to 27 ft.
.FRI THROUGH SAT...NW wind 15 to 30 kt. Seas 10 to 18 ft.
.SUN...S wind 10 to 25 kt. Seas 10 to 18 ft.

$$

PKZ412-210215-
Bering Sea Offshore 171W to 180 and North of 56N-
345 AM AKST Wed Feb 20 2019

...GALE WARNING THROUGH THURSDAY...

.TODAY...W wind 25 to 40 kt. Seas 12 to 16 ft.
.TONIGHT...SW wind 20 to 35 kt. Seas 9 to 17 ft.
.THU...S wind 25 to 40 kt increasing to 35 to 45 kt in the
afternoon. Seas 12 to 20 ft. Snow showers with rain showers.
.THU NIGHT...SW wind 30 to 45 kt. Seas 19 to 25 ft.
.FRI THROUGH SUN...S wind 20 to 35 kt. Seas 13 to 21 ft.

$$

PKZ413-210215-
Bering Sea Offshore 171W to 180 and South of 56N-
345 AM AKST Wed Feb 20 2019

...GALE WARNING TONIGHT AND THURSDAY...

.TODAY...W wind 20 to 30 kt. Seas 9 to 13 ft.
.TONIGHT...SW wind 25 kt becoming S 30 to 45 kt after midnight.
Seas 9 to 14 ft.
.THU...S wind 30 to 45 kt. Seas 15 to 23 ft. Snow with rain
showers.
.THU NIGHT...SW wind 30 to 45 kt. Seas 16 to 24 ft.
.FRI...SE wind 20 to 35 kt. Seas 11 to 19 ft.
.SAT THROUGH SUN...S wind 15 to 30 kt. Seas 15 to 23 ft.

$$

PKZ414-210215-
Bering Sea Offshore East of 171W-
345 AM AKST Wed Feb 20 2019

...GALE WARNING THROUGH THURSDAY...

.TODAY...SW wind 20 to 35 kt. Seas 11 to 19 ft.
.TONIGHT...W wind 20 to 35 kt. Seas 11 to 16 ft.
.THU...SW wind 15 to 30 kt becoming S 25 to 40 kt in the
afternoon. Seas 10 to 15 ft.
.THU NIGHT...S wind 25 to 40 kt. Seas 11 to 19 ft.
.FRI THROUGH SAT...SE wind 20 to 35 kt. Seas 11 to 19 ft.
.SUN...SE wind 10 to 25 kt. Seas 11 to 17 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
452 PM AKST Mon Feb 18 2019

.ANALYSIS AND UPPER LEVELS...
A front associated with a weakening, vertically stacked low over
Bristol Bay continues to rapidly push eastward towards the
eastern Gulf and ALCAN border. An upper level trough over
mainland Alaska is slowing moving eastward. Cold air wrapping
around the backside of the low is causing some cumulus clouds over
the Bering this afternoon. Southwest flow is moving into Bristol
Bay and Southwest Alaska, as well as a few snow showers over the
K-Delta. Light snow showers have also been observed across
Southcentral, along with a mix of rain/snow along the coastal
regions. One key weather feature to keep an eye on is quick moving
low center developing in the North Pacific south of Adak.

&&

.MODEL DISCUSSION (through Wednesday afternoon)...
Numerical models are in very good synoptic agreement through
Wednesday afternoon. All have similar handling of the outflow
pattern across the North Gulf on Tuesday and the developing low
and surface front moving into the eastern Bering Sea Wednesday.
The GFS will be used overall in the western domain and the higher
resolution NAMNEST in the east capture outflow winds.

&&

.AVIATION...

PANC... MVFR/IFR conditions possible in snow showers until after
trough passage overnight. North winds should develop on Tuesday
and bring drying and VFR conditions.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
(Mon night through Wed)

The main items of interest in the short term are refreeze
potential tonight as temperatures drop back into the upper teens
to lower 20s for most locations across the Anchorage Bowl.
Then, strong northerly winds will develop for Tuesday as an area
of low pressure crosses southwest Alaska tonight and into the Gulf
by morning, reaching the Yakutat area by Tuesday evening.

As this occurs, a brief ridge of high pressure will build across
Southcentral, with it being centered north of Broad Pass. This in
turn helps promote a tight pressure gradient along the eastern
slopes of the mountain ranges, with the winds increasing for the
Prince William Sound region, Whittier, Thompson Pass/Keystone
Canyon, and the Copper River Delta. For these locations look for
peak wind gusts to top out in the 40 to 50 mph range. As such, we
hoisted a Winter Weather Advisory for this section of the
Richardson Highway for Tuesday morning through Wednesday morning.
Visibilities could drop to a half mile or less in blowing/drifting
snow through Thompson Pass.

&&

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

Low pressure crossing over to the gulf tonight will bring snow
along the Kuskokwim Valley and Bristol Bay areas east of
Dillingham and then taper off toward Tuesday morning. A ridge
builds across the Southwest in the wake of the front which
supports fog development across the Alaska Peninsula and the
Southwest as low level moisture is abundant and temperatures cool
to dewpoint values overnight.

The next front moves across the Alaska Peninsula Tuesday
morning. Precipitation will likely start out as snow along the
boundary, however the warm core system is expected to warm the
column enough to change over to rain. The boundary pushes to the
west coast during the afternoon, however the ridge just inland
shunts its progression. Gusty southeasterly winds are expected to
increase along the front with snow and blowing snow, especially
further north, for Wednesday night.

On Wednesday night into Thursday, a strong short wave develops
along the base of the upper trough and swings north which brings
another frontal push which is expected to bring widespread snow
across the area. We will be monitoring this closely for potential
advisory (6") level accumulations.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3...Mon
night through Thu)...

Low pressure keeps an unsettled pattern over the Bering through
Thursday. While low pressure across the eastern waters exits
tonight, another track north along the west Bering. The next
North Pacific storm moves up to the Central Aleutians tonight and
continues on a northward track. This system will bring rain and
snow across the Aleutians tonight along with gusty easterly gales.
The storm picks up northward momentum Tuesday morning which
swings the front at a fast pace to the northern waters making
blowing snow issues for Pribilof Islands fairly brief. The
following system enters late Wednesday across the Western
Bering...bringing blowing snow possibilities across the western
Aleutian Chain as the cold core center passes close to Shemya.

&&

.MARINE (Days 3 through 5...Thu through Sat)... A very active
storm track continues across the Western Bering Thursday through
Saturday. Models have come into agreement that a mid-960 mb low
will move up the Western Bering on Thursday, bringing southerly
gale force winds through most of the Bering Sea. Another low
pressure system is expected to develop on its tail in the Northern
Pacific, crossing the Aleutians and moving into the Bering on
Friday afternoon. Winds with this next system are expected to
remain near max gale force, but northwesterly winds on the western
side of the system may increase to storms by Saturday.

Of note in the Gulf of Alaska, high pressure will build in behind
the low expected to move into Prince William Sound on Thursday.
This has the potential to cause strong northwesterly outflow
winds across the Western Gulf and through the Barren Islands
Thursday afternoon. Right now winds are expected to peak below
storm force but this bears watching as the two systems develop.

&&

.LONG TERM FORECAST (Days 3 through 7...Thu through Mon)... The
westerly storm track will continue across the mainland on
Wednesday and Thursday before a ridge builds in over the eastern
mainland on Friday. The ridge will shift the weekend's storms to
a more south to north track through the Bering Sea. The storm that
moves through the mainland on Weds and into the Prince William
Sound on Thurs will bring snow across the region, with the
potential for 6 inches or more through the Mat-Su Valley. By
Friday, the ridge will be settling into place, which means that
any weekend potential for precipitation will be kept from the
Kuskokwim Mountains westward.

Although there is certainty in the ridge building over the
mainland through the weekend causing a change in the general storm
track, some uncertainty still exists in the strength of the ridge.
This could make the difference in whether some precipitation makes
it further inland Saturday and Sunday, or whether it is mainly
held to the coast. Regardless, it does look like an influx of warm
air is likely, so precip type for the western mainland will
likely be a forecast challenge as we move into early next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Coastal Flood Advisory: 161
		 Winter Weather Advisory: 131
MARINE...Gale Warning: 120 129 130-132 138 351-352, 150-170 176 179-185
411 414.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...AH/RMC
SOUTHCENTRAL ALASKA...PD
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
MARINE/LONG TERM...LF

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE ANCHORAGE AK
959 PM AKST MON FEB 18 2019

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

0956 AM     SNOW             2 SW CAMPBELL           61.16N 149.94W
02/18/2019  M2.0 INCH        ANCHORAGE          AK   PUBLIC

            2 INCHES OVERNIGHT.

0945 AM     SNOW             5 ESE WASILLA           61.56N 149.32W
02/18/2019  M2.8 INCH        MATANUSKA-SUSITNA  AK   CO-OP OBSERVER

0730 AM     SNOW             NEAR MM. 61.5           61.80N 148.80W
02/18/2019  E3.0 INCH        MATANUSKA-SUSITNA  AK   TRAINED SPOTTER

            330PM SUN-730AM MON. STILL SNOWING.

&&

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE ANCHORAGE AK
1058 PM AKST MON FEB 18 2019

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

0658 PM     SNOW             4 MI SSW MEADOWN LAKES  61.59N 149.66W
02/18/2019  M5.0 INCH        MATANUSKA-SUSITNA  AK   PUBLIC

0956 AM     SNOW             2 SW CAMPBELL           61.16N 149.94W
02/18/2019  M2.0 INCH        ANCHORAGE          AK   PUBLIC

            2 INCHES OVERNIGHT.

0945 AM     SNOW             5 ESE WASILLA           61.56N 149.32W
02/18/2019  M2.8 INCH        MATANUSKA-SUSITNA  AK   CO-OP OBSERVER

0730 AM     SNOW             NEAR MM. 61.5           61.80N 148.80W
02/18/2019  E3.0 INCH        MATANUSKA-SUSITNA  AK   TRAINED SPOTTER

            330PM SUN-730AM MON. STILL SNOWING.

&&