High Wind Warning 15, NWS Anchorage, AK

734 
WWAK72 PAFC 231327
NPWALU

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
427 AM AKST Mon Nov 23 2020

AKZ181-232100-
/O.CON.PAFC.HW.W.0015.000000T0000Z-201123T2100Z/
Alaska Peninsula-
Including the cities of Cold Bay and Sand Point
427 AM AKST Mon Nov 23 2020

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON AKST TODAY...

* WHAT...Northwest winds 35 to 55 mph with gusts up to 80 mph.

* WHERE...Alaska Peninsula.

* WHEN...Until noon AKST today.

* IMPACTS...High winds may move loose debris, damage property, 
  and cause power outages. Travel will be difficult, especially 
  for high profile vehicles.

* ADDITIONAL DETAILS...Strongest winds will continue through the
  early morning hours especially for eastern areas. Winds will
  gradually subside below warning level from west to east by late
  morning but still remain gusty.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People are urged to secure loose objects that could be blown
around or damaged by the wind. Prepare for the possibility of
widespread power outages. Use caution if you must drive.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/afc

911 
WWAK72 PAFC 232057
NPWALU

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
1157 AM AKST Mon Nov 23 2020

AKZ181-232200-
/O.EXP.PAFC.HW.W.0015.000000T0000Z-201123T2100Z/
Alaska Peninsula-
Including the cities of Cold Bay and Sand Point
1157 AM AKST Mon Nov 23 2020

...HIGH WIND WARNING WILL EXPIRE AT NOON AKST TODAY...

Winds are no longer gusting to warning levels.

$$

For more information from the National Weather Service visit
http://weather.gov/afc

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
450 PM AKST Sun Nov 22 2020

.ANALYSIS AND UPPER LEVELS...

The dominant feature on Satellite is the powerful occluding low
pressure system tracking near the eastern Aleutians. Surface
observations show the low pressure somewhere just to the southwest
of Cold Bay. Winds have been recorded from 50 to 60 mph, with the
highest gust at Nikolski at 60 mph. Light rain was recorded along
the eastern Aleutians with over a half inch at Dutch Harbor. Rain
changed over to snow recently at Dutch Harbor with temperatures
in the mid 30s. Across Southwest Alaska there was quieter weather
with clear skies at Bethel and low stratus around the Bristol Bay
area. Temperatures are 20s to near 30 across the Kuskokwim Delta
and Bristol Bay regions with upper 30s to near 40 across the
AKPEN from King Salmon down to near Cold Bay. The Pribs are
reporting low 30s and some light snow flurries, with mid 30s from
Dutch Harbor westward along Aleutians as cooler air filters across
the Bering behind the low pressure system. Radar is showing rain
south of King Salmon near Port Heiden moving north. Farther east
across Southcentral is a shortwave trough near the Copper River
Basin that brought some light accumulating snowfall to Anchorage
and the MAT-SU valleys this morning. Radar is showing some
showers across the Prince William Sound area. Current observations
show light rain at Cordova and Whittier with snow reported at
Valdez. Farther inland no precipitation reported with low stratus
at Gulkana. Temperatures are in the 30s from Kodiak to the Kenai
Peninsula with 20s across Anchorage and MAT-SU valleys and cold
air hanging tough in the Copper River Basin with single digits and
below zero readings

&&

.MODEL DISCUSSION...

Guidance is in good agreement with the placement and intensity of
the large low and with the major synoptic features at the surface
and upper levels and confidence is increasing with forecast.
Models have come into very good agreement with the strong low
pressure and frontal system with hurricane force winds moving into
the Gulf on Monday and tracking across the southern Gulf. Models
have come into better agreement with track and strength of a front
moving across the Bering/Aleutians Sunday evening through Tuesday
night, models are now consistent with showing storm force winds
with this front. As the front moves into the Gulf on Wednesday the
models are still in good agreement, however there are some
differences on a triple point low forming near the Shelikof Strait
and tracking either up Cook Inlet or farther east towards Prince
William Sound. These differences will influence whether or not it
will snow for the western Kenai into the Anchorage area.

&&

.AVIATION...
PANC...VFR conditions are expected through the night and then MVFR
ceilings are possible toward morning. Wind shear is also likely to
develop tomorrow thanks to a powerful low in the Gulf of Alaska.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 3...Sunday
Night through Wednesday)...

The trough responsible for the brief period of snow showers across
the Anchorage Bowl and Matanuska Valley this morning is
continuing to lift north and east. Snow showers linger with this
features along Prince William Sound this evening. These snow
showers are beginning to track back to the west as the upper level
flow turns more southerly ahead of the next storm system tracking
quickly east from the north Pacific toward Kodiak Island.

This low is currently pegged at 959 mb and is expected to deepen
further as it moves east of Kodiak Island by Monday morning.
East-southeasterly hurricane-force winds will develop tonight
along the front stretched out over the Gulf, mainly channeling
across the Barren Islands and the coastal waters off the southern
Kenai Peninsula. Storm force winds, with hurricane=force gusts,
will then develop across the coastal water of Southcentral for
Monday morning. This system will also bring a period of moderate
to heavy rain, along with strong easterly winds, to Kodiak City
later this evening through the first half of Monday. Over 2 inches
of rain is expected as sea surface temperatures will support
temperatures in the 40s for coastal Kodiak Island.

As this system deepens east of Kodiak Island, precipitation and
gusty winds will impact Kenai Peninsula and Prince William Sound.
A more southerly track should keep precipitation mainly in the
form of snow, with the exception of coastal locations and areas
where downsloping winds may mix in some warmer air. For Portage
Valley and Turnagain Pass, expect snow and gusty winds to reduce
visibility along the road network from late this evening through
late Monday morning. A Winter Weather Advisory is out for this
event. Gusty gap winds will also develop for Turnagain Arm,
Matanuska Valley, and Thompson Pass late tonight through Monday
due to the increased pressure gradient. Winds, combined with a
period of snow on Monday, will also likely cause some blowing snow
for Thompson Pass Monday.

This system will move to the eastern Gulf Monday night, but gusty
winds will continue in the wake of the low. Conditions are
expected to improve for Tuesday with an upper-level ridge building
in. However, the active weather pattern will continue through the
week with the next system looking to move toward Southcentral for
Wednesday.

&&

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

Generally quiet weather is expected across much of Southwest
today. There are a few snow showers around this morning
especially in the YK-Delta near Bethel, though, these are largely
expected to dissipate by 8-10 am this morning with any activity
remaining over the Kuskokwim Mountains and the western Alaska
Range. Temperatures have also remained up overnight across the
Bethel area, therefore, nudged min temperatures for this morning
up a couple degrees to account for this. Expect temperatures to
remain fairly steady throughout the daylight hours before colder
air begins to filter in later this afternoon and into the evening
hours.

Attention then turns to a strong area of low pressure currently
developing to the south of the Aleutian Chain in the North
Pacific. This low is expected to keep rapidly deepening as it
continues to move off to the north and east reaching the western
Gulf of Alaska by Monday morning. On the north and west side of
the storm track, expect snow to overspread much of Bristol Bay
beginning this evening and continuing through Monday morning.
Areas along the AKPEN such as Egegik to Pilot Point to Port
Heiden will be near the area of warmer air as the low passes by to
the south of the region. This will cause a mix of rain/snow
especially from this evening into the early morning hours Monday
before the flow turns to more northwesterly and colder air filters
in to change any mix or rain to all snow. Farther north and west,
areas such as Dillingham to Egegik but west of King Salmon have
the risk for a deformation band to develop. If this occurs, higher
snowfall amounts can be expected. A Winter Weather Advisory was
issued with this forecast package from 10 PM this evening to 9 AM
Monday morning for snow and blowing snow. North winds of 15-25
mph and gusts 30-35 mph may reduce visibilities to a half mile or
less in blowing snow. Expect the steadiest and heaviest snow
overnight into the early morning hours before tapering off to
snow showers later Monday morning and then ending by afternoon.

&&

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

A rapidly deepening storm system currently southeast of Adak will
continue moving to the north and east reaching the Gulf of Alaska
by Monday morning. Expect periods of rain and strong gusty winds
along the central and eastern Aleutian Chain today through
tonight. As a result of this rapidly deepening storm system, rapid
pressure rises and cold air advection on the back side of the low
will create for very windy conditions across the Pacific side
marine zones this afternoon through Monday afternoon. Storm force
winds are expected to develop across the marine area south of
Dutch Harbor this afternoon and are expected to continue through
early Monday morning. Winds will continue to increase to the east
across the marine waters south of Sand Point to south of Kodiak
Island this evening through Monday evening. Hurricane force wind
warnings are out for the marine zones south of Sand Point and
south of Kodiak Island beginning this evening and continuing
through Monday evening. Wave heights in the Pacific side marine
zones south of the AKPEN and the eastern Aleutian Islands are
expected to be anywhere from 30-40ft with the highest waves the
furthest offshore. Areas on the Bering side will also see gale and
storm force winds with wave heights of 15-22ft Sunday evening
through Monday evening.

Another developing storm system over the North Pacific to the
southwest of the western Aleutians will send a storm force front
through the Bering Sea beginning this evening reaching the
eastern Bering by early Tuesday morning. Periods of rain will
accompany the front as a strong push of warm air northward occurs.
Cold air wraps in the back side that will provide the chance for
snow showers as colder air filters in. Wave heights with the front
will be anywhere from 20-28ft.

&&

.MARINE (Days 3 through 5: Wednesday through Friday)...

Gulf of Alaska:

Good confidence with overall pattern but some uncertainty remains
in the details during the 3-5 day timeframe. A front enters the
Gulf Wednesday with Gales and locally storms southeast of
Cordova. A low forms along this front Wednesday near the Shelikof
Strait and moves either up Cook Inlet or towards Prince William
Sound but low confidence on the track of this low. This front
moves inland Wednesday night. Thursday afternoon a Gale force low
enters Gulf with a chance of a small area of storm force winds
south of the low, however low confidence on track and strength.
The low will weaken and move into eastern Gulf Friday morning.
Friday afternoon a gale force front moves into the southwestern
Gulf with more uncertainty on timing of this front

Bering Sea:

Fair confidence as a weak front with small crafts moves across the
Bering Wednesday and moves into Southwest Alaska by Thursday
morning. Another low enters the western Aleutians late Thursday
with high end Storms mainly across the Pacific side of Aleutians.
This low will move along the Aleutians/south Bering on Friday.
There is a low chance of Hurricane force winds, but lower
confidence with strength and track of this low.

&&

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

Progressive flow will dominate the long term with a series of
fronts and lows moving across the Aleutians and Bering into
Southwest and Southcentral Alaska. These systems may bring chances
of accumulating snow. Fair to Good confidence for Thursday and
Friday but lower confidence Saturday and Sunday as models are all
over the place with timing and track of systems. A weak front
will move across the Bering on Thursday with rain and snow showers
from the Pribilofs into the Aleutians. This front moves into
southwest Alaska Thursday morning as it dissipates with areas of
light rain and snow, but no impacts. Across Southcentral a
weakening front moves inland on Thursday with light accumulating
snowfall. Another low is expected to move across the Gulf late
Thursday into Friday with light rain and snow, but minimal
impacts. A strong low will move across the southern Bering near
the Aleutians late Thursday into Friday with an accompanying front
moving south of the Aleutians. This will produce storm force
winds and possibly even Hurricane force winds mainly on the
Pacific side of the Aleutians. Friday into Saturday southwest
Alaska may receive some accumulating snow on north side of this
low. This low and frontal system will track into the Gulf late
Friday and Saturday with at least Gale force winds along front,
there is a chance of heavier rain and snow from Kodiak Island
towards the Kenai and Prince William Sound. However, a lot of
uncertainty Saturday with the evolution of this system progressing
across the Gulf. Sunday models are all over the place with
placement of lows and fronts, but there is good confidence that
the active pattern will continue
&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 125 161.
MARINE...Gale 125 140 141 171 180-185.
		 Storm 119 120 130 132-139 160-170 172-179.
		 Hurricane Force Wind 131 150 155.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...RC
SOUTHCENTRAL ALASKA...TM
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BB
MARINE/LONG TERM...RC