High Wind Watch 16, NWS Anchorage, AK

702 
WWAK71 PAFC 130055
NPWAER

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
355 PM AKST Sun Nov 12 2017

AKZ131-131400-
/O.EXT.PAFC.HW.A.0016.171113T1500Z-171114T0600Z/
Northeast Prince William Sound-
Including the cities of Valdez and Thompson Pass
355 PM AKST Sun Nov 12 2017

...HIGH WIND WATCH NOW IN EFFECT FROM MONDAY MORNING THROUGH 
LATE MONDAY EVENING...

* LOCATION...City of Valdez and Thompson Pass.

* WIND...Northeast winds 40 to 60 with possible gusts to 80 mph. 
  Thompson Pass will see higher sustained winds, but gusts in 
  both the Pass and City of Valdez may reach 80 mph. 

* TIMING...Strong winds will develop rapidly through this evening
  and then may reach warning levels Monday morning. These warning
  level winds may persist until late Monday evening and then 
  slowly diminish. 

* IMPACTS...Travel may be difficult. Trees may be blown over. 
  Loose debris can be moved and damage property. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A high wind watch means there is the potential for a hazardous
high wind event. People are encouraged to closely monitor this
weather situation. Preparation for this potentially dangerous
weather event should begin now.

&&

$$

376 
WWAK71 PAFC 130547
NPWAER

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
847 PM AKST Sun Nov 12 2017

AKZ131-130700-
/O.CAN.PAFC.HW.A.0016.171113T1500Z-171114T0600Z/
Northeast Prince William Sound-
Including the cities of Valdez and Thompson Pass
847 PM AKST Sun Nov 12 2017

...HIGH WIND WATCH IS CANCELLED...

The National Weather Service in Anchorage has cancelled the High
Wind Watch. 

Winds are still expected to strengthen from Valdez through
Thompson Pass overnight tonight then persists through Tuesday. 
However, winds will remain below warning criteria, with gusts
peaking at around 60 to 70 mph.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
422 PM AKST Sat Nov 11 2017

.ANALYSIS AND UPPER LEVELS...
The amplified upper level pattern remains in place over Alaska
today. A large surface and upper level high is over the eastern
Aleutians into the western interior while a upper trough from the
eastern interior into the Gulf of Alaska supports a surface low
over the southeastern Gulf/northeast Pacific. An upper trough
extends from off the Kamchatka Peninsula into the North Pacific
with a large surface low well south of the Western Aleutians. A
front runs from this low to a low over Siberia.

The strong southerly flow west of the ridge is pumping warm moist
air into the Aleutians and Bering Sea. This air has +8 degrees C
850 mb temperatures in it and is expected to work over the top of
the ridge eventually into southwest Alaska. Subsidence is
prevalent under the ridge over southwest Alaska now. This is
supporting the very foggy conditions over the Kuskokwim Delta.
Strong northerly flow aloft across the southern Mainland is
supporting the strong outflow winds through many of the mountain
gaps of the coastal mountains.

&&

.MODEL DISCUSSION...
The models are in excellent agreement through the short-term in
this persistent pattern. The primary challenge is resolving the
gap flow winds. The models are in good agreement on the gap flow
winds and the development of a low along the North Gulf Coast
Sunday night. The overall pattern is well handled, and confidence
is high. More challenging is the fog forecast for the Kuskokwim
Delta. The models are not in lock step with the next upper trough
moving across the top of the ridge, and this will be an important
factor for determining how much fog persists. At this point we are
leaning toward the GFS solution.

&&

.AVIATION...
PANC...VFR conditions will persist. Gusty north winds will diminish
this evening.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The outflow pattern continues through early next week. A ridge
aloft moves over the area tonight which will help to temporarily
relax winds around the area. The break will be very short-lived as
a shortwave trough and upper level jet push over the area from the
northwest. Some light snow will be possible over the eastern
Copper River Basin beginning Sunday afternoon, lingering through
Monday. However, the main impact with this system will be outflow
winds. The disturbance will advect a cold air mass from the
interior over Southcentral Alaska and into the Gulf. The strong
advection over the mountains will create potential for a window
of warning level winds in the Valdez area Sunday evening. Winds
there, and all along the gulf coast, will remain very gusty
through at least Tuesday, and possibly beyond. Otherwise expect
clear and dry conditions through the period with seasonable
temperatures and light northerly winds.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
High pressure will remain over the eastern Bering through Monday
which will keep fog as a problem along the coast and for the
Kuskokwim Delta through Sunday. As flow becomes more northerly
and drier on Monday, fog should diminish. A weak wave will also
move through southwest Alaska tonight bringing light snow to
higher elevation areas into Sunday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Ridging will remain over the eastern Bering through Monday keeping
most of the precipitation over the Western and Central Aleutians
with southerly flow moving up the west side of the ridge. Several
different shortwaves will move through the southerly flow with
enough warm air that precipitation will be rain. Sunday afternoon
some of the rain will make it over the Pribilof Islands and linger
through early Monday.

&&

.LONG TERM FORECAST (Days 3 through 7)...
Little overall change is expected in the forecast early next week
as widespread offshore flow continues to bring outflow winds to
much of the Gulf Coast with clear and cold conditions to the South
Mainland. There is however good agreement that this pattern will
begin to break down Tue-Wed, with a North Pacific low strong
enough to begin weakening the persistent ridging over the Bering.
This low will push through the Bering through Wednesday, which
should help both scour out the widespread fog over the
Bering/Southwest Mainland as well as begin to diminish the outflow
winds along the North Gulf Coast. This pattern shift should also
allow for a series of deeper lows to move through the Bering and
into the Gulf beginning late next week into next weekend, leading
to a much more active and progressive weather pattern than the
last week. There is however a large spread in the model guidance
in both the track and intensity of these lows, largely because of
differences in how much cold air will be available over the
mainland, so the details in the long term forecast are very broad
brushed for now.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Watch 131.
MARINE...Gale Warning 120 127 130 131 132 150 175 176 177.

&&

SYNOPSIS AND MODEL DISCUSSION...SA
SOUTHCENTRAL ALASKA...MTL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DK
LONG TERM...DEK