High Wind Watch 7, NWS Anchorage, AK

483 
WWAK72 PAFC 151212
NPWALU

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
412 AM AKDT Fri Sep 15 2017

AKZ195-160115-
/O.UPG.PAFC.HW.A.0007.170916T0300Z-170916T1500Z/
/O.NEW.PAFC.HW.W.0006.170916T0400Z-170917T1300Z/
Pribilof Islands-
Including the city of Saint Paul
412 AM AKDT Fri Sep 15 2017

...HIGH WIND WARNING IN EFFECT FROM 8 PM THIS EVENING TO 5 AM
AKDT SUNDAY FOR SAINT GEORGE ISLAND...

The National Weather Service in Anchorage has issued a High Wind
Warning, which is in effect from 8 PM this evening to 5 AM AKDT
Sunday. The High Wind Watch is no longer in effect. 

* LOCATION...Saint George Island.

* WIND...Northwest wind 45 to 60 mph, with gusts to 80 mph. 

* TIMING...Winds will begin to increase late this afternoon, 
  peaking in intensity Friday night into early Saturday morning. 
  Winds will slowly diminish below critical values Saturday 
  morning. 

* IMPACTS...High winds may move loose debris and may damage 
  property. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A high wind warning means a hazardous high wind event is expected
or occurring. People are urged to secure loose objects that could
be blown around or damaged by the wind.

&&

$$

AKZ181-160115-
/O.NEW.PAFC.HW.A.0008.170916T1200Z-170917T0600Z/
Alaska Peninsula-
Including the cities of Cold Bay and Sand Point
412 AM AKDT Fri Sep 15 2017

...HIGH WIND WATCH IN EFFECT FROM LATE TONIGHT THROUGH SATURDAY
EVENING...

The National Weather Service in Anchorage has issued a High Wind
Watch, which is in effect from late tonight through Saturday
evening. 

* WIND...West to northwest wind 40 to 55 mph with possible gusts 
  to 75 mph.

* TIMING...Winds will increase late tonight into early Saturday
  morning. The high winds will first show up on the Bering side of
  the peninsula through Saturday morning. In the late morning to
  afternoon hours, the threat shifts to the Pacific side where
  winds will channel through the terrain. Winds will diminish on 
  Saturday evening.

* IMPACTS...High winds may move loose debris and may 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. 

&&

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
520 AM AKDT Thu Sep 14 2017

.ANALYSIS AND UPPER LEVELS...
Water Vapor imagery shows a broad longwave trough encompassing
the Bering waters with an amplified ridge to the east over the
Gulf and eastern Alaska. A long fetch of abundant Pacific moisture
is streaming inland between these two synoptic features however
low level southeasterly flow is downsloping rain on the leeward
side of the mountains around the Cook Inlet region.

&&

.MODEL DISCUSSION...
Models are in good general agreement with the synoptic pattern
through the short term, however there are slight differences on
the quickly developing surface low over the Bering today into
Friday leading to uncertainty on the strength of this system. The
ECMWF and Canadian models were used to make updates for this
system across the Bering and southwest. Only minor adjustment were
made for Southcentral and the Gulf with influences from the
higher resolution NAM models. One important adjustment noted from
the 00Z/06Z model runs is that both the GFS and NAM solutions
trended closer to path of the ECMWF/Canadian through Friday night.

&&

.AVIATION...
PANC...VFR conditions will persist with showers in the vicinity
through the next TAF package. A tight pressure gradient remains in
place, gusty winds are expected to continue through early evening
before diminishing tonight.

&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...

Gusty conditions continue to persist through local gaps across
Southcentral from Turnagain Arm to the Copper River Basin, as the
ridge in the eastern Gulf of Alaska continues to maintain its hold
and the front in the west Gulf drifts eastward. Today the front
will finally be able to push eastward and northward. As the front
pushes northward, precipitation will be enhanced in the upslope
areas of the east Kenai Peninsula throughout the day today.
Although the front will push east, the coastal ridge will remain
enhanced and maintain pressure gradients today. As a result,
downslope flow is expected to remain across the Anchorage Bowl and
west Kenai Peninsula and will result in lower precipitation in
these areas. Unsettled weather will remain along the north gulf
coast into Friday as the front lingers along the mountains and
dissipates. Pressure gradients will also remain intact as the
potent low in the Bering pushes eastward Friday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Areas of rain today will taper off to showers, and give way to a
very short period of dry weather and clearer skies. The upper
level trough responsible for active weather of the past couple
days will finally push out of the area late this evening. However,
a stronger front and low pressure system comes quickly on the
heels of the first. The strong storm system, very fall-like, will
swing a front over the mainland on Friday, bringing rain and
gusty southeasterly winds. The front will exit on Saturday leaving
the area in a moist, showery cyclonic flow.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A strong fall storm system develops in the southcentral Bering
Sea today. On the front side, gale-force winds will push from
Unalaska Island through the Pribilof Islands by late this evening,
spreading rain across the area. The system peaks in intensity late
Friday morning near the Pribilof Islands when the back-bent
occlusion wraps around the system on the southwest quadrant of the
storm. Cold advection in this area will allow the low level jet to
descend to the surface at times bringing gusts near 70 mph to the
surface. Saint George Island looks like a better bet to get the
highest winds at this point as opposed to Saint Paul Island, but
the exact track of the storm will play a role in where the highest
swath of winds goes. The system will track toward Bristol Bay by
the weekend as it weakens.

&&

.LONG TERM FORECAST (Days 3 through 7)...
A highly amplified pattern is expected across Alaska through most
of next week as a strong subtropical jet south of the state
interacts with Arctic shortwave energy to the north. To start, a
strong surface low over the Bering looks to weaken and cross into
the Gulf over the weekend, though there is still a fair amount of
model disagreement regarding this feature. The EC/Canadian models
continue to keep the system more south in the Bering and then
move the center directly into the Gulf. The GFS/NAM keep the low
center a bit further north then split the system after Saturday,
with the main center quasi-stationary near Nunivak Island and a
secondary low forming in the Gulf. This difference looks to
propagate through the midterm forecast as the EC/Canadian eject
the Gulf low out to the east and build an upper level ridge in
behind it, while the GFS keeps an upper level low centered over
the west/central part of the state, which in turn suppresses the
ridge trying to build in over the North Pacific. Due to the
inconsistent GFS runs over the past couple of days the
EC/Canadian model was the preferred solution for the long term
forecast. Looking past midweek, all models are hinting at a
shortwave trough dipping down from the Arctic into the central
Bering which, depending on how it interacts with Northern Pacific
energy, could form another strong Bering low.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 155 160 165 171 172 173 174 175 176 177 180 181 185.
         STORM 170 179.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...KH
SOUTHCENTRAL ALASKA...EN
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MTL
LONG TERM...KVP