High Wind Watch 4, NWS Anchorage, AK

256 
WWAK71 PAFC 102333
NPWAER

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
333 PM AKDT SAT SEP 10 2016

...HIGH WINDS EXPECTED ALONG TURNAGAIN ARM AND HIGHER ELEVATIONS
SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT...

.A STRONG WEATHER SYSTEM WILL PUSH INLAND OVER SOUTHERN ALASKA
SUNDAY...ALLOWING FOR THE DEVELOPMENT OF HIGH WINDS ALONG
TURNAGAIN ARM AND HIGHER ELEVATIONS OF ANCHORAGE. WINDS WILL
INCREASE FROM THE SOUTHEAST WITH GUSTS OF 70 TO 85 MPH. GUSTY
EAST TO SOUTHEAST WINDS WILL ALSO EXTEND DOWN THE HILLSIDE AND
INTO THE ANCHORAGE BOWL AT TIMES SUNDAY INTO SUNDAY NIGHT...BUT
ARE EXPECTED TO REMAIN BELOW WARNING LEVELS. DIFFICULT DRIVING
CONDITIONS ALONG TURNAGAIN ARM AS WELL AS DOWNED TREE BRANCHES
WILL BE THE PRIMARY THREATS FROM THIS EVENT.

AKZ101-111245-
/O.UPG.PAFC.HW.A.0004.160911T2100Z-160912T1300Z/
/O.NEW.PAFC.HW.W.0004.160911T2100Z-160912T1200Z/
ANCHORAGE-
INCLUDING THE CITIES OF...ANCHORAGE...EAGLE RIVER...INDIAN...
EKLUTNA
333 PM AKDT SAT SEP 10 2016

...HIGH WIND WARNING IN EFFECT FROM 1 PM SUNDAY TO 4 AM AKDT
MONDAY ALONG TURNAGAIN ARM AND HIGHER ELEVATIONS...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 1 PM SUNDAY TO 4 AM AKDT
MONDAY. THE HIGH WIND WATCH IS NO LONGER IN EFFECT. 

* LOCATION...TURNAGAIN ARM AND HIGHER ELEVATIONS.

* WIND...SOUTHEAST 50 TO 70 MPH WITH GUSTS 70 TO 85 MPH. THE
  STRONGEST WINDS WILL BE ALONG TURNAGAIN ARM.

* TIMING...SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT.

* IMPACTS...TRAVEL MAY BE DIFFICULT. TREES MAY BE BLOWN OVER. 
  LOOSE DEBRIS CAN BE MOVED AND 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.

&&

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
433 PM AKDT FRI SEP 9 2016

.ANALYSIS AND UPPER LEVELS...
We are in a rather progressive pattern with a fairly strong low
moving into the panhandle of the state and another much stronger
low approaching the central Aleutian Islands this afternoon. The
rest of the area is under high pressure between these two systems
but that high will be short lived as the low near the Aleutians
moves into Southwest mainland Alaska Saturday night and then into
Southcentral Alaska Sunday.

There is a strong jet stream around the northern periphery of the
upper level ridge which will strengthen as the storm in the
Aleutians moves northeastward.

The subsidence associated with the ridge caused widespread fog
over southwest Alaska this morning and areas of locally dense fog
in the Cook Inlet area as well. The clearing skies over
southcentral Alaska will cause temperatures to rapidly drop after
sundown except for areas that will keep the northerly winds such
as gaps and near Cook Inlet. A big question overnight tonight is
whether some of the agriculture and gardening areas in the Matsu
valleys and Anchorage bowl will get down to freezing and cause
crop damage.

&&

.MODEL DISCUSSION...
Models have come into very good agreement with the development of
a secondary low along the north Gulf Coast tonight and then the
movement of the strong low approaching the Aleutians. The biggest
impact from the convergence of model solutions comes Sunday and
Sunday night with the location of the jet stream coming over the
North Gulf Coast. Confidence is growing that the heaviest rain
from this storm will occur from Seward eastward to Cordova Sunday
night.

&&

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

A rather stout storm force low moving into the southeast Alaska Panhandle
this evening is continuing to support a rather robust outflow wind
event this evening. Winds along the coast and inland will peak
this evening before slowly diminishing through the day Saturday.
However, some inland locations around the Matanuska Valley and
into east Anchorage will remained sheltered from the wind, so
temperatures will drop much lower with the possibility of more
patchy fog by morning. Local areas of frost will also be possible
in sheltered valley areas.

High pressure building in aloft will allow for the development of
bluebird and clear skies across Southcentral Saturday before a
stout North Pacific warm front moves into the Gulf of Alaska
Saturday night and Sunday. Rain will overspread all of Kodiak
Island and Southcentral by Sunday afternoon along with the
strongest southeast gap winds of the early fall season. Winds are
expected to accelerate into the 60+ MPH range across Turnagain Arm
and into the higher elevations of the Anchorage Hillside. by
Sunday evening. Stay tuned to later forecasts as details are
hammered out.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2...Sat and Sun)...
A weak, progressive shortwave ridge will continue to move through
the area until mid-day Sat. Dry air and northwest flow should
keep skies mostly clear tonight. This will allow temperatures to
drop quickly after sunset and lead to another morning of patchy
fog across many areas. The most likely place for fog will be in
the Yukon- Kuskokwim Valley where it could become nearly as dense
as it was this morning.

The Bering low will dominate the weather the rest of the weekend. Rain
will start to spread into the Alaska Peninsula Sat afternoon. It
will then quickly track to inland Bristol Bay by daybreak Sun. The
heaviest rain will be from late Sun morning until late Sun night.
Gusty southeast to south winds will accompany the front. Winds
will be strongest through the southeast to northwest gaps of the
Aleutian and Alaska Ranges.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2...Sat and
Sun)...
The storm-force low just south of the Central Aleutians will
weaken slowly as it tracks eastward. Broad counter-clockwise flow
around the low will control the weather throughout the area. East
of the low, gusty south to east winds will drive rain into the
islands. The strongest core of winds will be just west of the low
center where a little cold air serves to tighten the gradient and
mix the atmosphere. Drier air will be pulled in further west of
the low and keep conditions considerably quieter for the Western
Bering and Western Aleutians. A deformation axis will set- up over
the Pribilof Islands as we head into Sun. This will keep wet
conditions firmly in place. A weaker mid-990mb system rolls off
the Kamchatka Peninsula towards the Western Aleutians on Mon.

&&

.LONG TERM FORECAST (Days 3 through 7)...
The models are in good agreement as the North Pacific Low tracks
near the Shumagin Islands, and a secondary low develops in the
eastern Bering by Sunday morning. The pressure gradients will
increase ahead of this system producing strong gusty gap winds
through the Barren Island, and the Turnagain Arm region. The
models are depicting the strongest Turnagain Arm winds peaking
during Sunday evening before tapering off by Monday morning. This
pattern brings abundant moisture to the Southcentral Alaska region
through this weekend before gradually diminishing as the system
exits the AOR going into Tuesday. Meanwhile, the Bering will have
a showery weather regime with northeasterly flow as the
aforementioned system tracks eastward towards the Eastern
Aleutians. This synoptic feature becomes elongated, and stretches
northward through the eastern Bering Sea before moving inland near
the Kuskokwim Delta by Monday afternoon. While, upstream the next
system moves into the Western Aleutians from the Kamchatka
Peninsula, and tracks eastward along the Aleutian Chain. This
brings gusty easterly to northeasterly winds with a swath of
rain/stratus through the Bering from Monday through Thursday. This
feature tracks almost the same storm path as previous storm.
Therefore, look for another round of southwesterly flow streaming
abundant moisture, and precipitation into the Southcentral Alaska
region by Thursday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gales 130 131 155 160 165 170 172 173 174 178 351 352 413
               414.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...JA
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...PD