High Wind Watch 6, NWS Anchorage, AK

158 
WWAK72 PAFC 112346
NPWALU

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
346 PM AKDT SUN MAR 11 2012

...STRONG STORM TO IMPACT THE WESTERN ALEUTIANS AND BERING SEA...

A PACIFIC SYSTEM WILL APPROACH THE WESTERN ALEUTIAN CHAIN ON
MONDAY AND BRING STRONG WINDS TO THE AREA. GUSTY SOUTHEAST WINDS
TONIGHT WILL SHIFT TO THE WEST MONDAY MORNING AND INCREASE
CONSIDERABLY. WINDS THEN LOOK TO DIMINISH BY MONDAY EVENING AS THE
PACIFIC SYSTEM WEAKENS AND MOVES AWAY FROM THE AREA.

AKZ191-121415-
/X.UPG.PAFC.HW.A.0006.120312T1700Z-120313T0400Z/
/X.NEW.PAFC.HW.W.0010.120312T1700Z-120313T0400Z/
WESTERN ALEUTIANS-
INCLUDING THE CITY OF...SHEMYA AND AMCHITKA
346 PM AKDT SUN MAR 11 2012

...HIGH WIND WARNING IN EFFECT FROM 9 AM TO 8 PM AKDT MONDAY...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 9 AM TO 8 PM AKDT MONDAY. THE
HIGH WIND WATCH IS NO LONGER IN EFFECT. 

* LOCATION...THE WESTERN ALEUTIANS INCLUDING SHEMYA.

* WIND...WEST WIND 60 TO 70 MPH WITH GUSTS TO 80 MPH.

* TIMING...THE STRONGEST WINDS ARE EXPECTED TO DEVELOP MONDAY 
  MORNING AND PERSIST THROUGH MONDAY EVENING. 

* IMPACTS...HIGH WINDS MAY MOVE LOOSE DEBRIS. WIND DRIVEN 
  PROJECTILES 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.

&&

$$

JAM

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT SUN MAR 11 2012

.MODEL DISCUSSION...

MODELS IN VERY GOOD AGREEMENT. NAM PREFERRED IN THE EASTERN DOMAIN FOR
ITS BETTER RESOLUTION. GFS PREFERRED OUT WEST FOR ITS BETTER GRASP OF
EASTERN HEMISPHERE LOWS...SUCH AS THE 976 MB LOW PRESENTLY HEADED
TOWARDS SHEMYA.

.UPPER LEVELS...

A BROAD LONG WAVE TROUGH EXTENDS ACROSS THE ALASKAN MAINLAND...GULF OF
ALASKA...AND INTO THE NORTHEASTERN PACIFIC. THE MAIN TROUGH LINE
GRADUALLY TRANSLATES EASTWARD...BUT A NEW CUT OFF LOW IS EXPECTED TO
DEVELOP OVER SOUTHWEST MAINLAND ALASKA TUESDAY AFTERNOON AND BECOME
THE DOMINANT FEATURE ALOFT.

MEANWHILE OUT WEST...A RIDGE OF HIGH PRESSURE BRIEFLY BUILDS OVER THE
CENTRAL BERING SEA THIS EVENING IN ADVANCE OF A DEVELOPING LOW TO THE
WEST. CUT OFF UPPER CENTER DEVELOPS JUST SOUTH OF THE KAMCHATKA
PENINSULA TODAY...STRENGTHENS OVER THE WESTERN ALEUTIANS TONIGHT THEN
WEAKENS OVER THE CENTRAL BERING MONDAY NIGHT.

.SURFACE ANALYSIS AND SHORT TERM FORECAST...

COMPLEX LOW PRESSURE WILL PERSIST IN GULF OF ALASKA. THE PRESSURE
GRADIENT ALONG THE GULF COAST WILL RELAX TODAY AS AN EMBEDDED 983 MB
LOW PRESENTLY NEAR MIDDLETON ISLAND DRIFTS SOUTHWARD AND DISSIPATES BY
LATE TONIGHT. STRONG WINDS THROUGH THE COPPER RIVER DELTA...PRINCE
WILLIAM SOUND...AND BARREN ISLANDS AND KAMISHAK BAY ARE PRESENTLY
PEAKING IN THE 40 TO 60 MPH RANGE BUT ARE EXPECTED TO DIMINISH BY
AFTERNOON. HOWEVER...THE GRADIENT IS EXPECTED TO RETIGHTEN ON MONDAY
WHEN A WELL DEFINED TROUGH LINE IS EXPECTED TO DEVELOP ALONG THE
NORTHERN AND EASTERN GULF COASTS. AT WHICH TIME...GUSTY NORTH WINDS
ARE EXPECTED TO REDEVELOP THOUGH NOT QUITE AS STRONG.

COLD AIR ADVECTION SNOW SHOWERS CAN BE DETECTED ON SATELLITE ACROSS
THE LENGTH OF THE NORTHERN GULF COAST...KODIAK ISLAND WATERS...EASTERN
ALEUTIANS...AND EASTERN BERING SEA. THE GREATEST CONCENTRATION OF
SHOWERS CAN BE FOUND JUST TO THE SOUTH OF THE BERING SEA ICED EDGE AND
TO THE NORTH OF ALASKA PENINSULA. CONDITIONS ARE EXPECTED TO PERSIST
FOR ANOTHER 24 TO 36 HOURS. MORE INLAND AREAS OF SOUTHCENTRAL AND
SOUTHWESTERN ALASKA WILL REMAIN UNDER COLD DRY OFF CONTINENT FLOW
THROUGH MONDAY. WIND CHILLS TO 45 BELOW ZERO POSSIBLE THIS MORNING
ACROSS THE YUKON KUSKOKWIM DELTA.

FAR OUT WEST...A 976 MB IN THE NORTHWEST PACIFIC WILL RAPIDLY
STRENGTHEN TO 963 MB WEST OF SHEMYA LATE TONIGHT THEN WEAKEN TO IN THE
SOUTH CENTRAL BERING SEA MONDAY NIGHT. THE ASSOCIATED WARM FRONT WILL
BE RAPIDLY OCCLUDING AS IT MOVES INTO THE WESTERN ALEUTIANS LATE
TONIGHT. THE FRONT PRESSES EASTWARD ON MONDAY...TRAVERSING THE
ALEUTIANS AND SOUTHERN BERING...THEN BECOMES NEARLY STATIONARY ACROSS
THE ALASKA PENINSULA AND SOUTHERN BERING MONDAY NIGHT.

A NARROW BAND OF STORM FORCE WINDS PRECEDES THE ADVANCING OCCLUDED
FRONT. THE COMBO OF STRONG EAST WINDS AND FRESH NEW SNOW MAY YIELD
ANOTHER YET ANOTHER BLIZZARD FOR THE PRIBILOFS ON MONDAY. FURTHER
SOUTH ALONG THE CHAIN...RAIN IS EXPECTED TO MIX WITH THE SNOW AND
FREEZING SPRAY TO CREATE AN ICY WINTRY MIX.

OF GREATER CONCERN IS THE IMPACT OF THE RAPIDLY DEEPENING LOW ITSELF.
WEST WINDS ALONG THE SOUTHERN FLANK OF THE LOW ARE EXPECTED TO REACH
HURRICANE FORCE ON MONDAY AND MONDAY NIGHT. THE WESTERN ALEUTIANS
SHOULD RECEIVE THE FULL BRUNT OF THIS STORM WINDWISE.

.LONG TERM FORECAST...

REMAINS OF BERING LOW MOVE INTO WESTERN GULF ON TUESDAY AND
RESTRENGTHEN WITH THE AID OF THE DEVELOPING LOW ALOFT. LITTLE WIND
EXPECTED WITH THIS SYSTEM BUT UPPER LEVEL DYNAMICS COULD TRIGGER SNOW
OR SNOW SHOWERS AS FAR INLAND AS THE SOUTHERN SUSITNA VALLEY.

A TROUGH OF LOW PRESSURE WILL PERSIST ALONG THE ALEUTIANS EVEN AS WEAK
HIGH PRESSURE ATTEMPTS TO BUILD OVER THE BERING SEA. SHOWERY
CONDITIONS ARE EXPECTED TO LINGER ACROSS THE CHAIN THROUGH THE WEEK
BUT LITTLE IN THE WAY OF WIND IS EXPECTED.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 195
MARINE...GALE 121 129 130 132 138 150 155 170 179 185 352 414
         STORM 172 176 411 412 413
         HURRICANE FORCE 175
         HEAVY SPRAY...121 129 130 132 138 140 141 150 155 165 170 179
FIRE WEATHER...NONE

ASB MAR 12