Wind Chill Advisory 18, NWS Anchorage, AK

221 
WWAK41 PAFC 290133
WSWAER

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
433 PM AKST WED NOV 28 2012

AKZ131-291445-
/X.CON.PAFC.WC.Y.0018.121129T0900Z-121201T0000Z/
NORTHEAST PRINCE WILLIAM SOUND-
INCLUDING THE CITIES OF...VALDEZ...THOMPSON PASS
433 PM AKST WED NOV 28 2012

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO
3 PM AKST FRIDAY THROUGH THOMPSON PASS...

* LOCATION...THOMPSON PASS.

* WIND...NORTH WINDS 40 TO 55 MPH.

* WIND CHILL VALUES...35 TO 45 BELOW ZERO.

* TIMING...STARTING MIDNIGHT TONIGHT THROUGH EARLY FRIDAY
  AFTERNOON. WINDS CHILLS WILL MODERATE SOME DURING THE DAY
  THURSDAY.

* IMPACTS...INCREASED RISK OF HYPOTHERMIA AND FROSTBITE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND CHILL ADVISORY MEANS THAT VERY COLD AIR AND STRONG WINDS
WILL COMBINE TO GENERATE LOW WIND CHILLS. THIS WILL RESULT IN
FROSTBITE AND LEAD TO HYPOTHERMIA IF PRECAUTIONS ARE NOT TAKEN.

&&

$$

AKZ145-291445-
/X.CON.PAFC.WC.Y.0018.121129T0900Z-121201T0000Z/
SUSITNA VALLEY-
INCLUDING THE CITIES OF...TALKEETNA...WILLOW...CANTWELL
433 PM AKST WED NOV 28 2012

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO
3 PM AKST FRIDAY NORTH OF TALKEETNA...

* LOCATION...NORTH OF TALKEETNA.

* WIND...NORTH WIND 30 TO 45 MPH.

* WIND CHILL VALUES...35 TO 45 BELOW ZERO.

* TIMING...STARTING AROUND MIDNIGHT TONIGHT AND CONTINUING INTO 
  FRIDAY AFTERNOON. 

* IMPACTS...INCREASED RISK OF HYPOTHERMIA AND FROSTBITE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND CHILL ADVISORY MEANS THAT VERY COLD AIR AND STRONG WINDS
WILL COMBINE TO GENERATE LOW WIND CHILLS. THIS WILL RESULT IN
FROSTBITE AND LEAD TO HYPOTHERMIA IF PRECAUTIONS ARE NOT TAKEN.

&&

$$

AHSENMACHER

906 
WWAK41 PAFC 291330
WSWAER

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
430 AM AKST THU NOV 29 2012

AKZ131-300130-
/X.CAN.PAFC.WC.Y.0018.000000T0000Z-121201T0000Z/
/X.NEW.PAFC.WC.Y.0019.121130T0700Z-121202T0000Z/
NORTHEAST PRINCE WILLIAM SOUND-
INCLUDING THE CITIES OF...VALDEZ...THOMPSON PASS
430 AM AKST THU NOV 29 2012

...WIND CHILL ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO 3 PM
AKST SATURDAY THROUGH THOMPSON PASS...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A WIND CHILL
ADVISORY...WHICH IS IN EFFECT FROM 10 PM THIS EVENING TO 3 PM
AKST SATURDAY. 

* LOCATION...THOMPSON PASS.

* WIND...NORTH WINDS 40 TO 65 MPH.

* WIND CHILL VALUES...30 TO 45 BELOW ZERO.

* TIMING...STARTING 10 PM AKST TONIGHT THROUGH EARLY SATURDAY 
  AFTERNOON. WINDS CHILLS WILL MODERATE SOME DURING THE DAY 
  FRIDAY. 

* IMPACTS...INCREASED RISK OF HYPOTHERMIA AND FROSTBITE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND CHILL ADVISORY MEANS THAT VERY COLD AIR AND STRONG WINDS
WILL COMBINE TO GENERATE LOW WIND CHILLS. THIS WILL RESULT IN
FROSTBITE AND LEAD TO HYPOTHERMIA IF PRECAUTIONS ARE NOT TAKEN.

&&

$$

AKZ145-300130-
/X.CAN.PAFC.WC.Y.0018.000000T0000Z-121201T0000Z/
/X.NEW.PAFC.WC.Y.0019.121130T0700Z-121202T0000Z/
SUSITNA VALLEY-
INCLUDING THE CITIES OF...TALKEETNA...WILLOW...CANTWELL
430 AM AKST THU NOV 29 2012

...WIND CHILL ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO 3 PM
AKST SATURDAY NORTH OF TALKEETNA...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A WIND CHILL
ADVISORY...WHICH IS IN EFFECT FROM 10 PM THIS EVENING TO 3 PM
AKST SATURDAY. 

* LOCATION...NORTH OF TALKEETNA.

* WIND...NORTH WIND 30 TO 45 MPH.

* WIND CHILL VALUES...30 TO 45 BELOW ZERO.

* TIMING...STARTING AROUND 10 PM AKST TONIGHT AND CONTINUING INTO
  EARLY SATURDAY AFTERNOON.

* IMPACTS...INCREASED RISK OF HYPOTHERMIA AND FROSTBITE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND CHILL ADVISORY MEANS THAT VERY COLD AIR AND STRONG WINDS
WILL COMBINE TO GENERATE LOW WIND CHILLS. THIS WILL RESULT IN
FROSTBITE AND LEAD TO HYPOTHERMIA IF PRECAUTIONS ARE NOT TAKEN.

&&

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKST WED NOV 28 2012

.ANALYSIS AND UPPER LEVELS...
HIGH LATITUDE BLOCKING AND TWO VERY BROAD AREAS OF CLOSED LOW
PRESSURE ALOFT ARE CONTROLLING THE WEATHER OVER ALASKA. THE FIRST IN
THE SOUTHERN GULF/NORTHEASTERN PACIFIC IS COMPRISED OF THREE
SHORTWAVE TROUGHS AS WELL AS THREE OR FOUR SURFACE CIRCULATIONS. THE
SECOND IS A BROAD LONGWAVE OVER THE CANADIAN ARCTIC WHICH COMBINED
WITH SURFACE HIGH PRESSURE AND PERIODIC SHORTWAVES ARE KEEPING THE
COLD NORTHERLY FLOW IN PLACE. HIGH PRESSURE ALOFT STRETCHING FROM
GREENLAND OVER THE POLE INTO THE BERING SEA IS KEEPING THE OVERALL
SYNOPTIC PATTERN VERY STAGNANT. AN UPPER LOW PRESSURE CENTER WEST OF
KAMCHATKA CONTINUES TO SEND FRONTS TOWARD THE WESTERN ALEUTIANS.

.MODEL DISCUSSION...
GUIDANCE CONTINUES TO REMAIN IN EXCELLENT AGREEMENT THE UPPER LEVEL
PATTERN THROUGH THE SHORT TERM FORECAST. CONSENSUS HAS BEEN REACHED
BETWEEN MODELS ON SPEED AND PLACEMENT OF A STRONG SHORTWAVE DROPPING
OVER THE WEST COAST OF ALASKA AS THE BERING SEA RIDGE STRENGTHENS
TODAY. THE SAME GOES FOR A SERIES OF DEAMPLIFYING TROUGHS ROTATING
DOWN THE BACKSIDE OF THE CANADIAN TROUGH FROM THE NORTH SLOPE DOWN
THROUGH THE SOUTHCENTRAL MAINLAND.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...AS GUIDANCE HAS COME INTO AGREEMENT CONFIDENCE
HAS ALSO INCREASED ON A WIND EVENT TAKING SHAPE FOR THE USUAL GAP
FLOW LOCATIONS. SEVERAL TROUGHS DROPPING SOUTHWARD HAVE TIGHTENED THE
PRESSURE GRADIENT FROM THE ALASKA RANGE DOWN THROUGH THE TALKEETNAS
AND CHUGACH RANGES AS WELL AS BEGUN TO REINFORCE COLD AIR OVER THE
CENTRAL INTERIOR AND COPPER RIVER BASIN...BOTH OF WHICH WILL COMBINE
TO REALLY RAMP UP THE WINDS IN THE COMING DAYS. THE ONLY CAVEAT TO
THIS IS THE STRENGTH OF THE INVERSION CURRENTLY OVERHEAD. GUIDANCE IS
SIGNALING COLD ADVECTION TO BEGIN TO ERODE THE INVERSION FROM THE TOP
BUT IT IS UNCLEAR IF THE STRONGEST WINDS WILL MAKE IT ALL THE WAY TO
THE SURFACE...AT LEAST WITH THE INITIAL WAVE PASSAGE LATER THIS
AFTERNOON. AT THE VERY LEAST IT WILL PRIME THE ENVIRONMENT FOR A MORE
SIGNIFICANT WAVE LATER THIS WEEK. WINDS FOR THOMPSON PASS/VALDEZ WILL
BE GUSTING UPWARDS OF 60 MPH. HOWEVER...THE UPPER LEVEL SUPPORT LOOKS
A LITTLE BETTER FOR THE MATANUSKA VALLEY THAN THE VALDEZ AREA SO A
HIGH WIND WATCH HAS BEEN ISSUED. THE OTHER FORECAST CONCERN WITH THE
INCREASING WINDS IS THE CHANCE FOR DANGEROUSLY LOW WIND CHILLS WITH
THE COLD AIR ALREADY IN PLACE FOR THOMPSON PASS AS WELL AS THE
NORTHERN SUSITNA VALLEY.

SOUTHWEST ALASKA...CLEAR COLD AND DRY CONDITIONS WILL PREVAIL THROUGH
THE SHORT TERM FORECAST. GUSTY NORTHERLY OFFSHORE WINDS WILL AGAIN
DEVELOP AND CONTINUE THROUGH THE REST OF THE WEEK.

BERING SEA AND ALEUTIANS...NORTHERLY WINDS WILL CONTINUE FOR THE
EASTERN BERING THROUGH THE SHORT TERM. HIGH PRESSURE SETTLING IN OVER
THE CENTRAL BERING WILL PREVENT A FRONTAL BOUNDARY OVER THE WESTERN
ALEUTIANS FROM MAKING MUCH EASTWARD PROGRESS. STRONG SOUTHEASTERLY
WINDS WILL CONTINUE FOR THE WEST TODAY UNTIL THE FRONT DISSIPATES AND
LATER ON THIS EVENING.

.LONG TERM FORECAST...
PERSISTENCE WILL CONTINUE FOR THE EXTENDED FORECAST AS TROUGHING AND
NORTHERLY FLOW REMAIN OVER THE MAINLAND AND SOME SEMBLANCE OF RIDGING
OVER THE BERING SEA. GUIDANCE IS IN AGREEMENT WITH SHOWING A
BREAKDOWN OF THE BERING RIDGE TOWARD THE END OF THE SHORT TERM...BUT
A REX BLOCK TYPE PATTERN WILL STAY IN PLACE FOR THE TIME BEING.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WATCH 111
MARINE...HEAVY FREEZING SPRAY...121 126 127 129 140 141
         GALE...127 128 130 132 140 155 160 175 176 180
FIRE WEATHER...NONE

MTL NOV 12