Blizzard Watch 31, NWS Anchorage, AK

365 
WWAK42 PAFC 221254
WSWALU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
454 AM AKDT THU MAR 22 2012

...A STRONG LOW PRESSURE SYSTEM WILL MOVE INTO THE WESTERN BERING
SEA TODAY. MUCH WARMER AIR ALOFT WILL ACCOMPANY AN ASSOCIATED
FRONT TOWARD THE PRIBILOF ISLANDS AND SOUTHWEST ALASKA TODAY AND
TONIGHT...

AKZ161-230400-
/X.NEW.PAFC.BZ.W.0046.120323T0800Z-120323T1800Z/
BRISTOL BAY-
INCLUDING THE CITIES OF...KING SALMON...DILLINGHAM...NAKNEK...
PILOT POINT
454 AM AKDT THU MAR 22 2012

...BLIZZARD WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 10 AM AKDT
FRIDAY ALONG THE WESTERN CAPES...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A BLIZZARD
WARNING...WHICH IS IN EFFECT FROM MIDNIGHT TONIGHT TO 10 AM AKDT
FRIDAY. 

* LOCATION...ALONG THE WESTERN CAPES.

* SNOW...STORM TOTAL ACCUMULATION 3 TO 6 INCHES.

* VISIBILITY...ONE QUARTER MILE OR LESS AT TIMES.

* WIND...SOUTHEAST 25 TO 40 MPH WITH GUSTS TO 55 MPH.

* TIMING...CONDITIONS WILL RAPIDLY DETERIORATE AFTER MIDNIGHT
  WITH THE WORST CONDITIONS EXPECTED AROUND SUNRISE.

* IMPACTS...SNOWFALL COMBINED WITH STRONG WINDS AND BLOWING SNOW WILL PRODUCE
WHITE-OUT CONDITIONS. DRIVING WILL BE VERY DIFFICULT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. FALLING AND BLOWING SNOW WITH STRONG WINDS
AND POOR VISIBILITIES ARE LIKELY. THIS WILL LEAD TO WHITE-OUT
CONDITIONS...MAKING TRAVEL VERY DIFFICULT. ALL TRAVEL AND OUTDOOR
ACTIVITY IS STRONGLY DISCOURAGED.

&&

$$

AKZ155-230400-
/X.UPG.PAFC.BZ.A.0031.120323T0200Z-120323T2000Z/
/X.EXB.PAFC.BZ.W.0045.120323T0300Z-120323T1800Z/
KUSKOKWIM DELTA-
INCLUDING THE CITIES OF...BETHEL...HOOPER BAY...NUNIVAK ISLAND
454 AM AKDT THU MAR 22 2012

...BLIZZARD WARNING IN EFFECT FROM 7 PM THIS EVENING TO 10 AM
AKDT FRIDAY ALONG THE COAST...

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A BLIZZARD
WARNING...WHICH IS IN EFFECT FROM 7 PM THIS EVENING TO 10 AM AKDT
FRIDAY. THE BLIZZARD WATCH IS NO LONGER IN EFFECT. 

* LOCATION...ALONG THE KUSKOKWIM DELTA COAST.

* SNOW...STORM TOTAL ACCUMULATION 2 TO 6 INCHES.

* VISIBILITY...ONE QUARTER MILE OR LESS AT TIMES.

* WIND...SOUTHEAST WIND 25 TO 40 MPH WITH GUSTS TO 55 MPH.

* TIMING...WINDS WILL INCREASE THURSDAY AFTERNOON WITH SNOW
  DEVELOPING THIS EVENING. THE WORST CONDITIONS ARE EXPECTED
  BETWEEN MIDNIGHT AND 3AM.

* IMPACTS...SNOWFALL COMBINED WITH STRONG WINDS AND BLOWING SNOW WILL PRODUCE
WHITE-OUT CONDITIONS. DRIVING WILL BE VERY DIFFICULT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. FALLING AND BLOWING SNOW WITH STRONG WINDS
AND POOR VISIBILITIES ARE LIKELY. THIS WILL LEAD TO WHITE-OUT
CONDITIONS...MAKING TRAVEL VERY DIFFICULT. ALL TRAVEL AND OUTDOOR
ACTIVITY IS STRONGLY DISCOURAGED.

&&

$$

AKZ195-230400-
/X.CON.PAFC.BZ.W.0045.120322T1800Z-120323T0400Z/
PRIBILOF ISLANDS-
INCLUDING THE CITY OF...SAINT PAUL
454 AM AKDT THU MAR 22 2012

...BLIZZARD WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
8 PM AKDT THIS EVENING...

* SNOW...STORM TOTAL ACCUMULATION 2 TO 5 INCHES.

* FREEZING RAIN...POSSIBLE FREEZING RAIN OR SLEET THURSDAY
  AFTERNOON AND EVENING.

* VISIBILITY...LESS THAN ONE QUARTER MILE AT TIMES.

* WIND...SOUTHEAST WIND 40 TO 55 MPH.

* TIMING...SNOW AND WINDS WILL INCREASE LATE THURSDAY MORNING AND
  CONTINUE INTO EARLY THURSDAY EVENING. SNOW AND BLOWING SNOW WILL
  POSSIBLY GIVE WAY TO SLEET AND FREEZING RAIN DURING THE
  AFTERNOON AND EVENING...BRINGING AN END TO THE BLIZZARD
  CONDITIONS.

* IMPACTS...SNOWFALL COMBINED WITH STRONG WINDS AND BLOWING SNOW 
  WILL PRODUCE WHITE-OUT CONDITIONS. TRAVEL WILL BE VERY 
  DIFFICULT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. FALLING AND BLOWING SNOW WITH STRONG WINDS
AND POOR VISIBILITIES ARE LIKELY. THIS WILL LEAD TO WHITE-OUT
CONDITIONS...MAKING TRAVEL VERY DIFFICULT. ALL TRAVEL AND OUTDOOR
ACTIVITY IS STRONGLY DISCOURAGED.

&&

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
110 PM AKDT WED MAR 21 2012

.ANALYSIS AND UPPER LEVELS...
A VERY LARGE AND DIFFUSE UPPER LOW REMAINS OVER MAINLAND ALASKA AND
WESTERN CANADA WHILE A HIGH AMPLITUDE RIDGE IS POSITIONED OVER THE
CENTRAL BERING SEA. ANOTHER BROAD TROUGH IS LOCATED JUST WEST OF THE
KAMCHATKA PENINSULA WITH A STRONG JET FLOWING AROUND THE BASE SENDING
A LARGE PLUME OF MOISTURE TOWARD THE WESTERN ALEUTIANS. AN OLD
FRONTAL BOUNDARY IS EVIDENT ON SATELLITE IMAGERY DISSIPATING NEAR THE
EASTERN ALEUTIANS AND WESTERN ALASKA PENINSULA. THIS FRONT WAS
SHEARED APART AS IT MOVED UNDER THE INFLUENCE OF THE UPPER RIDGE.

AT THE SURFACE...A FEW WEAK CIRCULATIONS ARE VISIBLE ON SATELLITE OUT
OVER THE GULF OF ALASKA BUT VERY FEW SHOWERS ASSOCIATED WITH THESE
FEATURES. MOSTLY CLEAR SKIES AND BELOW NORMAL TEMPERATURES PREVAILING
OVER SOUTHCENTRAL WHILE AN AREA OF STRATUS AND FOG EXTENDS FROM THE
UPPER KUSKOKWIM TO BRISTOL BAY...ACTING AS A BLANKET TO HELP KEEP
TEMPERATURES FROM BOTTOMING OUT THIS MORNING. FURTHER WEST...THE
INITIAL PLUME OF MOISTURE AND WARM AIR ASSOCIATED WITH A STRONG
SOUTHWESTERLY SURGE IS USHERING A GALE FORCE FRONTAL BOUNDARY TOWARD
THE CENTRAL AND WESTERN ALEUTIANS TODAY. A STRONGER SYSTEM IS
DEVELOPING FARTHER SOUTH AND WEST WHICH WILL BE THE KEY PLAYER IN THE
POSSIBILITY OF SNOW OVER SOUTHCENTRAL BY THE WEEKEND.

.MODEL DISCUSSION...VERY STRAIGHT FORWARD FORECAST IN THE EASTERN
DOMAIN WITH ALL OF THE MODELS PAINTING A VERY SIMILAR PICTURE. THE
STRENGTH AND TIMING OF A TRIPLE POINT LOW DEVELOPING JUST SOUTHWEST
OF KODIAK ISLAND FRIDAY IS VERY SIMILAR REGARDLESS OF MODEL. THE
CHALLENGE WILL BE OUT WEST WITH THE STRENGTH OF A DEVELOPING SYSTEM
OVER THE WESTERN BERING. THE LAST THREE RUNS OF THE GFS HAD DEPICTED
A STRONGER AND SLOWER TREND...UNTIL THE 12Z RUN CAME IN...WHICH HAS
BACKED OFF SLIGHTLY ON THE STRENGTH FROM THE 6Z VERSION. THE NAM HAS
BEEN THE MOST CONSISTENT WHICH IS A BIT SURPRISING GIVEN THAT THE
SYSTEM IS DEVELOPING WELL OUTSIDE OF ITS DOMAIN. EQUALLY SURPRISING
IS THE LACK OF CONSISTENCY FROM THE GEM AND ECMWF...BUT HAVE RECENTLY
BEEN TRENDING TOWARD A STRONGER LOW NOT TOO DISSIMILAR FROM THE GFS
OR NAM. AT THIS TIME WILL NUDGE TOWARD THE 12Z GFS/NAM WITH GROWING
CONFIDENCE IN A MAXIMUM STRENGTH AROUND 964 MB THURSDAY AFTERNOON
OVER THE WESTERN BERING SEA.

.SHORT TERM FORECAST...
SOUTH CENTRAL...CIRCULATION IS VISIBLE ON SATELLITE AND THE MIDDLETON
ISLAND RADAR THIS MORNING APPROACHING THE EASTERN KENAI PENINSULA. A
FEW CONVECTIVE BANDS ASSOCIATED WITH THIS FEATURE ARE BRINGING
SHOWERS TO COASTAL AREAS INCLUDING CORDOVA. IT ALSO APPEARS THAT A
PERSISTENT CONVECTIVE BAND HAS SET UP NEAR SELDOVIA BRINGING THAT
REGION STEADY LIGHT SNOW SHOWERS. BESIDES THE COASTAL
SHOWERS...GENERALLY CLEAR SKIES ARE PREVAILING WITH TEMPERATURES
ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR AROUND
SOUTHCENTRAL.

THE FORECAST REMAINS RELATIVELY BENIGN UNTIL FLOW ALOFT BECOMES TURNS
FROM THE NORTHWEST TO SOUTHWEST DURING THE DAY FRIDAY. THIS WILL
USHER IN THE SUBTROPICAL MOISTURE AS IT OVERRUNS THE COLD AIR AT THE
SURFACE. CLOUDS WILL BE ON THE INCREASE RAPIDLY FRIDAY AS A RESULT
WITH LIGHT SNOW SPREADING NORTH BY AFTERNOON. A FEW CHALLENGES TO THE
FORECAST WILL INVOLVE THE STRENGTH OF THE TRIPLE POINT LOW THAT
DEVELOPS SOUTH OF KODIAK AND MOVES OVER THE CENTRAL GULF SATURDAY. AS
THIS LOW TAKES SHAPE...FLOW AT THE SURFACE WILL BECOME EASTERLY ALONG
THE NORTH GULF COAST AND LIKELY DOWNSLOPE ANCHORAGE AND THE WESTERN
KENAI. THE JET SUPPORT QUICKLY MOVES TO THE EAST WITH ONLY SLIGHT
COLD AIR ADVECTION ON THE BACK SIDE OF THE SYSTEM...SO AT THIS TIME
ONLY LOOKING LIKE A BRIEF PERIOD OF LIGHT OVERRUNNING SNOW DEVELOPING
AS EARLY AS FRIDAY AFTERNOON AND LASTING THROUGH FRIDAY
EVENING...BEFORE SHUTTING OFF.

SOUTHWEST ALASKA...CLEAR AND COLD CONDITIONS PERSIST OVER SOUTHWEST
ALASKA. A FEW RECORD COLD TEMPERATURES WERE POSTED YESTERDAY WITH
TEMPERATURES 20 TO 35 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. IT
LOOKS LIKE ONE MORE NIGHT OF COLD AND CLEAR CONDITIONS FOR THE
SOUTHWEST AHEAD OF THE BERING SEA SYSTEM.

CLOUDS WILL QUICKLY INVADE THE SOUTHWEST COAST THURSDAY NIGHT
SPREADING SNOW INLAND BY FRIDAY MORNING TO MANY LOCATIONS. BEFORE THE
WARM ALOFT HAS A CHANCE TO BE PINCHED OFF BY THE TRIPLE POINT
LOW...THERE WILL BE A GOOD CHANCE OF FREEZING RAIN ALONG THE ALASKA
PENINSULA. WE ARE STILL FAR ENOUGH OUT THAT WE WILL NOT ISSUE AN
ADVISORY BUT CONFIDENCE IS GROWING WITH EACH MODEL RUN.

ANOTHER POTENTIAL IMPACT WITH THIS STORM IS BLIZZARD CONDITIONS ALONG
THE DELTA COAST. WILL BE CONSIDERING A BLIZZARD WATCH FOR THAT REGION
BEGINNING SOMETIME THURSDAY NIGHT.

WITH THE SOUTHWEST FLOW ALOFT THURSDAY NIGHT AND FRIDAY...EXPECTING
MOST OF SOUTHWEST ALASKA TO SEE PRECIPITATION DURING THIS EVENT. SNOW
AND MIXED PRECIP ALONG THE PENINSULA EVENTUALLY TAPERS OFF SATURDAY
AS THE LOW DEVELOPS SOUTH OF KODIAK AND MOVES TO THE EAST.

ALEUTIAN ISLANDS AND BERING SEA...WILL HAVE TO PAY VERY CLOSE
ATTENTION TO THE WEATHER OUT WEST FOR ANY INDICATIONS OF HOW THE
SYSTEM IS DEVELOPING. AN INITIAL GALE FORCE STORM IS PUSHING ACROSS
THE ALEUTIANS THIS MORNING BUT WILL BUTT UP AGAINST THE RIDGE OF HIGH
PRESSURE POSITIONED OVER THE CENTRAL BERING. IT WILL TAKE THE SECOND
AND MUCH STRONGER SYSTEM TO FORCE THE RIDGE TO AMPLIFY AND EVENTUALLY

SHIFT TO THE EAST...ALLOWING THE STORM FORCE LOW TO RAPIDLY INTENSIFY
OVER THE WESTERN BERING. AS PREVIOUSLY MENTIONED...THE SOUTHWEST FLOW
OF WARM AIR ALOFT WILL BRING MANY AREAS PRECIPITATION...BUT THE TYPE
OF PRECIPITATION WILL BE A CHALLENGE FROM THE ALASKA PENINSULA TO THE
PRIBILOFS.

THURSDAY EXPECTING PRECIP TO START AS SNOW AND LIKELY BE BLIZZARD
CONDITIONS FOR THE PRIBILOFS. AS THE WARM AIR ALOFT ARRIVES THURSDAY
AFTERNOON AND EVENING...PRECIP WILL LIKELY CHANGE OVER TO FREEZING
RAIN FOR A PERIOD FOR AREAS INCLUDING THE ALASKA PENINSULA AND
POSSIBLY THE EASTERN ALEUTIANS. THE TRAPPED WARM AIR ALOFT EVENTUALLY
GIVES WAY TO COLD AIR WRAPPING AROUND THE OCCLUSION...SWITCHING THE
PRECIP BACK TO A MIX OF RAIN AND SNOW AND THEN ALL SNOW BY FRIDAY
AFTERNOON.

THE LOW WEAKENS IN THE NORTH PACIFIC WHILE ANOTHER WEAKER LOW
DEVELOPS AND MOVES TOWARDS THE CENTRAL ALEUTIANS SATURDAY MORNING.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 155 195.
MARINE...GALES: 160 165 170 172 175 176 179 180 185
FIRE WEATHER...NONE.

AB MAR 12

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1225 PM AKDT WED MAR 21 2012

AKZ155-161-181-185-195-220600-

...A LARGE STORM SYSTEM TO IMPACT THE BERING SEA AND ALASKA PENINSULA
THURSDAY...

AN AREA OF LOW PRESSURE OVER THE NORTH PACIFIC WILL RAPIDLY INTENSIFY
TONIGHT AS IT MOVES INTO THE WESTERN BERING SEA. PRECIPITATION ALONG
AND AHEAD OF THE ASSOCIATED FRONT WILL BRING SNOW AND POSSIBLE
BLIZZARD CONDITIONS TO THE PRIBILOF ISLANDS THURSDAY. THE SUBTROPICAL
FETCH ASSOCIATED WITH THIS SYSTEM WILL USHER WARM AIR FAR NORTHWARD
FROM THE CENTRAL ALEUTIANS TO THE ALASKA PENINSULA. THE COMBINATION
OF THE WARM AIR ALOFT AND THE COLD AIR AT THE SURFACE WILL LIKELY
RESULT IN PERIODS OF FREEZING RAIN ACROSS THIS REGION.

FREEZING RAIN WILL FIRST EFFECT THE EASTERN ALEUTIANS AS EARLY AS
THURSDAY MORNING AND THEN SPREAD EAST TOWARD COLD BAY SHORTLY AFTER
NOON. FREEZING RAIN IS POSSIBLE ALONG THE ALASKA PENINSULA IN THE
EVENING TOWARD PORT HEIDEN AND AS FAR EAST AS EGEGIK THURSDAY
EVENING.

THE PRIBILOF ISLANDS WILL LIKELY SEE BLIZZARD CONDITIONS STARTING
AROUND NOON...BUT SNOW AND BLOWING SNOW MAY BEGIN TO MIX WITH
FREEZING RAIN DURING THE LATE AFTERNOON...BEFORE SWITCHING BACK TO
SNOW SHOWERS IN THE EVENING.

BY THURSDAY NIGHT...SNOW AND BLOWING SNOW WILL REACH THE KUSKOKWIM
DELTA BRINGING POSSIBLE BLIZZARD CONDITIONS TO THE COASTAL AREAS.

STAY TUNED TO THE FORECAST AS CONDITIONS DEVELOP. ANY MINOR CHANGES
TO THE NORTH PACIFIC LOW OVERNIGHT MAY CHANGE THE AREA OF CONCERN AND
TIMING OF THIS EVENT.

AB MAR 12