Alaska Megastorm Update III: Winds as High as 85 mph, 40-Foot Waves Reported

Images (click to enlarge): Water levels and wind speeds through 12:00 AKST, November 9, 2011 at Nome, Alaska; Peak wind gusts along western Alaska coast through 8 am AKST, November 9, 2011, from National Weather Service

The National Weather Service reported that wind gusts as high as 85 mph were observed from the Bering Sea storm at Tin City, Alaska. The maximum gust at Wales was 84 mph. Waves as high as 40 ft. were reported in the Bering Sea.

The storm moved over the northeastern tip of Russia early this morning with a minimum barometric pressure of 946 mb., heading into the Chukchi Sea. This makes it "one of the deepest systems in recent history to move through the Bering Sea."

Other peak wind reports (mph) include:

CAPE LISBURNE(AWOS)                   75                     
KOTZEBUE/RALPH WIEN (ASOS)            73                     
KIVALINA ARPT                         71                     
POINT HOPE (AWOS)                     69                     
CAPE ROMANZOFF (AWOS)                 60                     
ST MICHAEL                            58                     
TELLER                                58                     
EMMONAK                               56                     
NOME (ASOS)                           55                     
BETHEL AIRPORT (ASOS)                 54                     
SAVOONGA AIRPORT                      54     

Alaska Megastorm Update II: "Epic Magnitude" Developing

1 PM AKST Update: The latest surface weather map, from this morning, shows the major storm in the western Bering Sea with a minimum pressure of 948 mb, down 8 more millibars in the past 6 hours and 32 mb in 24 hours:



Original post:

Image (click to enlarge): Surface weather map for Alaska and northern Pacific at 12 noon GMT, November 8, 2011, from National Weather Service

A National Weather Service Special Weather Statement issued within the last hour warns of an "EXTREMELY DANGEROUS AND LIFE THREATENING STORM OF AN EPIC MAGNITUDE RARELY EXPERIENCED" for the west coast of Alaska. Over the Bering Strait coast and St. Lawrence Island, sustained hurricane force winds with gusts as high as 90 to 100 mph are predicted. Wind gusts have already been reported as high as 45 mph at Kivalina and 55 mph at Point Hope on the Chukchi Sea.

The storm moved past the western Aleutians around 3 am AKST this morning and is expected to move past the Bering Strait tonight. The surface weather map (above) from this morning shows a rapidly deepening 956 mb low of bomb proportions, down 24 mb in the past 18 hours.

From the National Weather Service:

...ALASKA WEST COAST TO BE HIT BY ONE OF THE MOST SEVERE BERING  
SEA STORMS ON RECORD...  
  
A POWERFUL AND EXTREMELY DANGEROUS STORM OF NEAR RECORD OR   
RECORD MAGNITUDE IS BEARING DOWN ON THE WEST COAST OF ALASKA.   
AT 9 AM THIS MORNING THE STORM CENTER WAS LOCATED ABOUT 600   
MILES SOUTHWEST OF ST LAWRENCE ISLAND. THE STORM IS FORECAST   
TO MOVE RAPIDLY NORTHEAST TODAY AND TONIGHT WITH THE CENTER   
MOVING ACROSS THE CHUKOTSK PENINSULA TONIGHT. ON WEDNESDAY   
THE STORM WILL TAKE A NORTHWESTWARD TRACK INTO THE CHUKCHI SEA.  
  
THE STORM WILL BRING EXTREMELY STRONG WINDS TO ALL OF THE  
ALASKA WEST COAST BEGINNING THIS AFTERNOON OVER ST LAWRENCE  
ISLAND AND BEGINNING THIS EVENING OVER THE REMAINDER OF  
THE WEST COAST...ACCOMPANIED BY WIDESPREAD MAJOR COASTAL  
FLOODING AND SEVERE BEACH EROSION OVER MANY PARTS OF THE  
COASTLINE. THE WIND WILL PUSH LARGE AMOUNTS OF WATER INTO NORTON   
SOUND...RAISING SEA LEVELS TO 7 TO 9 FEET ABOVE NORMAL IN NORTON   
SOUND AND ALONG THE BERING STRAIT COAST. THE EXTREMELY STRONG   
WINDS WILL PRODUCE HIGH WAVES WHICH WILL PUSH THE HIGH WATER   
FARTHER INLAND.   
  
OVER THE BERING STRAIT COAST AND ST LAWRENCE ISLAND...  
SUSTAINED WINDS ARE EXPECTED TO REACH 75 MPH WITH MAXIMUM  
GUSTS OF 90 TO 100 MPH. ALONG THE CHUKCHI COAST...WIND  
SPEEDS OF 65 TO 70 MPH WITH GUSTS AS HIGH AS 90 MPH ARE   
EXPECTED. IN THE NOME AREA...SUSTAINED WINDS AS HIGH AS   
60 MPH ARE EXPECTED...WITH GUSTS TO 70 MPH. ALMOST ALL OTHER   
AREAS OF THE WEST COAST WILL EXPERIENCE MAXIMUM WIND SPEEDS   
OF AT LEAST 50 TO 60 MPH.  

...THIS WILL BE EXTREMELY DANGEROUS AND LIFE THREATENING  
STORM OF AN EPIC MAGNITUDE RARELY EXPERIENCED. ALL PEOPLE  
IN THE AREA SHOULD TAKE PRECAUTIONS TO SAFEGUARD THEIR LIVES  
AND PROPERTY.  

Alaska Megastorm Update I: Hurricane Force Winds Predicted

Image (click to enlarge): The latest (8:30 pm GMT, November 7) satellite image shows an intensifying storm moving away from northern Japan and east of the Kamchatka Peninsula as it approaches the Bering Sea, from SSEC, University of Wisconsin

3:30 PM AKST Update: The National Weather Service is calling for this to be "one of the most severe Bering Sea storms on record":

A RAPIDLY DEVELOPING STORM LOCATED ABOUT 600 MILES SOUTHWEST  
OF SHEMYA THIS AFTERNOON WILL INTENSIFY INTO ONE OF THE  
MOST SEVERE BERING SEA STORMS ON RECORD AS IT MOVES NORTHWARD  
ACROSS THE CHUKOTSK PENINSULA TUESDAY NIGHT. THIS STORM  
HAS THE POTENTIAL TO PRODUCE WIDESPREAD DAMAGE.  
  
THE STORM WILL PRODUCE WIDESPREAD WINDS OF 40 TO 55 MPH  
WITH HIGHER GUSTS OVER THE WEST COAST TUESDAY NIGHT INTO  
WEDNESDAY EVENING. STRONG WEST WINDS ARE EXPECTED TO CONTINUE   
OVER ST LAWRENCE ISLAND WEDNESDAY NIGHT. GUSTS TO 70 MPH CAN BE  
EXPECTED ALONG THE CHUKOTSK PENINSULA AND IN AREAS NEAR KOTZEBUE.  
WINDS OF 60 TO 75 MPH ARE EXPECTED OVER ST LAWRENCE ISLAND AND   
THE BERING STRAIT COAST. WINDS ARE EXPECTED TO APPROACH HURRICANE  
FORCE OVER THE CHUKCHI SEA AND NORTHERN BERING SEA. THE STRONG  
WINDS WILL GENERATE SEAS TO AS HIGH AS 20 FEET OVER THE CHUKCHI  
SEA...AND TO 15 TO 25 FEET OVER THE NORTHERN BERING SEA.  
  
THE STRONG WINDS WILL PUSH LARGE AMOUNTS OF WATER INTO NORTON  
SOUND...RAISING SEA LEVELS TO AS HIGH AS 8 TO 9 FEET ABOVE NORMAL  
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE HIGH SEA LEVELS  
COMBINED WITH HIGH WAVES WILL PRODUCE SEVERE BEACH EROSION AND  
MAJOR COASTAL FLOODING ALONG THE NORTHERN AND EASTERN SHORES OF  
NORTON SOUND AND ALONG THE BERING STRAIT COAST. HIGH WATER  
LEVELS WILL PRODUCE COASTAL FLOODING ALONG THE SOUTHERN  
SHORE OF NORTON SOUND. STRONG WINDS AND WAVE ACTION MAY PUSH   
ICE IN NORTON BAY ON SHORE.  
  
MODERATELY ELEVATED SEA LEVELS AND HIGH WAVES WILL CAUSE  
SEVERE BEACH EROSION AND MAJOR COASTAL FLOODING ALONG THE  
SOUTH AND WEST FACING COASTS OF ST LAWRENCE ISLAND TUESDAY   
THROUGH WEDNESDAY NIGHT.  
  
ALONG THE CHUKCHI SEA COAST FROM CAPE KRUSENSTERN NORTHWEST...  
SOUTHEAST WINDS GUSTING TO A HIGH AS 70 MPH WILL PRODUCE HIGH  
WAVES AND SOME ELEVATION OF SEA LEVELS...RESULTING IN SEVERE   
BEACH EROSION AND MAJOR COASTAL FLOODING. THE VILLAGE OF  
KIVALINA WILL BE HIGHLY VULNERABLE TO DAMAGE CAUSED BY  
BEACH EROSION AND COASTAL FLOODING.  
  
THE STORM WILL ALSO PRODUCE SIGNIFICANT SNOWFALL AND BLIZZARD  
CONDITIONS OVER ALMOST ALL OF THE WEST COAST TUESDAY NIGHT  
AND WEDNESDAY. SNOWFALL AMOUNTS OF AS MUCH AS 14 INCHES  
ARE EXPECTED ALONG THE SOUTHERN SEWARD PENINSULA COAST AND  
IN PARTS OF THE INTERIOR SEWARD PENINSULA.  
  
AGAIN...THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING  
STORM WHICH WILL BE ONE OF THE WORST ON RECORD OVER THE BERING   
SEA AND THE WEST COAST.  

Original Post:
This morning's forecast discussion from the National Weather Service notes that the storm developing in the northern Pacific has been well predicted so far by both the U.S. GFS model and the European model. The models have also been consistent from one run to the next. Winds are forecast to be locally as high as 75 mph along the Alaskan coast. Although the water level may not reach the record height of 1974, the potential for severe coastal damage is very high because of the lack of sea ice. From the NWS forecast discussion:

THE STRONGEST WINDS ARE EXPECTED TO BE SOUTH 75 MPH NEAR SAVOONGA  
AT THE HEIGHT OF THE STORM ON TUESDAY NIGHT. SAVOONGA IS A  
SINGULAR POINT WITH STRONG SOUTH WINDS BECAUSE ATUK  
MOUNTAIN...SUMMIT ELEVATION 2207 FEET...IS JUST SOUTH OF THE  
VILLAGE.   
  
THE STORM IN THE BERING SEA TUESDAY AND WEDNESDAY IS REMARKABLY  
SIMILAR TO THE BERING SEA STORM OF NOVEMBER 11 AND 12 1974. THE  
1974 STORM REMAINS THE MOST SEVERE AT NOME IN 113 YEARS OF  
RECORDS THERE. THE CREST AT NOME WAS A 13.2 FOOT RISE IN STATIC  
WATER LEVEL ABOVE MEAN SEA LEVEL. THE CREST THIS TUESDAY NIGHT  
AND WEDNESDAY AT NOME IS EXPECTED TO BE 10 FEET.  
  
DUE TO A STRONG SOUTHERLY INFLUX OF WARMER AIR OVER THE BERING SEA  
COAST STARTING LATE TONIGHT...BLIZZARD CONDITIONS ARE NOT EXPECTED  
AROUND THE ZONES OF THE YUKON DELTA AND NORTON SOUND COASTAL  
ZONES. HENCE...WINTER STORM WARNINGS FOR HEAVY SNOW ARE IN EFFECT  
FOR THOSE AREAS.  
  
INDEED...THE SNOW ON SAINT LAWRENCE ISLAND WILL BE MIXED WITH  
RAIN TUESDAY AND TUESDAY NIGHT. A HIGH WIND WARNING IS IN EFFECT  
FOR SAINT LAWRENCE ISLAND AND THE BERING STRAIT COAST. 

A Public Information Statement from Fairbanks says, in part:

ALL SOUTH AND WEST FACING COASTS ON THE BERING SEA FROM THE YUKON  
DELTA UP TO BERING STRAIT...AND THE CHUKCHI SEA COAST NORTH OF  
KOTZEBUE UP TO POINT HOPE...ARE EXPECTED TO HAVE MAJOR COASTAL  
FLOODING AND BEACH EROSION TUESDAY NIGHT AND WEDNESDAY. SOUTHERLY  
WINDS FROM 40 TO 75 MPH ARE FORECAST TO DRIVE UP THE SEA FROM 4 TO  
10 FEET ABOVE NORMAL LEVELS. THE STRONGEST WINDS AND COASTAL  
FLOODING WILL SPREAD OVER THE NORTHERN BERING SEA TUESDAY NIGHT  
AND THEN OVER THE CHUKCHI SEA COAST ON WEDNESDAY. THE STORM WILL  
SUBSIDE THURSDAY. 
  
NEARLY ALL OF THE ALASKAN NORTHWEST COAST REMAINS ICE FREE AS OF  
TODAY...AND THIS WILL NOT CHANGE FOR SOME TIME. KOTZEBUE SOUND AND  
NORTON BAY ARE ICE COVERED. LARGE STRETCHES OF NORTHWEST ALASKA  
COASTLINE HAVE VIRTUALLY NO ICE COVER TO LESSEN THE IMPACT OF  
INCOMING SURF. THIS WAS NOT SO IN THE 1974 STORM.   
  
THIS IS A DANGEROUS STORM. ALTHOUGH IT MAY NOT TURN OUT TO BE AS  
INTENSE AS THE 1974 STORM...IT HAS THE POTENTIAL TO CAUSE  
WIDESPREAD DAMAGE.   

Indirect Effects: Arctic Ice Loss Has Immediate Consequences

Images (click to enlarge): Arctic sea ice extent, November 5, 2011, from National Snow and Ice Data Center; GFS model forecast weather map for northern Pacific and Alaska, November 9, 2011, from NCEP/National Weather Service.

See update for later information.

Original post:
Although it didn't quite break the record low of 2007, this year's minimum Arctic ice extent was the second lowest since satellite observations began in 1979. If current forecasts work out as expected, however, this near-miss is likely to have drastic consequences for the northwest coast of Alaska. This morning's northern Alaska forecast discussion from the National Weather Service Fairbanks office describes the potential impact of a very strong storm developing in the northern Pacific and headed across the Aleutians into the Bering Sea early this week (h/t Stu Ostro):

LOW NUMBER 2 IS REMARKABLY SIMILAR TO THE STORM THAT CAUSED MAJOR  
COASTAL FLOODING ON THE NORTHWEST ALASKA COAST ON NOVEMBER 11 AND  
12 IN 1974. THE ONLY DIFFERENCE OF ANY NOTE IS THAT THE 1974 STORM  
CENTER CROSSED THE ALEUTIANS NEAR THE INTERNATIONAL DATE LINE.  
THIS NOVEMBERS STORM IS DUE TO CROSS THE ALEUTIAN CHAIN AT ITS  
WEST END ON TUESDAY MORNING. THIS NOVEMBERS STORM IS FORECAST TO  
REACH BERING STRAIT WEDNESDAY MORNING. THE 1974 STORM ALSO ENDED  
UP AT BERING STRAIT. IN A FEW WORDS...THE ORIGINS AND PATHS OF  
THESE STORMS ARE SLIGHTLY DIFFERENT...BUT THEIR DESTINATIONS ARE  
THE SAME.  

THE OCEAN TIDES ALONG THE NORTHWEST ALASKA COAST THIS WEEK ARE AT  
AVERAGE LEVELS. THE OCEAN TIDES AT THE TIME OF THE 1974 STORM WERE  
AT MOST A FOOT OR TWO ABOVE THIS YEARS. HENCE...THIS IS A MINOR  
FACTOR. IN THE 1974 STORM...THE WIND DRIVEN RISE IN SEA LEVEL WAS  
CLOSE TO 10 FEET.  
  
IN THE 1974 STORM THERE WAS CONSIDERABLE SEA ICE IN NORTON  
SOUND. THE SOUTHEAST CHUKCHI SEA...FROM BERING STRAIT UP TO  
BARROW INCLUDING KOTZEBUE SOUND...HAD EXTENSIVE ICE COVER DURING  
THE 1974 STORM. THIS YEAR THERE IS ONLY A SMALL AREA OF SHORE ICE  
IN EASTERN NORTON SOUND. ON THE CHUKCHI SEA COAST THERE IS ONLY A  
NARROW STRETCH OF ICE...LESS THAN 10 MILES WIDE...FROM BERING  
STRAIT TO POINT HOPE. KOTZEBUE SOUND IS 50 TO 70 PERCENT ICE  
COVERED. ALL OF THIS MEANS IS THAT THERE WILL BE VERY LITTLE SHORE  
ICE TO PROVIDE SOME PROTECTION TO THE COAST.  
  
THE COASTAL FLOODING IN THE 1974 STORM BEGAN AT MID DAY IN NORTON  
SOUND...AND TOWARD EVENING IN KOTZEBUE SOUND. IF LOW NUMBER 2  
FOLLOWS THE SCRIPT OF THE FORECAST MODELS...THE COASTAL FLOODING  
WITH THIS YEARS STORM WOULD BEGIN IN NORTON SOUND ON TUESDAY  
EVENING...AND ALONG THE CHUKCHI SEA COAST FROM BERING STRAIT TO  
POINT HOPE ON TUESDAY NIGHT.  
  
THE LATEST GFS MODEL FORECASTS INDICATE A SHARP CHANGE IN THE  
WIND OVER NORTON SOUND ON WEDNESDAY MORNING...SHIFTING FROM  
SOUTHEAST TUESDAY NIGHT TO SOUTHWEST WEDNESDAY MORNING. IF THE  
OUTCOME ON WEDNESDAY FOLLOWS THIS FORECAST...THERE WOULD BE  
ADDITIONAL COASTAL FLOODING ON THE YUKON DELTA AND IN EASTERN  
NORTON SOUND.  
  
LOW NUMBER 2 IS GOING TO BE A DANGEROUS STORM.    

The top image shows the Arctic ice extent as of yesterday, November 5. The southern edge is well north of the northern coast of Alaska, leaving the Bering Sea, Norton Sound, and Chukchi Sea along Alaska's west coast ice-free.

The second image shows an output weather map from the main U.S. global forecast model, the GFS. It is a 60-hour forecast for 6 am GMT on Wednesday, November 9. A very strong storm with a minimum pressure of 940 mb is centered in the Bering Sea, moving toward the Bering Strait and pounding the west coast of Alaska with dangerously high winds.

The sea ice extent doesn't need to set a new record in order to have serious consequences.