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.

Arctic Sea Ice Melt Equals 2007 Record Pace

After lagging somewhat in August, the current Arctic total sea ice extent has caught up with the record low area of early September 2007. This puts it very close to the all-time record low at the 2007 seasonal minimum. The average ice extent for last month was the second lowest for August, behind only 2007. The chart (click to enlarge) from the National Snow and Ice Data Center (NSIDC) shows data through Sept. 5.

The NSIDC reports:

Arctic sea ice extent averaged for August 2011 reached the second lowest level for the month in the 1979 to 2011 satellite record, and has now fallen below the minimum daily extents in 2010 and 2008, previously the third- and second-lowest Arctic sea ice extents in the satellite record.

North Pole Webcam Displays 2011 Ice Melt

From NOAA/PMEL:

Deployed on an ice floe at the North Pole in Summer 2011 as part of the North Pole Environmental Observatory.

In 2011, melt was very rapid in July, and the web cam tipped over on July 23 in the melted snow and ice.

Arctic Ice Extent Reaches Record January Low

The National Snow and Ice Data Center reported yesterday that Arctic ice extent reached an all-time low for the month of January:

Arctic sea ice extent averaged over January 2011 was 13.55 million square kilometers (5.23 million square miles). This was the lowest January ice extent recorded since satellite records began in 1979. It was 50,000 square kilometers (19,300 square miles) below the record low of 13.60 million square kilometers (5.25 million square miles), set in 2006, and 1.27 million square kilometers (490,000 square miles) below the 1979 to 2000 average.

Ice extent in January 2011 remained unusually low in Hudson Bay, Hudson Strait (between southern Baffin Island and Labrador), and Davis Strait (between Baffin Island and Greenland). Normally, these areas freeze over by late November, but this year Hudson Bay did not completely freeze over until mid-January. The Labrador Sea remains largely ice-free.

New Satellite Data Contradict Antarctic Ice Loss Assumptions

Update: SkepticalScience puts some additional context on the new results:
East Antarctica is now losing ice

Original post:
A paper published online this week in the journal Nature Geoscience, "Accelerated Antarctic ice loss from satellite gravity measurements", shows increased rates of ice reduction in Antarctica. The data from the GRACE satellite confirmed earlier indications of ice loss in West Antarctica at the rate of 132 gigatonnes of ice per year. More surprising, however, was the result that East Antarctica, which had been considered stable, is also losing ice mass. The rate of decline in East Antarctica is estimated at 57 gigatonnes a year. The estimates, based on satellite data from 2002 to 2009, show the maximum loss rates in coastal areas.

Lead author Jianli Chen of the University of Texas Center for Space Research said:

While we are seeing a trend of accelerating ice loss in Antarctica, we had considered East Antarctica to be inviolate. But if it is losing mass, as our data indicate, it may be an indication the state of East Antarctica has changed. Since it's the biggest ice sheet on Earth, ice loss there can have a large impact on global sea level rise in the future.

Image (click to enlarge): GRACE estimate of Antarctic ice loss, from University of Texas at Austin Center for Space Research

Highest Arctic Temperatures in 2000 Years

Images (click to enlarge):

• 2000 years of Arctic temperatures from Science, via University Corporation for Atmospheric Research
• Changes in Earth-Sun distance during Arctic summer over time, from National Science Foundation

Midnight Update: Naturally, this research is too important to escape a hatchet job by the anti-science Anthony Wassup site. We don't go there or provide links, because the computer needs to get a tetanus shot after dipping in that bilge. However, the intrepid Tamino is already on the case.

Original post:
A new study published in today's issue of the peer-reviewed journal Science shows that current Arctic temperatures are the highest in the past 2000 years. Based on an analysis of lake sediments and comparisons with previous studies of ice cores and tree rings, the researchers extended the previous record of Arctic climate from 400 years to 2000 years in the past. They found that over the 1900 years prior to the 20th Century, there was a slow rate of cooling in the Arctic. This cooling is consistent with the relationship between small changes in the tilt of Earth's axis and its orbit around the sun. Over the last 7000 years, this has caused Earth's closest approach to the sun to shift from September to January. As a result, the intensity of sunlight in the Arctic summer has been slightly reduced, producing the cooling trend. Over the 20th Century, however, that trend has been overcome by warming which has generated temperatures that are now higher than in the preceding 1900 years. By the year 2000, average Arctic temperatures were 1.4° C (2.5° F) above where they would otherwise have been. Four out of the five warmest decades in the last 2000 years occurred in the 50 years between 1950 and 2000.

The paper's abstract:

The temperature history of the first millennium C.E. is sparsely documented, especially in the Arctic. We present a synthesis of decadally resolved proxy temperature records from poleward of 60°N covering the past 2000 years, which indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age. A 2000-year transient climate simulation with the Community Climate System Model shows the same temperature sensitivity to changes in insolation as does our proxy reconstruction, supporting the inference that this long-term trend was caused by the steady orbitally driven reduction in summer insolation. The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000.

The paper has generated considerable press interest, including:

• BBC News, Arctic 'warmest in 2,000 years'
• AP, Arctic reverses trend, is warmest in two millennia
  
• Reuters, Arctic now warmest in 2000 years, researchers say
  
• National Geographic, Next Ice Age Delayed by Global Warming, Study Says
• McClatchy Newspapers, Warming Arctic follows 1,900 years of cooling, scientists find
• UK Guardian, Global warming has made Arctic summers hottest for 2,000 years
• UK Telegraph, Global warming has reversed 2,000 years of cooling in the Arctic
  
• USA Today, Arctic temperatures hit 2,000-year high
• Bloomberg, Arctic’s 2,000-Year Cooling Ended With Coal Burning, Ice Shows
• WaPo, Emissions Linked to End of 2,000-Year Arctic Trend

Arctic Ice Melt Continues Near Record Rate in July

See here for other posts on Polar Climate.

The National Snow and Ice Data Center (NSIDC) reported yesterday that the average rate of Arctic ice melt in July was nearly equal to that in the record-breaking year of 2007. Total ice extent for the month was the third lowest for the satellite record in July, following behind 2007 and 2006.

A strong area of high pressure over the western Arctic brought warm temperatures and clear skies to the region, helping to promote the melting process. (The same high pressure ridge brought record breaking high temperatures to much of the western U.S. from Arizona through Oregon and Washington and into Alaska.)

The NSIDC overview stated:

Sea ice extent averaged over the month of July 2009 was 8.81 million square kilometers (3.40 million square miles). This was 680,000 square kilometers (263,000 square miles) above the record low that occurred in July 2007, 250,000 square kilometers (97,000 square miles) below July 2008, and 1.29 million square kilometers (498,000 square miles) below the 1979 to 2000 average. Sea ice extent is unusually low in the Kara Sea, Baffin Bay, and along the Russian coast. The only area with significant above-average ice extent is southern Hudson Bay.

Image (click to enlarge): Arctic sea ice extent as of August 4 from NSIDC

Arctic Melt Rate Ahead of Last Year

Images (click to enlarge): 2009 Arctic sea ice extent through July 21 from National Snow and Ice Data Center; September 2009 sea ice outlook from Study of Environmental Arctic Change

The mid-July Arctic sea ice analysis shows that this season's melting is proceeding at a higher rate than last year, but less than the record year of 2007:

On July 21, Arctic sea ice extent was 8.28 million square kilometers (3.20 million square miles). This is 617,000 square kilometers (238,000 square miles) more ice than for the same day in 2007 and 1.36 million square kilometers (523,000 square miles) below the 1979 to 2000 average. Ice extent on July 21, 2009 remained 8.06% higher than the same day in 2007, yet was 2.44% below the same day in 2008 and 14.06% below the 1979-2000 average for that day.

The latest outlook from 16 individual estimates for the September seasonal minimum shows a range of levels from below the 2007 record to above the 2008 level:

The range of individual outlook values this month is from 4.0 to 5.2 million square kilometers, with most of the estimates in a narrow range of 4.4 to 5.2 million square kilometers. The two lowest estimates, 4.0 and 4.2 million square kilometers, would represent a new record minimum. All estimates are well below the 1979–2007 September climatological mean value of 6.7 million square kilometers. The uncertainty / error values, from those groups that provided them, are about 0.4 million square kilometers, thus many of the values essentially overlap.

Arctic Sea Ice Melt Continues to Accelerate Decline Now Beyond 2007 Record Pace

The National Snow and Ice Data Center (NSIDC) reported last week that the Arctic sea ice melt season had gained momentum in May following a slow start. (The rate of decline in April was the third slowest on record.) The latest chart of sea ice extent now shows that the current measurement exceeds even the record-setting pace of 2007.

As Herr Hare points out, however, that hasn't stopped the denialists from declaring the exact opposite.

Image (click to enlarge): Time series of Arctic sea ice extent as of June 9, from NSIDC

Analysis Indicates Ice-Free Arctic in 30 Years

A new analysis published yesterday in the journal Geophysical Research Letters of the American Geophysical Union (AGU) predicts that the Arctic could be virtually ice-free as soon as 30 years from now. Previous forecasts had indicated that such an event was likely by the end of the century. The researchers, Muyin Wang of the University of Washington and James E. Overland of the NOAA Pacific Marine Environmental Laboratory, stated

Using the observed 2007/2008 September sea ice extents as a starting point, we predict an expected value for a nearly sea ice free Arctic in September by the year 2037. The first quartile of the distribution for the timing of September sea ice loss will be reached by 2028.

The analysis was done using the 6 IPCC models which were most accurate in simulating currently observed sea ice conditions.

Image (click to enlarge): "The heavy red line is the sea-ice extent observed since the 1950s. Six models that most accurately depict that ice extent are shown with thin colored lines. The heavy blue line is the average of those six models and projects ice-free Septembers in 20 to 30 years. In contrast, the heavy yellow line is the average sea-ice extent of all 23 models including outliers unable to reproduce current sea-ice conditions." (From Univ. of Washington/NOAA)

December Rollercoaster

Now

Clear, mild. After a solid week of lows below freezing, this morning's official low was only 33°. Brilliantly clear skies and some downslope air flow have allowed even the weak December sun to push temperatures into the low 60s and above in the Washington metro region this afternoon. Highs were 63° at National and BWI, 62° at Dulles.

Some clouds and a more easterly wind direction will likely put a somewhat lower lid on temperatures tomorrow, although the exact extent of the cooling is a bit uncertain.

CapitalWeather.com chart from NWS data, photo © Kevin Ambrose

Tonight and Tomorrow

Some clouds, seasonably mild. With a few scattered clouds, tonight's lows will be near 38° downtown to around 30° in the cooler 'burbs. Clouds will increase somewhat tomorrow with highs in the mid 50s.

For the outlook through the rest of the week, scroll down to Dan's post below.

Climate Corner

The National Center for Atmospheric Research (NCAR) announced today the results of a study being published tomorrow in the scientific journal Geophysical Research Letters. The study results, which are also being presented at the annual Fall Meeting of the American Geophysical Union this week in San Francisco, indicate that Arctic sea ice melting is likely to accelerate to the extent that the polar region will be essentially ice-free in summer as early as 2040. The researchers, from NCAR, University of Washington, and McGill University state

We examine the trajectory of Arctic summer sea ice in future climate projections and find that abrupt transitions are a common feature of 21st century model simulations. These events have decreasing trends in September ice extent that are typically 4 times larger than comparable observed trends. One event exhibits a decrease from 6 million km² to 2 million km² in 10 years, reaching essentially ice-free September conditions by 2040. In the simulations, ice retreat accelerates as thinning increases the efficiency of open water formation for a given melt rate and the ice-albedo feedback increases shortwave absorption. In one climate model, the retreat is abrupt when ocean heat transport to the Arctic is rapidly increasing. Analysis from multiple climate models and three different future forcing scenarios suggests that reductions in future greenhouse gas emissions moderate the likelihood and severity of these events.

Political Science: End of an Error

Yesterday's WaPo editorial, "Mr. Inhofe's Last Hearing", bids a not-so-fond farewell to the reign of error by the Senator from Oilahoma. RealClimate.org's post last week, "Inhofe’s last stand", however, admits a touch of nostalgia in noting the last performance at the political theater formerly known as the U.S. Senate Committee on Environment & Public Works.

Want Stickiness With Those Fries?

Now

Seasonably warm and humid: If the weekend weather had you thinking that August itself had gone on vacation along with most of the rest of Washington, this afternoon should bring you back to what passes for reality in Spin City. Upper 80s are prevalent in the immediate Beltway vicinity, and the Usual Suspects toward the south, such as Stafford, Culpeper, and Fredericksburg, are all at or above 90°. Those pesky dewpoints are into the sticky upper 60s to 70°. Regional radar is dry except for some extremely isolated showers along the Blue Ridge.

Tonight and Tomorrow

AC weather: The MOS (Model Output Statistics) are predicting MOS (More of Same) through tomorrow, except for a better chance of PM thunderstorms, as a not-so-cold front approaches from the west. Lows tonight: low to mid 70s, highs tomorrow: upper 80s. Chance of afternoon or evening thunderstorms: 50%.

Scroll down to Jason's post below for the outlook through next weekend.

Tropical Topics

There are two areas of interest in the tropical Atlantic. A low pressure area just north of the Bahamas shows some signs of developing a circulation, and a reconnaissance flight is tentatively scheduled for tomorrow to investigate. A strong low pressure area off the coast of Africa has already had wind gusts of up to 50 mph in squalls today. A tropical depression could develop out of this as it approaches the Cape Verde Islands tomorrow.

Climate Corner: Greenland Ice vs. Antarctic Snow

While PM Update was on break, Friday's WaPo had an article, "Greenland's Melting Ice Sheet May Speed Rise in Sea Level" about two issues related to the question of sea-level change. On the subject of Greenland's ice sheet, a new study has found that the recent rate of melting, although based on a short period of observation, is 3 times higher than the rate of the previous 5 years. The other subject is much more significant to sea-level change, since global warming critics frequently claim that everything balances out because more snow in Antarctica compensates for Greenland melting. In fact, a study published in the latest AAAS Science magazine finds that

There has been no statistically significant change in snowfall since the 1950s, indicating that Antarctic precipitation is not mitigating global sea level rise as expected, despite recent winter warming of the overlying atmosphere.

An animation of Antarctic snowfall trends is available online.

Squeeze Play Sends Fine Weather Into Extra Innings

An atmospheric squeeze play is extending the fine spring weather from April into May in the Washington DC metro area. A ridge of high pressure extending along the entire east coast of North America is being squeezed from two directions by "cut off" low pressure areas over the upper Midwest and near Bermuda. While the ridge holds in place, the sunny, dry weather will continue over the Mid Atlantic area as Jason describes below, but the unusual northwestward motion of the eastern low will bring the threat of some clouds and rain to New England.

Surface pressure (solid lines) and 500 mb height (colors) at 8am today from Unisys

At mid afternoon today, 68° was the lowest reported reading around the region; most places were 70° or higher. The bright sun was accompanied by delightfully dry dewpoints of 45° or less. The nearest showers were over the lower Ohio Valley and eastern New England.

Tonight and Tomorrow

Mostly clear skies should continue through tomorrow afternoon, with only a few clouds late in the day. Lows tonight under light winds should again be in the mid to upper 40s city to near 40 in the colder 'burbs. Highs tomorrow will be near 72.

Capitol Climate

The American Meteorological Society has posted more details on the next Capitol Hill Environmental Science Seminar this week:

• Topic: Changes in Cold Places: A Look at the Greenland Ice Sheet, Arctic Sea Ice and the Antarctic Ice Sheet
  
• Date: Wednesday, May 3, 2006
  
• Time: 12:00 Noon - 2:00 pm
  
• Location: Russell Senate Office Building, Room 428

The public is invited; no pre-registration required.

The questions to be addressed are:

Are parts or all of the Greenland and Antarctic Ice Sheets undergoing a net melting? What is the nature of the observational evidence of melting? How far back in time do these observations extend? Are the melting and rates of melting consistent with model simulations and projections of melting? What are the factors deemed responsible for the melting? Is Arctic Sea Ice thinning? If so, by how much and over what period of time? What is the nature of the observational evidence for this thinning? Are the thinning and rates of thinning consistent with model simulations and projections of thinning? What factors are deemed responsible for the thinning of Arctic Sea Ice? Are there implications with respect to sea level rise? Is there any evidence of a fundamental change in the rate at which the Greenland ice sheet is changing and the manifestation of those changes? If so, why? How well do model simulations capture the dynamics of ice sheets and sea ice relative to observations? How well are these ice sheet models poised to project future changes in ice sheets, sea ice and sea level?

Photo, via AMS, is also the cover picture for the April 2006 Weather Magazine of the Royal Meteorological Society (Special Issue: Climate Change in high latitudes 2). It shows surface melt water entering a moulin in the Greenland Ice Sheet.