Stratospheric temperatures are greatly influenced by the presence of Ozone.

~The start of the stratosphere is where ozone concentration begins rising significantly
~This creates a massive world wide upper inversion called the tropopause
~A cold ground air is not necessarily under a  high stratosphere deep freeze
~The best temperature level to judge the troposphere is 600 mb

   The tiny bit of atmospheric ozone in our world  has a huge influence ,  not only in keeping us safe from harmful UV light, but seems largely forgotten as the main greenhouse gas warming the stratosphere.  A lack of Ozone basically cools the stratosphere,  the famous CFC driven ozone holes
exist at about -80 C.   Too much ozone warms the stratosphere.  Not to confuse with sudden Stratospheric warming,  which does occur not too often ,  but some place too much emphasis on it.   Stratospheric ozone is key in stratospheric temperatures.   Some people strongly believe that stratospheric temperatures influence the troposphere.  Let's look at this:

April 25 2019,  NOAA daily composites, 600 mb temperature is very close to the temperature of the entire troposphere.  We see here a spring time  Tropospheric Polar Vortex ,  which its coldest vortices in dark purple.  So as a few experts like to say the stratosphere influences this.   Not so, the warmest 50 mb temperatures are right above the coldest Cold Temperature North Poles of the troposphere:

Is warmest, -44 C near the center of the locations having more ozone,  while over Europe,  at 50 mb level, it s -61 C  where there was far less ozone:

       The areas with the least ozone are in this case the warmer surface places.    So the stratosphere in  does not  seem to cool the troposphere.  Therefore emphasis on any explosive stratospheric warming event,  as rare as they may be,  must be taken that what happens in the Stratosphere,  often stays there. WD April 28 ,  2019

NOAA & ECMWF AI vs EH2r long range summer projections

~Astounding if not fascinating outlook differences
~El-Nino or ENSO is not the only player on planet Earth

   First,  EH2r outlook audaciously looks quite different than the 2 largest forecasting giants,  NOAA heavily relies on ENSO    :

This temperature chart for May June and July looks amiss.   It relies on ENSO dominating cloud coverage and therefore affect Midwest US temperatures,  which looks good for May ,  not at all,  according to EH2r for June and July.   First of all,  if there are more clouds coming from ocean sources,  the coast would be cooler :

  NOAA AI is in the clouds!   According to EH2r, not going to happen,  which unlike NOAA makes midwest USA June July quite hot because the flow will indeed come from the oceans,  but on West coast clouds keeps things cooler,  clouds dry out migrating East.  On SW coast I don't think there will be any dominant circulation,  favoring Death Valley records NOAA got this covered.  On East coast the simmering dry Midwest heat should  move to the Northeast coast making it indeed warmer than usual,  the Southeast should suffer same fate as SW coast,  no general circulation especially from July August  and more precipitation records should occur.


ECMWF surprisingly has some similar outlooks:

ECMWF long range likely has the NE Pacific temperature blob right.  North America warmer temperature anomalies are a bit illogical as well.  SW USA cool is perhaps cloud driven,  but this suggests something strong moving things Eastwards,  From the stand point of the Midwest not being dry and hot,  quite unlikely.  East coast of North America way cooler than should be.  Since EH2r projection makes the waning Polar Vortex smaller than summer 2018,  which had Midwest June July quite warm.  so I expect this same area warmer than 2018.    Western Europe may be off for JJA,  the Gulf Stream cyclones should mainly whisk to the NW of the  UK, this brings dry heat from Espana.   Basically I think ECMWF model is heavily influenced by ENSO.  Which is fine,  only if ENSO is foreseen correctly.  However,  ENSO's range is huge,  and there was no signals of a pending stronger El-Nino.   On the right bright midnight sun side,  the Arctic projection looks good but for over estimated cooler Tundra zones,  and North Japan is off as well.  WD April 26 2019

2019 Annual end of Spring and Summer projection, by unorthodox means -trying to grasp rapidly changing climate

~Projection very much similar to last year ,  except there are some strange features which suggest subtle differences.
~Most ENSO models call for El-Nino,  but all Arctic data suggest La-Nina conditions
~Extraordinary Canadian High Arctic dominant Cold Temperature North Pole returns 2nd consecutive year in a row,  a statistical improbability.
~Last years projection was again extremely successful except for sea ice minima extent,  as usual.
~2019 wont be warmest year in history,  likely # 4 to 6 for the Northern Hemisphere.

Synopsis 

    We start by last years  Minima sea icescape,  particularly interesting because the refreeze stalled..

Melting and diminishing extent as late as October 3.  The course of winter weather was set,  the bulk of sea ice was North Pole centric,  triggering a High Pressure spreading out from the Pole. This caused a distinct early Polar Vortex,  warming and keeping the Northern Urals snow free and especially Bering Strait kept continuously warmed by North Pacific warmer flow.  The snow free North Central Russia  eventually froze more rapidly,  vast tracks of exposed lands with the sun less than 20  degrees in sky,  night longer than day,  a strong North Central Russian vortex subsequently continued the Bering sea environs warming,  nearly for the entire winter.  Thus Beaufort sea ice Northwards to Pole set thinner,  ready for onslaught of the higher sun.  The entire winter was first mainly dominated by North Central Russian Vortex,  very slowly ceding dominance to the Canadian Arctic as late as now.  The warmth,  especially onto Alaska was  again a main feature of winter.   The broken up sea ice of summer 2018 filled the Canadian Archipelago channels,  cancelling huge cruise ships from accomplishing the NW passage,  an impossible adventure in the not so distant past,  now a routine schedule voyage,  was cancelled by extra melting.  Mid-winter  Pole centric vortex cut off snow carpeting Arctic Ocean sea ice as much as preceding winter. Therefore increasing accretion of Pole region sea ice during the long night..  In North America,  winter came late and eventually fierce by same reasons,  especially with lands not covered by snow,  warm at first,  eventually bitting cold since land looses heat quicker than land covered by thicker snow layers.  As a result the same thinly covered by snow lands warmed up faster than the regions with greater snowfall, mainly Eastern Canada.  The duality of warmth in the West versus colder in the East fueled the Canadian vortice to become more extreme,  yet smaller than last year.  It is known,  smaller vortices within the Polar vortex are usually colder,  even as late as April a strong Canadian side vortice dominated the High Arctic.  This late event was not hampered by clouds,  a mainstay of Arctic April weather,  hence a strange very unusual "Big blue"  sky event ,  the biggest in more than 20 years was created, strange since a modest  El-Nino is on,  unlike 2017-18 when it was more borderline La-Nina:

 Mid April Sea Surface Temperatures anomalies,  2015 vs 2019,  both official El-Ninos,  2015 to become warmest in history,  2019 ,  not offering any strong warmer or colder trending,  but there is a difference,  2015 had signals sent all the way to the Arctic,  2019 far less, Archipelago weather from January onwards was remarkably cloud free.  Very unlike 2015.  2019 Archipelago cloud free skies strongly suggest an ongoing La-Nina or Neutral conditions.

   The main difference between a true trending  El-Nino vs La-Nina sky is the lack of clouds,  especially the very high ones,  2015 had more,  seen darkening twilight,  2019 same Mid-April  less to none, very good condition to cool the atmosphere deeply.   Yet 2019 SST charts suggest El-Nino.  As if post massive El-Nino of 2016 La-Nina or trending towards La-Nina is happening,  even though the charts show no such thing. 

Look carefully at this NOAA chart,  97-98 and 2009-2010 El-Nino  were followed by significantly long La-Ninas,  not so for largest 2015-16 El-Nino.  This strangeness suggest 2 possibilities,  a truly big La-Nina is coming,  or sst anomalies calibration  need a correction since Earth Oceans have warmed a lot, even since 1998  (by about 0.5 C).   I tend to think it is the latter,  the Arctic has had 2 La-Nina like late winters in a row.  But there is also the shrinking Polar Vortex to consider.  Namely not near Alaska   having March 2019 being warmest in history temperatures,  +8.8 C above average.   It is strange,  but true that a smaller vortice or a rogue vortice about to detach from the Polar Vortex, can be extremely cold.  In our current Canadian Archipelago case,  the reason for this is a very long period of clear air,  with sun appearing after the long night insufficiently high in the sky to warm up a snow laden polar land and sea surface.  In the CAA, the clear sky period started in January till today,  more than 3 months and a half long.  

The continuing  shrinking late winter early spring Vertical sun disk size anomaly.....

  What is the score?   

     0, that is right,  0 % average vertical sun disk size growth the second year running,  a statistical near improbability,  given every usual late winter early spring had a season to season variance for each 17 preceding seasons.   

                                             Year              VSDM        Rank
                                             2016                 19                1 

                                             2015                 14                2
                                             2006                 11                 3
                                             2013                  9                 4
                                             2011                  9                 5
                                             2010                  9                 6 

                                             2009                  9                 7
                                             2005                  9                 8
                                             2012                  8                 9
                                             2017                  5               10
                                             2014                  4               11 

                                             2008                  4               12
                                             2007                  4               13
                                             2004                  4               14
                                             2002                  2               15
                                             2003                  1               16
                                             2019                  0               17
                                             2018                  0               18

     2019 shares  the bottom of the pack,  of 120 sun elevation mean decimal levels,  not one was above average,  again compared to 19 in 2016 right after peak strongest  El-Nino warming in recent history.  2019 was arduous with data acquisition of nearly 640 sun disk observations,  a record exceeding 2008 which was a true La-Nina trending late winter.   Vertical sun disk expand in size when the upper atmosphere is warm,  shrink when colder, these measurements include vast swats of the atmosphere, from 210 to even more than 1295 Kilometers.  Despite March 2019 being warmest month in history worldwide,  the center of coldest was right here in the Canadian Archipelago,  when the sun disks shrank in size as the sun is getting higher in the sky. The table above reads almost like ENSO trends or peaks.  So it is a very significant piece of information, having forecast powers, especially for the Northern Hemisphere temperature record,  suggesting in advance that 2019 will be about 4th to 6th warmest in history, similar to last year.    But the size, or footprint of cooling was smaller than last year.  This implies different circulation patterns:

Prognosis projections

                                        APRIL-MAY 2019

    Alaska will finally share a bit of winter namely because the Cold Temperature North Pole "C1",  which grew colder  even with the rising sun, literally defied joining the warmest month in history just past.   The main story for sea ice here is the very persistent High pressure over the Arctic Ocean Gyre,    keep in mind Fram Strait had sea ice dumping growth since October 2018.    Therefore sea ice extent is all time lowest at present,  also the Bering sea very little extent contribution shaped this unfavorable for sea ice scenario.  Note the wide area "C1" circulation entails.  all the way to Florida.  Its circulation horizon.  Obviously Midwest North America starts colder along with Eastern North America,  because there was more snow, inviting the CTNP to wander about Southwards.  The jet stream can only weaken and migrate Northwards from here.  

                                                    JUNE-JULY 2019

June-July circulation horizon shrinks,  midwest North America warms a whole lot with mainly drier air.  Last summer's record warm Eastern Canada USA summer heat will be exceeded.   Barents and Kara sea will be spared the presence of the higher sun by clouds.  The switchover from persistent anticyclone to cyclone over the Arctic Ocean Gyre with persistent cyclone will be not lasting as long as last year.  The North Pole will get a healthy dose of insolation at peak of sun elevation.  The persistent cyclone over the Arctic Ocean Gyre will have "see through" characteristics, not necessarily cooling the air below as much as it normally should. 

AUGUST-SEPTEMBER  2019

The net peak of heat impact of the higher sun would be to shrink the Cold temperature North Pole to barely exist at North of Greenland and Ellesmere Island.  Now the influence of overall  more heat than compared to 10 years ago or so  will be a generally slow circulation world wide.  The impact of a much smaller CTNP horizon have already been observed to a lesser extent in 2017,  hurricane Harvey lack of mobility  being a good example.   The further away areas from the CTNP  will languish with no circulation but by the grace of large anticyclones not moving quite readily,  it does not look wetter for California.  The net general weather scene will be very similar to summer 2018 but with lesser circulation primarily due to encroaching stronger heat signal from land and ocean.   Again tornadoes should be hopefully less numerous than average and more prominent Northwards.  The very weird, if not expected by AGW,  ENSO not reverting to a deep cold  La-Nina, especially after the great El-Nino of 15-16,  means also lesser in numbered hurricanes but dangerous by them not moving Northeastwards as much.   Not so for typhoons, again readily guided and supercharged by doldrums or weaker circulation on top of a much bigger Pacific. 

    Now with the easiest projections out of the way,  let's try , once again to forecast the sea ice minima:

   Last summers sea ice extent projection failed because I didn't take into account a particularly strong Gyre current  ,  which I knew about,  especially at peak melting period.  However, sea ice was very much churned by this strong current massively replenishing Beaufort sea with broken up ice,  the key not taken into consideration factor was fluid mobile pack ice, which did have a persistent cyclone above at peak insolation period (as expected),  this slowed overall melting. The difference between 2018 and 19  is a thinner ice footprint resulting from more prominent winter warming over the same area.   This means that even with switchover from persistent High to a Low over the Gyre ,  the sea ice should vanish more since it is thinner from 2019 ice extent maxima extent onwards, which is currently at all time lowest expansiveness ever.   Sea ice should look grim come end of September,  near or lesser than 2012 extent,  with next to North Pole navigable by non ice breaking ships, with Northeast Passage opening first followed by Northwest passage more open than,  not as clogged as last year,  but not readily navigable.  WD April 21 2019

Arctic sunset like none other, prettier than black holes, but eerily similar,

This is a sunset.......  With sun light morphed by gravity waves.... 


     Called a Wegener blank strip event ,  where sunlight gets cut off due to extra long atmospheric "ducts" some spanning  more than 1000 kilometers,  similar to fiber optics,  but consists of more or less flat steep inversion layers.  Some ducts are shorter in length and funnel whatever object or photons there is  at the beginning ,  at the other end of its "fiber optic "  air duct tunnel.  Named for and theorized by Alfred Wegener,  the same scientist who proposed tectonic plates science.    The atmosphere is not necessarily stratified in straight layers.   This is a great complexity which computer models can't duplicate with ease.    Atmospheric refraction is very much similar to Black hole optics,  is equally nearly  identical in appearance with Einstein;'s gravitational lensing.   Refraction techniques are also used to find dark matter.   Horizon refraction on Earth is not very well understood and may help explain refraction cousins found everywhere in the universe.   WD April 11, 2019

Late winter 2019 major circulation change , from minima sea ice architecture

~Winter 2018-19 main atmospheric circulation main feature was driven by sea ice morphology and snow on ground or lack thereof

     A common basic meteorological mis-concept is to ignore sea ice having anything to do with weather.  To the contrary it has everything to do with world wide weather. 

     2012 sea ice extent minima was all time lowest,  so the weather following mid September 2012 was marked  by split Cold Temperature North Poles during winter 2013,  while 2018 minima extent was characterized by a great depletion or wide open water  North of Beaufort sea,  100% driven by summer time circulation, given a remainder sea ice core close to the North Pole :

And so the circulation was shaped ,  2012 split the Polar Vortex into 2 main vortices,  while
2019 sea ice strong near North Pole remainder made the vortex more unified but elongated.  Here at 600 mb,  we see the Vortex true configuration difference,  coming from the conclusion at sea ice minima.  WD March 31 2019

North Ellesmere/Greenland biggest in memory open water/very thin sea ice at peak of cold season

~Stunning,  given a quite cold winter in this particular region

    NASA EOSDIS March 19 2019,  huge thin ice open water area usually circular because of full moon tidal current towards the South.  Note the band of ice NW breaking away towards Kennedy Channel :

  March 12 2019,  this area is long standing,  despite temperatures in the -40's C.......   The only possible explanation I can come up with,  is the ratio of thin and old multi-year sea ice is greater than can be surmised by remote sensing means.  This follows last summer 's discovery of vast areas of never seen before open water just to the North of this anomaly.  Sea ice current was predominant towards same area all winter pushing summer's ice towards the Canadian Arctic Archipelago coast,  by persistent presence of Anticyclones over the Arctic Ocean Gyre area.   WD March 20 ,  2019

A Polar Vortex study; pre & post great sea ice melts

We start with the familiar look,
<<<left<< January 15 to February 15 2013 to 18  temperatures at 600 mb.    Right >>>>>>>>>
same pressure level and period for 1980-1985.               

NOAA daily composites dedicated 238-245 Kelvin (-28 to -35 C ),  the left animation depicts latest years of great ice melts,  to the right  the pre great melt look.    What strikes as significant is the lesser cooling influence of the Arctic Ocean during the greater melt years.  The Vortex appeared always elongated or much warmer over this Ocean,  as opposed to 1980-85 having a mostly much colder Arctic Ocean atmosphere.  We note also very cold vortices above the continents occurring more prominently during the 2013-2018 years as opposed to vortices over East Siberian , North Greenland and Barents seas ,  now a days a very unlikely event given more extensive open water.      Deep cold vortices starting over land can be explained by the specific heat capacity characteristics of land varying a lot depending on snow coverage along with warm cyclonic intrusions circumnavigating vortices perimeters, being largely outside of them (more clouds covering the Polar oceans). .   

Logically we would expect winters to start  earlier and colder during the 1980 to 1985 period.

In fact winters started colder more often, 4 times out of 5  on top of the Arctic Ocean during November 15 to December 7 1980-85 (left) ,  as opposed to starting mainly above the continents  5 out of 5 times during 2013-2018 (center).   I observed the latter frequently for a long time,  was often puzzled by this until making the simple connection,  the Arctic Ocean emitted more warmth during these latest years,  winters can only really start over land when sea ice is thinner along with the greater presence of warmed sea waters.  WD February 15 2019.     

A dwindling coldest atmosphere creates a greater meandering of the jet stream

~The often used presentation of the jet stream causing weather is nebulous and confusing,
it does not intuitively link current Global Warming as its cause
~ A  laser clear and correct description of the generator of extreme weather simply starts with defining where the coldest atmospheres are located
~The worlds coldest  atmospheric regions are shrinking, stretching  and bending in these days of AGW (Anthropogenic Global Warming),  this explains the sudden extremes in temperatures which often happen in the span of a few days.

     Again and again popular medias fail in describing very clearly what is driving these days of extreme weather,  the failed linkage occurs daily, repeatedly to millions if not billions of people.
The description of jet stream being linked with AGW is correct, but utterly does not explain why.
But rather more accurate would be to present the latest "Polar Vortex"  , which made a recent  news blast,  as a stretched out much weakened  in strength winter zone. Such a definition is more a common sense presentation rendering any unspecialized person, immediately very well informed about climate change implications. 

    I can show TV weather videos,  hundreds of them,  always not educating people as perfectly as they can do about extreme weather correlations.  Is best to present it this way:

University of Maine current day weather, February 14 2019.  500 mb Geopotential levels, pressure heights,  is not the best pressure level to express the Polar Vortex.  600 mb is,  in this standard map, pressure heights confuse where the coldest air lies,   but for sake of this presentation, observe and use your mouse pointer at the limits of lower heights (with mostly colder temperatures) match with the location of the jet stream. The jet stream is a creature which lives at the outside perimeter of coldest air and southern limits of intense cyclones. Therefore by simple projections,  jet stream meanders happen when the coldest atmosphere has a much smaller area:

The day a Polar Vortex froze Chicago and environs still had a stretched out coldest atmosphere.  Properly defined like this:

Again use your mouse pointer and determine where the jet stream starts with respect to coldest air.
Temperatures at 600 mb NOAA daily composites,( map largely in red)   at about -30 C  is where the jet stream is formed. look at Japan's intense jet and how cold 600 mb was at that location.  There are also cyclonic peripheral adjuncts  which extend the coldest atmosphere/jet border line by pressure dropping  the thickness of pressure heights.    Basically January 30 had a stretched out coldest atmosphere.  The jet stream morphed around the coldest air, and did not exactly drag Arctic Air southwards.  Equally, colder temperatures in winter can be created over continents well away from the Arctic, and depend on basic geophysics such as snow cover with little or none  and clear or covered skies under very little insolation ......  WD February 14 2019

2016 2017 2018 new class extreme low sea ice extent maxima along with 2019, despite different atmospheric circulations.

       At present,   February 8 2019  Arctic sea ice extent is #2 in lowest extent:
  
       2009----  2010-----  2011-----  2012-----  2013----  2014----  2015----  2016-----  2017----  2018----  2019

   
   January 31 to February 8 JAXA  sea ice measurements reveal only 2018 being lesser in extent by about 16 thousand kilometers square on the 8th.  This is an extraordinary feature of winter 2019 with a distinctively dissimilar general circulation than the preceding 6 seasons.......

2019's general circulation to date can be characterized in part by by a snow footprint:

                    Snow cover has very similar features to sea ice extent,  it can define the degree of winter,
mild , severe or extreme.  If sea ice is widely spread out and thick,  Northern Hemisphere winter may be more  severe as well.  These two Cryospheric features make the story of winter which shapes the Arctic Polar Vortex:

   NOAA daily composites 600 mb temperatures (close to the density weighted temperature of the entire troposphere),  Arctic Polar Vortex average location January

4 to February 4 2019.   Siberia dominates,  which is contrary to all winters going back to 2012.  There are some similarities from season to season, but very prominent differences were distinguishable by analyzing maps daily,  overall PV average extent calculations may appear somewhat similar,  but they are not:

The way to analyze any given Polar Vortex season,  is to break it down in smaller periods,  January 24 to February 4  sequences 2016 to 2019 demonstrate differing flow structures.  These are winters of interest having the least sea ice extent in history.  All 4 recent seasons including 2019  had different Arctic Polar Vortex configurations,; 2016 had a very mangled weaker  and smaller Polar Vortex,  with mainly 2 continental much weaker and smallish  vortices acting independently from each other. Arctic Ocean  sea ice  became badly broken up by minima 2016.   2017  had a Pole warming  flow pattern in particular with North of Greenland Atlantic in origin cyclones heading Northwards,  2018 had a massive extreme Polar vortice dwarfing all others above the Canadian Arctic Archipelago,  Russian side vortice appeared weaker on most occasions then.   2019 to date has the opposite of 2018,  but with a difference,  continental vortices within the Polar Vortex were more balanced with Siberia dominating on most days, so far  the Polar Vortex rarely split  in two and appears stretched out.  This gives open sea water inroads from the North Pacific,   a strong  Siberian vortice pushes massive cyclones Northeastwards more often,  To date, North Atlantic cyclones went towards Eurasia, and in effect help refreeze the North Pole area sea ice which keeps the Polar Vortex more or less together.

    Given that 4 recent seasons created differing circulation features,  it is amazing that sea extent at Maximum extent date remains near all time record lows.  This strongly suggests a greater warming of the Oceans and sea ice has the potential to collapse to extreme low summer extents only not doing so because of,  you guessed it, summer circulation features. WD February 9th 2019

-39.3 C 700 mb coldest temperature of winter to date, where?: White Lake Michigan USA

~The entire Arctic winter of 2018-19 was never colder at that altitude.
~Until next day in Siberian Russia
~North American continent is easily capable of creating such temperatures
~Provided less snow insulation covering ground frozen hard from extensive exposure at the peak of darker winter, from a just prior warmer or late coming winter,  a barer dark lit Great Plains ground is onto itself a byproduct of Antthropological Global Warming (AGW).

    The specific heat capacity of dry soil is less than snow or ice, it means soil can loose (or gain) its temperature quicker,  especially if continental snow coverage has been reduced:

                                                 
     ASCAT 02/28 2019 gives a good idea of where the snow lies,   it shines bright white here,  there are many locations with scant coverage namely the Prairies or the Great North American Plains:

  January 29 2019 winds over none existent forests areas (link)  coincided with the 700 mb flow hitting  the State of Michigan (link).  Consider also vast American deforested farmlands adding to different specific heat capacity characteristics of the landscape.  Note ,  same day entire  North American Arctic was warmer than Michigan at that level as well,  even for since the start of winter (from actual Upper Air measurements)!  This is a very compelling bit of evidence suggesting that vortices within the Arctic Polar Vortex,  may take quite independent temperatures then the rest of the APV.    I call one of these vortices simply as a vortice.  Usually a Southern NE American vortice becomes rogue because it is pushed Southwards by Quebec\Labrador massive cyclones ascending towards Baffin Bay,  which also warms a great chunk of the Polar Vortex concurrently,  cutting off the Southern vortice to be on its own, thus a rogue.  The idea suggesting the jet stream pushing down a rogue vortice has long been accepted as the reason why they are displaced,  but a vortice is usually part of the Polar Vortex where the jet stream is at its perimeter,  not within.

   As the world warms extreme weather increases because the Polar Vortex is shrunken and or stretched. 

         To make this evident,  consider thinner Arctic Ocean sea ice warming the Upper Air directly above.  Observing what happens to the Upper Air there is key.  What has and is happening is Arctic Polar Vortex stretched to from Maine towards Northern China, on the Axis aligned with Greenland to Vladivostok.  The core of the Vortex is hollowed over this Ocean once frozen with mainly 10 meters of sea ice, now reduced to 1.5 to 2 meters.   therefore the Polar Vortex of late is usually stretched and can split in two,  especially  during a warm winter similar to 2016.    The weather of the Northern Hemisphere is thus rapidly changing by the shrunken Polar Vortex which favors the winter warming of Alaska and Norway,  but cooling at times of Central Southern Russia  and Midwest North America during winter.  As an example I use the Polar Vortex event of January 29 2019:

                             White Lake         Fairbanks
                            Michigan  USA  Alaska USA
January 29              -19.7                     -11.5
January 30              -39.3                      -9.5
January 31              -28.3 C                  -16.5   700 mb temperatures.

      The North was and is very often warmer some 3000 Southwest miles away

    It is very possible to have such extreme events given the right circumstances.   However winters great deep freezes well South of the Arctic are furtive,  they may not be long lasting,  as White Lake's current +9C weather may attest, compared to Fairbanks current -13 C even still warmish.  As AGW increases,  the weather in many places in the Northern Hemisphere will get even more strange and extreme. WD February 3 2019