0800 EDT   9  NOVEMBER

First let me start out with a couple of announcements.  There is going to be a new subcategory  on  the WXRISK.COM   page.. called  HARDCORE

This subcategory will be dealing with the serious meteorological  analysis.  I hope to update this subcategory/ page   EVERY DAY  around 0700  EDT  or so.   It is going to be primarily aimed at energy meteorologists   Grain Meteorologists   TV Meteorologists  and  all those who have a need or dseire to read    serious hardcore meterology.   It will be free  for all.   The subcategory HARDCORE    will NOT  be for  the layman or average  person  and I  hope I will make that  make that quite clear.      For  average folks   that are NOT     Hardcore   weather   nuts or  professional   Meteorologists …     I will be using   WINTER  2011-12  subcategory/ page. 

Increasingly there are more signs that a significant pattern change is coming for North America.  And that even though the next 7 to 10 days over most of eastern  CONUS — and  eastern Canada  for that matter — are going to see some pretty impressive warm temperatures for the middle of November— things are starting to move and the pattern is beginning to shift. 

In the last discussion  -NOV 5– I pointed out the several key players hemispherically  which have to change with regard to the current pattern…  in order for some sort of reasonably winter like hemisphere pattern to develop. 
IMAGE # 1  we see TWO  Maps ….   the Map on the LEFT  side  is the CURRENT  hemispheric  pattern as of November 8.  This is from the 12z initial European model  (ECMWF)    ENSEMBLE  and again of highlighted some important key features.

As I pointed out back on Saturday we still only have one large intense Polar Vortex which is situated over the northeast the slopes of Siberia.  There is no PV  anywhere in the western hemisphere…  which is  one of the primary reasons why the pattern has been so Mild.  With the polar  Vortex  on the other side of the arctic circle there  is no large pool of cold air in the western hemisphere to draw on.  We can see this on the map on the right side….  The white line shows the boundary of the arctic air and as you can see it’s extremely far to the north a specially for early and middle of November.    So even if there  was want to get a large cold High to come south it would consist of mile Pacifc  air.     In addition we can see the strong ridge over the eastern third or eastern half of the  CONUS  and the Scandinavian rage extending from the Ukraine  into central and northern Norway and Sweden.

In IMAGE #2 …     there are  3 maps…. all   based on the 12z   ECMWF of 12z  NOV 8… and  all 3  are valid for NOV 15.  The first map again is a large scale hemispheric  view.  First we can see that the model is showing that the PV   is SPLITTING  into two pieces. 

 SECOND  the RIDGE over Scandinavia has now moved into the UK and is building towards Iceland.  This movement counts as a eastern based  – NAO feature. 

THIRD… the   strong ridge over the eastern half of the country has been pushed more towards the southeast and  Northeast  US coasts. 

  FOURTH… We can clearly see a massive trough developing over western and Central Canada….  and the big ridge  over the north Pacific  is sliding WEST  towards the international dateline.  This is allowing for the mean trough which has been over the West Coast to slide into the Rockies.

 The   2nd  map  in IMAGE  2…  Shows the large scale cold air pouring across the Arctic circle into western and North Central Canada for the first time this season.  The third map is just a more localized view of this…  with the arctic cold finally poaching the was Canada border for the first time this season. Also  note how  very warm it is  the Southeast  and Northeast  US.

IMAGE  #3  is the day 10 European map…  Valid for November 18.   Again we have three maps in image number 3 to look at.

The first image shows the hemispheric projection of the day 10 European.  We can clearly see two polar vortexes have  formed….  with the first or original   PV   now located over Central Russia near the Ural Mts.  This is important because if you recall the original position was over  north  side of eastern Siberia.  This movement  of PV #1  to the   central Russia   is  allowing to  Pac Jet to relax—   meaning that the Pacific jet is more likely to buckle or change shape.     And note that the powerful southeast U.S. ridge is now mostly out into the Western Atlantic Ocean.

The second map  in  image #3   shows the arctic air now moving into an across the U.S. Canada border…  And that the Arctic air is rapidly building up too impressive levels over all of western and North Central Canada!  Again why is important?–  IF Canada does not have any colder air in it…   it neither will the U.S.

The  Third image   is  again the   US Map …  of the  day 10 European model.  We can see the cold air finally moving into Northern Washington State hide a whole Montana North Dakota and Minnesota.

IMAGE  #4   is the chart of the 12z MODEL showing  the   NAO    and EPO   patterns. 

 There are four charts:   the  top   left  one shows the overall NAO.     And you can see that most of the models show this feature becoming consistently but moderately negative over the next 10 to 14 days.  The image on the top right  shows the west based  or GREENLAND  NAO.   Note here that the graphs  are all very close to Neutral…  which is telling us that the Scandinavia block has not reached as far west as Greenland.

The bottom  LEFT  map is the  east based  -NAO   and here we see  a strong   Negative signal which tells us that the Scandinavian ridge   does move    west  over the next 2 weeks.    The Bottom  RIGHT  map   shows the  EPO  phase which finally moves into the positive phase.

LASTLY  image #5  shows the  PNA   trends and all the model data continues to show this feature to be running strongly negative for the next two weeks. 

 SUMMARY:  the pattern is clearly going to start changing over the next 10 days.  But the key here is to recognize that it’s starting to change.    While all this is going on in the northern hemisphere at the high latitudes most of the next 10 days over the central and eastern U.S. will be mild.     For most people today will be seeing the weather pattern and their conditions every day…  and be wondering  “ where is  winter?”….   ” where is the cold air?”…

Assuming that the European   ENSEMBLE means  are correct….  true arctic air  will finally reach western and central Canada   by the 15th…  BUT  not the leading edge of the cold air will Just be  reaching the U.S. Canada border  by NOV 18 .  Assuming all this is correct seasonally cold air will NOT  reached the East Coast before November  20-22.

In addition even though the cold air buildup in western and central and Northern Canada will be impressive over the next 14 days… as  long  as the  PNA   remain   negative…   ( as long as the trough  remains over the  West coast or western   third of the US)     we are talking about a seasonally cold pattern in the U.S.    With a  -PNA there will be no mechanism for the arctic air building up and Western Central Canada to come south.

Now eventually  once the  -PNA   turns neutral and   then positive…  All that cold air building up in central northern and Western Canada will be able to come south.  And that could make for some mighty impressive cold air masses come  DEC  2011…. let me tell you. 

All in all if you like cold weather…  Things are trending your way.  Just remember…  We have a long way to go before we get out of this     super Mild  pattern.