2200  EST  15 FEB   2012

I am often asked a question like  ” what does my  gut say…?”   or   “what is my instinct about this particular event ?..”    My response has been and will always be I do not forecast by gut or by emotion or by instinct .  There are some other well known meteorologists — and a lot of   weather   weenies–  who do that and  it usually results in disaster.  By committing to  one particular  forecast Model or  idea days ahead of time …   their  bias  becomes involved the forecast process.   When one model comes out which shows what they think is going to happen… they  Have  TO  latch onto   to that idea it because they have decided days out to go with that particular solution.  In other  words  by   committing so early  to only solution  one loses  the ability  to think   critically.

DT ‘S MEDIUM  RULE #3…   when  ANY  Model … which has been showing  XYZ   for many consecutive runs in a row…  Suddenly shifts and in 1  run shows  ABC….  The other pretty good that that shift is wrong…  Unless all the other weather models also show the same sort of  BIG shift.

The reason why this rule works is that in the current state of  numerical model prediction   — weather models– they are sufficiently accurate and of high enough quality that  it almost all cases if one model shows a shift of significance the other models will fairly quickly follow suit.
This is why I NEVER  Forecast by instinct or Gut.  This is why   REFUSE  to even  consider   the GFS past 72   -84  hours hours when it comes to East Coast winter storms.      Now that being said    I am sure others e are going to manipulate or lie or change this assertion into something that I haven’t said.     I do  NOT have a problem with the GFS model for certain weather patterns   OR  once  we are within 84 hours.  The  0z 15FEB   GFS  model run  was a massive …severe  unprecedented shift…  sSifting the coastal Low  from  the Georgia Coast …  suddenly  300 Miles to the nw  over  ATL…  from passing south and east of Cape Hatteras   to passing   west of Norfolk … fromn showing NO precipitation of any kind north a Washington, DC …  to driving heavy snow and rain into New York City Albany and will Willaimsport  PA.   The fact that you may be living in the northeast big cities and the  0Z GFS  is the picture perfect and one that you want to see for your location does it mean that the solution is a viable.

The proof ? all the OTHER  weather models did not show any significant change in their track or forecast and the updated  6z GFS has gone back to the southeast U.S. coastal solution.

This is supported by the Canadian and the British models 0Z  FEB  15   runs    as well as the 0z  ECMWF     and  the 0z European  Ensemble….  All   showed  ABOUT  the same  SORT  of thing”    the surface Low  tracking along the SE US   coast   in a  ENE direction   then over   or close to  Cape Hatteras.  There   was   absolutely no supported  at all for the ridiculous  0z GFS . None.

In fact the 0z FEB  15 European model had no precipitation of any kind north of Fredericksburg…  The Canadian and the British models do not have any significant snow north of the Washington, DC Baltimore area.   Again I Hope  realize  that   reporting and  discussing   the weather models does  NOT  mean that   the point I am Making   is   MY forecast..     I am  CERTAIN that this will    event wiill become  a mjaor    Precip  event .

We  saw  the same sort of thing   with the 12z GFS  ..  Another solution which was unsupported by even the GFS   Ensemble .  It became so bad   that at midday   15 FEB  HPC had issued a special statement regarding the bizarre scenarios and solutions being proposed by the 12Z  15FEB  operational GFS run.

From HPC Model discussion-THE GFS APPEARS TO HAVE WORSE INITIALIZATION OF THE TROUGH’S PLACEMENT OVER BRITISH COLUMBIA AND NUNAVUT THIS MORNING COMPARED TO THE NAM/ECMWF. MEANWHILE…THE GFS IS MOST AGGRESSIVE IN ALLOWING AN UPSTREAM PERTURBATION CURRENTLY OVER THE PACIFIC TO CUT THROUGH THE SHORTWAVE RIDGE OVER THE CANADIAN ROCKIES ON THURSDAY…WHICH THEN PHASES WITH THE NORTHERN STREAM AND SLOWS THE ENTIRE GFS SOLUTION. THE COMBINATION OF WORSE INITIALIZATION AND QUESTIONABLE AND EVEN SUSPICIOUS PHASING OF THE SEPARATE STREAMS IS SUFFICIENT TO DISCARD THE GFS

But     the   Model  fiasco   last night with the  0z 15 FEB GFS  and  12z  15 FEB GFS  does  emphasize again why I think the  GFS  model …  with espect the East Coast winter storms … is a  piece of  crap..  Note that so far  NONE  of the other medium   range large scale models has shown any sort of  HUGE  wild  swings   in  6  or 12 hrs time increments.      NONE.

Increasingly this looks to me more and more as a Shenandoah Valley /  western VA….and Northern Virginia snowstorm    then up into   DCA/ BWI  area  and possibly  into  southern NJ  .  Richmond I think is going to be more wet than white but I am not absolutely convinced of that all of the event is   going to be all rain   for  central VA.

The area from Lexington south to Roanoke then down to   Hillsville poses of what I think to be the biggest challenges forecast.  Clearly areas which are in elevated terrain have  much better chance of seeing or staying all snow and clearly areas which are and north of interstate 81 have a even better chance of seeing snow…  Either in its entirety or a mixture of rain / snwo  going over to snow as the cold air is pulled into the system.  Once you move north of Lexington and Lynchburg there should be and of cold air east of interstate 81 so that the rain

Of course if one follows the   12z  FEB  15  European model…  And if you have access to the precipitation panels you  will have  seen that very little precipitation falls north of a line front Richmond to Roanoke Virginia.  However the European  Ensemble is much weather and has a large significant precipitation shield …with    precipitation amounts   of  0.25″    that extends    to the Virginia West Virginia border as well as the Maryland Pennsylvania border and into Southern New Jersey .

There could of course the snow to the north of that…  into Philadelphia and New York City.   In fact I suspect is probably going to be even though as a deceiving most of the TV stations in those markets are not forecasting snow into those cities.  That being said a honest interpretation of the pattern and what the model data has been showing in trending   – again ignoring all 4 runs of   15 FEB GFS    –   0z   6z   12z ans 18z  – shows that this is not going to be tracking up towards Cape COD with a benchmark.  That sort of thinking and analysis is just  outright delusioal   and  shows a  poor grasp of basic meteorology .

That  is not to say there aren’t meteorologists out there who are forecasting that but the data does not support a track of the   Low to the benchmark of   40N/ 70 W.   And more importantly the overall 500 MB clearly does not support that a specially with a large  closed 500 Low over  se   Canada.

1330  EST   13  FEB  2012

click on the image to  see   FULL SIZE

so much  to say  so much to say   so much to say –   DAVE MATHEWS    BAND.

Really I do.  If you  are a energy meteorologist  or   a TV  meteorologist…   this winter has not been particularly enticing here in the  U.S.     Of course given  that the last two winters have been gangbusters  those two types of  Meteorologists   probably need a break.  BUT if you are  agricultural /Grain  meteorology   –  and I do far more Gain  weather than energy weather -    and it’s been gangbusters  all around the world and helluva lot of fun.

Every single day I am issuing forecasts not just for the U.S.  Plains /  Midwest but for Argentina and Brazil …South Africa… Australia Europe… the Ukraine… Southwest Russia and Kazakhstan and then when their growing seasons are up and running China and India  as well.

wow…. Ya know when  I think about it… I do a lot of work every day.  Plus the  web site and the FB  page.  But really it’s not work at all because if I couldn’t forecast weather I probably starve to death.  Right now for example  much of Argentina and Southeast Brazil bring areas have been devastated by a  drought and three prolonged key ways since mid December.    One location in West Central Argentina  — Santiago Del  Estero — reported a Max temperature of 50°  C   or  122 degrees  F.  Now that reading is probably in error but a lot of  places and Argentina on the 30th sought Max temperature of 40 degrees  C   or 105  degrees F.   However a monster  HEAT DOME  has moved into Eastern Brazil which is  going too slowly drift towards Bolivia and Paraguay over the next several days while at the same time a cold front moves into Central Argentina.  This cold  front is going stall because of the heat dome blocking its path and portions of  Central Argentina could see some pretty good rains…  But then  there may be yet another interval of significant heat in Argentina in mid February!

Now if we take a look over in Russia … several locations this morning January 31 temperatures drop to -28° C /-18F. !  Even more important is that for most of December and January the Ukraine and southwest Russia has seen much  above normal temperatures.  There  has not been a lot of snow cover and some of  the winter wheat crop has already tried to break ground in Southern Ukraine and
southwest Russia.  Now along comes as monster arctic HIGH at  1061 mb  over  Northwest Russia near Saint Petersburg which has spread the cold all way to the  Rhine river!  This morning in Bulgaria  many locations had temperatures dropped to zero degrees Fahrenheit .

If this sounds like I am  really enthusiastic about  weather worldwide…  I really am.  But the truth of the matter is that I get this  excited about ALL weather almost every single day.  As a result I can go out of my way to  post about how warm it’s going to be in the Middle Atlantic states 7 to 10 days out with the same amount of enthusiasm  that I have for a big winter storm.   So while it  IS true  that I do love East Coast snowstorms and East  Coast hurricanes a lot …I try not to let my fondness for those particular type of weather events distract me or by state in any way.  And one of the ways I do that is to get excited about weather which many of you may not feel is all that
great or noteworthy.

Some of you have noted over the past week  that  in the  debate   about the  idea of FEB 2012 turning   colder and  or stormier for the  eastern Conus … my overall perspective  or  attitude    has changed.    Lead me be upfront and frank about this     YES  my perception  and  views  about February 2012 has changed from   from  what it was last week.  Now  some of you…  may view me  as   “Johnny come lately“  to the party as other well known meteorologists have been talking about a much colder and potentially more winter like February 2012 for the last couple weeks.     OK fair enough.

But if you are going to make that same judgment then it’s only fair to note that some of these other same meteorologists have been banging the drum for a major pattern change over North America several times this winter and  as we all KNOW .. it has NOT  happened.    One energy trader made a joking comment  to  me   that this well known private meteorologist up in New England    “has forecasted seven of the last zero pattern changes…”     OUCH…

In the arguments I made  over the past few weeks against the  idea of  a  BIG  pattern change …  I tried  to drive home the importance and the significance of the huge Polar Vortex in the jet stream sitting up north of Alaska …on the Asian side of the Arctic circle.  Time and time again I stated that in order to get a pattern change in North America that feature has to move or break down or shift or do something  …because as long as it stays there  nothing is going to happen  regardless of what any model might or might not be  saying .

Now  we are  finally  seeing that huge Polar Vortex breaking down and changing.  That is why I am  more bullish about February than  I was before.    I set up by specific criteria or checklist of things which I had to see happen  FIRST  before I jump on board.  Now that I see those    things happening my perspective has changed.    To me is not important as to whether or  not to   “call it FIRST!  “   You don’t get extra money …the girls don’t think  you are any  sexier and you don’t dance any better.
I think it is very important to notice that few if any of the meteorologist   that have the  “ call it first  “  attitude never come out and say  ” the issue is uncertain”  or  “ the issue is undecided“.     Yet as we all know small changes often lead to very big variations   as you go further out in time.  Therefore the perspective / goal of always trying to   CALL IT FIRST  can only  Blow   up in your face because sometimes you can not call it First.  Sometimes you cannot  make the call   right now  based on the current data.

The problem is that if you decide to chase the  goal   of   “Calling  it  first “   is the most important thing as a professional meteorologist …  you may get on TV the most  but  in the end     you will  also  get the reputation   of    “forecasting seven of the last nonexistent pattern changes”.   In the end you will end up cutting off  your  nose despite  your face because all  of your forecasts  will be looked at with a great deal of skepticism and of little value to people who have serious money and  would d normally be interested in what you  have to say.

THE FEB 5-6  EVENT….  its coming  North !!!!!

The models at midday are clearly not in agreement.    All the models do  agree that a strong ocean Low was going to form and stall over Southeast Canada/ Newfoundland over the next 4 days .  This deep system will set up a strong  CONFLUENT  flow in the polar jet …  That will allow for a relatively cold area of High pressure over Eastern Canada  too develop  (near Montreal ).  So far so good.
However the European Model with its bias  to develop systems too far to the west …ends up closing off the upper Low over western KS.     At the same time the  Ridge  over the West Coast  of  N America –part of the +PNA    – begins to develop so the Ridge traps the upper Low  over  KS is delayed for several days.  The precipitation shield completely falls apart as  the Upper Low  tries to Under cut the Ridge and move into the Great Lakes.  By the time the precipitation finally reaches the Appalachians and the East Coast the cold air source over southeastern Canada is gone so whatever falls is mild and rain.  I believe that the European solution  for  FEB 5-6  at  Midday  is   NOT   the correct solution.

On the other hand      some   of you  out there  –and I   know you who are   because I have seen your posts on various whether forms–   are arguing that the flat weak Low   on the  12z and 18z JAN 31  GFS solutions   that moves off the NC / VA coast is underdone…  and / or that we will see a bigger Low pressure area come off the coast and it will come further  North…  Well that  is not correct either.

The problem is that strong northern branch of the jet stream cutting  across New England.  As long as that feature  is there and supplying the cold   air this Low pressure area cannot  possibly come UP the coast.  If anything  the Low will continue to get crushed and stay fairly flat and unorganized the cause of the strong polar jet over New England.

Now let’s be careful  with what I just said.    I did NOT  say the Low that comes off the North Carolina Virginia Coast cannot possibly come north the matter what.  What I said was that as long as that strong polar jet remains over  New England the Low cannot   come north.

My view is that we are going to see a system that will be struggling to hold together as it moves off the North Carolina were Virginia Coast.  It will bring some snow and ice to MD   se PA  s NJ     Northern DEL  and ice to rain over eastern  and central  VA.  It is possible that the northern half of the Shenandoah Valley could see pretty good ice event…  say from Charlottesville  North to Winchester and Martinsburg.

THEN WHAT?

The operational European this afternoon as well as the European ensemble was  very bullish on the much colder pattern coming into the U.S.  However I have to  let you know that a LOT of energy meteorologist treated the European model with a tremendous amount of skepticism and disbelief.  The general view is that the pattern is going to turn colder for a 10 or 15 day  period …say from   FEB 5/6   to   FEB 15-19.  But that the cold is not going to be nearly as severe as some other meteorologists have been screaming about for the past two weeks.

That argument is based on the fact that the Polar Vortex that forms in North America stays over northeastern Quebec Canada and is not really far enough to the south or west to drive the arctic air into  the CONUS.     Indeed if you look at the day 10 European map at the 500 mb  you will see a a very deep intense and large    PV  in Eastern Canada.   And as you can see the   COLD air   pool around the   PV is equally impressive .  But  notice that the  deep blues  and purples are not coming south into the U.S.   as the   arctic  cold is   pretty  much trapped around the immense circulation of the Polar vortex.

In order to get this severe cold into some portion of the Great Lakes or New England in the second or third week of February …the PV has got to come  further south and west more towards the northern Great Lakes.  The current  position as forecasted by the  Day 10 operational European  or the   day 10  European  Ensemble is just not far enough to the south and west to drive true  arctic air into the U.S..

In other words its cold but it is not bitter cold and it is not severe cold.  If you like cold weather   then  FEB 2012  is going to be the  pretty  good.  The cold pattern could last for a couple weeks of February.  But it may be that some have been overselling this colder  pattern by a significant amount.

One last point before I  close.  Since January 29 I have been talking  about the possibility of a significant East Coast winter storm threat sometime around February 10-11-12.  I continue to see the potential  on the 0z and 12z  models …on the  GFS  and European operational models .. and on the  GFS and  European    ensemble mean  patterns.  It’s quite likely over the next few days that the GFS model in particular   will  LOSE  the  possible    southern Low….  By either crushing a completely in the cold a pattern or by losing the   southern feature.  My view is that the system for February   10-11-12 has far more serious potential then the  FEB 5-6   event .

Again this sort of confidence I have  for this  potential threat may seem to some of you to be a surprise or hard to figure given my reluctance to forecast the pattern change earlier in January.     But as I said many times once you know what sort of features   at  850  700    500    and 300 mb  mb   and what   those  maps  look  like for  big East coast snowstorms…   then the   favorable  pattern are  rather easy to detect several days out.    When the pattern is there  I am   there  and if the  potential is there  I can be rather positive about the chances if I think it’s warranted.   But if the pattern is not there I don’t give a hoot  in  hell  what  ANY weather model   is  depicting or  not   depicting — I won’t jump and I will be pessimistic .

My goal with East Coast snowstorm has always been to walk the line where you can see it coming and tell people it’s going to be big event several days out but not to oversell it or overhyped the event  just to get viewer clicks or readings .  My goal has been and will always be  here at wxrisk.com when it comes to East Coast  snowstorms… that If I say  its   coming   it is…  And when I say it’s going
to be serious   it is.

Well that’s the goal anyway.

0130  JAN   8  2011…. STARDATE  201201.8

It is 1:00 AM and I probably should not be doing this but after   looking at the latest data this evening I am so excited about the upcoming pattern change that I actually cant  sleep.    I am reminded of the U2 song      Something is about to give… I can feel it coming… and I think I know   what it means…

The problem is I don’t know how to begin to describe this pattern  change.  On the one hand I don’t wanna go   ballistic and sound like I am  freaking out…  But on the other hand it’s hard to look at this stuff and  NOT  salivate .    The  POTENTIAL   for the upcoming pattern flip to be historic in  terms of the reversal of what we have seen so far is pretty darn impressive.

Even though the pattern remains quite warm across  of most of the U.S.  there   are major changes under way.  This is   the current hemispheric jet stream map   at 500 MB   JAN 7….  and we can see three distinct ready areas which represent   positive height anomalies or ridges  which are building.  The first one is over  the West Coast  of North America.  The second one is over Central Russia of which is building in towards the Asian side of the arctic circle…  And the  third one is building over the the Azores the northeast and Atlantic and in  towards the UK.

The large and powerful rain storm which is likely to hit much of the eastern U.S. in some form or another on JAN 10-11…  will probably be the  beginning of the event and set off the pattern change.    Once this Low  moves through the northeast US and into southeastern Canada there will be a  large scale arctic outbreak  JAN  12-15 across all of the CONUS east of the  Mississippi River.  This outbreak has been showing up with the model for several  days and is well handled by most of the medium range models.  However is a lot  more to this   than   just     this  arctic air mass outbreak…  which will be  reinforced by a second  cold front   JAN 15 .

This next image shows the overall pattern  at  Day 9- JAN 16.  The map of  the left hand side is the European the map and the right hand side is the GFS.   The models do not agree on what   is going  happen over the eastern US– the  European as a deeper trough  ( dark blue shading)   whereas the GFS   shows a   zonal flow.  The model disagree because the European has a    Low off the Pacific Northwest coast… which in turn shows a bit of are Ridge  over  southwestern Canada… which in turn   allows the  model  to  orm that trough  over the eastern US.

However that’s not what’s really important here.  The key thing here is to  look at what happens over Alaska and the Bering sea as well as Scandinavia/ Northern Europe.

Both model show a rapid explosion in positive height anomalies at 500 MB over the the Bering sea Alaska and far eastern Siberia.  In other words there  is a strong Ridge  which  is building in the jet stream  and  rapidly expanding into the arctic region .  This feature is called the  the negative phase of the  WPO- — western Pacific oscillation.  For most of the winter we been in a  strongly positive phase   of the WPO….  which is featured a large   500 Low over Alaska and the Bering sea.

The massive warming which is occurring at the stratospheric level –  SSW– is causing the entire western Pacific oscillation to reverse phase and  alignment.

In the classic case of the -WPO/-EPO  pattern which you can see here…  The development of a huge ridge over the Bering sea and Alaska is not a great pattern for  the Northeast quadrant of the country…  But it’s a pretty good winter storm pattern  for the Pacific Northwest…  Most of the Rockies…  the central & upper Plains the Great Lakes and  sometimes   New England.

In the  -WPO/-EPO  pattern the mean trough position is centered   over southwestern Canada and there  is often a large upper Low which develops over the Pacific Northwest / southwest Canada.  The arctic air comes pouring southward…  sometimes over the continental divide and the Pacific Northwest will suddenly turn bitterly cold and it could even be snowstorms in places such
as Portland and Seattle   right  on the coast .!!  ( see early  FEB 1989 and  DEC 2008) .

All other things being equal this pattern will often results in a flat Ridge existing over the southeastern U.S.  which allows much of the Deep South into the Middle Atlantic states to run either seasonal temperatures or mild temperatures and that means storm track is to the north along the Jet stream.     This  because    the    trough over the   western  or sw  Canada into the   Pacific NW still counts  as   -PNA

However there are exceptions to this.  There have been cases where the expansion of the ridge in the  Bering sea / far eastern Siberia and Western Alaska becomes so strong as it pushes into the arctic regions that the  deep 500 Low over Greenland  — the  super  +NAO  — it’s forced east away from Greenland it into Scandinavia.   At the very least such a movement would cause the  NAO  to  move from  strongly positive to neutral.   But as the   -WPO   ridge continues to expand into the arctic regions…    two things  can  and  do result .

FIRST   the    500 Mb heights over  Greenland begin to rise and move into  the positive anomaly stage which is the beginning of a   -NAO / Greenland ridge.  SECOND the super intense Polar Vortex …. aka   the super intense  +AO  (arctic oscillation)  is forced southward .   The   +AO heads  increasingly  further   and  further south in to  Hudson’s Bay.  This in turn forces   arctic air to spread south and east in all directions … across the  US  Canada border from the Pacific Northwest into New England.  The   further south the AO   moves  the colder and gets and the further south the arctic air drives  into  the CONUS .

In addition of course this movement of the  AO south forces the entire Jetstream pattern southward….  So even though we do not have a Ridge  on the West Coast per se  and the  PNA is still technically   negative  the pattern becomes  one that features below and much below normal temperatures over 80% of  the CONUS  and a very active and engaging winter storm track.

Of course this is a somewhat unusual scenario but not unprecedented.  True     this sort of  development in the   pattern  does not happen very often   but  the  massive stratospheric warming is of course helping this entire pattern develop as I’ve described above and we can see that  by taking a look at the CPC    super  ensemble  day 11  map .  Notice the large areas of red with lots of con tours around which had built across the Bering sea and eastern Siberia…  all the way into Greenland   by JAN 18.

The  + AO  is clearly being force    towards Hudson’s bay and deeper towards the U.S. Canada border.  Indeed this is exactly what the day 10 European  Ensemble is showing as well.  Notice here that the  AO  which has been over the  arctic circle for most of the winter is now south of the arctic circle over Baffin island and approaching the far northern portions of Hudson’s bay.

In  severe cases sometimes we even see a linkage between the -WPO  and the   -NAO o ver the arctic region.  The last time this happened  was in the severe cold winter Nov 15-  dec  31  of 1989.  This winter featured the second coldest  DEC   ever  on record for the entire United States and featured a historic blizzard for Eastern North Carolina Iin late  DEC.

All that being said let me be clear here…  I am not in any way forecasting a historically severe prolonged six week period of extreme cold…  At least not yet.  Nor my forecasting a historic snowstorm for Eastern North Carolina.  But as we can now will clearly see the stratospheric warming is real    it IS  impacting the entire pattern and things are rapidly changing.  We  are going to see the entire AO get forced southward but the only question is how  far to the south.

The 0z JAN 18   EURO  shows the trend nicely…

of course  there are   STILL lot of things  that can  go  WRONG  here…   for example   IF   the  -WPO  decides to slide  back  WEST into    central Siberia  that could be    problem.  If the NAO  goes  Neutral    and does NOT  go  negative…   THAT would also  lead to a different  result.

1000  EST   DEC  9…  STARDATE   201112.9

MODIFIED  1900 EST 

In case you did not  know it… the  final NOV   NAO   figures have come in… and the  actual NOV number   showed the NAO at +1.30.  Only 7   times    has  NOV  NAO been above  +1.0 

NOV 1952……  +1.04
NOV 1958……  +1.64
NOV 1977……..+3.04
NOV 1982 ……. +1.60
NOV 1986…….  +2.29
NOV  1992…..  .+1.19
NOV 1993……   +2.56
What did the NAO  do in the following   DJF periods?   Some  of the  NAO turned positive some   stayed negative  and  some split ….. with DEC staying positive while JAN  FEB turned  negative
NOV 1952……  DEC   -0.47    JAN  +0.37    FEB   +0.74
NOV 1958……  DEC   -0.70    JAN  -0.87     FEB   +0.68
NOV 1977……..DEC   -1.57    JAN  +1.38    FEB   +0.67
NOV 1982 …….DEC   -1.29    JAN  +1.59     FEB    -0.53
NOV 1986……. DEC  +0.99    JAN  -1.15      FEB   -0.73
NOV 1992…..   DEC   +0.47    JAN  +1.60    FEB  +0.50
NOV 1993……  DEC   +1.56   JAN  +1.04     FEB   +0.46

Keep in  Mind   we  have    weak to moderate  La Nina   event  underway  and   weaker  than last  winter.  Of course 1982-83   was   raging very strong El Ninio…. strongest ever    so that  is   NOT  really  relvant…    1986-87  was a moderate   El Nino  so again   I wouldnt   give that winter   much consideration  and  1977-78  was a weak  El NIno  winter.

1952-53  was   a neutral year as was  1958-59 and 1992-93   and 1993-94…so again  not good matches

Thus right now  we do not really have any  good analogs  of    strongly   Positive NAO and  La  Nina.  But  it  is also a  FACT   that  there  has  never been a   winter with a WEAK / Moderate La Nina    SHORT  DURATION   events    (  1962-63   1964-65   1984-85   1995-96    2010-11 )     where the NAO   has stayed  positive in all 3  months    DEC  JAN FEB   

Over in EUROPE   we can see the   continuing affects   of the super positive NAO  by the   frequent  development of these huge  ocean Lows  that   have  deen  dropping mdown to 960 and 950  mb.    I posted  on one of these monsters   Thursday afternoon  on the FACEBOOK  page.      The     Parade  of BIG  Ocean Lows  does NOT end  as the     day 5   Models  all show   another  a 950 mb Low    tracking   very close to the Ireland and Scotland at  950 MBs.

EURO  http://meteocentre.com/models/ecmwf_eur_00/GZ_PN_096_0000.gif

GFS   http://meteocentre.com/models/ukmet_eur_00/GZ_D5_PN_120_0000.gif

UKMET  http://meteocentre.com/models/gfs_eur_00/GZ_D5_PN_120_0000.gif

I raise  the  European  monster low tracks  because     the Primary reason why   NW   Europe — especially the UK and Norway -are   getting  battered by these  huge  Hurricane like ocean Lows …   is because of the   strongly  Positive   NAO.

The PSD   GFS  and  EURO  ensemble means keep the PNA  negative…  while the NAO  is  in   general   trend towards neutral
http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.pn.png

BUT keep in  mind all of the forecast Models have been  AWFUL…  I mean truly  wretched  this season  in forecasting the   NAO.  This image says it all…  on the  top graph  we can see the  NAO  actual  TRACK… and its   EXTREMELY positive      values   since mid NOV..

The  Bottom two   charts  shows  the GFS  ens PREDICTION at day 10 and at day 14 …  and   the   forecast  has   been  extreme in  the other  way…  consistenly  showing   the  exact WRONG   phase and intensity.

The  EPO  currently pos  moves  into   Moderate   negative values  but the  euro ensemble  does not support that .
http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.we.png

PSD  6-10 day  ens  mean is  very warm over the   eastern US … far warmer than   any of the recent GFS and  EURO ens  means
http://www.esrl.noaa.gov/psd/forecasts/reforecast/images/pentad2/hgt500fcstanom_2011120900.png

The 8-14   day  shows  more of the same BUT  it implies  that   with the   strong    se  ridge  and   strong neg   5h ( 500MB) aomalies  over the    eas
tern Canada … systems   may come out of the sw states   and tack into the   Ohio valley then into  New  England http://www.esrl.noaa.gov/psd/forecasts/reforecast/images/week2/hgt500fcstanom_2011120900.png

Of course given how   BADLY the  PSD  did last week   this   solution  is not one that I think is  correct.  In addition the   PSD  esn has NO support from any other model

LET LOOK AT THE  MJO…

GFS  ens  for  MJO curls    the  current impulse inwards then back out to phase 4http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/foregfs.shtml

OP GFS kills  the current  Impulse  off  totally
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/foroper.shtml

0z UKMET  does the  same
http://www.esrl.noaa.gov/psd//mjo/Forecasts/images/bmo.mjo.latest.png

as  does the  ECMWF  ens MJO  model
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtml

SUMMARY..  the  pattern for   rest   of DECEMBER  looks      QUIET..  without any hints of major  winters storms for the   EASTERN Conus . On the other hand  the   the pattern  does NOT look  nearly  as warm  as  it did  last week.   Its a   Blah pattern… with a bias of  SEASONALY mild temps over the    Deep south and   Mid Atlantic .    On the other hand the  western US   into the Rockies     ( and Upper Plains)  look cold… not severe  or  even major  cold..   but     cold and  very  wet .     If  we can get the current  MJO  impulse to   NOT   turn into the circle of  death  and ake it to phase 7  we could  see the patetrn finally shift. to one   where the mean trough  moves into the   eastern US…   But  right now that is   not   supported  by the   data.

 1700  EST   2  DEC  2011… STARDATE   201112.02  

One of the primary    reasons why a lot of meteorologists have turned sour on the winter is because of the belief in some of the longer range weather models which go out to three in four weeks.  Specifically I am referring to the European weeklies.      Back in the winter of 2009-10 and   last winter …European weekly  models  did a very good job in latching onto the pattern early.  They got the timing of the coal pattern when develop exactly right and the European weeklies also got the timing and the method in which the cold patterns will break down in February of last year.
Given that the European weekly forecasts are a relatively new product these models have developed a significant following a specially given the very good forecast we saw from this model over the last two winters.

As  we moved    through November more and more of the European   weekly  models showed no cold air of any kind reaching any portion of the central and eastern  CONUS.    Week after week –  twice a   week now– the European weekly showed nothing but a Moderate to deep trough over the West Coast  (-PNA) and a strong +NAO.  However as I pointed out a couple times already the European weeklies completely messed the upcoming cold shot next week for the Plains  the Midwest and the Northeast where  was  the     CFS vs2  did  not.  That model has correctly predicted that temperatures would actually run  a little below normal during the first 10 or 12 days of December for much of the country east of the Rockies.
However there’s another model which can be used in trying to figure out the patterns in the   week 2   and week 3  time  frame besides the European weeklies.

So may I introduce to you,  The one an only Billy Shears…. opps I mean the  one and only PSD  Model  from  ESRL….. ( Sargent Pepper’s Lonely Hearts Club band)….

What is the PSD?  As many of us know the Operational GFS  past 180 hrs is NOT very good.    The Model resolution shifts   (truncation) . The GFS ensemble (GEFS) helps  but the GEFS have the same problems the op GFS has. The PSD version of the GFS is an UPGRADED version of the old MRF from 1998 BUT…. with all the Model biases and corrections.      The  PSD  — aka    “reforecast “  model is an ensemble of 16 members  and  it  been shown have significantly better skill than the op-GFS and somewhat better skill than the GEFS in the 6-10 day and 11-15 day.
http://www.esrl.noaa.gov/psd/forecasts/reforecast/

There   is not much doubt that much of the country eastern Rockies will turn pretty cold next week and once the cold front cross of the East Coast on December 7 it will turn cold  there for at least a few days.  However the operational European model completely breaks down the West Coast ridge  DEC  11-12…  which ends up shutting off the supply of cold air into the central and eastern CONUS.
The   12z operational GFS is a little better  and slower with a delay of the strong rage on the West Coast but it also a clearly appears to be weakening.
However if we take a look at the PSD   ensemble we see a very different solution. The PSD at 240  is depicting a much stronger ridge along the West coast of North America with a strong flow of cold or even arctic air into a good portion of the central and eastern CONSU : The PSD  is a  cold  looking map.

If we look further out in time….  I can tell you that the 12z  European  ensemble at day 15 is not a good looking map if you want cold temperatures and were possible winter storms for the central and / or eastern CONUS.  The model shows the entire pattern or flow going flat and zonal with no ridge on the West Coast or the eastern Pacific…  no supply of cold air into any portion of the central or eastern U.S.  and mild Pacific air overrunning most the country.

Again however the PSD model is significantly different and shows a very strong ridge e covering the West coast of North America with a strong flow of cold war even arctic air into a central and eastern CONUS.     I do not know which of these models / solution   is  or will be correct.  But I  can ell you that the PSD reforecast   model has been doing pretty good and it’s been doing better than the European weeklies   in some respects.  Clearly however that can be no compromise between these two models as they are showing diametrically opposing solutions

0845   EST  30 NOV  2011…. STARDATE  201111.30

for those of you that get the much heralded eECMWF weeklies… which now come out rwice a week   (Monday and Thurday at 1710 CST) … it is  important   to keep in mind for weeks   and  weeks   EVERY run  of the  euro weeklies have been showing a large   -PNA pattern and nothing but mild to warm temps over the central and eastern US.     Even LAST week Euro weeklies showed the week   3  — DEC 4-10– map with NO cold air anywhere.

Yet we now KNOW that the week of  DEC 4-10 IS going to be pretty darn cold. I raise this because once again the euro weeklies are very mild for all of the US from the Rockies east to the Coast in week 3 and 4 for most of DECEMBER.   Sure the new NOV 29 euro weeklies NOW show DEC 4-10 as finally being cold…  but the euro weeklies  have been   all that  good as of late.

The 0z GFS ensemble mean 6-10 day 500 Mb height  anomalies– the very Positive  anomaly can be seen over the Gulf of Alaska just west of the AK panhandle  http://raleighwx.americanwx.com/models/gfsensemble/00zENS6-10day500mbHeightAnomalyNA.gif

the 11-15 day GFS ensemble 500 mb height anomalies has shifted well WEST which pulls   the trough   thatbi  over the Midwest back into the Plains / Rockies and Pac NW and allows for a new but weak  Ridge to  re-form   over the southeast US ridge.
http://raleighwx.americanwx.com/models/gfsensemble/00zENS11-15day500mbHeightAnomalyNA.gif

0z EURO day 7 has the West coast Ridge but  withn a  new  LL over the sw states (model bias)http://raleighwx.americanwx.com/models/euro/00zeuro500mbHGHTNH168.gif

By day 10 the 0z Euro breakdowns down the entire West coast pattern . Even so one just has to take glance to see a much more “relaxed” flow of the Pac jet over the N Pacific  http://raleighwx.americanwx.com/models/euro/00zeuro500mbHGHTNH240.gif

Here we can see very different day 9 Maps. The 0z Euro argues that the cold blast is going to be very short lived as it breaks down the entire West coast ridge / -EPO very quickly which results in ZONAL flow and any cold air flow getting into the Conus. The day 9 Op-GFS still has -EPO / West coast Ridge and fairly deep trough over the eastern half of the US. Both models shows  a strong -NAO.  http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

Look at the teleconnection trends we see the EPO strongly negative   that then moves  rapidly back to neutral by DEC 12-13
http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.we.png

while the PNA which starts Positive moves steadily deeper as the -EPO weakens and moves towards nautral
http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.pn.png

I am seeing some changes in the pattern over in Europe and Russa that may have more significant implications for the NAO phase and that many are over looking.    Over the past 30 days NOV 2011 has featured VERY stormy conditions over Iceland into the UK the North Sea and into Norway and Sweden.   These Low have NOT been crashing into western central and eastern Europe because of a strong Ridge in the Jet stream stretching from Spain to the Ukraine.   The Ukraine and sw Russia winter wheat crop is in big trouble because of lack of all precip . But that ridge is moving — the temps in central and western Russia have turned warmer

This weekend the Biggest most intense Low on this current wavetrain may hit N Scotland then pass into southwest Norway — Monday data saw 944 mb but the 0z data today shows 940s.   Once this big Low passes it is possible that the ridge over western and central Europe will get the chance to ” JUMP”" into the Azores in the northeast Atlantic.    From there the 500 MB ridge will have to be watched to see IF she can build towards iceland.

0z GFS MJO plots  pushes current MJO into phase 5…. which is very warm for DC over the Plains and Midwest
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/ensplume_full.gif

CA -AR-PC MJO models show significant weakening as the MJO moves through phase 3 then  4   then into  5
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/forca.shtml

UKMO which KILLS the current Impulse as soon as it enters phase 4
http://www.esrl.noaa.gov/psd//mjo/Forecasts/images/bmo.mjo.latest.png

ECMWF ens mean same sort of thing
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtml

This  is  leaves open  the possibility that  IF  the MJO impulse  does collapse   the  pattern  could  suddenly   turn   cvery different   – PROBABLY colder  — very  rapidly.

0730  EST    21 NOV  2011…     STARDATE  201111.21

I am sure someone like Bill Karins the morning meteorologist on MSNBC is a good guy and all but I am listening to him tell everybody that Wednesday, November 23 is going be a “really bad travel day in the northeast US ” because of all this heavy rain coming.    While it is going to rain a lot on Tuesday night and early Wednesday morning ….the data clearly shows that by a Wednesday 7 0700 EST most of the heavy rain will be north of Boston up across Northern New England Montreal and Maine.    I am not exactly sure what he is looking at but based on what I am seeing early this morning … that forecast is a lot of nonsense.   Here is the 700 MN RH field from the 0z GFS valid at 0700 EST Wed 11/23. As you can see the heavy rain is about to pull out of Boston and is falling mostly over interior portions of New Hampshire Vermont and Maine and Montreal.    This does not like a bad travel day to me up and down the I-95 corridor– perhaps some early morning delays but things should rapidly improve as skies clear out.  http://mag.ncep.noaa.gov/GemPakTier/MagGemPakImages/gfs/20111121/00/gfs_namer_060_700_rh_ht.gif

The other major issue has to do with the development of a potentially large close cut off  Low at the base of the trough on November 27 over the Midwest.    The 0z and 6z GFS are going absolutely bonkers with the system developing a four or five closed off contoured 500 MB cut off Low over the Tennessee Valley late on the 27th into the 28th.
http://meteocentre.com/models/gfs_amer_00/GZ_D5_PN_168_0000.gifhttp://meteocentre.com/models/gfs_amer_06/GZ_D5_PN_168_0000.gif

The European model which was showing this sort of development on Sunday has backed off of that idea.   The 0z Monday 11/21 run now the shows a deep trough moving rapidly through the East Coast and does not close off a deep 500 MB Low at the base of thre trough. http://meteocentre.com/models/ecmwf_amer_00/GZ_PN_168_0000.gif

The 0z Canadian also develops this sort of feature.    The development of this potentially significant deep closed cut off Low would be hard to overstate. Since the entire feature develops a negative tilt at 500 MB the downstream difluent flow along with the extremely warm temperatures … southerly winds bringing in copious moisture and the slow movement of the system …could set up a significant severe weather event for much of the Middle Atlantic states into NY and potentially into western New England lay on the 27th into the 28th.   Taken verbatim both the 0z and 6z GFS development of the deep closed 500 Low argues for SNOW to fall over the mtns of TN eastern KY southwest VA western NC and southern WVA .

The 0z GFS ensemble shows almost no support for this solution. A FEW of the individual members to show a closed 500 Low over the Tennessee Valley that moves through the Middle Atlantic states at day 7.     http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f168.html

The 6z GFS ENSEMBLE is much more impressive with 7 of 11 supporting the idea of a deep closed cutoff 500 Low over the TN or Ohio valleys.
http://www.meteo.psu.edu/~gadomski/ENSHGT_6z/f156.html

on the 6z GFS ensemble … 13 of the 20 member ensemble support the idea of deep closed cutofff Low … so I cannot rule out of the GFS completely. I am however worried that this is from a 6Z run which statistically as been proven to be more unreliable than the 0z run.
http://www.meteo.psu.edu/~gadomski/ENSHGTWIDE_6z/f156.gif

More impressive is the vastly improved NOGAPS model with its 4dvar… and its 20 ensemble .As you can see here not only does this deep close 500 low show up on the ensemble mean but 18 of the 20 members as well.
http://www.meteo.psu.edu/~gadomski/ENSNAVYHGTWIDE_0z/f168.gif

The Euro ensemble does NOT support this and closely matches the operational run.   By day  9-10  the model has a strong cold front sweeping through the Plains the Midwest and the Northeast. Low pressure is forming over Texarkana and it looks like is going be a significant snowstorm for the Midwest DEC 1-2.

  My view is that since the European or r European ensemble is not yet on board with the idea of deep closed 500 Low over the TN Valley on the 27th and 28th …. in fact it was moved away from that scenario — I cannot go with it  . I am not convinced that the European solution is correct but right now… given the overall synoptic pattern and the lack of high latitude blocking ….I remain skeptical of the extreme solution posed by the GFS the Canadian and the NOGAPS and their ensembles.  If later on today the European model turns back towards a solution well I will be banging that big closed Low idea… like a cheap whore.

longer Term … It appears once again that the usual sources are jumping up and down about some sort a major pattern change coming as we move into DEC….   And clearly the data does not support that sort of excitment or hype.  The data does show the pattern turning someoine colder of the central and eastern CONUS and ace and to the excessively torrential rains overt the Pacific Northwest.

Here we can see the deep 500 Low… the PV … That has been over the gulf Alaska and the Yukon… Retrograding towards the Bering sea …. Which in turn allows for some MODERATE 500 MB height rises to occur over the Pacific NW.   So the pattern   IS  turning a bit colder and more seasonal as we move into December.
http://raleighwx.americanwx.com/models/gfsensemble/00zENS11-15day500mbHeightAnomalyNA.gif

This shows up on the European ensemble as well.
http://raleighwx.americanwx.com/models/ecmwfens/00zecmwfens500mbHGHTNA240.gif

Again nothing overpowering but certainly colder than it has been ( which is NOT saying Much). However if we change perspective and we look at this from the northern hemisphere view      http://raleighwx.americanwx.com/models/ecmwfens/00zecmwfens500mbHGHTNH240.gif

We see that the polar vortex– 2 of them — are still on the WRONG side of the hemisphere for any sort of significant sustained colder outbreaks getting into any portion of the U.S. Or Southern Canada. The AO is very Positive as is the NAO.
http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.pn.png

the EPO is beginning to come back towards earth and near neutral conditions by day 15
http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.we.png

One last note in this concerns the current WEAK MJO… Don’t forget to look at this link which shows other MJO models besides the CPC GFS stuff.   Most of the GFS / CPC MJO plots show the current MJO impulse weakening moving into the circle of death somewhere in Phase 2.   The European Briitsh Japanese and Brazilian models do  NOT   shows weakening actually shows the current Impulse gaining mater intensity as it moves into phase 3 and 4 in early DEC.   Clearly such a development would have potentially significant impact on the idea of a cold December over the central and eastern U.S.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

  16  NOVEMBER   1000  HRS  EST

From what I can see there is absolutely no reason at all to chaage to   current  attern  or even begin to speculate    WHEN things might   change. I know for the   ENERGY  markets and especially Nat gas  … those   who were  counting on a  cold  DEC  and a cold  DJF  are  already crying in their  beer ( for some reason)  and  some of  energy vendors  are   not looking very good right now…
 The first  vort max and   short wave  dropping southeast down the Br  Columbia coast  will develop into   the 2nd  BIG event of the   COLD  season OCT 1 – MARCH 30   for the nation.   The rains  over the Pacific NW over the next 7 days will be  impressive   and the  mtn snwos  evemn more so.

http://mag.ncep.noaa.gov/GemPakTier/MagGemPakImages/gfs/20111116/00/gfs_namer_168_precip_ptot.gif

 The  2nd short  wave coming into southern CALIF is  going to being BEST  rains   in the last 6 months   to the   DROUGHT   ridden areas of  TX and OK NOV 22-23 .
Longer term…  

 If we start out by taking a look at the day 9  European and GFS hemispheric maps we can see that the intense large PV  (polar vortex) that is situated over the Yukon and Alaska is not  being forecasted to move in any way …shape …or form from when   compared to the  model data showed   a few days ago.  Not only does this feature dominate the entire hemisphere a pattern but also the moderate negative anomaly over the day the straits approaching the Greenland ensures that the NAO  stays strongly positive for the next seven days at least.

The one thing that all the data does agree on is that the  EPO  stays  strongly positive  and given the humongous  PV in the Alaska -  Yukon region that obviously makes sense and should not be in any dispute.

http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.we.png

http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.pn.png
The  0z and 6z GFS  operational and the  ensemble are trying to bring the NAO and the AO  down to   near neutral levels by  11-15  day…  But for the life of me I cannot figure out why or how this actually occurs given the fact that the enormous and intense  PV    apparently is not moving from the gulf Alaska anytime soon.

 
Indeed if we take a look at the  0z  GFS   ensemble  and the  GFS  ensemble mean  at  240   hrs  we see the humongous   PV  sitting their dominating the entire pattern over Alaska and the Yukon.  

For those of you that have the European  ensembles   that Model’s ensembles  shows nothing that is substantially   different from what the   0z CMC  ensemble… the 0z GFS  ensemble or 0z  NOGAPS   ensembles  are all showing at  day 10  and at day 15.

The 0z  CMC    ensemble is  VERY  warm   over  all of the eastern half of the  CONUS    in the 6-10 day and the 11-15  day… at both the the  mean and each  individual   member

 as is the 0Z  GFS  ensemble.. 

All this being said I remain   unconvinced  that this  massive PV  is going to  stay  in its current position through say   DEC 15  or the rest of this winter.   It would NOT   take  a major  displacement   of the  PV   in  the  Yukon/Alaska to cause  a  significant impact on the pattern.    For example IF  the  PV were to say  slide  west   towards the  Aleutiains Island ….  then the  entire   pattern over   western N America would  change  and cold air would move into the  eastern Conus.   OR… if  for  example the   the PV were to slide  a few hundred miles to the east   into   central Canada  … that too  would have a profound impact on the current mild/ super mild pattern.

0800 14 NOV  2011

If it wasn’t clear last week in the weather models… it certainly is clear now:     there is  little chance of a turn towards a significantly colder  pattern over   any portion of the CONUS before December 1.  Again that in itself is not that unusual   per se.  But obviously as we move towards Thanksgiving and  the last   days of VOV  there will   be a big emphasis on whether or not we are going to see a significant large scale pattern change.  Last December that  is exactly what happened…  but  back in 2007-8   the   pacific jet   never let  up  and all of the DEC    cold in the    eastern  CONUS forecasts busted horribly.

In  looking at the “overall”   pattern I do see some changes of current  pattern. But with respect to affecting sensible weather conditions  in the  Conus….  there  is  not much to get excited about if you like cold weather.  It  is important that as a meteorologist we communicate in a clear and effective manner.  So while I can talk about changes occurring in the overall pattern at the high latitudes which over the long term could be more positive towards   getting a colder  pattern… the fact  is that  for most people this will sound like a bunch of esoteric   gobbledygook  because  their forecast shows  more  mild  temps. From the  average person point of  view   there  appears to be  no significant change in the overall pattern.

If we compare the current hemispheric  500 MB  map   as of 0z NOV 14   to the one from  NOV  7 we do indeed see significant changes.   The  PV has split which is what most of the models were  e forecasting and we now have one of the PV centers moving into far northwest portions of North America    (the  north  slop of    eastern Alaska/ Yukon).   The   other  PV has  retrograted and is now moving towards the north side of central Siberia on the arctic circle.   And we also seeing the widespread introduction of arctic air across all of Central  and Northern Canada which is something we did not see last week  or the  week before.  This is leading to increase in snow cover across Canada as well.  

 Another key aspect to the overall pattern is the powerful European or Scandinavian  Ridge.  Last week most of the model data show this Ridge  retrograting  into Iceland   or Greenland  but clearly that is not happening on any the model data over the weekend or this morning and that’s one of the reasons why the pattern change at the high latitudes is not working its way down to the mid latitudes.

Part of the problem is that the new polar vortex over Northwest North America splits into two sections. The  Eastern   portions  slides to Eastern Canada by the end of the week and moving towards Baffin island and the Davis straits by Day 7.  This movement initially causes a  moderate   trough to develop over the eastern CONUS   but once this feature moves into Eastern Canada were labrador in actually  cuases the NAO  to  flip  back to Neutral or  Positive and it also kills any chance of the Scandinavian   ridge   retrograting to Iceland.

This is reflected in the the  Teleconnections  Indicies…   http://raleighwx.americanwx.com/models/00zlinegraphs.html

However the western portion  of the  North  American  PV…. continues to move from the north slope of Alaska southeast into the gulf Alaska and along the Alaskan panhandle  by  day 3.  This feature slides down towards Vancouver Island and the Pacific Northwest    by day 7.     It  is a very intense vortex and if this was the middle of December  there is no doubt that this feature bring a major snowstorm to locations such as Vancouver and Seattle.  It still might give an how  impressive this feature is.   A piece of this energy  breaks off and develops  a  significant surface Low  that tracks of the western high plains this weekend with the arctic air pressing south across sea was Canada border into Montana and the Dakotas.  This will probably be the first serious winter storm for the Upper Plains of the season  — there was a moderate one last week .

By day 10  the  operational European and the European  ensemble show a dual center pattern with one PV  over central Siberia and the other one located over northwest Canada –perhaps in the Yukon. The PV  over   the  Yukon is clearly was stronger on most of the model data with  its  value     below 500 DM .   The Teleconnections from this intense vortex over far Northwest North America of course supports a strong southeast U.S. to ridge so all of the Model  data here  apears to be  very consistent and  meteorologically sound. 

In addition if you take a look at the  500 MB   height lines over the north Pacific you will see that the extremely strong central north Pacific    positive   height  anomaly  — the   Ridge   at 588dm– is located surprisingly close to the   498  dm   very strong and negative  height anomaly over the Yukon.  This of course is causing the Pacific jet to become squeezed causing ncreased  velocities to a extremely powerful  180 knots on the 0z GFS   at 192 hrs.    And  having the jet streak slam into    the  West coast  / br Columbia   ensures the mean trough stays on the West coast and  the  the cold air   building Canada  cannot possiblly   drop south of the   US Canada  Border .

Clearly the impediment in terms of getting the pattern to turn significantly colder is the extremely intense polar vortex over the Yukon.   This  fat  pig   has  got  to MOVE  or slide    southeast into   north central  Canada.  As long as that feature  is in  that part of the western hemisphere the pattern is absolutely no chance of changing.  This position for a  PV  has   long been know  as the Kiss of  death if one is forecasting any sort of sustained colder outbreak were pattern developing over the eastern half of North America.  Of course there have been plenty of winters where the vortex up there in northwest Canada in November has moved  to the southeast  which ends up altering the entire pattern.  But as long as that feature  is  there and the 180  knot    long jet streak ….     the central and eastern  CONUS stays Mild.

1000  EDT   NOVEMBER   10

 Why is it that whenever I start   some sort  of  new venture ….all sorts of weird stuff seems to happen …both culturally and with me personally? …. Just one of those things I guess.

I will start out this morning by taking a look at some of the MJO forecast models and see how or what they are forecasting in the current MJO pulse over the next 2 weeks and what… if anything …they that can tell us about the evolving pattern. The Current MJO is of moderate intensity and located in phase 6.    This corresponds to the map   below where we can can see several important features.     There is a large area of strong positive height anomalies over Scandinavia and over the north slope of Siberia… And a strong negative high anomaly over the gulf Alaska.

http://raleighwx.americanwx.com/MJO/NovemberPhase6500mb.gif

In the general sense this appears to be a fairly close match to what most of the medium range models of forecasting over the next several days with the strong negative anomaly developing in the gulf Alaska as a series of strong Lows crash into Western Canada the Alaskan panhandle and eventually down by Vancouver and Seattle day 8-9-10.

In fact the operational European and the GFS Models do show a pretry potent system traveling down the Alaskan panhandle and slamming into Vancouver and Seattle November 19 – 20.    It does so because all the models are developing or expanding a Ridge over the Bering sea into Western Alaska.    Right now the model data shows 850 MB   temperatures clearly cold enough to support snow even in downtown Seattle and maybe even Portland…. which in mid November is pretty darn usual. The development of this Ridge at 500 MB allows for the first large cold arctic High of the season in Northwest Canada .

So whats happens with the current MJO impulse?

The first link here represents the NCEP GFS Ensemble mean which is forecasting the current impulse to reach phase 1 close to region 2 by November 24
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpe.shtml

The operational European MJO  model shows the impulse collapsing by the time they reached the thanksgiving weekend…
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmf.shtml

And this trend is supported by the European MJO ensemble mean and spaghetti plots
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtml

Therefore if we assume that the current MJO impulse will make it to at least PHASE 1 and POSSiBLE Phase 2….  We end up with this sort of pattern.     In PHASE 8 we can clearly see strong positive height anomalies at 500 MB increasing southeastern Canada…  and over Northwest Russia into Scandinavia. In addition we can also see strong negative height anomalies over the Siberian side of the arctic circle— which is currently were the PV is
http://raleighwx.americanwx.com/MJO/NovemberPhase8500mb.gif

By phase 1 however we see a strong positive height anomalies developing over southeastern Canada into Greenland and extending into northwest Scandinavia. This would count as a -NAO.    The very strong negative anomaly just to the west of the  UK   ould also be significant as would the intense Neagtive  anomaly over eastern Siberia.  http://raleighwx.americanwx.com/MJO/NovemberPhase1500mb.gif

 The PNA and NAO plots from ERSL show a moderately negative –NAO but it extremely strong a persistent West Coast trough / -PNA.   http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.pn.png

Even though the WPO changes phase sometime  around the Middle of   the month the EPO does not.   It moves into a persistently strong positive phase which of course means more strong negative anomalies over Alaska and the Gulf Alaska and above Normal Heights over southeastern Canada.    http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.we.png

This sort of solution matches all of the model data in the 11 to 15 day from the GFS and European ENSEMBLES .    What we are left with then is pretty neat tidy package of strong model agreement that matches the MJO November pattern for Phase 8 1 and 2.

While the strong ridge over the eastern half of North America and especially over the CONUS is going to be very slow to move out with a +EPO and a strong – PNA …    this pattern will allow for the significant buildup of arctic cold and rapidly increasing deep snow cover over the next two weeks for most of Canada.   If you are bored looking at thisn pattern east of the Rockies you might want a look at the increasingly cold temperatures and deepening cold air mass across all of Canada rght up to the U.S. Border.

One last point is to focus on the connection between the strong Ridge over the dateline into the Bering sea and the strong Negative anomaly over the British Columbia region.    I am sure it’s obvious to many but I thought I would emphasize the point that until the Ridge in the north Pacific over the dateline / Bering sea shifts or e altars position ….the -PNA is not going anywhere.   On the other hand if you are in Seattle… over Portland… Boise   Spoakne    Redding  Calif  into the N Rockies your winter is going to start early