1615 PM EST   DEC 30

                    

       

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1300 EST    DEC 28 

Now that this major nor’easter is over and   I have had a chance to get some rest and catch my breath it is time to move on to more things and get NEW things rolling.  When you are the private weather business it have to strike when the weather is hot and then once folks see what you can do  you  end up  getting  some loyal clients and fans.

Of the the explosive growth over the past 10 days here at  WXRISK.COM again caught me by surprise.  I thought last winter was a season of significant growth   but this  one?   Holy  cow.

FIRST   when  you to get the chance take a look at this letter which was email to me by   Matt  Dinardo   the Morning and Midday  met  at TV 8  WRIC here and Central Virginia Richmond.  He asked me  to  place it on the   facebook.com/ wxrisk page

You can find    the letter over at the discussion  section  over the  facebook.com/wxrisk.  I  am  going to make a few comments  about the letter — from MY point of view— since it is a very well written  and worth   talking about. 

The next major event is going to be a the impressive winter storm which comes a roating  out of the central Rockies  DEC 30  and into the Upper Plains  DEC 31.    The large cold High pressure area now over the Delta will move off the SE Coast on  DEC 29…  So winds will naturally turn around to a West or Southwest   direction for all areas east of the Mississippi River.  So by itself we are in for warming pattern but the development of the big   Low over Minnesota and the western Great Lakes DEC 31 is going to cause temperatures to really warm east of the Mississippi River for two or three days.      The  big MN  Low  will send a cold front that sweeps into the   Midwest and  into the  East Coast  DEC 31-JAN 2.  The interaction between this cold front and the High off the SE coast will cause temperatures to really warm even over the snow laden areas of the Nnortheast   US.    60 degree is possible  over  the   Ohio valley   as well as    WVA NC  VA  on JAN 1.

CLICK  ON  IMAGES

The front should come through fairly dry   as it reaches the  East coast on January 2.  There will be some cooling behind the front but not a big deal. 

The cold front will stall across the Deep south and there may be some overrunning precipitation along the front across the Deep south but this  will be mostly the rain.

The general consensus from a lot  of  private weather services  and  energy  meteorologists   for January 2011  is  that  is  going to be a significantly milder month than normal especially from the Rockies over to the East coast.     This is the  reason that Natural gas  prices (and  to a lessor  degree heating oil)   have been going down over the last few months.  But there is a lot of data which has  come out which is showing that those who have been forecasting a very mild January 2011 are in some trouble…  from a forecasting perspective .

One of the leaders in the mild or very mild January 2011 idea has been Accuweather.  Unfortunately over the last two weeks the change the January forecast three times!  So at this point it is a little difficult to figure out exactly what their January 2011 forecast is.     Clearly if you make a forecast for particular a month ….a few months ahead of time …then  the given the state of the science ….you  SHOULD have the right to updated as you get closer to the month in question.  But three updates in the last 14 days is a little much.

The premise  for the mild January 2011 forecast from the Rockies to the East coast is based on the proven idea that moderate La Nina events have a strong correlation to Above Normal temperatures in the months of January and February.  Of course that being said….  that   idea is…itself   premised on the idea that the moderate strength   La  Nina does NOT   weaken.    However that  is   Just general guideline  about  Moderate/ strong  La Nina  events and it doesn’t always work out .

One of the reasons why the La Nina  pattern often turns mild in January and February is   that  in  Moderate &  strong La Nina  event…  the Pacific jet becomes very strong as it approaches the West coast of North America.  Because the Pacific jet becomes stronger than normal it is resistant to any sort of pattern shift   or     ” Buckling”.   In other words the jet stream  cannot be  deflected     so that it comes out of Canada.   Instead  the Pacific Jet   brings in stormy and mild Pacific Air from Washington State   down to California.

This brings a lot of precipitation to the entire West Coast and heavy snows into the the mountains of the Western CONUS  but east  of  Rockies… this is pattern  means  mild Pacific air overruns the nation all away to the East coast    and  there is  no  path  for cold air masses to enter the  central and  / or eastern CONUS.
 
Got it?

One of the basic rules  in the weather business  whether its   2 days  or 10 days… is that for every   TROUGH  in the  jet stream there is a  RIDGE and  for every RIDGE there is a   TROUGH.  All this La  Nina energy  means we get a trough on the West coast that  helps bring in  that storminess.    BUT   to counter that   there must be a  RIDGE in the  Jet stream over  se states.  

That it is the typical  Jan and FEB  La Nina   weather Pattern.     Of course when you  are dealing with the real world there are a lot of things  that can change that.  One of them  is the  -NAO/ Greenland Block which has been in existence for over 30 days.    The Greenland block is one several manifestations of the  -NAO  (there are several other different types of  -NAO patterns as well).     Having a block in the jet stream over Greenland is  very favorable for East Coast major snowstorms and the the event over the holiday weekend clearly supports that assertion.   But it also    keeps the pattern colder than  otherwise it would be .

For January and February to stay mild the block over Greenland which is  currently weakening …has to stay nonexistent.    Unfortunately the new data is showing that is  not going to be the case as all  the data  shows  the block over Greenland  will begin to expanded into eastern Canada  in the  11-15 day.  

This image shows the   day 10 European   ensemble Model  pattern over the northern hemisphere valid for January 7.  This is not just one model but 51 versions or individual members of the  European model all   “averaged”  together.    I  have highlighted a couple features on this map.     First is the the black oval   shape which I have drawn in over Greenland.  We can see the   ‘ BEND”  or  ” BUMP” in those white lines which represent the jet stream beginning to develop  over Greenland  again.    We can  also see the two very deep areas of Low pressure in the jet stream:   one located over northern Siberia and the other one over Hudson’s Bay Canada.     The model also shows a disturbance  in the jet stream over the lower Mississippi Valley which is  why  I placed a  short thin black line there.     This  show the potential for some sort of significant precipitation event around January 7 for some portion of the eastern US….  possibly including    the TN  th  and OH  valleys and the Middle Atlantic states.

We can see this enlarged imaged  on this next image  – which is  the  euro  ensemble   (the LEFT  side)    and the  operational or regualr  European model (on the RIGHT side).  This is not  a  severely cold pattern because   there   is no ridge on the West coast and we are still getting to a significant Pacific jet crashing into the West coast but it certainly not a MILD pattern by the any stretch of imagination.  Again  note the the same black line  over the Mississippi Valley and the    QUESTION  MARK  near the East coast.

Here  is the GFS ensemble at 300 hrs   VALID    JAN  9.     It shows more of the same pattern with   a  Ridge or bulge in the jet stream over Greenland building into northeastern Canada.  (Note the bright red shading  over Northern Canada and Greenland and the white squiggly line that I have drawn over it).    There is also another bright red area   in the northern Pacific pushing into Alaska which represents another Ridge or bulge in the jet stream.      And the   BLUE   shaded areas  –one on the West coast and  one  right along the East coast represents    the mean trough positions .

If we can get the ridge over the northern Pacific to build into Western Canada the pattern could turn severely cold and stormy around the middle the month over the eastern half of the nation.    But there is no guarantee that this is goning  happen and it is possible the ridge can stay out there by Alaska for several weeks . 

Eventually   IF  the Model data is correct and the Greenland  Block   really does come   back  in force and moves into   eastern Canada  by   Jan  10-14    then the  idea of a  Mild  January   2011  is  not going to  work out.   That does not mean  it has to be a  COLD  January either.