Update 11/17/16

This sure has been a messed up weather pattern for our part of the world!  I just saw this morning that Minneapolis Minnesota (at the airport) has NOT been below 32 degrees yet this fall!  WOW!  The latest date for the first 32 at that location was November 7 (normal is October 10) and here it is 10 days after that event.  Incredible!  For Kansas we finally got a vegetation killing freeze at most locations although I've noticed those pesky Asian Beetles are still active.  That will soon come to an end.

If you missed it, the previous post was done on the 7th and you can read it by clicking here.  In the outlook portion of that post, I had ideas of it becoming pretty cold by Thanksgiving and into the first of December.  It would also serve as a catalyst for a significant storm to develop Thanksgiving week.

So, where are we at in those regards?

First let me revisit the record cold and snow that has been in place across the northern parts of the Asian continent.   There has NOT been any change!  The "really" cold air continues bottled up across that part of the northern hemisphere.  BUT, changes are taking place.  Those changes actually started with the development of a weak Madden Julian Oscillation (MJO) that I discussed in the blog post I did on the 7th.

Here was the most current map of snow and ice calculated on Wednesday :




























It's just incredible that for mid-November much of southern Canada remains snow free!  Closer to home, what is absolutely amazing is the lack of snow in the Colorado Rockies (as of early Thursday morning).  For the Arkansas River Basin, the snowpack was only 8 percent of normal!  Yes, EIGHT percent!  For instance, in the vicinity of Pikes Peak, the normal amount of moisture in the snowpack for the 17th of November is 1.7 inches.  As of this morning...ZERO!  North of Leadville at the headwaters of the Ark the amount of moisture was only 0.3" where normal is 3.0". 



The early afternoon temperatures (6 PM UTC or 12 Noon CST) across the pole showed the extensive area of cold across north Asia:
 
Click for a larger map


The cold STILL has not migrated to this side of the hemisphere.  But, one way that might occur is for the Madden Julian Oscillation (MJO) to continue propagating eastward AND the North Atlantic Oscillation (NAO) to dive into a negative index.  The latter is forecast to happen soon.  Here is the latest forecast for the NAO:



There has also recently been a big disruption in the stratosphere (Sudden Stratospheric Warming) that should lead to blocking of the flow across eastern Canada or Greenland.  So with this SSW, the MJO and the NAO possibly going strongly negative, the confidence of the cold spilling over into Canada and the U.S. has increased substantially.  This shouldn't occur overnight, but cold air intrusions should become more frequent as we go into December (and especially late December).

First, looking at the Thursday afternoon satellite....

Click for larger image


There was a vigorous storm (finally) over western Colorado and it is expected to track northeast into Iowa. For the high plains about the only thing we get will be wind but with temperatures turning sharply colder by Friday and Saturday.   If this system was in this position in May, there would be an outbreak of severe weather (and probably tornadoes).  For now, it is simply moving out into the plains too far north.  But the northern plains and into the upper midwest will get their first taste of winter with wind and heavy snow.

Not shown on this map are several other weather systems that will be approaching the plains during the next week to 10 days.  The first will bring a chance for precipitation on Monday or Tuesday (21st and 22nd).  It may also track in a similar fashion but there "might" be enough moisture to get some precipitation farther south and west.  I'm not that confident, but hopeful.

Another system should arrive around Thanksgiving day or Friday but this far out it is impossible to know exactly where (north/south, etc) and the magnitude and impacts.  Yet another system will be possible by the end of Thanksgiving weekend and perhaps the biggest threat another around the 1st or 2nd of December! Details are highly uncertain at this time.  The point is the pattern is finally getting active and should stay that way into early December.  Hopefully at least one of these systems will benefit the plains with decent moisture.  Temperatures will be more seasonal and at times quite a bit below normal.

One final thought.  Despite a record or near record warm fall (likely will end up top 3), this does NOT necessarily mean the entire winter will follow suite.   But what I have observed in this type of setup, is the weather for January and February typically mirrors December.  I'll have more thoughts on December in a post I hope to do next week before Thanksgiving.  My motto...."those that don't get it in the fall, come winter will get it all".  Well, we'll see.