This blog is great news for fans of colder weather and snow, but the bad news is you have to be patient!  After January 20th the pattern should flip to one that is very very cold and brings the chances for several snow events as we head into February.  The next 15-16 days we are going to be influenced greatly by the Southeast Ridge as areas to ur west get in on the winter action.  If any model shows a snow storm for the Middle Atlantic or Northeast in this timeframe you can dismiss it right away!

Tropics

As you can see the MJO composite does not match up to our current phase 4! The reason is because the global IR above shows us that convection is refusing to let go across the ITCZ from South America into Africa.  This is typically where see see enhancement during the favorable phases for cold in the east.  The convection around Tahiti is also contributing to daily SOI values around -10 for the last few days.  However, convective trends and the obvious enhancement over the Maritime Continent show the pattern will start to resemble a phase 4-5 with the ridge returning to the East.  The enhancement over this area has led to the tropical storm Sonamu over the South China Sea.  

Latest GFS ensembles for the 8th of January show higher heights headed for the Eastern US.  Green line is CLIMO and the rest are the respected DM.  White is the operational GFS.

Now many are going to be saying "Winter just got started and now its over".  That is going to be wrong as the QBO analogs for this winter strongly pointed to one month being well below average in temperatures following a very warm December.  Many meteorologist and models thought it was going to be January, but right now it looks like February will be that month.  

Many models are showing a rather fast eastward progression of this MJO signal and this is very good news.  The phase 4-5 is going to help us out for late January by allowing another positive Mountain Torque event over East Asia.  This will add to the warming in the Stratosphere that is already taking place.  Models do show this warming in the next 5-10 days which matches up with the current MJO and GWO (Global Wind Oscillation) which should push into phase 4-5 given better defined tropical convection and ongoing positive frictional torque.

Notice the most impressive values are favored in East Asia.  This is a sign that another fairly significant East Asian MT event should happen shortly allowing for the stratosphere to warm even more and further weaken the PV and force it south.  The significance of the Polar Vortex moving south is the cold air comes south and we can establish a blocking pattern.  Right now with a strong PV we cannot establish any blocking given the very strong jet.  

The East Asian MT event around December 20th is the one I think will be the pattern changer come January.  This MT event led to negative AAM anomalies which have begun to make there way poleward.  This coincides to what some models show returning convection around the dateline.  

At 192hr we can see the warming over the Aleutian Islands and extending down 180 favoring a trough over the dateline which is where we are going given the eastward propagating MJO and stratosphere.  This is showing up on the models in the medium to long range with higher heights buliding into the Gulf of Alaska.  This is going to favor a -EPO.  Once this forms we will most likely see a Midest snow storm around the 19-21st time frame that will really bring winter back to the east after its departure.  

Models typically rush these changes.  We can clearly see in the GFS forecast of the MJO is an outlier and very fast with the eastward movement.  The Euro is the slowest but still shows these changes taking place but slower.  The MT events and warming in the stratosphere are showing a timeframe around the 20th.  These observations point to the 20th and that is the date will go with for now! 

QBO Update:

Latest December value is -10!  This shows us that based off history we have a very high % of estabilishing a -NAO as we go through the remainder of the winter:

 *DT wxrisk.com

So rest up now because we have a lot of winter to track going into late January and February!