Golf7270 wrote:Ntxw, are we getting into a pattern change more favorable for cold or is it another head fake?
More favorable? Not yet. But the pattern isn't horrific like it was. Back in late November and early December I was very pessimistic because the Nina standing wave + EPO was showing no change. We were at risk of a 2011-2012, 2015-2016 type repeat with no shot and shaking up the pattern. Cold was locked up in Alaska everything shot through to Eastern Canada.

But in December the tropical convection began shifting east (and you saw the MJO climb out of the P4-6 standing wave) and with it the Aleutian ridge began. It shifted the cold from Alaska to W-Can a little closer. The Nina standing wave is still resisting it though.
Now we're sitting waiting for the Ridge to go poleward which then takes the cold a little deeper into the US, predicating that the MJO/convection is sloooowly moving east. Much slower than guidance forecasted.
At some point we want the Aleutian trough to show up. Some hints but not there yet. It can kick off an SSW and/or height rises off the west coast and open the door.
So to answer your question, are we getting a pattern change? We have. We're not moving into an unfavorable pattern like we were in November but rather moving out of one. We'll get shots of cold due to source region loaded up, but is it sustainable is the big question that has yet to happen.
FYI I've been out of the ENSO loop for a couple of years now but the strong WPAC standing wave now has a real possibility of pushing the heat pool out there with WWBs. That will increase our odds of shifting into an El Nino for 2022. So the MJO movement has more implications than just winter weather.