We are seeing two different solutions and trends showing up here on the models.  The main part of this event is the development of the southern low and how strong and or sheared it gets as it pushes eastward.

1) European has progressively shown a weaker ridge resulting in the northern stream shearing the southern low more.  If it continues to do this it will end up with a GFS like solution.  However, current pattern argues against this trend.

2) UKMET and NAM don't necessarily build a strong ridge but show the southern stream stronger and more developed allowing a more organized system.  This pulls the northern stream down resulting in a more organized southern low with a lot of moisture.

1) Euro Trend - From top down the images are the previous 3 runs of the Euro with the dotted lines representing the 573 and 576dm.  You can clearly see the model has been trending weaker and more progressive. 

This has led to less qpf to the north of the system as the southern low takes longer to get going because of the shear felt from the faster more progressive northern stream.  The euro ensemble mean came in with a sfc low a little farther north than the operational but had a weird look to it like a lot of disagreement was being felt amongst members.

Notice the individual members are mostly in agreement with a stronger ridge, but they factor in the outliers south of the operational where less agreement is seen.  Same goes for the northern stream where most members want to dig it down farther south but the mean ends up to the north.  

What does this mean?

The Euro ensembles say the south trend on the Euro with the qpf should reverse it self at least slightly in the next model run.  

2) UKMET and NAM strong southern stream

The UKMET shows a nice ridge allowing the interaction with a stronger southern low and a big system.  This is a big time snow storm.

The GGEM ENSEMBLES- Notice how much higher most are!

Observations

MJO PHASE 8 COMPOSITE IN JANUARY

MJO PHASE 7 COMPOSITE IN JANUARY

The IR above shows we are in a phase 7 to 8ish.  The strong southern jet extending west of Mexico with another branch through the Gulf of Mexico is a key component to this forecast as it agrees with the composites above that a deep trough will establish itself in the Eastern CONUS with a ridge out west.  This argues for the models to adjust towards a more amplified solution.  

Conclusion:

With the tropical forcing setting up I would expect models to trend more amplified with a stronger southern low and a more qpf filled system.  Latest models have backed off but the ensembles clearly suggest (along with the observations) that this one is far from over.  Current WV imagery does suggest this incoming energy does look more impressive than modeled.  And the southern branch associated with this system will allow for a more southern stream system just by eyeing the ascent downstream.

Notice how I can see the phase 7-8 of the MJO on WV imagery and apply it to the forecast.  We can clearly see the convection NW of HI building in response to the Upper level low near the Aleutian Islands.  This teleconnects to a big ridge about to form in the Western US.  The main system extends from the Gulf of AK to off of Mexico.  This will split and move inland being our main event.  How much of the southern low gets cut off? Models might be having trouble because I see a lot of lifting spreading east that models did not have but time will tell how significant that is.  Best model runs of this system will come tomorrow night so don't give up hope yet!