Easy explanation to crappy pattern. It's not enough anymore that NAO/AO is very negative.
We need a strong PNA due to warmer SSTs causing stronger ridging east of New England and more south based blocks.
This is more true for 1st half of winter. This is why Decembers have sucked over the last 10-12 years and why Jan-March have seen better patterns.
NAO block was too far south, which allowed it to link with SE ridge at times and there wasn't much of a PNA to counteract it.
That's why this month sucked. Simple explanation
A good PNA ridge is becoming a most for winter particularly in December
It's not done yet and just because you didn't experience anything major doesn't mean it's not significant.
A lot of places are seeing major coastal flooding right now. A lot of places have already had 50+ gusts.
The temperature drop will be very significant. From mid to upper 50s to single digits with wind-chills in the -10 to -15 range.
I notice this happens during strong CAD, onshore flow in the spring/early summer & with arctic fronts otherwise temps will usually be warmer than forecast