Here's a highlight look at how ensemble smoothing and just using 500mb does not always work well, especially the further out you go.
If you looked far out and all you saw were above normal heights, reds and oranges you'd believe a winter heatwave was coming.

But even here the flow is out of the NW for our region, which of course at the surface would mean from a cooler region rather than a warmer region, even if they are above normal.
Would have completely missed the weakness over the Southern Plains, which this early winter has shown persistent storm energy, despite lack of actual precip but they have been there. The North Pacific resembles a Nino, the tropical Pacific resembles a Nina, lots of variability. Quixotic nailed it I think, Aleutian low eventually translates to Southern Plains lows.

The torch of all torch Decembers featured strong Aleutian flat ridge (Nina) and cold trough in W-Can coast that created zonal and SW flow aloft with a strong Southeast Ridge. The flow above would've come out of the desert SW at the same time surface returns were coming out of the gulf where it's 70s and 80s.


This has been my learning curve the past few years both ways for cold and warmth. Relying too much on 500mb charts and disregarding source regions gets us waxed. Pun intended (wxman57!)