eduggs

I can't remember such a convoluted height field in decades of model watching. Probably there have been other such periods, but none that are memorable to me. On the NA chart, there are too many shortwaves and pockets of vorticity to count, haphazardly evolving in sometimes opposing directions. I can't imagine the mid-range models will demonstrate high forecast skill during this period.

I think this is a great point. It also makes tracking this week more fun as long as we don't look completely out-of-the-game heading into Tue. or Wed.

If we pretend this run is real we have 3-4 wintry "threats" to track in the next 10 days. If the GFS is real we have a week long deluge. The real reality will likely incorporate elements of both plus some unexpected changes.

The block is blocking on the EC. We have cold/coldish air!

Regardless of the surface outcome, I like this 12z EC run so far. It's the first OP run in a while that I've been excited about. Maybe it's the Irish Coffee I just drank putting me in an optimistic mood... not really sure.

12z EC shifted a little south with the weak upper level wave sliding east at the end of the week, reversing a northward trend of the past few cycles. This will likely leave precip. just south of us, but I prefer this scenario to the GFS washout. It's also a colder solution, which IMO increases the changes of wintry precip. on Fri or Friday night. Right now I'd prefer to get the cold first and worry about the precipitation later.

Should we expect otherwise? It would be a fluky coincidence to have two relatively unchanged runs at the surface 7+ days out. Small changes aloft can lead to large changes locally at the surface.

1 week of near-continuous precipitation (mostly rain) on the GFS is I think I would be mildly excited about snow potential if I lived in the higher elevations of northern or western New England. But if I kind of squint at the charts I can even imagine a long-duration fantasy snow scenario for the Cities. To get any local snow out of the medium range I think we would need the cold air source to push a little further south than currently modeled.

I still think this is true - but it would be late week not mid-week. The CMC, ICON, and EC bring frozen precip. near or to the area. It's exciting to get a wintry threat as close as 5 days out! That said, the GFS remains much warmer and wetter and the other models have been shifting northward for a few cycles. My gut says this ends up rain with a few high elevation cat paws or sleet pellets. I expect high inter-cycle and inter-model variability in this regime.

Are we in a stable "pattern" now that we expect to cleanly change out of? It looks to me more like continuously evolving climatic and meteorological characteristics that change on a daily and even intra-daily basis. Despite what some people have convinced themselves, there is no guarantee of a new or favorable "pattern." Snow chances will likely increase as we move deeper into winter. But the atmosphere doesn't know what NAO, PNA, AO, and La Nina mean. These are not tangible things that can be switched on and off. There is no discrete era of snowfall that can be promised or delayed. And to the degree that some meteorological characteristics are loosely correlated with weather outcomes, our ability to forecast them beyond 10 days is extremely limited, to the point of frequently misleading.

I don't care how good the long range ensembles look. Multiple rain events in December with snow threats pushed out beyond 10-day fantasyland is never a good thing for snow enthusiasts. When the goods are relegated to the distance extended timeframes, there's a reasonable chance they will never come. Eventually it will snow. But right now I see as many signs to be concerned as to be excited. Hopefully that changes for the better tomorrow.

Humans love to categorize everything. We are compelled to separate things into boxes to understand a complicated world. But in truth, every 500mb height field is unique. There are no true patterns - only a collection of general characteristics that we lump together. I believe we do a disservice to ourselves by obsessing over these "patterns." And if long range 500mb anomaly charts ceased to exist, we would be smarter, happier people

I think we root for the late week event as a compromise between the 0z CMC and GFS. It looks like a viable threat. In the dream scenario that starts out as some light snow into weak CAD and evolves into an wraparound Ocean storm.

Averaged 500mb anomaly charts of perturbations of the 0z GFS and CMC operational runs would look really encouraging. But what looks good through the vagueness of long-range time and averaging can be ugly when crystallized into a discrete event.

I agree that it will be worth the wait if we can get a good snow event or even string a few decent ones together without a rainer to spoil things. But I would not be at all surprised if we go through December with little or no snow.

We're a little bit behind schedule for the first trackable wintry threat. We're not really behind in snowfall to date locally, just something tangible to get excited about.

Good patterns are recognized in hindsight not foresight.

The 12z CMC shows an unusual scenario with rain approaching the area from both the west and the east at the same time around 240hrs. That's certainly uncommon. That specific depiction is unlikely to occur, and a wintrier outcome is definitely possible.

Well we do have 2 or 3 rain events to track. It would be fun if this December could end up being the first month in a long while with more frozen liquid equivalent than rain.

GFS, CMC, and EC are all still basically snowless out to 10 days. As we move into December we really should start to see some discrete threats within that time period. The reliability of modeled patterns beyond 10 days is somewhat tenuous. So we shouldn't get overconfident about long-range 500mb anomaly charts. Snowstorms are really about well-timed features at the regional-scale more than continental scale patterns. The large-scale features are typically a prerequisite for big storms, but we still have to get lucky.

There looks to be some longshot potential for something wintry mid to late week next week. Some encouraging hints on the op runs, but nothing specific to get excited about yet.

It would be nice to at least have something trackable as we head into December. The polar jet remains pretty far north even in the extended on the ensembles despite the blocking regime.

Let's get the "potential" comfortably inside 10 days. Otherwise we might just be wishing for something fantastical or ephemeral.

The 18z GFS abruptly lost the 50/50, but GEFS, GEPS, and EPS all look pretty sweet. Can't ask for too much more in mid November, 8+ days out.

The 12z GFS looks tasty for Friday. Unfortunately the 12z CMC and 0z EC squash the key southern s/w along the gulf coast. There's some potential if all the waves can align favorably. But the majority of ensembles are still against the wintry threat. It's still exciting to have something to halfheartedly track after a long hiatus.