ORH_wxman

Yeah and these dates could move all over the place given that the models won't "see" some of these shortwaves....either that or they manifest/eject from their original location in a different manner than the models thought at further lead time. I mean, just as en example, the OP Euro in clown range at D10 is ready to try and pop an OH valley---> NJ coastal type model.....which is prob one of the few types of coastals that could be supported in the still-high gradient pattern there which I don't have to tell you (582dm heights hanging out over N FL fighting the slowly retreating PV lobe to our north)

Dec '81 is actually not a terrible analog either for this pattern. I think late Dec '10- early Jan '11 is a better one, but Dec '81 had that block dominating the pattern for weeks. Parts of Dec 1995 are a good match too.

Euro is still mostly rain for Dec 6 system....but there is a bit of ice/snow for NNE this run. That's pretty close though to being something more wintry for a lot of the region....would need another 100-200 miles press on that PV lobe in hudson bay which is certainly doable at D5-6. However, the follow up wave is more intriguing to me....would still be a fast mover, as the gradient hasn't relaxed yet, but that one looks like it could produce something wintry if gradient doesn't grind it up. That would be in the Dec 8-9 range.

I wasn't talking about you btw....your view of whether this upcoming pattern is favorable or not is not tied to D10-15 OP GFS runs. The satire of the SE NH/S ME/Essex county MA screwzone was a different topic....

You can see why some people jump off the tobin when the OP models don't show snowstorms....all you have to do is look at the inverse reactions when there's a huge storm at 300 hours.

GEFS are trying to get that Dec 11 period in a favorable look for a larger type storm....a few days ahead of previous runs and particularly the EPS. GEFS pop that Rockies ridge which is very bullish signal for a coastal given the block already in place

Looks like ORH over to my hood is just far enough south.

It's probably one reason (even if minor) that causes models to sometimes underestimate cold in a favorable pattern....on the front side of that, we may lay down snow pack in upstream areas and the models then struggle with how to handle that...and then of course, if the model guidance is wrong on where the snow pack increases, it will be wrong on its lower level boundary layer gradient in that area so all the future frames are corrupted too.

Lavarock just saw this run

Yes, Dec 6-7 would be an overrunning/SWFE type winter system if it trends cold. The potential for coastal storms would be later into the pattern....most likely beyond 12/12.

To steal a term from Tip....when you have that type of arctic configuration, the "Correction vector" is colder for us more often than not.

The extremely amplified EPO ridge is often something that causes systems to trend colder inside of 7 days....we have been talking a lot about the developing monster NAO block, but in the early stages of that, we actually have a very stout EPO ridge dumping cold into Canada....see below.....this is what is starting to cause the flow to become flatter over the east....pressing the cold further south ahead of the Dec 6-7 system

Gotta hedge for being unlucky sometimes....we remember the good patterns that smoked us, but sometimes we have good patterns that don't produce...there's been some big disappointments in good patterns before (see Dec 1987, Jan 1985, Feb 2010 in SNE, Jan/Feb 1980) Man, the '80s sucked considering we had some good patterns, lol

2020-2021 def left some on the table. This year though, we do have significantly better blocking than that year had at least in December....we'll see how later in the winter goes. We also had a poor Pacific for the first 3 weeks of January 2021....even a neutral N PAC would've probably produced more snow events for us those first 3 weeks. Instead, we basically condensed winter in a 3 week period from end of January through mid-February....sans the 1 wintry week we had in December before the cutter from Dante's Inferno. Seems like you are going for a better N PAC in January than Jan 2021 had.

N PAC was also pretty damned ugly in Jan 2021 until later that month...once it shifted to a better look, we really went to town for about 3 weeks. The block also kept retrograding and became a Davis Strait block by the end of the month. We did have a bunch of close calls though earlier that January which easily could have been decent storms. That block essentially kept us from blowtorching all month....we didn't have any fresh cold, so it was still above normal, but if you recall, I think we struggled to get warmer than 40-45F in any of those days....most being in the 30s with lows in the 20s...minimums were a lot more AN than the maximums were.

Hard not to compare these two...people shouldn't expect the same results, but there's obviously potential

Full blown El Nino North Pacific look. I'm a bit skeptical it looks that nice, but the EPS were showing a more favorable PAC near the end of the run.

Yeah I think we want COD for the MJO right now after it passes through 8 and 1....no need to screw up a good pattern with some other variable.

Euro and EPS have really started compressing the flow after 12/5 so as Scott said last night, NNE may have to watch the 12/6-7 threat for more wintry solution. Still think SNE is skunked in that one but there could be a follow up threat around 12/8-9…and if that one doesn’t pan out there are likely to multiple additional threats beyond that. 00z EPS is a pretty loaded pattern.

I’m sure there will be OP GFS and Euro runs in the next week days that pop fantasy storms. It’s funny though how much hand-wringing there is over not seeing them consistently yet. GFS has shown some modest snow events out in clown range but the angst over no KU type storms showing up reveals just how much the operational runs are dopamine for some of the forum. Show me something inside 6 days, and then we’ll talk.

10 days a little short for snow threats if we're talking Euro OP....you're only out to like Dec 9 on the 10th day. I think msot threats would be beyond that date....save maybe if Dec 6-7 trends colder for NNE which is an outside possibility.

The PAC at the end of that run gives me hope that even if NAO starts to break down later in December, we won't go into a torchy pattern. That was a pretty weenie run of the EPS.

When it comes to ensembles, I usually look for a few things to be more confident: 1. Consistency.....are the runs more or less showing the same thing for several cycles in a row? 2. Timeline gets closer....is the pattern on the ensembles getting closer or staying out in clown range? Typically you want to see the pattern starting to get established inside of 10 days 3. Cross-guidance ensemble support. Are the EPS and GEFS agreeing with each other or are they showing different patterns? When you have multiple ensembles suites showing the same pattern, that increases confidence.

They will be quite a bit more accurate than operational runs though out in that time range.