ORH_wxman

Yes....the remnant EPO/PNA ridge sort of teams up with the reotgrading NAO block and forms a ridge-bridge right in the Baffin Island/N Davis Strait region.....it presses that PV lobe down into SE Canada....below is the look on Tday on that run. This is what sets the stage for the winter wx. If we don't get that, then it will be pretty mild like the Euro.....night and day solutions.

Yeah you have the cold firmly established prior to the system getting in here. That's a classic long duration overrunning look there. Probably not gonna happen, but that is what you want to see for those looking at model guidance for next weekend if you are trying to get a wintry system in here.

GFS is showing the colder Tday and beyond solution....you can see the overrunning setup there with the classic Scooter high from the Canadian prairies sprawling east. Euro does not show this though....this is where the model disagreement is on how much that cold presses south.

With really weak sun angle now, I wouldn't be surprised to see a lot of local ponds with ice on them by next Wednesday. Even when you're hitting like 38-41F during the day, it's only for a few hours and you have a lot of shade now these days at 2-3pm with the low sun angle. Then you're going 18-25F at night for 10+ hours.

Higher terrain in SNE may struggle to hit 40F for the next week after today. Full on winter in NNE...esp at elevation. Should be plenty of Tip's pond ice (albeit thin) by middle of next week. T-day and beyond still kind of a wildcard on model guidance. GEFS looks MUCH colder than EPS for Tday weekend. So we gotta see how that unfolds over the next few days on model guidance.

The NAM warm layer was like 10-15mb thick....lol. It didn't really make a lot of sense. It was something that could get wiped out anyway with good lift. The fact that all other guidance disagreed with it too was kind of a red flag. Usually when NAM does well, you'll at least see some other guidance hedging a little toward it even if it's not as robust as NAM, but that wasn't the case yesterday.

Yes, it looks quite unstable on the soundings. I'd be surprised if there wasn't some reports of TSSN.

Went back and looked at yesterday's model runs....one red flag on the NAM was that it's warmest layer was basically right at 850mb....it didn't have that big elevated warm tongue around 750-800mb that we often see on front enders. And it was pretty cold in the layer below 850 down to around 950mb. When the NAM scores a coup on these, it's often a larger elevated warm layer significantly higher than 850mb...we didn't have that yesterday. PRobably something to think about the next time the NAM is the warmest....see exactly where in the column the warm layer is.

There was still some waterlogged snow on winter hill this morning.

We had about an inch of snow late last night but mostly washed away now. 2 inches out in ORH.

18z GFS shows it too. Pretty vigorous shortwave so widespread snow showers or even a steady period of light snow wouldn’t be shocking.

Yeah not even close. Maybe it was still hungover from the summer convection party it throws each year.

Big model differences between NAM and other guidance for tonight. Most other guidance prob gets like an inch or so (maybe even 2”) down near ORH while NAM would maybe start as a couple flakes before very quickly flipping. 18z NAM gets the mixing north of the VT/Canada border. 18z HRRR and 18z rap are still defying the NAM.

Yeah and Killington has already proven it can handle that race for several years now (I think since 2016 or 2017?). From memory, most years have had very good conditions.

That average snowfall map is horrific.

It’s not a super strong block on most guidance right now so I’d probably hedge warmer like the euro look. But can’t rule out the colder scenario. A lot will depend on how the EPO block breaks down…on some of the colder CONUS looks, it pinches off and retrogrades up into the AO region and strengthens the block which would produce a colder look Tday week/weekend.

@Damage In Tolland 18z GFS shows how to get it more wintry for Tday. Nice sleet bomb on this depiction

More likely to be rain or nothing....but if we're playing devil's advocate, you want that NAO block a bit more stout to push that system underneath us.

Oh nice....earlier in this thread there was talk of an "inspection" on Saturday 11/12 by FIS officials, and I was worried it would be so bad they'd cancel without realizing the next 2 weeks looks great for them.

Sounds good for retention but pretty terrible for orographics on heavy precip.

Weeklies backed off the furnace December....still show a bit of a relaxation in early December but it flips back to a colder pattern for second half of the month. But honestly, they haven't been consistent or skillful at all so far this cold season out beyond week 3 so not gonna put much stock into it....even if we like the holiday period pattern it shows.

Lol, ninja'd....your pattern recognition in the last few years has improved exponentially.

Prob a lot of clippers and SWFEs....you typically want a big western ridge for large coastal storms....but that type of pattern can also produce some miller Bs (Jan 12, 2011 was an extreme example of one)

A good analogy is it's like on a new car where they have the anti-collision system and rear-view camera for backing up....that's what the splitting of the PV aloft is adding. It helps, but there are still a hundred variables more important in being safe on the road than just having those features. All else equal, you'd rather have them than not.....but they aren't going to make a terrible driver safe. The stratospheric PV split just makes resistance to blocking a little less, which is good. But we don't want everyone to start throwing a party just because it shows up. It is still minor in the scheme of things.

It has shown up a couple times on various model runs, but it doesn't have anything close to widespread ensemble support. Certainly nothing thread-worthy.