CAPE

Early jumpers can step away from the edge until the next model cycle.

The ensembles have been showing a steady move towards a positive AO/NAO. It's really not that sudden. Anyway, the 12z GEFS looks fine- better actually than the 2 previous runs towards D15. EPO ridge looks more stout.

Nearly a perfect inversion of our ideal pattern

I am still kind of meh about the 'new and improved' site/interface. It's a wash to me. Still lags and then there are things like this.

Did you notice the ens mean does not seem to jive with the individual members on WB?

Yeah it's odd. It will be "fun" when we have a real threat in range and are trying to glean something useful- like from the snowfall means on the ensembles.

This one? https://simonleewx.com/polar-vortex-forecasts/

I have been watching it and the advertised temps in the upper strat have been on fire. Funny you made this post as I was just looking at the latests GEFS Strat stuff. I like looking at the 50 mb panels as well as it would seem to me to be more representative of how it will couple to the troposphere. This is way out there but would probably provide some serious cold in the east if it verified.

Yeah worrying about what might happen beyond D15 is not productive given what looks like a favorable period upcoming. The Dec 3-8 time frame continues to look pretty interesting. Plenty of NS energy and pieces of energy in the SS as well, with cold air in the east. Hopefully something comes together. Otherwise we can enjoy cold and dry followed by a warmup.

lol funny sht. And at the risk of (further) inducing panic, there is a decent chance the pattern is ultimately heading in an unfavorable direction. The EPS especially in the LR has a look of almost every index being in the "wrong" phase lol. At this point it looks like we are gonna see lots of blue in the HL regions, so we really need the PNA/EPO to work for us. Reality is, December in the MA almost always features some warmth, and ofc Nino and MJO impacts. My advice for those predisposed to panic to is to stay focused on the next 10 days or so. Looks active and generally cold.

18z GFS trying to deliver the goods. Pretty similar to the 12z CMC.

It's a pattern with fleeting cold shots and challenges of timing a disturbance with a fresh batch of cold. A pattern i will gladly roll with given most of the alternatives, but also one I think has a much higher success rate in mid to late winter than early December. Hopefully it becomes a clipper-fest, rather than a cutter-fest.

Yeah its certainly possible we see some ridging hold on in the NAO space as the PNA/EPO ridge builds. That would potentially provide the anomalous cold we need in early Dec but also keep enough of a suppression mechanism in place to maybe allow a stronger shortwave to track underneath.

Can never be totally confident in anything, but I will give you a few reasons. The ensembles have been strongly hinting at the breakdown, and now we see it across ens guidance for several runs now. NA blocks have rarely come to fruition as advertised during winter in recent years. Even though they are lower skill and tend to be discounted(unless they show a "good" pattern), cannot completely dismiss that the seasonal/climate models have pretty unanimously been depicting HL -heights for December.

Yeah we lose the NA ridging, but this is an intriguing look. As Bob said, its a pattern that can be frustrating with cold shots tending to be more fleeting, and I would like this pattern a lot more in mid Jan than mid Dec, but I am not going to be picky given what we usually see in Dec. I like the idea of having a piece of the TPV in that location with the big EPO ridge.

Its pretty clear now that whatever NA blocking does develop, it will break down around the Dec 5th time-frame. So it makes some sense we will get our 12/5 snowstorm. After that the EPO will bring the big cold and hopefully a clipper type pattern, as anything amped will likely cut if the NAO goes positive as advertised.

Yeah for our general region that has been the case lately. Overall though, it seems pretty logical. This makes the most sense for us: Jan-Feb-March = Winter April = Spring May-June-July-August-September = Summer October-November-Dec = Fall

In meteorology, every season is 3 full months. Makes much more sense than the sun angle deal.

Cutters wont stop happening because its winter. Met winter starts Dec 1. 6z GFS op run probably doesn't have the next 15 days nailed.

^Totally a gradient pattern look. Given climo, I would love that if I were in NE.

For anyone interested in today's edition of the weeklies - here are the 7 day height and temp anomalies a week or so beyond the end of the 0z EPS. Takes us out to mid Dec. Usual disclaimer..not a big fan of this tool in general, but that being said, I don't hate this look.

Yeah this is pretty close to the best possible setup/evolution to score a solid frozen event with a less than favorable Pac.

I am always 'cautious' when guidance advertises a NA block, for obvious reasons. Looks likely that there will be a period of blockiness at this point. Remains to be seen how long it persists. I haven't looked at the MJO forecasts for a couple days- last I looked it was forecast to move into the COD then perhaps emerge at a low amplitude, maybe in phase 1 or 2. The GEFS seems to be moving in the right direction overall in the LR on the Pac side and with heights building in the EPO region. Most recent runs of the EPS are showing some signs too. Time will tell. We just can't know.

I was looking at the ensemble runs and discussing what they are depicting for the first week in Dec. I try to keep the LR discussion in this thread, because that's what it is by definition lol. December is still 10 days away, and this has been an active thread for at least 10 days now. But yeah the op runs are useful for the early next week time frame.

The question is how long it lasts. It appears to break down pretty quickly on the EPS, while the GEFS at least keeps a neutral look towards the end of the run. Signs of some improvement on the Pac side and in the EPO domain, more so on the GEFS. Could be a warmish period ahead if/when the positive heights break down in the NA, and at the same time the Pac remains less favorable. Before that(should it occur), maybe there will be a chance or 2 at something the very end of Nov into the first few days of Dec with the favorable looks.