George001

That smaller cluster south of Long Island has my attention, if we see models start trending towards that things will get very interesting quickly…

That western ridge is pretty far west, there is some blocking in place, and there is plenty of cold air. On the Euro, the ridge is a bit too flat and positively tilted, but with the North Atlantic blocking in place I do believe that it is likely the models are too progressive with the pattern. Due to the North Atlantic blocking in place, I expect the models to trend more amplified overall. The western ridge has plenty of room to trend more neutral tilted and amplified, which would allow the northern stream to dig more. If that happens and it digs far enough south to phase with southern energy, this storm could turn into a big slow moving Miller B nor’easter.

A step in the right direction on the Euro, still a bit too offshore for the big snows but I like what I see.

When there is a Miller B that has been showing up off and on on the European and Canadian guidance, that’s worth keeping an eye on. Miller Bs are usually very tough to forecast due to minor changes with the northern stream energy thousands of miles away right now resulting in big shifts on the models with the storm. It isn’t super high probability, but if it does hit this would be the type of storm to pop up out of nowhere.

That looks a lot better than I expected looking at the polar vortex strength forecast. It isn’t weak, and while it’s centered over the North Pole I like how it’s displaced to the south a bit like you mentioned. I’m hoping this is right and we have a decent pattern for December, and then later in the winter when the polar vortex weakens, it is in a good position to be displaced into the eastern half of the country. That would turn the pattern from good to epic.

I took a look at the recent model guidance and it is now deepening the polar vortex into late December. That is concerning for early winter, however we have seen positive signs with the La Niña, enso 3.4, 3, and 1.2 are now -1 or below, while enso 4 is -.7. The models also have the MJO going into phase 7, if we get an MJO wave into 7,8 and then 1 that will be very good for us. With the latest guidance I am less optimistic about December, but more optimistic about late Jan to March. The La Niña moved east based mid November, so assuming a 2-3 month lag that would mean we start reaping the benefits sometime in the late Jan timeframe until the end of winter. However due to the delayed polar vortex weakening and the the lag effect with the MJO, my optimism for December has declined. I would not be surprised to see us average 3-4 degrees above normal with little to no snow for the entire month of December (I hope I’m wrong, but it’s not looking good right now with the latest polar vortex trends). The polar vortex right now is consolidated over the North Pole, and that’s just not going to cut it. I like our chances better the second half of winter, when the signs are that the polar vortex will drastically weaken, and the east based La Niña pattern will take over. This should not only result in an increased chance of North Atlantic blocking late Jan to March, but it should also lead to less troughing out west. As a weenie it is quite demoralizing seeing the long range models forecasting a massive trough out west in early December, but I believe in the process. Our best winter months are January and February, so the silver lining here is we are really wasting shit climo with the strong polar vortex pattern currently in place. In 2-3 weeks, this winter will show its hand. If it’s going to suck, the polar vortex disruption will be delayed even more on the models, and they will show it deepening in January. On the other hand, if this is going to be a big winter, the signs for a major polar vortex displacement or split in early to mid January will only strengthen. the path to a big winter (>75 inches in the Boston area) is still there, luck out and run into a nice storm or 2 in a bad pattern during December, then get hammered late Jan to early March. It’s a different path than I originally thought (I thought Feb would suck early on and Dec would be decent, now I have flipped), but it still exists. If anything the ceiling is higher since we are wasting Dec (shit climo 1st half especially) instead of Feb (peak climo).

Even if December does suck I’m not giving up on winter. If the polar vortex is showing no signs of weakening and things suck to late Jan then it’s a different story.

The Euro, Canadian, and Navy show a storm threat (though none are big hits), the gfs doesnt have a low. Gfs is garbage, it’s probably wrong. It may not snow, it is November after all so a lot of things have to go right, but I do expect there to at least be a storm.

The Canadian is really close as well, if the northern branch digs just a little more it would have likely phased with the southern branch. We need the blocking to strengthen a bit, if it does this storm has a lot of potential.

To my untrained eyes that looks like a Miller B to me. Is that correct or am I mistaken?

The La Niña strength is indeed similar to 2011-2012, but that doesn’t mean the weather will be anything like it. The 1995-1996 La Niña was of similar strength as well. Unlike the 2011-2012 winter this La Niña is more east based, where as the 2011-2012 was west based. In my opinion this winter will be closer to 1995-1996 than 2011-2012. The polar vortex isn’t weak right now, but it is expected to weaken soon, where as it was rapidly deepening in 2011-2012.

Looks like a Miller b that transferred off the lower mid atlantic coast. There is North Atlantic blocking in place and while it’s not deep cold, there is enough cold for a big storm if things line up. Due to the time of year, it’s going to be a long shot. If we see this setup in January however, watch out. That’s a Jan 2011 like pattern. Yes, that means multiple blizzards. Even if this threat doesn’t work out, the pattern is loaded so there will be more chances after that.

If the polar vortex is still deepening into January then I’ll give up on winter but there is still plenty of time.

Exactly, the people who are calling for a mild snowless winter are going to be in for a big surprise. The winter of 2010-2011 had an extremely strong La Niña with a supposedly “bad mjo” at times yet there were still multiple blizzards in my area that year. This La Niña is even more east based than that one was, though it is also weaker (moderate strength rather than strong, but still powerful enough to influence the pattern). The MJO looks pretty weak to me right now, and there are signs of severe North Atlantic blocking for early December. This winter has a lot of potential. The La Niña= bad thing is not accurate for NYC north.

The models have a great setup for the Nov 25th window, strong North Atlantic blocking developing with the La Niña induced active northern branch digging south. That has the potential to develop into a Miller B. The chances of a major storm are very high, the risk (especially in eastern Mass) is that the cold air supply is limited. We will need the low to undergo rapid cyclogenesis about 200-300 miles southeast of where it’s modeled on the european guidance to get a major snowstorm in eastern mass. I am expecting in my area for this to be a big rainstorm, but it could be big for areas north and west. It also looks like the start of a great pattern heading into December, this pattern with more cold air in place has a lot of potential.

I disagree with both of you. I agree with you that the La Niña will explode in strength come early December, but I disagree with you about the implications it will have on our winter in New England. While it is strengthening it is becoming more east based, which is good for us. As is typical with la ninas (especially one well coupled and of decent strength like this one), the northern branch will be more active. However, due to the structure of the La Niña from what I have read east based structure leads to a more favorable pacific pattern, with less troughing out west and a weaker pacific jet. If we can get North Atlantic blocking (There are signs of it coming in mid to late December into January), I would think it would buckle the flow. When combined with limited pacific jet influence that’s an amplified pattern with plenty of cold air in place. That’s a really damn good pattern for us in New England, east based mod-strong La Niña with North Atlantic blocking and limited pacific jet. It’s not going to be a true east based Nina, more east leaning basin wide as a Nina of this strength is going to expand into nino 4 as well. That’s still good though, the strong Nina= bad thing isn’t really true for us. In late Dec 2010, the official strength of the La Niña was 1.6 ONI, the MEI was below -2, and the SOI was raging positive with an extremely negative PDO. By all accounts, it was a strong La Niña that was well coupled with the atmosphere and a major pattern driver. I also got buried by 18+ inches of snow. In Jan 2011, 2 major blizzards in my area, they occurred while the La Niña was strong and driving the pattern. We had the same blocking pattern the year prior, and New England got skunked while the Mid Atlantic got buried in a strong west based El Niño pattern. Based on what I have seen, I am making no changes to my winter forecast. Mod-strong La Niña, 70-85 inches of snow in the Boston area. Yes early Dec is showing signs that it will be warm. There is still 3 and a half months of winter left after that, and the European guidance is saying the PV weakening is delayed but not denied. Strengthening of the La Niña is no reason to give up on winter.

This is a very simplified explanation, as I have a very basic level of understanding of this stuff. From what I understand, it means increased probabilities of Miller B nor’easters vs a more west based basin wide La Niña. For a more in depth explanation Ray discusses the forcing mechanism of the structural nuances on the Enso region in his blog post on the winter 2021-2022 forecast.

It’s interesting how the strongest negative anomalies are moving east as they surface, which could be a really good sign for a more favorable structure (more east based, basin wide right now) for winter taking hold as the La Niña continues to strengthen in the near term.

The gfs has a strong polar vortex throughout December wear as the Euro weakens it late December. The weakening of the polar vortex has been delayed a bit, but not denied in my opinion. As for the La Niña, the subsurface is starting to weaken but there is still significant negative anomalies just below the surface. These negative anomalies are rising to the surface, and should help strengthen the La Niña further. We are already at -1.0 on the weekly reading in the Enso 3.4 region, and with further cooling expected a moderate peak is very likely. A well coupled La Nina peaking at the -1.0 to -1.2 range isn’t exactly weak.

Guys get a look at the Canadian 200 hours out, it’s a coastal scraper but a massive 972 mb low offshore. If that comes up the coast, while cold air is marginal at this time of the year, due to the strength of the low, it would undergo rapid cyclogenesis and create its own cold air via dynamic cooling. That would result in severe blizzard conditions from NYC to Maine. The storm is caused by the northern branch diving to the south, tapping into the warm gulf coast waters, going negatively tilted. The low then transfers from the Midwest to off the mid Atlantic coast, turning into a Miller B. This is a low probability at this time (due to climo and limited North Atlantic blocking), but the model guidance is forecasting North Atlantic blocking to develop a couple days later. If that develops just a little earlier, the probability of this massive nor’easter coming to fruition increases. More likely, things don’t quite come together, but then when the North Atlantic blocking develops the last week of November, we start getting big winter storm threats.

Ray, I am wondering what your thoughts are about the pattern presented on the CFS from Jan-Mar. In Dec, the pacific looks decent, but with the lack of blocking I agree your area is in a much better spot than us in se ma. With the look the CFS has in January though I’d take the overall pattern it has for the winter and run. That January pattern looks straight up epic. Feb and March, im not a fan of the trough out west. But March looks to have some blocking and both Feb and Mar have a nice look on the precip charts. Maybe the Feb-Mar look would be something like 2005-2006 with a mild pattern overall, but active pattern with chances at a big one?

I’m not sure if I’ll be able to make it or not but I might stop by, can someone DM me the address

It’s weakening a little earlier than anticipated but make no mistake, this is a real La Niña that is well coupled with the atmosphere. The MEI value is at -1.5, that doesn’t happen in a La Niña that isn’t well coupled to the atmosphere. There has also been significant cooling over the past couple months off the northern pacific coast, another indicator that La Niña is already driving the atmospheric pattern. Strength wise, it is expected to be a low end moderate La Niña, maybe a tad weaker strength wise than last year (last year was -1.3, this year probably -1.1 or so peak). However, this La Niña despite being weaker is more well coupled to the atmosphere, the MEI is higher, the northern pacfic ssts are cooler ect. La Niña isn’t going to fade into the background while other factors drive our winter pattern, La Niña will likely be a major pattern driver, even more so than last year despite being a tad weaker.

That type of pattern would be a high ceiling one on New England, in some of the mid Atlantic boards they cringe at the thought of Miller Bs, but those Miller Bs that screw them over often bury us. It seems like Miller As just don’t have the crazy high ceiling Miller Bs do. Jan 2015, Feb 1978, Feb 2013, Jan 2005 ect all Miller bs.

Yeah it’s not good yet, but it’s close and if you extrapolate those 2 maps above to later December I would think the pattern becomes great. North Atlantic blocking looks like it is starting to develop there, even with a trough west of ideal that can work. The blocking should help turn those lows initially running inland redevelop off the coast and turn into Miller Bs.