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Exactly, anyone thinking snow in early December with a well above average source region is grasping for straws. As CAPE mentioned maybe the real deal, if we ever get one, is when Canada chills down through cross polar flow / - EPO later in the month of December, or beyond. Not sure I agree with Eric Webb about the South getting snow in the depicted pattern outside of the higher elevations. There was always some hope December may deliver by being a shoulder month with a less strong PV. ( But, hey it really is strong currently so... ) Also, there are signs zonal winds may decline later in December. This may assist with HL with blocking, along with a couple other factors.

As expected the weeklies have some major changes. ( for the better )

As we exit November and head into early December. I like !

A few things set in motion during the next week or so...... impact early to mid December for us.

When Anthony is interested you can't help but to be more hopeful. At least a December torch seems unlikely at this point, well at least until the 22 nd.

Some continuing signs this morning that we might be able to achieve a more blocked regime later in the month, and especially in early December. Also, some indications regarding higher pressures building into and near Greenland early to mid December. We all know the odds and the accuracy within the NAO domain, but well worth keeping tabs as we get closer to the holidays.

This is interesting, especially the what occurs after the first of the year, when the favored MJO phase(s) tends to change. This seems to be related to the Nina peaking in the OND period and then waning thereafter.

Expect the unexpected ..............

Let's re-visit this forecast in early December.

Not that it matters much, because the source region ( Canada ) is very warm at this time, but do you buy the + PNA look in early December? We are indeed getting unusual responses and progressions currently, as you mentioned. It will be fascinating to see what the pattern brings us in Jan and Feb where the majority of the seasonal consensus is little snow and much above normal temps. Hard to fight the warmer persistence whether from Nino or Nina like background states. But, I would still keep an eye open for the unusual outcome, in this new unusual climate recently.

Recalling last winter where robust West Coast ridging was forecasted a few times, only to breakdown or never develop, due to the compressed and rapid jet stream movement, culprits already discussed last year. But, if we can get a great Pac pattern in prime climo that lasts a week or more, maybe we can score. Watching the seasonal progression of shorter wave lenghts should be interesting as well later in December.

This does echo the thoughts of Isotherm's seasonal. We wait and watch. At the least the +PNA may help us from torching if indeed it develops.

@CAPE speculating that even if we get a +PNA what about the cold air source? If the EPS is correct Canada is very, very warm. Remarkable, and a sad situation for cold and snow lovers in the East. .

Mentioned the Pac wave train yesterday, and here you have the transition to a +PNA . Today, as you mentioned, more evidence of a + PNA , granted over 600 hours away, but plausible.

IRI update. Maybe some minor implications.

Pacific wave training getting under way soon. If you freeze the animation posted by Anthony you will see the Western ridge amp up and the East Coast trough response near day 9 to 10. I would cold expect a cold period lasting a day or two near the very end of the month. Euro not as thrilled so far. Afternoon run coming up shortly. Keep in mind the same trends as last Fall and winter may once again prevail this upcoming cold season which are the inland runner and Midwest/ GL cutter outcomes.

You can hibernate for the next 10 to 15 days because things look super boring in regards to the weather. However, some interesting developments with regards to SHPV and the NHPV. Currently an extremely cold Southern Hemispheric PV , while the Northern PV is ( quoted by Simon here ) " 100 hPa eddy heat flux averaged over the last 45 days is approaching the 10th %ile in the Arctic " As mentioned yesterday the fires in Aussie and the Western US fires may be responsible here to a degree, as is the QBO. HM mentioned the warmth between the two PVs and the role of aerosols and spoke about a volcanic winter similarity I believe. In my opinion we are witnessing the effects of the change last year with the behavior of the QBO along with the QBO's induced thermal winds manifested upon the aerosol released event, whether acting in unison or separably. Here are a couple great threads that talk about this. One from Dr. Amy Butler and the other from Simon Lee. Each thread is worth clicking on and scrolling through. And for the time being, nothing to be encouraged about. We may be entering as well something called a polar vortex intensification (VI) events https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005JD006302

Overnight models back to warmer for late month.

25 degrees here, with a heavy frost. Coldest air mass since the end of February around these parts.

Simon's GEFS 35 day regime forecast does show some indications of a shallow regime change coinciding with the early part of December. In my opinion a temporary cold period such as the one currently might be in the cards. AO drops in the days ahead , possibly towards neutral, as the SPV remains strong well above the ERA5 mean.

Surprised they went with that snowfall prediction. Would speculate lower.

From Bluewave. Maybe a role with the NAO in my opinion Here is his post : Rapidly warming SSTs off our coast go together with the record 500mb ridging that we have been experiencing. https://climate.nasa.gov/news/2798/watery-heatwave-cooks-the-gulf-of-maine/ Most of us are familiar with heat waves on land, but in a warming world, heat waves are starting to become common in the ocean, too. One basin in particular, the normally cool Gulf of Maine in the Northwest Atlantic Ocean, has seen several heat waves in recent years and has spent most of 2018 with unusually warm water temperatures. On August 8, 2018, scientists using satellite data and sea-based sensors measured the second warmest sea surface temperatures ever observed in the Gulf of Maine. Average water temperatures reached 20.52 degrees Celsius (68.93 degrees Fahrenheit) that day, just 0.03°C (0.05°F) below the record set in 2012. The maps on this page show sea surface temperature anomalies as compiled by NOAA’s Coral Reef Watch, which blends observations from the Suomi NPP, MTSAT, Meteosat, and GOES satellites and from computer models. Shades of red and blue indicate how much water temperatures were above or below the long-term average for the region. The map above shows conditions on August 8, the near-record setting day, while the map below shows conditions across the entire month of August 2018. The heatwave of 2018 fits with a much longer trend in the region, which is among the fastest-warming parts of the global ocean. In the past three decades, the Gulf of Maine has warmed by 0.06°C (0.11°F) per year, three times faster than the global average. Over the past 15 years, the basin has warmed at seven times the global average. The Gulf has warmed faster than 99 percent of the global ocean. August 1 - 31, 2018 “We’ve set 10 daily temperature records this summer, after setting 18 this winter,” said Andrew Pershing, chief scientist of the Gulf of Maine Research Institute (GMRI). “We’ve had to add new colors to our temperature illustrations to reflect just how warm the Gulf of Maine has been this year.” In recent years, oceanographers have come to define marine heatwaves as periods when water temperature rise above the 90th percentile (of average temperatures) for more than five days. In 2018, the Gulf of Maine has spent more than 180 days above the 90th percentile. The Gulf of Maine stretches from Cape Cod to Nova Scotia, and it is key intersection between cold water masses from the Arctic and warm water masses from the Gulf Stream. The warming trend in this basin likely has two main causes. First is the overall warming of the global ocean as air temperatures and greenhouse gas concentrations rise. Second is the melting of ice in Greenland and the Arctic Ocean, which provides pulses of fresh water that can alter ocean circulation patterns in the region. “We are seeing a major shift in the circulation in the North Atlantic, likely related to a weakening Atlantic Meridional Overturning Circulation (AMOC),” said Pershing. “One of the side effects of a weaker AMOC is that the Gulf Stream shifts northward and the cold current flowing into the Gulf of Maine gets weaker. This means we get more warmer water pushing into the Gulf.” “Climate change is likely contributing to the circulation changes through melting in Greenland and the Arctic,” he added, “as well as making long-stretches of warm weather more likely.” The warming waters are already affecting marine species in the area, according to several news media and scientist accounts. Herring populations (based on fishing catches) seem to be down this year, and researchers and fishermen are seeing more species usually found in warmer waters, such as butterfish and squid. The populations of copepods, a key food source for endangered Northern Right Whales, also seem to be moving with the changing conditions. And puffins have had to adapt in feeding their chicks this year, as the newly common butterfish are too large for hatchlings to swallow.

Impressive + PMM Pretty classic +PMM Eric Webb @webberweather Despite being in a La Nina w/ subseasonal forcing solidly over the Indian Ocean, the subtropical jet will actually be quite active in late Nov thanks to a positive Pacific Meridional Mode (PMM) event buttressing moist convection in the tropical off-equatorial central Pacific. 4:11 AM · Nov 18, 2020

Yep, will be interesting to watch the progression. Meanwhile, MJVentrice @MJVentrice A strong Stratospheric Polar Vortex is supporting -80C temperatures at 10mb, which is slightly earlier than normal to see these cold of temperatures. 7:34 AM · Nov 18, 2020·Twitter Web App

Matches the Euro weeklies. Comfortable outside decorating weather.