snowman19

The updated NWS CPC winter forecast FWIW: https://wjon.com/winter-weather-outlook-from-the-climate-prediction-center/

People are obsessed with seeing a high Atlantic ACE season because of 95-96. That winter was historic for more than that, you had a strongly +PDO/+PMM….extremely rare in a Niña, it was a weak east-based Niña and it was coming off an El Niño the winter before so it had the active STJ. You also had a classic Atlantic “tripole” look in the SSTAs

Got ya. Yea, I was just looking at SSWEs during official La Niña years and what solar and QBO were doing

Was 2009 high solar?

I’m seeing some UK forecasters on twitter talking about how there is going to be a high probability of a SSW this year….not sure what they are looking at or where they are getting this from. If you look at it statistically, this upcoming winter is very unlikely to see a SSW (La Niña/high solar/+QBO). In order of most likely to least likely to see a SSWE, it would be: Niña/low solar/-QBO, Niña/high solar/-QBO, Niña/low solar/+QBO, Niña/high solar/+QBO

The studies I’ve read have shown that the overwhelming majority of the time ENSO forces the PDO state, most notably in the fall. It is very rare to have an “out of sync” ENSO/PDO (i.e. Niña/+PDO or Nino/-PDO), that’s why 95-96 was such a rare breed. The PDO is still negative right now. Given the propensity for strong -PDO the last few years and that we have a healthy Niña, my guess is that we see a significant PDO drop by late November. We will see though

Question is, is this the beginning of an actual full scale PDO shift despite the -ENSO, or just a temporary, transient reflection of the current pattern? If it is still doing this in November, then something may be going on. I believe last year, the big PDO drop didn’t happen until we were into October and November. Definitely something to watch

There are no guarantees in weather

Given a favorable synoptic pattern, those super warm waters along the coast will enhance baroclinic instability/coastal fronts, but like you and I discussed earlier, good luck getting all snow events anywhere near the coast in December, there will be boundary layer issues galore in anything but an absolutely perfect setup

We agree it’s not going to get strong. The NMME is suggesting a +NAO, if you watch the loop, it has a big cold pool develop around and south of Greenland and up into Davis Straight during winter. That is definitely not a -NAO signature. Not saying it’s right so I’m not sure where Ben Noll thinks it’s showing a -NAO

Of course there are no absolutes or slam dunks, however, I will say this, La Niña, QBO, PDO, IOD, ACE, Atlantic SSTs, volcanoes aside, if the current high solar flux continues, it’s definitely not a good sign for this upcoming winter

I wouldn’t call that pattern an all out torch. The only thing saving that from happening is the east-based -NAO it’s showing. If @40/70 Benchmarkis right and we see a flat Aleutian high this winter, we will need all the help we can get from the NAO because I don’t think we are going to sustain any +PNA or -EPO. I’m also skeptical about the AO cooperating much

I never said December would torch. December may in fact be the best month of the winter. However, high solar flux and geomag/Niña/+QBO/record volcanic water vapor in the stratosphere/current Atlantic SSTs are definitely not screaming a -AO/-NAO winter to me. I don’t think HM is suggesting that we should expect that either in that tweet. I will also say the Niña and it’s configuration/west lean, whatever we want to call it and the -PDO are also not screaming a 2013-14 +PNA/-EPO to me either. I don’t think we are going to see the big poleward Aleutian ridging like we did last winter either

I’m not so sure this Niña is basin-wide

Lol I think we can rest assured we won’t see a record RNA like last December. The EPS seasonal depiction is showing an east-based -NAO which would probably be beneficial to interior central and northern New England. I think areas near the coast are going to have problems early on in the season with the bathwater just off shore

The new EPS seasonal for December is showing why you need a poleward Aleutian ridge (-WPO) to get cold into the pattern. At face value, it’s showing a flat Aleutian high and it allows PAC air to flood the pattern:

Some good articles Eric linked to if anyone would like to read up on this:

I would put the chances of a 13-14 or 14-15 style +PNA/-EPO on roids winter at very, very low and extremely unlikely, those winters were driven by ++PDO. Despite what I’m seeing from some of the twitterologists, besides this year having super low Atlantic ACE, it is nothing at all like 13-14, like not even in the ballpark of that year

We shall see. I think this is going to be an Aleutian Ridge/High dependent winter, I expect that to be the biggest main feature given the Nina, question is, is it flat or poleward (-WPO)? You want as much -WPO as possible to keep Canada from getting overrun by PAC maritime air, so when you get blocking it can pull some arctic down

While I don’t think 97-98, 01-02, 11-12 or 19-20 are walking through the door, IMO the preliminary indicators right now are not encouraging for any sustained Atlantic or arctic (-AO, -NAO) blocking nor are they for any sustained PAC (+PNA, -EPO) blocking. I also think this La Niña is being underestimated by some, it is very well coupled (MEI) and it will definitely make its presence felt. As I’ve said before, while I doubt strong, I can easily see a high-end moderate ONI peak

I don’t think anyone in this forum implied that, in fact if you look at the total shut out winters, they were either super El Niño or neutral/La Nada following a Niña the previous winter

I don’t think it goes strong ONI as I have already said. However, high-end moderate/borderline strong is absolutely possible