snowman19

@40/70 Benchmark @Donsutherland1 @Bluewave They are finally admitting the obvious… “A stratospheric wave-reflection event is becoming more likely. Energy that had been expected to propagate into the stratosphere and weaken the vortex now appears more likely to reflect back into the troposphere. This often strengthens the Atlantic jet stream and can trigger a rapid recovery in the stratospheric vortex. This is likely why recent modelling has shifted toward a more zonal pattern compared with earlier expectations. If this occurs, and we see downward coupling from the stratosphere into the troposphere during December, then even with supportive background signals for blocking, stronger westerlies aloft could flatten the pattern and favour a more zonal setup significantly reducing the risk of sustained blocking or cold.”

The ensembles (GEFS, GEPS, EPS) want to retrograde the Alaskan ridge (-EPO) to an Aleutian ridge (-WPO) by the beginning of the 2nd week of December. So you end up with a -WPO/+EPO/-PNA setup. It’s been a consistent theme for several cycles now

Coldest week so far in this La Niña event in regions 3.4 and 4…

Shocker! Wild run to run swings and flip flopping on the CFS

If I had to guess right now March would be the colder month if you end up being correct about a February SSWE. There would obviously be a lag (i.e. February, 2018). As of today I’m definitely on the canonical La Niña February thinking. That said, even if there is a February SSWE, I kind of doubt it would be as historic as 2018, since those are usually like a one in every 20 years event Edit: @40/70 Benchmark Yes, I’m not saying epic torch like February, 2018. That would be ridiculous, however, a canonical Niña warmer than average February? Absolutely

Yea Ray, DT really thought December was going to be a big +PNA month….

I don’t want to jinx you but it’s looking like a very good call on your part with the SPV, along with the increasingly likely flip to RNA/-PNA in December Edit: Also have to give credit to @bluewave with the -PNA December call (looks likely now)

@Stormchaserchuck1 It looks like the record +PNA streak is finally about to come to an end. The ensembles (EPS, GEFS, GEPS) have the most negative long range PNA forecast I’ve seen in a very long time….years in fact

@Gawx Just looked at the new ECM zonal wind forecast, this is looking like almost a sure bet for a classic wave reflection event with a rapid recovery and strengthening of the SPV in December

Yes. You went against the grain and said weeks ago that you thought the November stratospheric warming was going to be a weaker wave reflection event and the SPV was going to rebound and strengthen quickly again mid-late December. If that works out, then it will have been a very impressive call

If Paul Roundy is correct, the 2nd half of December is going to have more -PNA/RNA than the 1st half

This kept happening over and over again with the EPS in the long range back in 23-24

As far as the the SPV, it looks like there is going to be a rather fast recovery and rapid strengthening next month, as you predicted

@40/70 Benchmark Paul still expecting a -PNA/SE ridge to develop by mid-December based on the low frequency forcing:

December, 2022. People were all but guaranteeing a December, 2010 redux with textbook KU’s bombing up the coast and the I-95 corridor getting dumped on. It was even called a historic setup by many and we were told to “buckle up, get sleep now, it’s coming”. The hype was off the charts for the better part of 2 weeks….

Obviously way too early to declare victory, but if this SPV progression verifies, at least the December ideas in your winter forecast are going to be very good. Paul Roundy is also in agreement with you that the PNA goes negative/RNA once we start getting towards mid-December based on the expected progression of low frequency tropical convective forcing….. ^ “This morning's zonal GPH anomaly plot + GFS forecast, showing the strato PV disturbance peaking during the week/10 days, and reaching down to about 50 hPa. There appears to be some propagation to lower levels later on, but the models contrast sharply in this regard, with ECM showing a re-strengthening of the PV in the same timeframe. It aligns with the overall trend observed, with the current PV displacement resulting from a stronger strato anticyclone over Alaska/Canada, and the vortex core shifting over Siberia. After that, ENS members show a possible re-centering over the Arctic, with the anticyclonic area losing intensity and effects over the PV. We'll need to monitor what happens in the next two weeks or so.”

If Simon Lee is correct about 96-97 being a stratospheric analog, then a strengthening SPV into January would fit

Then I stand corrected on that part of my post. I thought December, 83 was +QBO, my bad on that. But the other aspects I mentioned are definitely correct

As per @GaWx research, 1983 did not have any stratospheric warmings in November or December. Furthermore, 1983 was a volcanic winter with a volcanic stratosphere; courtesy of a VEI-5 tropical eruption the year before in 1982. It was also a +QBO winter and a had a strongly +PDO

@40/70 Benchmark Would love December, 1996. That was when the famous Jim Cantore 4 inches per hour thundersnow storm occurred in Worchester, Mass

That post had nothing at all to do with the tropospheric MJO. It was the stratosphere only, which Simon Lee believes (in his professional opinion) resembles 96-97. But with regard to the MJO, we won’t know for certain that the MJO actually goes strongly into phase 8 until it happens, it’s simply a computer generated projection right now

Simon Lee has been saying 1996-97 is a good stratospheric analog for over a month now. It’s not like some twitterologist is saying this either. He’s one of the foremost authorities on the stratosphere, has written many published papers on it

There are no absolutes, definites or guarantees in weather. You, me or anyone else can’t guarantee MJO phase 8, a SSW or that December is going to be cold on November 20th. If I made a post like that saying it’s going to be warm you would have jumped all over me

I forget which winter it was recently…maybe 23-24? The EPS was awful all winter long with the MJO, November right through March. It kept showing amplified waves propagating right through phases 8-1-2 in the long range over and over again and it never happened once

So does the EPS