snowman19

I never thought this winter was going to be a full on wall to wall torch, that’s why I went with +2 - +4 for temps from Dec-Mar with below average snow. That said, I think the pattern becomes much more La Niña like mid-month and beyond given the waning AAM and EWBs/ENSO 3.4 cooling/MJO forcing/SOI developments. I also firmly believe that once that process gets going, AAM is going to drop significantly from what is being shown right now. There is going to be a lag effect. IMO the models get warmer than what is currently depicted today for mid-late month. As @bluewave pointed out in the NYC thread, the weeklies are already backing off the cooler pattern they had yesterday. Unlike Eric Webb, I see the models now going for SPV/TPV coupling and the SPV being record strong as a bad thing. Unless we see a exact replica of 13-14 (unlikely IMO), that coupling is going to lock the NAO/AO positive and trap the arctic air over the pole with no mechanism to readily bring it south

I’ll give Eric Webb credit for this, it looks like we are going to see the record strong SPV couple with the troposphere/TPV now and it moves them over the pole. Better hope he’s right that it plays out EXACTLY like 13-14 or all this is going to do is result in a very strong +AO/+NAO and lock in arctic air over the pole with no way to propagate south

Exactly and I see absolutely no comparison whatsoever to December, 2010. That was driven by severe AO/NAO blocking and a poleward Aleutian ridge. We are going to see a big moderation mid-month

For snow it was. After the early-mid December cold snap that winter just completely shut off. There was another short lived cold snap in early January but other than that…November had no snow and the one of warmest Thanksgivings on record, December had 2 minor snow and ice events early/mid month that turned to rain, January had a trace of snow, total, February had a minor snow event that turned to rain around mid month, then the biggest snowstorm of that winter late that month (just over 6 slushy inches in NYC), a very minor snow event the last day of February and that was it, winter ended and never came back, no snow in March, no snow in April

14-15 was all ++PDO driven. The PDO spiked at over +3 that winter. It fed back and resulted in virtually non stop +PNA, -EPO, -WPO for months on end. It was the only thing that saved that winter from disaster….it was one of the most +NAO/+AO winters on record. Extremely anomalous pattern

@bluewave While we saw the La Niña struggle to develop all met fall, there is going to be marked strengthening and cooling this month. Full scale change with respect to ENSO/trade winds/SOI/MJO propagation and it’s going to result in a flip of the Rossby wave train we’ve been seeing up to this point:

Your hero says the east is going mild mid-December. Didn’t expect you to post his new tweet

Twitter is saying it has that bias and an amped bias because it doesn’t show what they want….

Agree. The consistent +SOI run is indicative of ENSO-atmospheric coupling. And if people are correct that there’s tropospheric coupling with the upcoming record strong SPV, that’s a really bad sign with the PAC changing the way it is. That’s going to re-enforce +AO/+NAO and leave no way to possibly blunt the PAC onslaught

@Bluewave The entire ENSO gyre is switching into a mode much more favorable for region 3.4 cooling, +SOI and enhanced trades finally. This should wipe out the +AAM/Nino like effects. Paul is expecting this to continue throughout December and possibly into early January. It’s also going to constructively interfere with the MJO Maritime Continent forcing and the -IOD. The question is do we see enough cooling to get a trimonthly weak Niña ONI? Paul thinks the distinction between weak La Niña and cold-neutral really isn’t going to matter in this case:

It really wasn’t that long ago. Remember December, 2022? The “textbook, classic”, “OMG”, dream pattern for blockbuster KU’s up the coast? Some people were guaranteeing an arctic cold, crippling snow blitz and were making daily comparisons to January, 1996. “Buckle up, get sleep, it’s coming”. “This may be historic”. I remember that month very well

Agree about the MJO Maritime Continent forcing. My guess is that the models have to adjust to the new EWB/+SOI/ENSO 3.4 cooling regime before you see an across the board reflection in the AAM. Just like the models adjusted to the unexpected WWB/+AAM spike/ENSO warming we saw a couple of weeks ago

I don’t think there’s any question that the 1st 2 weeks of December look cold. The ambiguity starts mid-month. The GEFS is going to a -PNA/SE ridge pattern, EPS holding status quo. Shades of the last couple of years when the EPS was really bad with the PAC pattern and it played catch up as we got closer. Last winter in particular, the EPS was pretty bad in that regard. I’m not really sure what they did with the upgrades, but at least on the PAC side, the EURO leaves a lot to be desired

Eric Webb said so!! 2013-2014 redux!! In Eric we trust!! lol

We are starting to see the effects of the MJO forcing and the WWB induced +AAM wearing off on the models in the long range. They are becoming aggressive with developing a -PNA around mid-month and pumping a SE ridge/WAR. The models are also getting stronger with the EWB in 3.4 and developing a pronounced Modoki event. It looks like the SPV is going to get very strong with nothing to limit it strengthening into mid-December. Luckily still no signs yet of it becoming coupled with the TPV or it would completely rout any source of arctic air and lock it over the pole. It is however, following the typical high solar/+QBO/-ENSO progression so far

The RMM plots are way too noisy. @bluewave uses the VP/OLR plots, which are much more accurate

@Gawx Sunspots soar to over 200 again and geomag on the way up. Wish @Isotherm still posted on here to get his thoughts on everything going into winter….

Finally looks like we are going to see a very strong EWB in 3.4. This one looks real, gaining strength and moving up in time

With today’s rain, most areas are saved from the driest fall on record. However, this met fall will almost certainly end up in the top 5 driest falls on record region wide

The EPS playing catch up in the PAC again. While the PDO has weakened since the beginning of November, it is still extremely negative, as is the PMM and IOD. In the Atlantic, the New Foundland warm pool is still going strong (+AMO): The waters in MJO phases 4-6 are still anomalously very warm and that’s the general area where the atmosphere is going to want to fire convection, law of thermodynamics, convection over the warmest SSTs. I think the answer to what’s going to happen once the WWB/+AAM effects on the wave train wears off is starting to be answered. The models are starting to finally reflect an MJO response around mid-December. We are seeing a very positive push in the SOI and are also seeing a very strong EWB in ENSO region 3.4. It is no doubt going to cool (possibly significantly) in December. Very clearly, a “Modoki” event is taking shape. There is also an absence of upward wave flux/warming into the stratosphere and that is going to allow the SPV to significantly strengthen next month. This fits with the -ENSO/+QBO/solar max base state. The saving grace with regard to the stratosphere is that there aren’t any signs (yet) that the SPV is going to couple with the TPV:

IMO some people are being way premature (mostly in twitter land) with assurances at the end of November, that the early December pattern is “locking in” for the rest of winter. Who knows, maybe it does. But based on the totality of everything happening now and has happened synoptically over the last few weeks, I think that may be a really huge mistake to be so sure of something “locking in” and being completely dominant for the next 3-4 months. That’s how you paint yourself into a corner you can’t get out of and lose credibility if it all goes by the way side

@40/70 Benchmark While I firmly believe this period coming up is WWB/+AAM forced, the reality is that it’s not going to last forever. Eventually that WWB/+AAM effect wears off and the wave train will adjust. I’m seeing some folks arguing that the MJO is going to be a non factor this winter and IMO that is not going to be the case. While the MJO is getting muted right now, I don’t think that remains to be the case. Here’s a good discussion:

You were so sure December was going to roast lol

The CFS is a joke. It insisted on a huge blowtorch December for months on end then does a complete 180 the last week. Terrible model

You point out a real important and big difference between now and 13-14, 14-15….those winters both featured a very muted, retracted PAC jet that allowed the pattern to go stagnant and basically remain in place for months with very few, brief and far between interruptions