snowman19

So much for that big “upgrade”. They made it worse. Completely unreliable, they destroyed it. That model has become a joke

Might as well get wind to give us something to talk about because snow side looks like a total non event. The new HREF has basically nothing for the area

The background La Niña state just keeps chiving on unabated. The recent changes in the ENSO genre and constructive interference from the -IOD are just going to reinforce the whole process going forward

It’s thermodynamics 101. The atmosphere is going to fire the strongest and most persistent convection over the warmest SSTs (MJO 4-6). That’s where the global heat budget is centered. And even despite the rise in the PDO last month, it was still record strong at over -3 as @GaWx pointed out yesterday. I honestly fail to see any change from last year in the PAC other than ENSO. This La Niña is finally, at long last starting to really take off (EWBs, +SOI, region 3.4 cooling, AAM slowly falling, -IOD) and it is entirely central-based/Modoki now too

I think it may have a shot at being the strongest +QBO event on record. We’ll see

Ummmmm yea it sure does. If the EPS and GEFS are correct, the EPO floodgates open up and it will scour all the arctic air out of Canada. Won’t happen immediately, but it will happen. This pattern looks to have staying power. Don’t believe me? Fine. Here’s Eric Webb and Earthlight:

Looks like yesterday’s GEFS may have been onto something

The day before Thanksgiving someone had tweeted the actual data on La Nina’s and cold-neutrals in the NYC area, going back to 1945. Long and short of it, they found that the overwhelming majority of the time, when December produced above normal snowfall, the rest of the season (Jan-Feb-Mar) went on to see average above normal snowfall. The exact opposite was true for Decembers that produced below average snowfall. So it definitely backs up @bluewave findings

The JMA has also been suggesting the same for mid-late December

That’s the beginning of the drop I’ve been suspecting. There’s going to be a lag with the changes taking place in the PAC before the AAM catches up and really reflects it

It’s the op GFS so it’s probably not right but Jesus Christ is that ugly on the PAC side after 12/16 https://www.pivotalweather.com/model.php?m=gfs&p=500h_anom&rh=2024120212&fh=372&r=na&dpdt=&mc=&pwplus=1 @MJO812 Yea a ++EPO looks lovely. Better hope the op has no clue (likely) and the GEFS doesn’t show the same thing

The low and all the associated good forcing and lifting is going to be well north of here Wed night. We’re going to be lucky to get more than a dusting/coating out of that and looking at the soundings, there may be virga issues

@Bluewave

There is going to be a lag with the AAM. Once the mid-late December regime takes over, it will drop

There is going to be a lag with the AAM. Once the mid-late December pattern kicks in, it’s going to drop

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: