cbmclean

Meh, you might care too much about what they think.

That would make sense to me if the arctic cold pool was "standing its ground" as it were, but since the high latitudes are warming faster, I would expect arctic/polar jets to retract faster then than the STJ, thus lessening the latitudinal temperature gradient and leading to weakening of the jets.

I hope you're right...

That was what made it worse than 2019 to me. That year the epic look hovered just outside d16. But this year it was moving nicely up in time and then.... Just so frustrating.

Do you find that unexpected or surprising?

RDU record is 1,164 days from December 1989 to Feb 1993: https://abc11.com/north-carolina-snow-nc-drought-last-time-it-snowed/14449555/

Sure, but I was more referring to the fact that a +PDO might not have saved the Jan 6-7 event. But perhaps it might reduce the probability of such events because the cold wouldn't have to constantly fight against SER and thus it might take only 1 - 2 weeks for thermals to recover from pac puke instead of 3 - 4. It's all speculation of course. We simply watch and wait.

And I fear that this one is one we're not getting back because even when/if the PDO flips we'll still have the pac puke. This wasn't primarily a SER fail but the fact that the entire continent was taking weeks to recover from the near-record pacific onslaught that almost completely eliminated snow in the CONUS outside the high elevations. I think it is the tag-team effect of the PNA/SER and Pac Puke which has made this last period so hostile. A pac puke comes along and scours the cold out. Then once it shuts off the source regions begin to recover, but the PNA/SER tendency constantly fights against the cold making it to the eastern conus. It takes weeks to slowly push the thermal boundary back over us and then it just gets wiped out by another pac attack and the whole things starts over. I have hope that a PDO flip can improve the PNA/SER tendency, but I don't see how it can help much with the jet stream/Hadley cell problem. So at best we'll hopefully be able to recover faster from the pac attacks. I hope I'm just being pessimistic.

But is it a "reflection event" or an "absorption event"? Because if we have the "wrong" one it's just dookie.

One of my hobbies is now researching the nature of the PDO. Laugh at me but I usually start research on Wikipedia(it's a great place to get an overview!) and I came across mention of an "Interdecadal Pacific Oscillation". Anyone ever heard of that one before? https://en.wikipedia.org/wiki/Interdecadal_Pacific_oscillation

I'll have to see some studies on that; until then I see it as just idle speculation.

I've been told I'm a literalist.

I didn't really get the impression that the PDO was the number one villain this year. Sure it didn't help, but if I had to pick my number failure mechanism it could be the frequency/strength/duration of pacific trough jet extensions. The first event took out four weeks of good climo and was primarily the cause of the failure of the otherwise promising early January period. The second event killed late January and early Feb. Likewise the collapse of the modeled epic pattern in late Feb was due to the failure of the advertised HL blocking. Is that connected to the PDO?

Just curious, what is the risk?

They are definitely already working on this. Several AI or AI/physics hybrid models have been posted on the site this winter. They have the potential to be powerful but one thing to remember is that many AI methodologies (e.g. artificial neural networks) have to by definition "learn" by using past data. As has been mentioned many time here past data may have limited relevance in a changing climate. That may limit their effectiveness going forward.

I try to be open-minded. I agree that we probably place too much confidence in modeling in d10+. And I understand that human knowledge can do a lot from simple analysis roll forward say to ~ day 3. But from day 3 through day 10 I truly don't see any alternative to model-based forecasting. If you have a different alternative to propose I would honestly like to hear you out.

What, in detail, is your proposed alternative to model-based forecasting?

Maybe at some point we can max out the register and cause it to roll over into colds again.

I admit I am still curious to see what a nice strong Modoki Nino could do. I suspect I'd be disappointed but I am still curious. ETA: apparently Modokis were at one time thought to be becoming more common due to Babar. Can;t say I have seen it lately though. https://www.aoml.noaa.gov/ftp/hrd/annane/DIS/Q3.pdf

There's quite a bit of variability in the "snow response" to ENSO. Because I love to graph things I have made a scatter plot of ONI values vs snow at IAD. For the ONI values I have taken the data from here: https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php I have averaged the DJF and JFM values for each year to obtain the single "winter ONI" value for my plot. I got IAD snow data here: https://www.weather.gov/media/lwx/climate/iadsnow.pdf In the plot you can see the general trend for low ONIs to be lower in snow but there is still a ton of variation. The red point is 1996. The green point is 2010

Eh median is not out of the question then. I'll be rooting for you!

Yeah I guess we're just stuck waiting for the PDO flip to occur to see what happens. I don't really have a good feel as to what happens then. If a time traveler came from 30 years in the future and said "Yeah it flipped but it didn't help much and DCI is now Myrtle Beach", I wouldn't be surprised. On the other hand if they said "Yeah it flipped and we got back to maybe 85% of what we had" I wouldn't be shocked either.

What are you at for this season? My home forum is pretty much closing up shop and I'm just staying on here to try to help will you to at least median.

In today's base-state, between the two which do you guys think is more destructive to east CONUS snow: Pac Puke (Pacific Trough regime) or SER/-PNA/Pacific Ridge regime? They both suck ass, and the three previous winters had nearly endless -PNA but overall I think the SER is less evil than Pac Puke. At least in the SER regime the source regions are still cold and a nice -EPO can cause it to get shunted our way from time to time. For Pack Puke, once it sets in we're punting a bare minimum of the next three weeks (often four or five) as the source regions are completely scoured of cold and after it relaxes we have to gradually build it back up. On the other hand of course, when the -PNA is dominant and immobile like it was last year it is obviously a complete killer. While I'm hopeful that a switch to +PDO might help with the SER, will it do anything to improve the Hadley cell/pacific jet situation that seems to be making Pack Puke episodes longer and more severe?