December Medium/Long Range Discussion

[Maestrobjwa]

25 minutes ago, aldie 22 said:

I told you guys we have to wait until the back half of January 

If that does turn out to be the case that would eat up prime nina climo--February and that SE ridge man (unless something were to change that this season)

[bncho]

9 minutes ago, Maestrobjwa said:

If that does turn out to be the case that would eat up prime nina climo--February and that SE ridge man (unless something were to change that this season)

My take is that it isn't over until it's really over. Until mid-late January last year we thought February would be a torch... it ended up being around average and we got that 4-8" snow event. Unfortunately there was some heartbreak with the late-February phantom but it still could be argued that was our best pattern of the whole winter--in the month that we thought would torch.

[Ji]

man all the good vibes destroyed in 12 hours. 

The AI had a decent look though

[Eskimo Joe]

48 minutes ago, Maestrobjwa said:

If that does turn out to be the case that would eat up prime nina climo--February and that SE ridge man (unless something were to change that this season)

Agreed. If we punt all of January then winter is 75% over by that point and we're in sun angle season.

[Weather Will]

Bipolar crowd today....we had a decent December with sustained cold and some snow, even if nothing else happens before NY.  
Models are struggling with the pattern and we will have to wait to see what happens in January....BUT unlike a lot of years there is a lot of cold air lurking not too far to the North.  Patience....

[mitchnick]

 

[katabatic]

18 minutes ago, Weather Will said:

Bipolar crowd today....we had a decent December with sustained cold and some snow, even if nothing else happens before NY.  
Models are struggling with the pattern and we will have to wait to see what happens in January....BUT unlike a lot of years there is a lot of cold air lurking not too far to the North.  Patience....

Let's hope you're right because temps approach or exceed +40F almost up to the shores of the Hudson Bay around NYE (that's got to be 50-60 degrees above normal?). 12z GFS has essentially no snow (outside of a bit of lake effect or at the highest peaks of New England) east of the Mississippi and south of the US/Canada border. Fingers crossed this is a model burp and some semblance of normalcy ends up being what we actually experience. 

[aldie 22]

Lol you guys are du....ahhh skip it 

[wxdude64]

CPC's most recent 8-14 pushed the warmth a bit more to the west, the normal to first 'warm' now runs thru central VA NW up to Michigan. One or two more pushes west would be appreciated!

[mitchnick]

37 minutes ago, aldie 22 said:

Lol you guys are du....ahhh skip it 

You can say it....we're due! 

[hstorm]

 

2 hours ago, Maestrobjwa said:

If that does turn out to be the case that would eat up prime nina climo--February and that SE ridge man (unless something were to change that this season)

Remember when 1/2 of this forum cancelled winter back in October? 

[CAPE]

1 hour ago, Ji said:

man all the good vibes destroyed in 12 hours. 

The AI had a decent look though

lol only destroyed by those who continue to expect op runs to be consistent 10-15 days out. I'll stop contributing to the stupidity by not making anymore posts about what is possible based on an op run. It's pretty ridiculous how so many long time members of a weather forum still don't understand how this works.

[mitchnick]

1 hour ago, CAPE said:

lol only destroyed by those who continue to expect op runs to be consistent 10-15 days out. I'll stop contributing to the stupidity by not making anymore posts about what is possible based on an op run. It's pretty ridiculous how so many long time members of a weather forum still don't understand how this works.

I have always likened it to discussing how a sports team may perform if they can trade for this guy or that guy. It's harmless speculation on a subject we enjoy that costs nothing. And nobody's hurt by it because nothing can get through the scars we all have suffered from countless busts! Lol

[Ji]

1 hour ago, CAPE said:

lol only destroyed by those who continue to expect op runs to be consistent 10-15 days out. I'll stop contributing to the stupidity by not making anymore posts about what is possible based on an op run. It's pretty ridiculous how so many long time members of a weather forum still don't understand how this works.

it was the ensembles too that went south

[Stormchaserchuck1]

When it's deep -PNA like this, I don't even look at models for snow. Strong +EPO too. 98% of the time threats at Day 8+ don't pan out or are warm. While the OP may sometimes show a winter storm, the ensemble mean never really even has a trough. 

[CAPE]

14 minutes ago, Stormchaserchuck1 said:

When it's deep -PNA like this, I don't even look at models for snow. Strong +EPO too. 98% of the time threats at Day 8+ don't pan out or are warm. While the OP may sometimes show a winter storm, the ensemble mean never really even has a trough. 

Dammit Chuck, stop canceling winter!! We need a good vibe up in here. Read the room. 

[CAPE]

As advertised the Pacific is hostile on the means for the foreseeable future. We shall see if that verifies. It might not. If it does, what can 'save us' from a shit the blinds period to some degree is a favorable NA. In general the guidance indicates we may get that, but we just cant know yet. Just roll with it man. Keep monitoring. Have fun with it. This isn't life and death shit lol.

[mitchnick]

Imho, what has thrown a monkey wrench into the mix is the Niña has unexpectedly come back to life. A few weeks ago, it was supposed to have been dead with a solid neutral by now.  Instead, those effin' trade winds are back with a vengeance and look to be sticking around into late January. This 850 wind anomaly prog only goes through mid January, but the longer one has it going through most of January, then neutral. 

[Terpeast]

1 minute ago, mitchnick said:

Imho, what has thrown a monkey wrench into the mix is the Niña has unexpectedly come back to life. A few weeks ago, it was supposed to have been dead with a solid neutral by now.  Instead, those effin' trade winds are back with a vengeance and look to be sticking around into late January. This 850 wind anomaly prog only goes through mid January, but the longer one has it going through most of January, then neutral. 

We actually don’t want to root for a quick fade on the nina, the last several -enso winters that went neutral by Jan basically ended early. Those that maintained nina into Jan gave us wintry periods into Feb (yes despite the canonical Feb torch).

[bncho]

3 minutes ago, Terpeast said:

We actually don’t want to root for a quick fade on the nina, the last several -enso winters that went neutral by Jan basically ended early. Those that maintained nina into Jan gave us wintry periods into Feb (yes despite the canonical Feb torch).

Why is this the case?

[mitchnick]

4 minutes ago, Terpeast said:

We actually don’t want to root for a quick fade on the nina, the last several -enso winters that went neutral by Jan basically ended early. Those that maintained nina into Jan gave us wintry periods into Feb (yes despite the canonical Feb torch).

You mentioned that previously, but the Cfs has it getting stronger in its last few forecasts. Here's the latest.

When I say strongest, I  mean more members are calling for a temp drop.

[JenkinsJinkies]

Will this age like wine or milk?

https://x.com/capitalweather/status/2001702501557374997?s=46

[Terpeast]

16 minutes ago, bncho said:

Why is this the case?

Not sure why. I haven’t explored it deeply enough to find the reason. Maybe papers have been written on this already, but most are focused on El Ninos rather than La Ninas. 

[CAPE]

25 minutes ago, Terpeast said:

Not sure why. I haven’t explored it deeply enough to find the reason. Maybe papers have been written on this already, but most are focused on El Ninos rather than La Ninas. 

My WAG is ENSO neutral winters in general don't feature a predictable influence on the Pac side so the pattern is less predictable than in a Nina or Nino, and other factors tend to dictate the general pattern. I'm guessing if there isnt a favorable AO/NAO, winters tend to be milder overall and more variable wrt to snowfall, and there is increased chances of little to no snow. I think I recall PSU saying Enso Neutral brings an increased chance of a persistent SER.

[mitchnick]

Surprisingly, Euro weeklies are not quite as warm as yesterday fwiw. It keeps us near or just south of the normal line unlike yesterday which had us AN until the end of January. But it's not a pattern conducive to snowfall.  Looks more like our chances would be along the lines of threats advertised on the 6z Gfs, if anything. Here's a link. You can adjust the date of the runs to see what the previous 3+ weeks of runs looked like too.

https://charts.ecmwf.int/products/extended-anomaly-2t?base_time=202512180000&projection=opencharts_north_america&valid_time=202512290000

 

Edit: all weekly products can be found here:

https://charts.ecmwf.int/?facets={"Product type"%3A["Experimental%3A AIFS"]%2C"Parameters"%3A[]%2C"Type"%3A[]%2C"Range"%3A["Sub-seasonal"]}

[CAPE]

57 minutes ago, mitchnick said:

Surprisingly, Euro weeklies are not quite as warm as yesterday fwiw. It keeps us near or just south of the normal line unlike yesterday which had us AN until the end of January. But it's not a pattern conducive to snowfall.  Looks more like our chances would be along the lines of threats advertised on the 6z Gfs, if anything. Here's a link. You can adjust the date of the runs to see what the previous 3+ weeks of runs looked like too.

https://charts.ecmwf.int/products/extended-anomaly-2t?base_time=202512180000&projection=opencharts_north_america&valid_time=202512290000

 

Edit: all weekly products can be found here:

https://charts.ecmwf.int/?facets={"Product type"%3A["Experimental%3A AIFS"]%2C"Parameters"%3A[]%2C"Type"%3A[]%2C"Range"%3A["Sub-seasonal"]}

All the extended products have been indicating a transition to a -EPO going forward into mid Jan, with a southward displaced TPV. We have seen this look pretty often in recent winters and it brings the cold, then all we need is some luck with a wave riding the thermal boundary. This pattern has produced several moderate snowstorms in our region. I'll take it.

[bncho]

On 12/16/2025 at 10:10 AM, paulythegun said:

 

[Ji]

[87storms]

3 hours ago, CAPE said:

As advertised the Pacific is hostile on the means for the foreseeable future. We shall see if that verifies. It might not. If it does, what can 'save us' from a shit the blinds period to some degree is a favorable NA. In general the guidance indicates we may get that, but we just cant know yet. Just roll with it man. Keep monitoring. Have fun with it. This isn't life and death shit lol.

It’s a competitive sport, though…and I want to be on the winning side.

[Chris78]

21 minutes ago, Ji said:

Wasn't this the AI model that had us in the purple shade for days leading up to the storm that gave us 15 minutes of mix then a bunch of rain at the beginning of December?

Or was that the GFS AI?