2024-2025 Winter Ideas and Discussion

[Carvers Gap]

Well, we are just twelve weeks out from December, so I thought I would start a spec thread...

I actually like these ideas in the article below:

https://www.severe-weather.eu/long-range-2/winter-2024-2025-first-snowfall-predictions-united-states-canada-europe-fa/

I tend to think that our best shots at winter will be late November to late December, and then it gets warm and maybe stays warm.  That said, as others have noted in the main discussion thread for fall, the strength of this La Nina is important.  The IO is important.  The PDO is important.  The MJO is very important.  

PDO -> The September Cansips has the PDO staying solidly negative for the winter, and not really even coming up for air at that.

MJO -> This will tend to favor warm phases as phase 8 will be cooler than normal and that limits convection there.

IO -> Off the coast of Eastern Africa, there is warm water depicted.  That would favor phases 1-2 of the MJO.  It also favors warmer than normal water over the Maritime Continent which favors 4-6.  

500 Heights over NA -> November a ridge is shown to be out West.  It transitions eastward as December progresses, and then parks itself over eastern NA for Jan and Feb - monster SER of sorts.  Maybe by April it relents.  The NAO might be negative for the first 1/3 of winter before returning to a net positive state.  It would not surprise me to see the pattern relax by April, and we see chances for snow in early April (especially the mountains).  

SSTs ->  The La Nina on Cansips appears to fade significantly by February.  By next summer, we might be seeing Nino conditions for the western 3/4 of the Pacific.  

We have talked about gradient.  @Typhoon Tiphas mentioned gradient many times(I think I have the correct poster).  That means the delta (difference) between the La Nina and the waters around it matters.  The steeper that gradient, the more of a stimulus we get.  El Nino was kind of a washed out gradient last winter, and we got washed out results on the EC.

From the recent climate.gov ENSO blog, "Said more simply, it’s not just how much warmer or colder than average that part of the tropical Pacific is that jumbles up the tropical atmosphere, it’s the difference in warming or cooling compared the rest of the Pacific. And that’s where the relative ONI comes in!  So where do things stand? The regular ONI for May-July was +0.2°C. But the relative ONI was already down to -0.4°C. That means there could be a scenario later this year where the ONI is not yet below -0.5°C, but the relative ONI already is, and the atmosphere might start reflecting La Niña-like impacts. Doesn’t that seem like a pain to communicate? "

To me, since the Pacific basin is warmer than normal, La Nina might well have a threshold warmer than what we saw maybe 30 years ago.  That means that what we see as a weak La Nina might actually be a bit stronger than we think.  So, the weak La Nina forecast below might well be a bit stronger given that La Ninas might have increasingly warmer SSTs.

 

Overall Forecast:

I do think we see some crazy cold air masses at some point.  I do think the Mountain West does really, really well in terms of snow and cold.  In fact, the higher elevations there are already getting snow.  Their winter has already started above 8,000'!!!  I do think that middle and western portions of our forum will see a colder and snowier winter.  But beware, if this truly turns out to be a weak La Nina....all bets(and I mean all bets) are off the table.  Weak La Nina's in E TN can often be bitterly cold.  So, instead of doing a monthly J-F forecast, I am going to simply put out a general forecast.  One, well-placed cold shot during Jan-Feb could really skew things. During 2017-18 we had a crazy cold shot that straddled late December to January.  It didn't snow much but was crazy cold.  We were below freezing at TRI for seven straight days!  The monthly climate data doesn't really show that cold shot as it straddled the end of one month and the beginning of another.  That winter was also a weak La Nina.  I am liking that analog year 2017-2018.  If we had any precip in that pattern, we would have been buried.  As it was, it simply froze things solid.  December was -0.8F . Jan was -4.5F.   Feb was +9.4 F.  March was -2.1F.  April was -4.1 F.  Maybe we had a strat split late that winter???

I am going to go ahead and add these.  And I am far, far deeper into this than intended...Sorry, this is kind of a "stream of thought" post, and maybe not as scientific as it should be.  I also want to add 16-17 into the mix at it was a first year La Nina and should be weighted equally or more to 17-18.  But here is why I am far less confident this winter.  See the 94-95 moderate Nino listed in the graphic at the very bottom of this post.  This past winter reminded me of that type of winter - blah and not a lot of chances.  Now, what came after 94-95?  The winter that shall not be named, because I just won't invoke a winter that is a benchmark winter of my lifetime, and it was true winter.  It was a weak La Nina following a moderate El Nino.  It is also a winter that maybe doesn't fit the current warm basin look of the Pac which is why I haven't used it.  That said, it might deserve some weight though I haven't given it any.  Just beware.

So, for now, I like the 16-17, 17-18 blend of weak La Nina winters.  December looks chilly.  Jan is a tossup, but leans warm.  Feb looks warm.  I did break down the 16-17 winter by month as well as 17-18.  I also provided a blend of the two which I tend to like better, and is probably pretty close to my thinking.   In addition, the 16-17/17-18 analog blends might be of better use as they are recent analogs, and not almost 30 years old.  Plus, those two analogs came from a weak El Nino which I think is a better fit.  Notice that the March blend is not overly warm on the EC.  I do think maybe some late season chances exist north of I-40, especially in E TN and the southern Apps.

 

 

 

 

***The following would be my best guess for winter temps.***  Refer to the article at the very top of the page for snowfall anomalies.  Those looked about right.

 

 

Reference for ENSO graphic list:  https://ggweather.com/enso/oni.htm

 

 

And if you made it this far, thank you for reading this!  I intended to make a short post, but ended up just saying, "Screw it," and wrote a long post.  LOL.  I normally don't like long seasonal forecasts, and really, those long posts end up being very wrong much of the time.  I really think seasonal forecasting often involves false correlations, and I am sure my post is guilty of some of that.  In other words, sometimes my seasonal forecasts might "appear" to be correct, but often it is just blind luck that they even got close.  In other words it is like saying TN is going to win a ballgame because of Nico, but really they win because of great defensive line play.  They won, but not really my line of thinking.  

So, have some fun with this, but don't take it as the gospel.  This is just for fun. Feel free to post your winter ideas in this thread.  And this thread is not meant to be the December 2024 winter thread.  That will have its own thread.  This is merely a speculation thread, and won't be rolled into a winter thread.

If this verifies, we could see some cold college football playoff games during December....

 

 

 

[Terpeast]

Thanks for sharing. I agree with the general idea of a mild east and cold snowy west. Also with the torch Feb. 

My main hope is that January will be closer to average temp wise, which gives us more chances for snow before the Feb shutout. I’m in northern VA.

[Daniel Boone]

On 9/3/2024 at 9:17 AM, Carvers Gap said:

Well, we are just twelve weeks out from December, so I thought I would start a spec thread...

I actually like these ideas in the article below:

https://www.severe-weather.eu/long-range-2/winter-2024-2025-first-snowfall-predictions-united-states-canada-europe-fa/

I tend to think that our best shots at winter will be late November to late December, and then it gets warm and maybe stays warm.  That said, as others have noted in the main discussion thread for fall, the strength of this La Nina is important.  The IO is important.  The PDO is important.  The MJO is very important.  

PDO -> The September Cansips has the PDO staying solidly negative for the winter, and not really even coming up for air at that.

MJO -> This will tend to favor warm phases as phase 8 will be cooler than normal and that limits convection there.

IO -> Off the coast of Eastern Africa, there is warm water depicted.  That would favor phases 1-2 of the MJO.  It also favors warmer than normal water over the Maritime Continent which favors 4-6.  

500 Heights over NA -> November a ridge is shown to be out West.  It transitions eastward as December progresses, and then parks itself over eastern NA for Jan and Feb - monster SER of sorts.  Maybe by April it relents.  The NAO might be negative for the first 1/3 of winter before returning to a net positive state.  It would not surprise me to see the pattern relax by April, and we see chances for snow in early April (especially the mountains).  

SSTs ->  The La Nina on Cansips appears to fade significantly by February.  By next summer, we might be seeing Nino conditions for the western 3/4 of the Pacific.  

We have talked about gradient.  @Typhoon Tiphas mentioned gradient many times(I think I have the correct poster).  That means the delta (difference) between the La Nina and the waters around it matters.  The steeper that gradient, the more of a stimulus we get.  El Nino was kind of a washed out gradient last winter, and we got washed out results on the EC.

From the recent climate.gov ENSO blog, "Said more simply, it’s not just how much warmer or colder than average that part of the tropical Pacific is that jumbles up the tropical atmosphere, it’s the difference in warming or cooling compared the rest of the Pacific. And that’s where the relative ONI comes in!  So where do things stand? The regular ONI for May-July was +0.2°C. But the relative ONI was already down to -0.4°C. That means there could be a scenario later this year where the ONI is not yet below -0.5°C, but the relative ONI already is, and the atmosphere might start reflecting La Niña-like impacts. Doesn’t that seem like a pain to communicate? "

To me, since the Pacific basin is warmer than normal, La Nina might well have a threshold warmer than what we saw maybe 30 years ago.  That means that what we see as a weak La Nina might actually be a bit stronger than we think.  So, the weak La Nina forecast below might well be a bit stronger given that La Ninas might have increasingly warmer SSTs.

 

Overall Forecast:

I do think we see some crazy cold air masses at some point.  I do think the Mountain West does really, really well in terms of snow and cold.  In fact, the higher elevations there are already getting snow.  Their winter has already started above 8,000'!!!  I do think that middle and western portions of our forum will see a colder and snowier winter.  But beware, if this truly turns out to be a weak La Nina....all bets(and I mean all bets) are off the table.  Weak La Nina's in E TN can often be bitterly cold.  So, instead of doing a monthly J-F forecast, I am going to simply put out a general forecast.  One, well-placed cold shot during Jan-Feb could really skew things. During 2017-18 we had a crazy cold shot that straddled late December to January.  It didn't snow much but was crazy cold.  We were below freezing at TRI for seven straight days!  The monthly climate data doesn't really show that cold shot as it straddled the end of one month and the beginning of another.  That winter was also a weak La Nina.  I am liking that analog year 2017-2018.  If we had any precip in that pattern, we would have been buried.  As it was, it simply froze things solid.  December was -0.8F . Jan was -4.5F.   Feb was +9.4 F.  March was -2.1F.  April was -4.1 F.  Maybe we had a strat split late that winter???

I am going to go ahead and add these.  And I am far, far deeper into this than intended...Sorry, this is kind of a "stream of thought" post, and maybe not as scientific as it should be.  I also want to add 16-17 into the mix at it was a first year La Nina and should be weighted equally or more to 17-18.  But here is why I am far less confident this winter.  See the 94-95 moderate Nino listed in the graphic at the very bottom of this post.  This past winter reminded me of that type of winter - blah and not a lot of chances.  Now, what came after 94-95?  The winter that shall not be named, because I just won't invoke a winter that is a benchmark winter of my lifetime, and it was true winter.  It was a weak La Nina following a moderate El Nino.  It is also a winter that maybe doesn't fit the current warm basin look of the Pac which is why I haven't used it.  That said, it might deserve some weight though I haven't given it any.  Just beware.

So, for now, I like the 16-17, 17-18 blend of weak La Nina winters.  December looks chilly.  Jan is a tossup, but leans warm.  Feb looks warm.  I did break down the 16-17 winter by month as well as 17-18.  I also provided a blend of the two which I tend to like better, and is probably pretty close to my thinking.   In addition, the 16-17/17-18 analog blends might be of better use as they are recent analogs, and not almost 30 years old.  Plus, those two analogs came from a weak El Nino which I think is a better fit.  Notice that the March blend is not overly warm on the EC.  I do think maybe some late season chances exist north of I-40, especially in E TN and the southern Apps.

 

 

 

 

***The following would be my best guess for winter temps.***  Refer to the article at the very top of the page for snowfall anomalies.  Those looked about right.

 

 

Reference for ENSO graphic list:  https://ggweather.com/enso/oni.htm

 

 

And if you made it this far, thank you for reading this!  I intended to make a short post, but ended up just saying, "Screw it," and wrote a long post.  LOL.  I normally don't like long seasonal forecasts, and really, those long posts end up being very wrong much of the time.  I really think seasonal forecasting often involves false correlations, and I am sure my post is guilty of some of that.  In other words, sometimes my seasonal forecasts might "appear" to be correct, but often it is just blind luck that they even got close.  In other words it is like saying TN is going to win a ballgame because of Nico, but really they win because of great defensive line play.  They won, but not really my line of thinking.  

So, have some fun with this, but don't take it as the gospel.  This is just for fun. Feel free to post your winter ideas in this thread.  And this thread is not meant to be the December 2024 winter thread.  That will have its own thread.  This is merely a speculation thread, and won't be rolled into a winter thread.

If this verifies, we could see some cold college football playoff games during December....

 

 

 

Good work Carvers ! Looks along my line of thinking as well. Hopefully we luck into a major late November or December Snowstorm. 

  Along with all you detailed I will add the North Atlantic SST problem. We definitely need some major coolling of those SST'S off Newfoundland. Let's hope for some late season strong storms or TCs cross that area to help decrease those therefore enhancing the probability of 50-50 Lp setups in Winter.

[Carvers Gap]

There is an interesting thought that Joe B used to make.  It was this.  Wherever it rained the most during fail usually ended-up with a pretty cold winter.   We may be about to test that out.

[Daniel Boone]

51 minutes ago, Carvers Gap said:

There is an interesting thought that Joe B used to make.  It was this.  Wherever it rained the most during fail usually ended-up with a pretty cold winter.   We may be about to test that out.

Yep. JB was the one. There is some statistics showing a greater likelihood. DT also used the Soil Saturation as a Tool in respect to influence in Patterns.

[John1122]

Possibly completely random, but I looked at October rainfall from 2014, 2009, 1995, 1984, and 1976, which preceeded five big time winters here. Rainfall was over 200% of normal in 2014, over 200% of normal in 2009, 175% of normal in 1995, over 200% of normal in 1984, and over 160% of normal in 1976. 

[nrgjeff]

I figure the rainy falls were amplified and unsettled patterns, vs dry northwest flow or ridge. Helene is just one event and from the tropics. I'd kind of like to see mid-latitude drivers.

For now I have warm La Nina. Secondary cold push pattern might benefit the Mid South more than the Eastern Valley. I'm mentally prepared to get blanked again. I mean Heather last year, six inches in Soddy Daisy and nada East Brainerd. My level of jaded remains off the charts!

[Carvers Gap]

6 hours ago, nrgjeff said:

I figure the rainy falls were amplified and unsettled patterns, vs dry northwest flow or ridge. Helene is just one event and from the tropics. I'd kind of like to see mid-latitude drivers.

For now I have warm La Nina. Secondary cold push pattern might benefit the Mid South more than the Eastern Valley. I'm mentally prepared to get blanked again. I mean Heather last year, six inches in Soddy Daisy and nada East Brainerd. My level of jaded remains off the charts!

May be time for you to get a cabin in Banner Elk!  East Brainerd sounds like a further south version of Kingsport, man!

[*Flash*]

I know there's some new 2024-25 winter thoughts emerging in the summer/fall discussion. Just wondering if those ideas should move to this thread? From what it sounds, we have a warm November on tap. From there, we could see a few weeks of normal to below normal conditions in December before Nina climo takes hold and we stay mild through most of January/February (outside some token transient cold shots). I've noticed 2016-17 and 2022-23 analogs popping up in other forums which isn't good, granted for my location, we fared decently with 3-5" total snow in those seasons. Sure doesn't feel like 2010-11 when CPC went warm in their forecast but the pattern evolved almost to the opposite of what they forecasted. 

[Carvers Gap]

Probably could fire up a December 2024 thread in a week or so.  We are now within the 3-4 week window on weeklies...so less speculation and some weak forecasting skill by modeling at this range.  LOTS of possibilities are on the table for December.  The Euro Weeklies (now daily) run...the control has a sharp cold snap before Christmas.  There is some hint on the GFS ext that the ridge will move west.  However, that has been a mirage every, single time any model has shown that during fall.  Right now we should be running 15-20 degrees above normal if this week's models are anywhere close to being correct.  It still feels like summer during the afternoons here.  It is kind of surreal actually.  Mornings are cool, but the temps are jacked up during the afternoon.  I suspect modeling will be completely blind to the first cold snap.  There is probably a lot of feedback in modeling right now.  That said, La Nina falls are often not cold....until they are.  Personally, I think the base pattern is warm for the foreseeable future.  IDK if that means December, but I am starting to lean that way ever so slightly.  However, most modeling completely missed summer extending the extreme it has now - meaning climatology won.  I suspect we cool off for December, but that is an easy call given the extreme that this week will likely be.  No winter anywhere to be seen on modeling east of the Mississippi, and that includes the 4-6 Weeklies ensemble.  I suspect we will see some more Euro control ext runs which are cold.  This trough is parked in the West.  

It has been a LONG time since we have had a true non-winter.  We are over due.  I am talking "not a single flake" type of deal.  Those are usually reserved for super Ninos.  I suspect we see 1-2 extreme shots of cold this winter somewhere in the forum area. 

[nrgjeff]

Yeah the primary pattern is super warm. Secondary pattern will be very subdued this year, fewer weeks and weaker anomamies. I expect 3-4 cool weeks overall, perhaps over just a couple periods. Otherwise the SER wants to lock in hard. 

Mid-South might get one or two winter wx events. North of I-40 and along I-81 could get things on northwest flow. I truly expect to be blanked in southeast Tenn. 

[John1122]

We've still not entered La Nina, been holding neutral since August. It's running later than expected and the chance of it happening has fallen from earlier in the year. Still a 60 percent chance. The strength of the Nina, like Nino, usually greatly impacts what actually happens weather wise. 

[*Flash*]

Per WKRN (News 2): https://www.wkrn.com/weather-headlines/middle-tennessee-2024-2025-winter-weather-outlook-heres-what-to-expect/?fbclid=IwZXh0bgNhZW0CMTEAAR36JnLsixXVyMBjYYZREhfNnSgfheXBhetW0CFqNcPZ6Yh-5kqwlaX_UFY_aem_UgjxkAu77twDDCQ1TSv0HA

They sure seem optimistic!

[*Flash*]

Moving this here based on the content though it does tap into my Friday evening post. 

 

[nrgjeff]

Now the 12Z Euro Op. has an I-40 snow slider around December 3. Of course nothing in my neck of the woods.

So we get a couple very cold weeks in December. Then torch bal-winter. Like 2005-2006 warm fall, cold December, January thaw starts around Christmas. 

For a less pessimistic experience from me, we could get a winter mid-range forecast thread going. Unless this is it? Then I'll try not to post torch thoughts past Day 15. 

Yeah I'm still not over the January snow. Six inches within 15 miles. Blanked IMBY.

[Daniel Boone]

3 hours ago, nrgjeff said:

Now the 12Z Euro Op. has an I-40 snow slider around December 3. Of course nothing in my neck of the woods.

So we get a couple very cold weeks in December. Then torch bal-winter. Like 2005-2006 warm fall, cold December, January thaw starts around Christmas. 

For a less pessimistic experience from me, we could get a winter mid-range forecast thread going. Unless this is it? Then I'll try not to post torch thoughts past Day 15. 

Yeah I'm still not over the January snow. Six inches within 15 miles. Blanked IMBY.

Yeah, I was sold on a very mild Winter. Not so much now. Western Pac continues to cool rather fast and the SST'S in the N.ATL have rapidly took on a much better look , particularly close to the 50-50 Domain (a bit south) . More likelihood of LP settling there more often and pumping up a ridge into Greenland/NE Provinces. Of course, these days it appears there's a real Possibility of the -NAO SER Linkage. Hopefully the cold SST area being further S will help keep them spaced apart.