2023-24 Winter Speculation Thread

[John1122]

Carver's spoke of creating an early winter spec thread recently, and after another day in the 70s in August, I figured why not get the ball rolling. This for general long term talk about the potential winter patterns, etc. 

 

Right now, the EPO has went negative, it's at -12, and is in the East descending phase.  In 2021-22 it fell into the negative in May and stayed deeply negative until the following May. So it should descend throughout winter. 

Below, average pressure anomalies over NH when the QBO is negative. Higher in the PNA/NAO region, lower over the south and eastern U.S. (These maps may initially appear confusing, since they greens are positive numbers. It just means that the they are higher by those margins over those areas or lower by those margins over those areas when there isn't a -QBO in place. Just keep in mind green = lower pressure and cooler temps during -QBO years) 

 

 

There tends to be higher pressure over the North Pole during a -QBO, which results in a weaker jet stream/polar vortex on average.

 

During an El Nino/-QBO combination our forum region is slightly BN for temps DJF and pressures are quite a bit lower across the Southeast (our storm track). The map doesn't look unlike this for temps, but BN for Texas, Tennessee, North Carolina and up the east coast is more prominent than the CPC map here. Especially over Texas.

 

[Carvers Gap]

I'll drop this in here as well..

.

[Matthew70]

Is it really August?  Sure feels like late September.

[fountainguy97]

On 8/10/2023 at 2:54 PM, John1122 said:

Carver's spoke of creating an early winter spec thread recently, and after another day in the 70s in August, I figured why not get the ball rolling. This for general long term talk about the potential winter patterns, etc. 

 

Right now, the EPO has went negative, it's at -12, and is in the East descending phase.  In 2021-22 it fell into the negative in May and stayed deeply negative until the following May. So it should descend throughout winter. 

Below, average pressure anomalies over NH when the QBO is negative. Higher in the PNA/NAO region, lower over the south and eastern U.S. (These maps may initially appear confusing, since they greens are positive numbers. It just means that the they are higher by those margins over those areas or lower by those margins over those areas when there isn't a -QBO in place. Just keep in mind green = lower pressure and cooler temps during -QBO years) 

 

 

There tends to be higher pressure over the North Pole during a -QBO, which results in a weaker jet stream/polar vortex on average.

 

During an El Nino/-QBO combination our forum region is slightly BN for temps DJF and pressures are quite a bit lower across the Southeast (our storm track). The map doesn't look unlike this for temps, but BN for Texas, Tennessee, North Carolina and up the east coast is more prominent than the CPC map here. Especially over Texas.

 

With a descending QBO and solar activity rising toward peak the chances of blocking and a disrupted PV are increased.  
 

along with the active southern jet with the El Niño I'll take those chances any day. The only fly in the ointment is we need the El Niño to shift toward a more basin wide event vs eastern based. Models are predicting that so let's hope they are correct.  
 

Definitely some good signs heading into fall!

[Itryatgolf70]

13 hours ago, fountainguy97 said:

With a descending QBO and solar activity rising toward peak the chances of blocking and a disrupted PV are increased.  
 

along with the active southern jet with the El Niño I'll take those chances any day. The only fly in the ointment is we need the El Niño to shift toward a more basin wide event vs eastern based. Models are predicting that so let's hope they are correct.  
 

Definitely some good signs heading into fall!

I feel the same way. If the niño don't shift west and stays east based, the chances of wintry weather will decrease substantially imo. Especially as strong as it looks to be heading into fall and winter. A -qbo can only help so much and we need alot to com together. We shall see

[*Flash*]

On 8/13/2023 at 8:30 PM, Itryatgolf70 said:

I feel the same way. If the niño don't shift west and stays east based, the chances of wintry weather will decrease substantially imo. Especially as strong as it looks to be heading into fall and winter. A -qbo can only help so much and we need alot to com together. We shall see

I concur. We will need a strong -QBO if we have a strong east-based Niño. Preferably, our ENSO is weak to moderate so it doesn't drive mild pacific air all winter.  At least, the stage seems set for a more unsettled, perhaps frontloaded pattern for mid/east TN.

[Carvers Gap]

This wx pattern is one which often favors E TN. I made no bones about it when it came to last winter's forecast for NE TN and SW VA- it was going to be sparse, especially towards the mountains.  At this moment, I would literally flip last season's forecast for all regions of the forum area.  "Right now" the Nino is depicted by seasonal modeling as shifting to a basin wide event by Jan.  I think we start as east based and transition steadily to a basin wide event.  The 90s were Nino predominantly = snow dome for Nashville.  The 2000s have had many more La Ninas = often a good pattern for Nashville and points westward.  SST forecasts are notoriously fickle - I have been burned more times than I can count at this range. 

Temps/Precip/snowfall:

Dec:

eastern forum areas: normal to above/above/below

middle forum areas: normal to above/above/normal to below

western forum areas:  normal to above/above/normal to below

Jan:

eastern forum areas:  starts above and moves to seasonal/above/seasonal

middle forum areas:  above/seasonal to below(edit)/below

western forum areas:  above/above/below

Feb:

eastern forum areas:  BN to much BN / above / above

middle forum areas:  normal / seasonal to below(edit) / below

western forum areas: normal /above / much below

March:

Yes, March during El Nino's

eastern forum areas: BN / above / above

middle forum areas: BN/ above / crap shoot

western forum areas: BN/ above / crap shoot

 

Overall Season (Dec-March):

eastern forum areas: normal / above / normal to above

middle forum areas:  above / seasonal to slightly BN(edit) / below

western forum areas:  above / seasonal to slightly BN (edit) / below

 

Over-reaching ideas:

When it snows, the storms could be big.  El Nino seasons are often not nickel and dime stuff.  The primary pattern is coastal storms with secondary as inland runners.  There are always some cutters - we live in the South!  Cold sources will likely be an issue, but the storm track for E TN could potentially be good.  As others have noted, east based El Ninos don't favor a good winter pattern for all but the most eastern sections of the forum areas.  A super Nino which is east based is a bust for all regions.  Basin wide(which I expect from mid to late winter) favors E TN and the NC mountains.  I don't foresee week after week of snow on snow - unless you live in the mountains.  What I do think we see are big storms which bring us to average - maybe even just one storm.  The pattern should be active.   The trick is getting the cold to get far enough south while the STJ is absolutely ripping.  I think the MJO will favor trips into colder phases as plots 7-8-1 should have active convection.  The PDO is the wildcard...to repeat...the PDO is the wildcard.  To have a banner winter, we need it to flip from its phase last winter.

Of note:  Seasonal forecast is often woefully inaccurate.  I am basing my forecast on the Pacific driving the pattern - ridge out West, mean trough in the East. Get that trough east of Hawaii(per the Euro seasonals), that is a money pattern.  As always, it is important to remember that we live in a place where it wants to rain for about 48 weeks out of the year.  In Wyoming it is rare to see rain during DJFM.  Here, it is quite the opposite in the sub tropics.  It wants to rain.  But...there are times when we can coax a decent pattern from the chaos.  

[nrgjeff]

Carvers covers the different flavors of El Nino well, just above. John covers other hemispheric pattern drivers top of page. 

I prefer QBO trend to a steady value, trending down and ideally into negative. El Nino looks like it wants to stay basin wide. While I have concern about strength..

If the summer pattern can hold into fall and winter, it's of course favorable for temps Middle and East parts of our Region. Mid-South should get its turn too. We'll know more about this through Sept. and into early Oct. Note the polar source remains very warm. Canada and Alaska have MA temps this summer. In El Nino the Southeast relies on the southern stream anyway.

If the current Atmo response continues into autumn, I'd be cautiously optimistic. If by wavelength or other debacle we torch, I'll just chalk it up to living in the South.

[Carvers Gap]

I am going to trend downward precip for middle and western areas.  I got a bit carried away.  Seasonal modeling does see less precip in those areas as the winter progresses.

[*Flash*]

I haven't done much in terms of research but experientially going back 25-30 years, while I recall Nino ENSO bringing less precip to middle TN, I'm not 100% sold there's a mirror correlation to below average snowfall. This century specifically, 2002-03, 2009-10, 2015-16 were very kind to BNA. 2006-07 was decent. A few of those ENSO's were weak, a few others were moderate. 2015-16 was super strong...basically a rare lottery win for our area as we were able to cash in during a 2 week window. 

 

[Carvers Gap]

1 hour ago, *Flash* said:

I haven't done much in terms of research but experientially going back 25-30 years, while I recall Nino ENSO bringing less precip to middle TN, I'm not 100% sold there's a mirror correlation to below average snowfall. This century specifically, 2002-03, 2009-10, 2015-16 were very kind to BNA. 2006-07 was decent. A few of those ENSO's were weak, a few others were moderate. 2015-16 was super strong...basically a rare lottery win for our area as we were able to cash in during a 2 week window. 

 

Yeah, of all the things to forecast seasonally....snowfall is the toughest and has very little skill.  I often don’t include a lot of snowfall discussion in seasonal outlooks.  The coastal areas adhere to pretty strong ENSO correlations...but this region is no slam dunk.  I tend to like winters where the SST gradient is reset after La Niña.  Snow in this forum are can be random at times.  I do like the storm track clusters across seasonal modeling for the mountains...that would be one area where my confidence is slightly higher.
 

Like Jeff says as well...there are some torch possibilities for all of us.  

Again, most of this by me is conjecture at this range with a heavy reliance on fickle seasonal models and SST trends.  

[Stormchaserchuck1]

There is a strong correlation between El Nino/-QBO = +10mb, and La Nina/+QBO = -10mb, It's a 70% correlation since 1948. We are going solidly El Nino and solidly -QBO, so we'll see if the correlation holds this Winter.  The main impact to +10mb is -AO at +15 to +45 days, depending when in the Winter it happens, and -10mb correlates to +AO at 0 days all Winter. 

[Itryatgolf70]

9 hours ago, Stormchaserchuck1 said:

There is a strong correlation between El Nino/-QBO = +10mb, and La Nina/+QBO = -10mb, It's a 70% correlation since 1948. We are going solidly El Nino and solidly -QBO, so we'll see if the correlation holds this Winter.  The main impact to +10mb is -AO at +15 to +45 days, depending when in the Winter it happens, and -10mb correlates to +AO at 0 days all Winter. 

Imo, I believe the base of the niño will be the most important this winter. 

[Carvers Gap]

The PDO is very important as sea temps in the eastern Pac correlate nicely with troughs or ridges in the West depending on phase.  Sometimes, that index is the only one that matters.  D'Aleo talked about it today.  It is being stubborn in switching phases.  I have seen great patterns completely muted by a PDO which is out of phase.  East TN winters turned crappy around 2018...want to take a guess when the PDO flipped negative?  Yup.  Go find your favorite winter, and I bet most of them are weakly negative or positive.  Strongly negative PDOs will park a trough in the West more times than not.  During the past 6 months, I have really just about decided that it is probably the most important teleconnection for winters in E TN and maybe one of the least discussed.  With very few exceptions, strongly -PDOs = bad outcomes(lack of stormy pattern).  Somehow, it has to be connected to the QBO as the QBO mirror this quite nicely.  

https://www.ncei.noaa.gov/access/monitoring/pdo/

I do think the MJO is one teleconnection which might outweigh the PDO during winter.  Again, and others have noted this, it all begins with SST in the Pac and IO.  MJO looks decent this upcoming winter IMHO.  PDO....it should start to rapidly ascend, but not sure it gets there by winter.  Could be a close call.  It "should" switch to positive with the expected El Nino.  But again, look at the plot in the link...find your favorite winter if you live in E TN.

[Itryatgolf70]

19 hours ago, Carvers Gap said:

The PDO is very important as sea temps in the eastern Pac correlate nicely with troughs or ridges in the West depending on phase.  Sometimes, that index is the only one that matters.  D'Aleo talked about it today.  It is being stubborn in switching phases.  I have seen great patterns completely muted by a PDO which is out of phase.  East TN winters turned crappy around 2018...want to take a guess when the PDO flipped negative?  Yup.  Go find your favorite winter, and I bet most of them are weakly negative or positive.  Strongly negative PDOs will park a trough in the West more times than not.  During the past 6 months, I have really just about decided that it is probably the most important teleconnection for winters in E TN and maybe one of the least discussed.  With very few exceptions, strongly -PDOs = bad outcomes(lack of stormy pattern).  Somehow, it has to be connected to the QBO as the QBO mirror this quite nicely.  

https://www.ncei.noaa.gov/access/monitoring/pdo/

I do think the MJO is one teleconnection which might outweigh the PDO during winter.  Again, and others have noted this, it all begins with SST in the Pac and IO.  MJO looks decent this upcoming winter IMHO.  PDO....it should start to rapidly ascend, but not sure it gets there by winter.  Could be a close call.  It "should" switch to positive with the expected El Nino.  But again, look at the plot in the link...find your favorite winter if you live in E TN.

I maybe be incorrect, but back in the 60s and 70s the PDO was negative at times and we had colder winters.

[Carvers Gap]

2 hours ago, Itryatgolf70 said:

I maybe be incorrect, but back in the 60s and 70s the PDO was negative at times and we had colder winters.

In weather, there are always counter examples for sure.  And some winters, other things can over-ride the PDO such as the MJO, NAO, and just random things we don't think of (volcanic activity, AMO etc).  I think lately, the PDO has been responsible for the trough going into the Mountain West regardless of other teleconnections.  The negative phase really wants to pull that trough west.  

[*Flash*]

12 hours ago, Itryatgolf70 said:

I maybe be incorrect, but back in the 60s and 70s the PDO was negative at times and we had colder winters.

Per Carver's post and the link provided, it seems the best winters relative to PDO generally (key word) coincide with weak phases. To me, I wouldn't get too caught up in positive vs. negative but focus more on signal strength. Can the PDO be overridden by other factors like MJO/ENSO/QBO, etc. That may be the question to ask, specifically can the PDO recover into weak territory by peak winter? We shall see. Whatever transpires in 2023-24, give me some mobile amplification. Not a fan when troughs park in the same areas for months at a time. 

[nrgjeff]

The 1960s and 1970s featured a -PDO and -AMO. Water off the coast of both oceans were cooler than normal. It's a recipe for cold everywhere with jet stream stuck south. 

The PDO and AMO are offset by about a decade. +PDO -AMO in the 80s was great for full latitude East troughs. -PDO +AMO in parts of the 1950s is a mixed record, sometimes stormy sometimes drought. Both + is warm everywhere, none of the advantages of one, just the disadvantages of the other. 

Question is, can we ever get the oceans to sink heat again? Aaannnd, off to the Climate subforum.

Maybe I'm just pissed off about the forecast heat next week. I'm still optimistic about some dumb luck with El Nino this winter. 

[*Flash*]

This guy needs to update his AMO page but it seems like the overall AMO trend is decreasing. Still net '+' but coming down.  It's been going back and forth in bi-decadal stretches since the turn of the 20th century.

https://www.daculaweather.com/4_amo_index.php

[fountainguy97]

4 hours ago, *Flash* said:

This guy needs to update his AMO page but it seems like the overall AMO trend is decreasing. Still net '+' but coming down.  It's been going back and forth in bi-decadal stretches since the turn of the 20th century.

https://www.daculaweather.com/4_amo_index.php

Yeah these decadal sequences are tough to really apply just because of the sheer length of time between pattern changes.  The current massive -PDO has surely been stubborn and may not flip at all.
 

AMO is such a long pattern sequence it's tough to really get a grasp on. I haven't been alive in a -AMO regime. And I think it's not irrelevant to consider in this climate IF we will get a -AMO signal in the near future. Or maybe decades.
 

I don't think we struggle with precip this winter. I'm more worried about too much of a good thing with the El Niño. Especially if we don't transition to more of a 3.4 focused Nino. We may blow right through any blocking we manage to get.

 

 

there has been some cooling going on in the PDO region. Maybe we see it transport across the Pacific this fall.

[Carvers Gap]

Long term teleconnection winner for MBY in NE TN...AMO and it isn't close.  Jeff had some great comments on the optimal accompanying teleconnections for that.  When the AMO flipped during the late 80s, our winters changed over night.  Maybe we still have 5-10 years before it flips back???

Seasonal teleconnections...MJO and then everything else.   QBO, NAO and/or EPO, PDO(but moving up the list).   I do think the MJO can trump most patterns.  But what I really enjoy about all of this, that SSTs drive the boat in some form or fashion.  That is a lesson that it took me a long time to learn.  The MJO is very closely related to Nino/Nina status.  When we have a La Nina, it is very tough to get convection over cold water at the dateline which is phase 8 of the MJO.  When it is El Nino, convection near the dateline is more likely if we have a basin wide El Nino.  

But in all reality, seasonal forecasting is a true crapshoot.  There are some strategies to get better outcomes (SSTs are a great option), but if you can hit the bullseye one out of every three winters...that is decent skill.  By hitting the bullseye, I am talking longwave patterns.  Snow is so random at this latitude.  It is always amazing to me to think about those great, snowy winters...only to realize those winters would have been colossally terrible with the exception of a 10-14 day stretch.  Those 10-14 day stretches of winter are nearly impossible to predict at this range.

Also, optimal teleconnections differ quite surprisingly for eastern forum areas when compared to middle/western areas.  

[nrgjeff]

Good points about ENSO enhancing corresponding phases of the MJO. That's kind of how the pieces come together. Until the secondary pattern crashes the party. Like this 600 dm hell ridge!

I find the least value in forecasting weeks 4-6. We've done statistical studies that show zero commercial value over climo, sometimes even negative value. I don't even look past week 3 on the weekly products. 

The 2nd month out to seasonal can add a little commercial value. Month 2 if one can get the MJO or other meaningful teleconnection it can help. ENSO is better at less granular multi-month time frames. Even such very general forecasts can add commercial value if the sign is right. Unfortunately that's maybe 1/3 to 1/2 of seasons. The other half we live with it. Nobody should make detailed plans based on a seasonal forecast anyway.

Still that's actually greater commercial value than weeks 4-6 forecasting at zero. 

[Carvers Gap]

I had no idea weeks 4-6 were that bad!  LOL!!!  Kind of guessed they were bad, but that is wild.  

[Stovepipe]

On 8/22/2023 at 6:20 PM, nrgjeff said:

Good points about ENSO enhancing corresponding phases of the MJO. That's kind of how the pieces come together. Until the secondary pattern crashes the party. Like this 600 dm hell ridge!

I find the least value in forecasting weeks 4-6. We've done statistical studies that show zero commercial value over climo, sometimes even negative value. I don't even look past week 3 on the weekly products. 

The 2nd month out to seasonal can add a little commercial value. Month 2 if one can get the MJO or other meaningful teleconnection it can help. ENSO is better at less granular multi-month time frames. Even such very general forecasts can add commercial value if the sign is right. Unfortunately that's maybe 1/3 to 1/2 of seasons. The other half we live with it. Nobody should make detailed plans based on a seasonal forecast anyway.

Still that's actually greater commercial value than weeks 4-6 forecasting at zero. 

You are an absolute treasure to this forum, thank you for sharing your insight.  

[*Flash*]

Did anyone catch JB's 2023-24 winter weather forecast? Too soon to be putting these maps out in my opinion. Plus, why do I get the feeling our viewing area finds itself in the blue almost every year? Latest trends seem to suggest a stronger ENSO with effects pushing further into the fall/early winter. Unless that -PDO signal backs off and/or unless we get a more 'Modoki' look, I lean towards a milder winter with the classic hyperactive STJ bringing in an above average amount of precip/cloud cover days. Will likely be sticking with this take until I see overwhelming evidence to the contrary. 

 

[Itryatgolf70]

The euro seasonal is out for September if Carver or someone wants to post it.

[Carvers Gap]

On 9/5/2023 at 5:50 PM, Itryatgolf70 said:

The euro seasonal is out for September if Carver or someone wants to post it.

Didn't change much from what I posted last month.  Troughs and ridges are in the same spots.  Pac trough is less.  Trough over the SE is slightly more.  Otherwise, cut and paste-a.  Slightly BN temps for Jan/Feb.  Source regions are going to be a problem IF the model is correct.  BUT when seasonals show BN temps at this range on the Euro, it is worth noting.  It has a big time warm bias at that range IMHO.  500 maps are generally my go-to.  Temp maps are less dependable IMO. 

[Carvers Gap]

On 9/5/2023 at 8:31 AM, *Flash* said:

Did anyone catch JB's 2023-24 winter weather forecast? Too soon to be putting these maps out in my opinion. Plus, why do I get the feeling our viewing area finds itself in the blue almost every year? Latest trends seem to suggest a stronger ENSO with effects pushing further into the fall/early winter. Unless that -PDO signal backs off and/or unless we get a more 'Modoki' look, I lean towards a milder winter with the classic hyperactive STJ bringing in an above average amount of precip/cloud cover days. Will likely be sticking with this take until I see overwhelming evidence to the contrary. 

 

Is that his prelim forecast? I haven't seen an official from them, but that doesn't mean it isn't there.  I haven't looked closely.  Maybe it was on a video?  

That would be a very aggressive forecast for a five month window.  I could see maybe mid-Jan to mid-March making a run at that.  I am less enthused about Nov/Dec...but, LR modeling doesn't support my warm Nov/Dec idea.  However, w/ so many BIG warm-ups during our recent winters....anything BN would be a score in my book.  

[*Flash*]

14 hours ago, Carvers Gap said:

Is that his prelim forecast? I haven't seen an official from them, but that doesn't mean it isn't there.  I haven't looked closely.  Maybe it was on a video?  

That would be a very aggressive forecast for a five month window.  I could see maybe mid-Jan to mid-March making a run at that.  I am less enthused about Nov/Dec...but, LR modeling doesn't support my warm Nov/Dec idea.  However, w/ so many BIG warm-ups during our recent winters....anything BN would be a score in my book.  

From what I understand, it's a prelim. Haven't caught a playable forecast, just this graphical eye-candy that I'm taking with a major rigid of salt. I agree with you in the sense whatever transpires DJF will feature large-scale amplification. I'm encouraged by the potential for a big-hitter or two but of course, it's too soon to know how long our window will be. 

[nrgjeff]

Euro is relying too much on classic El Nino. I'm more with the climate trend and CFS. Blowtorch. No hope.