El Nino 2023-2024

[GaWx]

23 hours ago, GaWx said:

 Today’s EPS continues with the idea of a weak SPV by mid Dec with the mean of the members’ 60N mean wind at 10 mb (well up in the strat.) dipping down to only 21 m/s on Dec 16th vs average for that date of 35 m/s. The % of members with a major or impending major SSW during early to mid Dec is similar to yesterday’s of 18%. Longterm climo based chances of a major SSW at any point in Dec is only ~10%. So, this means that the chance for a major SSW next month is per the EPS well above the normal chance even though it still isn’t likely as of now. Regardless, a weak SPV favors a -AO.

Edit: ~85% of the 101 members are below the normal of 35 m/s at the end of the run, which is 12/16/23. This all means that the signal for a weak SPV is probably just about as strong as you’ll ever see at day 45 keeping in mind that ensemble means have a tendency to revert closer to climo the further out they go. In other words, it would be virtually impossible for day 45 to have 100% of members below climo. Getting 85% to do that is very hard to do unless there’s an unusually strong signal.

Today’s EPS backed off some (though nowhere near completely) vs yesterday’s run, which had shown the strongest indications for a weakened SPV in Dec yet. Yesterday’s had the 60N 10 mb wind dip way down to 21 m/s vs the normal of 35. Today’s has the EPS mean dip to 25 m/s, which is still significant. The prior two days of runs implied ~18% of members with actual or impending major SSWs in early to mid Dec. Today’s backed off to ~10%, which is similar to the run from three days ago. At day 45, yesterday’s had ~85% of members with a SPV weaker than climo. Today’s is ~75%.

[so_whats_happening]

1 hour ago, GaWx said:

Today’s EPS backed off some (though nowhere near completely) vs yesterday’s run, which had shown the strongest indications for a weakened SPV in Dec yet. Yesterday’s had the 60N 10 mb wind dip way down to 21 m/s vs the normal of 35. Today’s has the EPS mean dip to 25 m/s, which is still significant. The prior two days of runs implied ~18% of members with actual or impending major SSWs in early to mid Dec. Today’s backed off to ~10%, which is similar to the run from three days ago. At day 45, yesterday’s had ~85% of members with a SPV weaker than climo. Today’s is ~75%.

I would be awfully careful about SPV forecasts that far in advance. You can typically start to see it on models in the 15 day but it is recommended to wait for 10 days max. You want extensive wave breaking events in the troposphere to help create the waves along the SPV rim. It also is nice to Urals blocking occur as this usually is an early indicator something may be on the way. 

You also want to see more than a wave 1 flux happen, wave 2 is the desired for many of us in the east which means the atlantic/european side needs to get involved and this has been an issue over the years. It is also important to remember that just because an SSW may be occurring does not mean it affects us in the same manner we think it will. I have some papers i can share from over the years when i get to my computer.

As bluewave said it is rather rare to see anything happen before the new year, typically it is after mid january we see enough wave activity to induce a warming event whether it be a mid grade warming or a major event.

 

[Itryatgolf70]

2 minutes ago, so_whats_happening said:

I would be awfully careful about SPV forecasts that far in advance. You can typically start to see it on models in the 15 day but it is recommended to wait for 10 days max. You want extensive wave breaking events in the troposphere to help create the waves along the SPV rim. It also is nice to Urals blocking occur as this usually is an early indicator something may be on the way. 

You also want to see more than a wave 1 flux happen, wave 2 is the desired for many of us in the east which means the atlantic/european side needs to get involved and this has been an issue over the years. It is also important to remember that just because an SSW may be occurring does not mean it affects us in the same manner we think it will. I have some papers i can share from over the years when i get to my computer.

As bluewave said it is rather rare to see anything happen before the new year, typically it is after mid january we see enough wave activity to induce a warming event whether it be a mid grade warming or a major event.

 

Another thing to consider is we don't want it to happen too late either like last winter where only a select few locations, mainly in the north got any effects from the SSW. Me personally would like to see it early rather than later

[Stormchaserchuck1]

For reference, Stratosphere warmings average "downwell" time to effect Winter -AO:

Oct 15-30: +60 days (Dec 15-30 -AO correlation)

Oct 30-Nov 15: +45 days (Dec 15-30 -AO correlation)

Nov 15-30: +40 days (Dec 25-Jan 10 -AO correlation)

Dec 1-15: +35 days (Jan 5-Jan 20 -AO correlation)

Dec 15-30: +30 days (Jan 15-30 -AO correlation)

Jan 1-15: +25 days (Jan 25- Feb 5 -AO correlation)

Jan 15-30: +20 days (Feb 5-20 -AO correlation)

Feb 1-15: +15 days (Feb 15-Mar 2 -AO correlation)

Feb 15-Mar 2: +15 days (Mar 1-15 -AO correlation)

Mar 1-30: +10-15 days (Mar 10-Apr 15 -AO correlation)

[CDC daily climate composite maps day-by-day going back to 1948.]

Oct 30mb QBO should come in the next few days. Sept was -13, and down 5 from September, so Nov should come in more negative. <-10 30mb QBO and El Nino correlate strongly with Winter Stratosphere warmings (I think there is a >60% +10mb Winter correlation (NDJFM), and >+10 30mb QBO and La Nina has a >60% -10mb Winter correlation (NDJFM)). 

Strong 10mb vortex (Stratosphere cooling) has a +0-Day correlation to +AO from Oct 30 - Apr 5 (all Winter), no lagtime. The images posted earlier in this thread of a cold 10mb are correlating with MR/LR models showing 500mb +NAO.

[so_whats_happening]

22 minutes ago, Itryatgolf70 said:

Another thing to consider is we don't want it to happen too late either like last winter where only a select few locations, mainly in the north got any effects from the SSW. Me personally would like to see it early rather than later

Yep but you also need to watch out for too early of an SSW, especially if it is not a major event, as there will be recovery before the final warming takes place. So anything before January and you run the risk of losing February snow potential with a recovering SPV. There is a sweet spot needed in not only the wave activity but timing.

[mitchnick]

19 minutes ago, so_whats_happening said:

Yep but you also need to watch out for too early of an SSW, especially if it is not a major event, as there will be recovery before the final warming takes place. So anything before January and you run the risk of losing February snow potential with a recovering SPV. There is a sweet spot needed in not only the wave activity but timing.

I'd be happy with a weak pv to at least avoid a December shutout and hope for the SSW down the road. Heck, we don't require a SSW event in strong Niños with well placed forcing anyway.

[so_whats_happening]

48 minutes ago, mitchnick said:

I'd be happy with a weak pv to at least avoid a December shutout and hope for the SSW down the road. Heck, we don't require a SSW event in strong Niños with well placed forcing anyway.

Right id rather not rely on a winter that has an SSW, would rather it just enhance the winter already in motion. Ill just wait and watch as we get toward December for the most part im not too concerned about the path we are going thus far. Should be an interesting month.

[griteater]

14 minutes ago, mitchnick said:

I'd be happy with a weak pv to at least avoid a December shutout and hope for the SSW down the road. Heck, we don't require a SSW event in strong Niños with well placed forcing anyway.

Agree.  If you look at 09-10, it had weak zonal wind in the lower stratosphere at 100mb (1st image) from mid-Nov all the way to April (makes it much easier for blocking to develop in the troposphere).  At 10mb (2nd image) in the upper stratosphere, there was a sharp weakening in early November, then another in late Jan into early Feb, with an official SSW occurring.  But bottom line, we want to see elevated heat flux (3rd image) / disruptions to the Strat PV...getting an official SSW is an extra bonus.

Excellent description of heat flux on the NASA Ozone Watch site (https://ozonewatch.gsfc.nasa.gov/meteorology/flux_2009_MERRA2_NH.html):

"Variations of temperature are strongly affected by weather systems in the troposphere. Very large-scale weather systems or waves can move or propagate upward into the stratosphere. The upward propagation of these weather systems warms the polar region. We measure this upward flow of wave energy with the eddy heat flux. The eddy heat flux is the product of north-south (meridional) wind departures and temperature departures from their respective zonal-mean values. There is a strong anticorrelation between stratospheric temperature and the 45-day average of the eddy heat flux lagged prior to the temperature. A more positive value of eddy heat flux indicates that wave systems are moving into the stratosphere and are warming the polar region. Wave events distort the polar vortex and allow for greater mixing inside the vortex. These events can result in major and minor polar warmings."

 

 

[GaWx]

 The WCS PDO for Nov 1st of -1.02 was actually slightly warmer than that for Oct 31st. This means that the corrective fall from the huge earlier rise may be over.

[40/70 Benchmark]

16 hours ago, griteater said:

October numbers won't be out until a few more days, but here was the update that includes Aug/Sep.  Based on Oct SST images, I don't think it will change much for the Sep/Oct value

Right....whenever available.

Thanks, man.

[40/70 Benchmark]

17 hours ago, snowman19 said:

Unfortunately the Modoki index is going to be on life support. The WPAC has begun cooling significantly and the warmth in 1+2 moved as far west as it’s going to, it moved into the middle of region 3.4 and has stopped there. Also, found this interesting:

 

 

 

 

Dude, region 4 is near record levels....what are you looking for, Jesus to piss near the dateline?

Its basinwide.

[40/70 Benchmark]

TBH, I don't even mind the W PAC cooling some....all set with a great deal of phase 6 this winter....I am not concerned about canonical forcing setting up in the seasonal mean, though I am sure there will be some thawing periods that do feature that.

[rclab]

48 minutes ago, 40/70 Benchmark said:

Dude, region 4 is near record levels....what are you looking for, Jesus to piss near the dateline?

Its basinwide.

Good morning 40/70 B. I understand your frustration/response. I must say, however, it’s a unique take on Divine intervention. Stay well and calm, as always …..

[40/70 Benchmark]

16 minutes ago, rclab said:

Good morning 40/70 B. I understand your frustration/response. I must say, however, it’s a unique take on Divine intervention. Stay well and calm, as always …..

I am actually not frustrated with @snowman19....he has grown on me TBH....good guy with a lot of great insight, even if a healthy dose of it is recycled from Mr. Roundy's keyboard. lol

We disagree and I accept that.

[pasnownut]

15 hours ago, so_whats_happening said:

Yep but you also need to watch out for too early of an SSW, especially if it is not a major event, as there will be recovery before the final warming takes place. So anything before January and you run the risk of losing February snow potential with a recovering SPV. There is a sweet spot needed in not only the wave activity but timing.

I'll take my chances with an early SSW, and hope for Feb climo to do its thing.  I also feel its beneficial for early cold/snow to help the boundary stay further south w/ cold/snow established up north.  

[pasnownut]

15 hours ago, mitchnick said:

I'd be happy with a weak pv to at least avoid a December shutout and hope for the SSW down the road. Heck, we don't require a SSW event in strong Niños with well placed forcing anyway.

Just read your post after I responded to his.  We agree (not that my opinion amounts too much....but your not alone in your thinking.  

[pasnownut]

13 hours ago, griteater said:

Agree.  If you look at 09-10, it had weak zonal wind in the lower stratosphere at 100mb (1st image) from mid-Nov all the way to April (makes it much easier for blocking to develop in the troposphere).  At 10mb (2nd image) in the upper stratosphere, there was a sharp weakening in early November, then another in late Jan into early Feb, with an official SSW occurring.  But bottom line, we want to see elevated heat flux (3rd image) / disruptions to the Strat PV...getting an official SSW is an extra bonus.

Excellent description of heat flux on the NASA Ozone Watch site (https://ozonewatch.gsfc.nasa.gov/meteorology/flux_2009_MERRA2_NH.html):

"Variations of temperature are strongly affected by weather systems in the troposphere. Very large-scale weather systems or waves can move or propagate upward into the stratosphere. The upward propagation of these weather systems warms the polar region. We measure this upward flow of wave energy with the eddy heat flux. The eddy heat flux is the product of north-south (meridional) wind departures and temperature departures from their respective zonal-mean values. There is a strong anticorrelation between stratospheric temperature and the 45-day average of the eddy heat flux lagged prior to the temperature. A more positive value of eddy heat flux indicates that wave systems are moving into the stratosphere and are warming the polar region. Wave events distort the polar vortex and allow for greater mixing inside the vortex. These events can result in major and minor polar warmings."

Great info Grit.  Thanks for sharing.

[snowman19]

FWIW

[40/70 Benchmark]

4 minutes ago, snowman19 said:

FWIW
 

Makes more sense to me. Glad to see that.

All three months look good, though.

[snowman19]

Makes more sense to me. Glad to see that.

[Terpeast]

25 minutes ago, 40/70 Benchmark said:

Makes more sense to me. Glad to see that.

All three months look good, though.

I like how January looks…

[Terpeast]

31 minutes ago, snowman19 said:

 

 

He’s trolling ofc

[40/70 Benchmark]

1 hour ago, snowman19 said:

 

 

I don't see anything wrong with it....Dec looks rather uneventful, though not a torch...and January is fine.

That is a split flow.....there is enough cold there IMO.

[40/70 Benchmark]

45 minutes ago, Terpeast said:

He’s trolling ofc

Guy is an ass and he knows he is full of hot air....only type of people that do that. Anyone confident in their abilities doesn't feel the need to constantly try to prop themselves up on the shoulders of others.

[ORH_wxman]

6 minutes ago, 40/70 Benchmark said:

Guy is an ass and he knows he is full of hot air....only type of people that do that. Anyone confident in their abilities doesn't feel the need to constantly try to prop themselves up on the shoulders of others.

I made a comment in here about his posts....I don't follow him on twitter, but every time I see a post in here of his, it sounds really snarky and condescending. Not a good way to conduct scientific inquiry.

[stadiumwave]

58 minutes ago, Terpeast said:

He’s trolling ofc

 

He always does & its annoying! He has constant consternation aimed at Bastardi. 

[mitchnick]

5 minutes ago, stadiumwave said:

 

He always does & its annoying! He has constant consternation aimed at Bastardi. 

Betcha' I  know who loves Webb...

[George001]

19 minutes ago, stadiumwave said:

 

He always does & it’s annoying! He has constant consternation aimed at Bastardi. 

I don’t have an issue with that. Bastardis AGW denial agenda is problematic and is a big reason why his forecasts have been busting too cold and snowy.

[GaWx]

2 hours ago, snowman19 said:

FWIW

 

 “FWIW” is the key. I’ve found these long range/climate model predictions to be of little value. I’ve seen this and other ones totally blow their winter forecasts even on Nov 30th! Here’s a great example from the 11/30/22 CANSIPS for last DJF that shows the MidAtlantic states near normal (+0.25 to +0.5C or ~+0.5 to +1F) vs 1981-2010 normals. The 1981-2010 NYC normal DJF is 35.5F. This CANSIPS was forecasting NYC to be ~36.2F. The actual winter averaged way up at 41F! So, this model’s Nov 30th run was a whopping 4.8F too cold for last winter there and similarly much too cold all around there/too cold throughout the E US. Also, it was much too warm in the W US. So, it totally blew most of the country and this was released the day before winter started:

CANSIPS 11/30/22 forecast for last DJF (1981-2010 normals)

Actual (1981-2010 normals): much warmer E US and much colder W US vs Nov 30th CANSIPS forecast

[40/70 Benchmark]

26 minutes ago, stadiumwave said:

 

He always does & its annoying! He has constant consternation aimed at Bastardi. 

My LICSW mind sniffs out some jealousy of the career he has built and insecurity about this own professional standing...people act overtly aggressive like that when they feel threatened and inadequate.