Absolute Vorticity

UKMET Seasonal model has updated for the October run. Below are DJF at 500 MB, JFM at 500 MB, and ENSO.

tron777 wrote: ↑Wed Oct 11, 2023 9:03 am UKMET Seasonal model has updated for the October run. Below are DJF at 500 MB, JFM at 500 MB, and ENSO.


UKMET DJF500 MB.jpg


UKMET JFM 500 MB.jpg


UKMET ENSO.jpg

Sign me up and take our chances.

tpweather wrote: ↑Wed Oct 11, 2023 9:05 am

tron777 wrote: ↑Wed Oct 11, 2023 9:03 am UKMET Seasonal model has updated for the October run. Below are DJF at 500 MB, JFM at 500 MB, and ENSO.


UKMET DJF500 MB.jpg


UKMET JFM 500 MB.jpg


UKMET ENSO.jpg

Sign me up and take our chances.

Agreed and two things stick out to me. One is the -PDO is weakly negative if not neutral. Also the Nino is not so East Based as it is right now. That is also very critical in keeping the +PNA and -EPO going.

Bgoney wrote: ↑Wed Oct 11, 2023 1:05 pmIMG_0681.jpeg

That is also of a concern. The +IOD is trying to out do the last record setting event we had in 2019.

Bgoney wrote: ↑Wed Oct 11, 2023 1:05 pmIMG_0681.jpeg

This is really interesting. Les and I posted before how the one in 2019 was the start of La Nina and this one is at the start of El Nino. This time it seems to be climbing higher quicker than 4 years ago. I would need to look further back in time to see if the IOD has looked like this during an El Nino.

tpweather wrote: ↑Wed Oct 11, 2023 1:15 pm

Bgoney wrote: ↑Wed Oct 11, 2023 1:05 pmIMG_0681.jpeg

This is really interesting. Les and I posted before how the one in 2019 was the start of La Nina and this one is at the start of El Nino. This time it seems to be climbing higher quicker than 4 years ago. I would need to look further back in time to see if the IOD has looked like this during an El Nino.

Funny the IOD when positive is more likely during an El Nino while a negative is more likely during La Nina. The one in 2019 was a La Nina and that threw forecast off big time and was a really bad winter for us winter lovers around here. Just taking a guess it will be a bi-product of El Nino but probably not have the same outcome as 2019.

tpweather wrote: ↑Wed Oct 11, 2023 1:19 pm

tpweather wrote: ↑Wed Oct 11, 2023 1:15 pm

Bgoney wrote: ↑Wed Oct 11, 2023 1:05 pmIMG_0681.jpeg

This is really interesting. Les and I posted before how the one in 2019 was the start of La Nina and this one is at the start of El Nino. This time it seems to be climbing higher quicker than 4 years ago. I would need to look further back in time to see if the IOD has looked like this during an El Nino.

Funny the IOD when positive is more likely during an El Nino while a negative is more likely during La Nina. The one in 2019 was a La Nina and that threw forecast off big time and was a really bad winter for us winter lovers around here. Just taking a guess it will be a bi-product of El Nino but probably not have the same outcome as 2019.

I'm not sure if that will help or hinder the Subtropical Jet. You'd think it would help cause the Pacific firehouse Jet from hell but right now that hasn't happened. I am thinking that if the Nino stays moderate, the impacts may not be as strong from the IDO and ENSO as you'd otherwise expect.

I don’t know if this is what you would call “a standing wave” term that I’ve seen thrown around previous years, but with this look at 850 winds the MJO is going to be pretty much stuck where it has been for some time. Still think the MJO is being controlled for the most part atm by the IOD , which this map imo is evidence.




Also , I don’t see enough evidence atm, that our ElNino will develop into a full Modoki. I need to see more WWBs and a better sub-surface anomaly , maybe we get a sort of hybrid where the waters are warmer in between 1.2 region and 3.4 region at peak winter anomalies

Latest ONI (JAS) was +1.3c

Bgoney wrote: ↑Mon Oct 16, 2023 6:28 pm Latest ONI (JAS) was +1.3c

I could see it peaking in that 1.5 to 1.7C range. Certainly peaking moderate in other words.

tron777 wrote: ↑Wed Oct 11, 2023 1:08 pm

Bgoney wrote: ↑Wed Oct 11, 2023 1:05 pmIMG_0681.jpeg

That is also of a concern. The +IOD is trying to out do the last record setting event we had in 2019.

I have been trying to find out more about what may happen with a very +IOD and yes and El Nino. One place I saw throws out that an extreme IOD event with and El Nino can have opposite impacts. I thought that was interesting and yes the +IOD will have impacts and will it be opposite of what we saw 4 years ago during the start of a La Nina

The latest JMA Seasonal looks really good. It showed a trough working under the block for December then the ridging really gets going in AK and Western Canada / Pacific NW with the Greenland Block (-NAO) also continuing for January.

tpweather wrote: ↑Tue Oct 17, 2023 9:41 am

tron777 wrote: ↑Wed Oct 11, 2023 1:08 pm

Bgoney wrote: ↑Wed Oct 11, 2023 1:05 pmIMG_0681.jpeg

That is also of a concern. The +IOD is trying to out do the last record setting event we had in 2019.

I have been trying to find out more about what may happen with a very +IOD and yes and El Nino. One place I saw throws out that an extreme IOD event with and El Nino can have opposite impacts. I thought that was interesting and yes the +IOD will have impacts and will it be opposite of what we saw 4 years ago during the start of a La Nina

I haven’t decided yet if it’s a concern or not for the winter months. But right , like I mentioned earlier, I think it is controlling the MJo. Reason is , I put a lot of weight for last years control of the MJO never making it through the Pac during winter due to the cold water brick wall in the central PAC , so I think it’s only fitting to put that same thought to where that brick wall is currently as shown in the 850 anomalies map above and the sat anomaly. That’s why the MJo has been floundering in 8/1 and not advancing into the Indian Ocean. I have no idea if this will continue once the winter months arrive , just another thing to keep an eye on

Bgoney wrote: ↑Tue Oct 17, 2023 11:22 am

tpweather wrote: ↑Tue Oct 17, 2023 9:41 am

tron777 wrote: ↑Wed Oct 11, 2023 1:08 pm

Bgoney wrote: ↑Wed Oct 11, 2023 1:05 pmIMG_0681.jpeg

That is also of a concern. The +IOD is trying to out do the last record setting event we had in 2019.

I have been trying to find out more about what may happen with a very +IOD and yes and El Nino. One place I saw throws out that an extreme IOD event with and El Nino can have opposite impacts. I thought that was interesting and yes the +IOD will have impacts and will it be opposite of what we saw 4 years ago during the start of a La Nina

I haven’t decided yet if it’s a concern or not for the winter months. But right , like I mentioned earlier, I think it is controlling the MJo. Reason is , I put a lot of weight for last years control of the MJO never making it through the Pac during winter due to the cold water brick wall in the central PAC , so I think it’s only fitting to put that same thought to where that brick wall is currently as shown in the 850 anomalies map above and the sat anomaly. That’s why the MJo has been floundering in 8/1 and not advancing into the Indian Ocean. I have no idea if this will continue once the winter months arrive , just another thing to keep an eye on

In this case, the +IOD would be a good thing as the MJO should either move into the COD or go very weak through Phases 3, 4, and 5. That is if we see the same impacts occur with the cooler waters as we did last season. Too early to know of course, but maybe just maybe, something favorable could come out of it.

DT's Prelim winter outlook is now out. You will need Adobe Reader installed to view the information.

https://wxrisk.com/wp-content/uploads/_ ... 023-24.pdf

EDIT: It's a really great write up and DT's Prelim Outlook shows what could happen if the El Nino does not get above Moderate levels, QBO is -10 to -20 range for the winter, as well as the -PPM that he talked about. It kind of fits my own thoughts as I am also expecting December to be the warmest month with an improving Jan then a good Feb into March.

Love seeing the DT posts. He no doubt put out tons of information. Many items we talked about on here especially the amount of Atlantic Hurricanes compared during this El Nino. That was way above normal. During the late summer and early fall several storms on the east coast and that does happen during most El Nino's but this was earlier than normal. Usually folks to the north and west of the main precip will have below normal rain or snow and if you look at this summer and early fall that is exactly what happened. Again some of the storms on the east coast were due to the much above Hurricane season

Plenty of items to go over on this outlooks and will no doubt look at each item. Some I know already but some I had no ideal which is wonderful to learn something new. I will bring the 1973-summer of 1976 and a constant La Nina and very similar to the 2019-spring of 2023. Then we went into a weak El Nino for a few years and we know what those winters produced. That does not mean it will happen this season but you can take some info from that and enter it into your forecast.

Like I have said for many years DT is a great long range forecaster and I always end up with more good than bad info. Once we get into each storm is where he has more problems and like Les mentioned everyone has strengths and weakness. I believe this helps our forum because we know those strengths and weakness of folks that try and forecast.

So yes tons of info to go over which is great to have plus just watching the current trends across the globe. He did mention the snowfall in Siberia and that one I still have a problem with and I understand the theory behind it but not enough proof in the pudding for me to use.

Agreed Tim. The Siberian snow cover theory gained some steam a few years back when the theory actually worked out for 1 winter. Since then, it has not worked out. I think it is a piece of the climate puzzle. I mean you need snow cover to build up for cold air production. Then it is all about the PV, blocking, and the jet stream with where the cold air goes.

tron777 wrote: ↑Thu Oct 19, 2023 10:08 am Agreed Tim. The Siberian snow cover theory gained some steam a few years back when the theory actually worked out for 1 winter. Since then, it has not worked out. I think it is a piece of the climate puzzle. I mean you need snow cover to build up for cold air production. Then it is all about the PV, blocking, and the jet stream with where the cold air goes.

Les the theory is the less snow cover in October the stronger the PV will be and hard to interrupt. I am with you that snow cover is important but I believe fresh snow in Nov-Feb is even more important. Again if it works 5 out of 10 times then it means nothing at all but if it starts happening 8 our 10 years for a few decades then we may be on to something. If only the weather was that easy to forecast.

tpweather wrote: ↑Thu Oct 19, 2023 10:22 am

tron777 wrote: ↑Thu Oct 19, 2023 10:08 am Agreed Tim. The Siberian snow cover theory gained some steam a few years back when the theory actually worked out for 1 winter. Since then, it has not worked out. I think it is a piece of the climate puzzle. I mean you need snow cover to build up for cold air production. Then it is all about the PV, blocking, and the jet stream with where the cold air goes.

Les the theory is the less snow cover in October the stronger the PV will be and hard to interrupt. I am with you that snow cover is important but I believe fresh snow in Nov-Feb is even more important. Again if it works 5 out of 10 times then it means nothing at all but if it starts happening 8 our 10 years for a few decades then we may be on to something. If only the weather was that easy to forecast.

Exactly. That is the reason why weather is hard to predict especially seasonal forecasting. The atmosphere is dynamic, complex and changeable ala the chaos theory. 1 + 1 may equal 2, but it could also equal 3, 4 or 5. The point is, there is no direct 1:1 correlation with any of these theories we read, learn , and talk about. Like you just said, if only the weather was that easy to forecast. You're exactly right!

The October run of the Jamstec is out and has a modiki or central based El Nino (+3.0C) which I think is overdone. The model does show near normal precip for the winter and below avg temps.

Go here to see the information:

https://www.jamstec.go.jp/aplinfo/sinte ... tlook.html

Make sure it is on October 2023 for the start date then for the parameter, look at SST Anom, Precip and 2M Temps. Also make sure that the drop down labeled as Target Season, says Dec - Feb.

tron777 wrote: ↑Thu Oct 19, 2023 10:49 am The October run of the Jamstec is out and has a modiki or central based El Nino (+3.0C) which I think is overdone. The model does show near normal precip for the winter and below avg temps.

Go here to see the information:

https://www.jamstec.go.jp/aplinfo/sinte ... tlook.html

Make sure it is on October 2023 for the start date then for the parameter, look at SST Anom, Precip and 2M Temps. Also make sure that the drop down labeled as Target Season, says Dec - Feb.

Models have been overdoing the strength of ElNino since August and agree they continue to do so( as well as the BOM’ers) Still going with a hybrid where water are warmest in the eastern part of 3.4 and the western part of 1.2 during winter months. I’m still not seeing enough evidence currently to go with a full modoki( sounds like a wrestling move)

Bgoney wrote: ↑Fri Oct 20, 2023 11:20 am

tron777 wrote: ↑Thu Oct 19, 2023 10:49 am The October run of the Jamstec is out and has a modiki or central based El Nino (+3.0C) which I think is overdone. The model does show near normal precip for the winter and below avg temps.

Go here to see the information:

https://www.jamstec.go.jp/aplinfo/sinte ... tlook.html

Make sure it is on October 2023 for the start date then for the parameter, look at SST Anom, Precip and 2M Temps. Also make sure that the drop down labeled as Target Season, says Dec - Feb.

Models have been overdoing the strength of ElNino since August and agree they continue to do so( as well as the BOM’ers) Still going with a hybrid where water are warmest in the eastern part of 3.4 and the western part of 1.2 during winter months. I’m still not seeing enough evidence currently to go with a full modoki( sounds like a wrestling move)

Agreed. I currently also believe it is east based but will slowly move more west in time. I do not think it will qualify as a modiki either but as long as the strength stays moderate or low end strong, we should be fine in that regard as long as the QBO continues to descend. Also still interested to see what impacts the -PDO will have as well.

tron777 wrote: ↑Fri Oct 20, 2023 11:43 am

Bgoney wrote: ↑Fri Oct 20, 2023 11:20 am

tron777 wrote: ↑Thu Oct 19, 2023 10:49 am The October run of the Jamstec is out and has a modiki or central based El Nino (+3.0C) which I think is overdone. The model does show near normal precip for the winter and below avg temps.

Go here to see the information:

https://www.jamstec.go.jp/aplinfo/sinte ... tlook.html

Make sure it is on October 2023 for the start date then for the parameter, look at SST Anom, Precip and 2M Temps. Also make sure that the drop down labeled as Target Season, says Dec - Feb.

Models have been overdoing the strength of ElNino since August and agree they continue to do so( as well as the BOM’ers) Still going with a hybrid where water are warmest in the eastern part of 3.4 and the western part of 1.2 during winter months. I’m still not seeing enough evidence currently to go with a full modoki( sounds like a wrestling move)

Agreed. I currently also believe it is east based but will slowly move more west in time. I do not think it will qualify as a modiki either but as long as the strength stays moderate or low end strong, we should be fine in that regard as long as the QBO continues to descend. Also still interested to see what impacts the -PDO will have as well.

Yea , that -PDO (strength) imo has been mis-modeled also , although it weakens somewhat over the next few months, I think it still is substantial enough to have a say in the position of any NPac ridging later on . The bully on the block continues to be the IOD

Bgoney wrote: ↑Fri Oct 20, 2023 12:40 pm

tron777 wrote: ↑Fri Oct 20, 2023 11:43 am

Bgoney wrote: ↑Fri Oct 20, 2023 11:20 am

tron777 wrote: ↑Thu Oct 19, 2023 10:49 am The October run of the Jamstec is out and has a modiki or central based El Nino (+3.0C) which I think is overdone. The model does show near normal precip for the winter and below avg temps.

Go here to see the information:

https://www.jamstec.go.jp/aplinfo/sinte ... tlook.html

Make sure it is on October 2023 for the start date then for the parameter, look at SST Anom, Precip and 2M Temps. Also make sure that the drop down labeled as Target Season, says Dec - Feb.

Models have been overdoing the strength of ElNino since August and agree they continue to do so( as well as the BOM’ers) Still going with a hybrid where water are warmest in the eastern part of 3.4 and the western part of 1.2 during winter months. I’m still not seeing enough evidence currently to go with a full modoki( sounds like a wrestling move)

Agreed. I currently also believe it is east based but will slowly move more west in time. I do not think it will qualify as a modiki either but as long as the strength stays moderate or low end strong, we should be fine in that regard as long as the QBO continues to descend. Also still interested to see what impacts the -PDO will have as well.

Yea , that -PDO (strength) imo has been mis-modeled also , although it weakens somewhat over the next few months, I think it still is substantial enough to have a say in the position of any NPac ridging later on . The bully on the block continues to be the IOD

Totally agree on both points. What a strange combo. Mod to low end strong El Nino, -PDO, -QBO, and a +IOD. It's going to be another tough winter to try and figure out. I am a big believer in trends until it's no longer a trend and one would have to believe that this winter should be vastly different then the previous 3. -PNA periods should be more transient and not having a trough did all the way down into the Baja giving snow to the Hollywood sign. I would expect to see more +PNA periods this winter with bouts of high latitude blocking (-EPO and -NAO). The PV's strength since this is only late October is still a bit of a wildcard in terms of figuring out the AO.