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Teleconnections: Advanced Meteorological Discussion


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Science is all about advancement, usually due to anomalies that emerge spontaneously in any given dataset. Most scientific advancement occurs not as a function of status quo, but because something aty

---The extirpation of the second half December as a paradoxical consequence of aberrant stratospheric perturbation---   1. My winter outlook included the hypothesis that a technical stratosp

The cyclonic energies associated with the stratospheric polar vortex split, propagating southwestward into SE Canada, are becoming evident in the troposphere. The principal reason why we're seeing mod

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31 minutes ago, Allsnow said:

@Isotherm we appreciate everything you bring too 33. You are a incredible forecaster with amazing talent in the long range. Thank you again. It’s disrespectful to see others calling you out on other forums. This will never happen here, i promise you the that. 

People are going after Isotherm at other forums?? People need to get a life 

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I think we will have a fully declared Nino by early Feb that'll meet both NOAA's and BOMM's standards(which I believe will last though next Winter season). I base this of course on the forecasted MJO(my opinion going inbetween Euro & GEFS leaning more towards GEFSish in amplitude and direction eventually through phases 6-7-8-1) and the GWO/AMM expected to take off!

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I probably should have added this here, instead of the Eastern US thread:

https://longrangesnowcenter.blogspot.com/2018/12/europe-on-long-term-28th-dec.html

 

Contains modelling, but more importantly my rough teleconnections forecast. I largely concur with Tom's excellently put thoughts last page.

 

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9 hours ago, Snowy Hibbo said:

I probably should have added this here, instead of the Eastern US thread:

https://longrangesnowcenter.blogspot.com/2018/12/europe-on-long-term-28th-dec.html

 

Contains modelling, but more importantly my rough teleconnections forecast. I largely concur with Tom's excellently put thoughts last page.

 

 

 

Great post, Zac.

 

As further support for my argument posed on the last page re: paradoxical result of increased strat perturbation - note the following.

 

Using z70 temperatures 25N-25S as a proxy, they're approaching record lows now. Very cold temperatures in the lower strat/upper troposphere of the tropics will significantly enhance the tropical convection signal, i.e., MJO, which in turn, modulated our sensible weather such that numerous cutters occured/occurring in late December.

 

70mb2525.png

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Brilliant work by Tom and Zac (as usual!). 


There's some humorous/tragic irony (depending on what forecasts you had at stake!) to be found in the way that Dec, in particular the festive portion of the month, has been effectively sacrificed in exchange for improved prospects for Jan. The sustained MJO amplitude through 4-5 has indeed been surprising (for a Nino background) and it's trashed my predictions of a markedly colder final third to the month here in the UK, though it has at least become more settled and cooler.

 

While I've been expecting Jan to be the main cold month since mid-Nov, there was uncertainty over how much it would deliver in absolute terms and I wondered if it would really amount to much HLB-wise. The way things are actually panning out is almost as good as could have been hoped, SSW notwithstanding (if that downwells fully, it'll be optimal!).

 

Hints in the 12z ECM of yesterday of the reversal making its way down to the lower stratosphere, albeit a bit tenuous with near-neutral rather than negative anomalies on D10. Not heard anything on the 00z of today; been out and about. Trying to avoid being as involved as usual in matters - got to cool my brain off sometime - but the unusual events taking place are making that kind of tricky!

 

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54 minutes ago, Isotherm said:

 

 

Great post, Zac.

 

As further support for my argument posed on the last page re: paradoxical result of increased strat perturbation - note the following.

 

Using z70 temperatures 25N-25S as a proxy, they're approaching record lows now. Very cold temperatures in the lower strat/upper troposphere of the tropics will significantly enhance the tropical convection signal, i.e., MJO, which in turn, modulated our sensible weather such that numerous cutters occured/occurring in late December.

 

70mb2525.png

I had a question. If it's not too complicated for a layperson to understand, what is the reason that a colder tropical stratosphere enhances tropical convection? I would have thought a warmer atmosphere would mean more convection in the tropics, since tropical systems/thunderstorms require warm water.  Thanks!

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30 minutes ago, NotSparta said:

Convection strength, among other things, is based on the lapse rate (temp change w/ height). A colder tropical stratosphere increases the lapse rate, since it increases the difference of temperature between the sfc and upper lvls. 

 

 

Thanks for answering - @Oglem - this is a good, succinct, explanation. 

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It's currently a whopper of a blocking high over Europe. Maybe a bit of sunshine for @Tamara :) 

 

IMG_6047.PNG

 

I posted this little musing on a ski forum I pop into time to time over there:

 

The Tropospheric Polar Vortex or at least part of it displaces into Siberia over the days leading up to the 10th, and forces a smaller Low into the European Alps, weakening the blocking high. 

This is all part of a much more -AAM (Atmospheric Angular Momentum) setup forcing upon Europe a slower jetstream overall, manifesting with the presence of this massive block. And it takes polar forcing to destroy it, which is predicted by GFS around the 10th. EC thinks the 8th/9th. I think it will be nice after the wait, and we should hopefully see a retrograde of the block over the UK to a -NAO (Greenland) position.

 

I think that North America will probably see impacts of the +AAM first, because of the NP Jet extension will be key to this pattern. But as I note, hopefully we start to see some form of downwelling from the stratosphere by the 10th, because that is the key to unlocking a colder pattern for Europe in particular, not so much for the United States IMO. It needs extratropical factors and the MJO to improve, which is of course in the forecast for the next week or so. The SSW would be what changes it from a cold pattern to a very cold pattern. Which is of course still a "work in progress".

 

 

 

 

 

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And I do like how this is quite a carbon copy of what is going on at the moment. Notice the high/low over Western/Eastern Europe.

 

IMG_6050.PNG

Look at all those anti-cyclones and cyclones together. North Pacific is a great example in this chart. Also around South America's tip.

 

and look at the -SAM and -NAM both in symphony.

This is what a somewhat -AAM can look like, there's certainly places where it can get more negative.

Note the +EAMT (endless as observed from Maisello).

 

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On 12/28/2018 at 1:39 PM, Weathergeek said:

I think we will have a fully declared Nino by early Feb that'll meet both NOAA's and BOMM's standards(which I believe will last though next Winter season). I base this of course on the forecasted MJO(my opinion going inbetween Euro & GEFS leaning more towards GEFSish in amplitude and direction eventually through phases 6-7-8-1) and the GWO/AMM expected to take off!

 

I cant see it, an El Nino has never been declared in January, and the SOI strength atm is enough to tell you that you can use all of the tools in the cupboard, none of them make sense right now. The QBO reversal, IMO, in February 2016 was the beginning of a very different weather period, what normally happens with La Nina and El Nino events is totally off in different places, and around the whole globe as well. When I look at the pressure charts above, massive alarm bells go off, especially at the Poles, as does the strength of the MJO at the moment. There is no way this will change whilst trade winds are strengthening as they have been, and if the ITCZ makes its way into the Indian Ocean then I think we ware going to see an abrupt shift into a La Nina at the end of 2019. To me the warming in the Pacific has 1 more month, the Westerlies have not progressed past Nino 4 in the last 3 months, and as such the SOI is now 4.50 for the 90 day average. That rules the BOM out, and should rule NOAA out too, and in turn, won't allow the Pacific to continue warming, and cooling is about to commence.

 

JB is right, extra water vapour is not allowing anything to set up, we will need a big and strong event either way to fix it, right now we have a climate that is out of sync. All fo the indicators on this thread show which way we should be going, yet it can't get it done, and the subsurface is now rapidly losing heat as the trades churn through the warm water. It's a great time to be alive, the next year or two will be extremely interesting to see if we can get the weather patterns back to some sort of normal, because as it stands now, we could not be any further away from normal.

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