January Medium/Long Range Discussion

[Bob Chill]

12 minutes ago, LP08 said:

I know one thing...I’m tired of seeing this look in the extended....

 

 

Another hideous eps run in the books. If d15 is right then Jan is toast. 

[poolz1]

The biggest difference I see is the handling of the upper ridge north of HI.  EPS keeps it on roids....shoves our Aleutian low around and keeps the PAC jet enhanced.  GEFS handle this feature differently whereas it weakens/get absorbed into the building EPO ridge.  I am curious if this all has to do with the MJO forecast?  I dont know enough to speculate but I would think a ridge like that seen on the EPS would be the result of some sort of trop forcing.

[BristowWx]

4 minutes ago, Bob Chill said:

Another hideous eps run in the books. If d15 is right then Jan is toast. 

That look should yield some grass growing tree budding departures.  

[frd]

23 minutes ago, LP08 said:

I know one thing...I’m tired of seeing this look in the extended

I still take that forecast with a grain of salt for reasons already discussed. 

And, as many have mentioned, the continued SSWE ( it peaks at a possible reversal in the next 24 to 48 hours see below ) will need time to be properly entered into weather modeling outcomes. 

Also, the proper MJO forecasted positions going forward in time will hopefully change the EPS current forecast as well.   

 

[MJO812]

The SSW is most likely messing with the models. Stay patient everyone.

[dallen7908]

Likely, wrong but over the next 10 days the EURO for my backyard has more days with highs in the 60s (4) than below 50 (3) ... and two of those below 50 highs are 49. 

[frd]

A fascinating read from over at 33andrain from a member. Bottomline, the models need time to take into account what is happening, I think whether you believe in the strat/MJO/tropical forcing interactions at play or not,the massive effects from the SSWE and extreme EAMT you have to at least think that the modeling, even in this day and age, is suffering from making proper outcomes due to all the complexities coming together recently. Just MHO. 

•  
• Posted 24 minutes ago

I just posted this across the pond for a slightly different audience - only slight editing:

 

REALLY GREAT NEWS!

Now some of you will not realise the significance of this:

  

Those of you who have been reading my posts and those from the likes of @Tamara, @Isotherm @Snowy Hibbo, myself and others who comment on the key teleconnections will know that we've been banging on about +ve EAMT (East Asian Mountain Torque) in particular. We could see this event unfolding a few weeks ago as part of the GSDM (global synoptic dynamic model), the GWO (global wind oscillation), GLAAM (global atmospheric angular momentum) and both FT (frictional torque) and MT (mountain torque) which all link in with tropical forcing, the ENSO state and the MJO. These charts are produced 2 days after the actual position - so this afternoon's chart (above) shows the position as on Dec 29th.  In my previous posts I said that EAMT was already rising strongly and that could be seen in the pressure distribution over eastern Asia (I showed the StormSurf charts, most recently yesterday).  Well, EAMT is not just rising but it's sky rocketing as can be seen by the red line in the chart and looks set to climb quite a bit higher, in fact with that 2 day chart time lag it already is.

 

I'll not go into the complexities but +ve EAMT events have an extraordinary influence on all levels of the lower and middle atmosphere and especially on the northern hemisphere global weather patterns and many of these assist directly or indirectly with setting up ridges and troughs and blocking patterns. Here are some of them:

 

1. A "major contributor" to wave breaking in the stratosphere (there are other influences too, of course) and vortex attacks by creating huge uplift and vertically propagating planetary waves from the Tibetan Plateau and particularly (as discovered more recently) the Mongolian Mountains, which can reach the upper stratosphere and even the lower mesosphere before reaching the "critical level" which is effectively "wind shear" in the troposphere as shown in this chart.

In the stratosphere the critical level has the easterlies above it which are the reversed winds and the planetary waves cannot break through it and are reflected (or even deflected) back down and they break at increasingly lower levels.  This produces one or more attacks on the spv (stratospheric polar vortex) and prolonged events can send up further planetary waves with attacks from above and below.  The last surge in EAMT occurred  during Dec 4th to 12th and peaked around Dec 9th/10th.  A few days later we saw some attacks on the SPV.    

                                                                                                                                                                                                                          

2. Now we have a further event which is likely to repeat the exercise and if there's any problem with the split or the downward propagation this may well deliver the final blow to the SPV in a few days.  In fact the timing is almost perfect with the split (if it happens) predicted for later this week.

 

3. EAMT also influences the tropospheric patterns with lateral planetary waves influencing the jet stream and downstream patterns in winter across the North Pacific and into N America. This can help the jet stream to meander and/or buckle.  This action in association with other factors can have knock on effects setting up the pattern and distribution of troughs and ridges around the hemisphere.

 

4. In the summer half of the year EAMT has a powerful influence on the Asian Monsoon.

 

5. The planetary waves also spread polewards and this is where it gets very interesting.  Some of us will have heard of and studied Judah Cohen's theories on early Asian Snow Cover extent and the greater likelihood of SSWs.  He recently admitted that it is more complicated than that and it was not a perfect correlation but nevertheless it does seem to work more often than not..  Over some years and particularly more recently, research has strongly suggested a link between North Asian blocking and the priming of the lower tropospheric layers and the surface to be receptive to a down welling SSW.  In several of my recent posts I've been showing those Asian pressure charts and the extraordinary expanse of HP over almost all central Asia northwards, Russia and Siberia.  I've been looking at the timing of these events and I'm pretty sure that it's no coincidence that a combination of +ve EAMT, extensive Asian snow cover (well above average right now as I showed yesterday) and the blocking regime are all coming together to make the patterns receptive or even highly conducive to downward propagation of the SSW to the surface. This obviously needs to be explored much more extensively and research into earlier SSWs (including near misses and failures) need to be considered. Another factor is GWD (gravity wave drag) which is mostly generated by the the east Asian mountains as well. That will be one of my 2019 projects amd Malcolm and Tom are likely to participate and others will be welcome.

 

Malcolm @Blessed Weather and I have been studying these events and found that they fitted in perfectly to last February's SSW.  Here's the MT chart for back then:

Note the 3 spikes in EAMT.  The first one around Feb 1st to 5th and the SSW was triggered a week later on Feb 12th. The second one around Feb 20th-25th and we saw the full propagation down to the surface and just a few days later with the "Siberian Express" rushing westwards and producing the "Beast from the East" in the UK and progressing around the hemisphere to N America about a week or so later..  The final spike was March 5th-10th and the "Mini Beast" followed about a week or so later and with further impacts on N America a few days later (and lasting much longer).

 

Overall, some of this is still theory but the extraordinary influences of +ve EAMT events have been studied for over 20 years. Now more of you might realise why I'm so excited about this month's two +ve EAMT events.  The models simply do not have much of these influences factored into how they churn out their nwp solutions and it's why they often need a few days to adjust to changes in the background signals.  Before long we are likely to see some much more sophisticated models being developed. The next few days of monitoring the model output will be totally absorbing and fascinating. 

 

Finally a Happy New Year to everyone and what a January we have in store for us!

 

David        

•  

[LP08]

5 minutes ago, frd said:

I still take that forecast with a grain of salt for reasons already discussed. 

And, as many have mentioned, the continued SSWE ( it peaks at a possible reversal in the next 24 to 48 hours see below ) will need time to be properly entered into weather modeling outcomes. 

Also, the proper MJO forecasted positions going forward in time will hopefully change the EPS current forecast as well.   

 

I sure hope so.  I’m with Bob, until we get rid of the troughing on the west coast in real time, we are cooked.

[Bob Chill]

2 minutes ago, Snow88 said:

The SSW is most likely messing with the models. Stay patient everyone.

Its possible but you cant just ignore what the eps is showing. It looks almost exactly like it did in early/mid December when the wheels came off. Winter base state could very well be showing its hand. We can hang our hats on the mjo being wrong or the ssw causing choas but seeing a repeating pattern is a big warning shot that cant be ignored. 

[H2O]

This winter is like Santa Claus. Imaginary bit some still want to believe

[Ji]

Bob said things couldn't get worse

[pasnownut]

13 minutes ago, Bob Chill said:

Its possible but you cant just ignore what the eps is showing. It looks almost exactly like it did in early/mid December when the wheels came off. Winter base state could very well be showing its hand. We can hang our hats on the mjo being wrong or the ssw causing choas but seeing a repeating pattern is a big warning shot that cant be ignored. 

But its also been discussed that the GEFS has been handling the MJO better than the EPS, so I think it fair to add in some skepticism at whatever the Euro suite is throwing out as we are likely in a state of flux...and if the SSW is part of that change, then as some have alluded to, we add weight to the GEFS for longer leads for the time being.  

Now if the EPS shows a massive bomb....discount everything I just said and hug the sh!t out of it.....

uh....just saw snow88's post...yeah what he said too.

[aldie 22]

This isn't really a winter anymore...basically we are in enjoying an event if we ever get one mode

[Ralph Wiggum]

19 minutes ago, dallen7908 said:

Likely, wrong but over the next 10 days the EURO for my backyard has more days with highs in the 60s (4) than below 50 (3) ... and two of those below 50 highs are 49. 

This is the thaw....deep freeze coming after Jan 20.

[psuhoffman]

2 minutes ago, pasnownut said:

But its also been discussed that the GEFS has been handling the MJO better than the EPS, so I think it fair to add in some skepticism at whatever the Euro suite is throwing out as we are likely in a state of flux...and if the SSW is part of that change, then as some have alluded to, we add weight to the GEFS for longer leads for the time being.  

Now if the EPS shows a massive bomb....discount everything I just said and hug the sh!t out of it.....

 

Yes but we can't be 100% sure the mjo is all of the problem or that the gefs is correct. I believe the gefs is more right...but I won't feel great about it until the euro gets on board and it starts moving closer in time. 

On the other hand it's also possible the euro is right but that look is only temporary. As awful as it looks if the trough in the west splits off from the Pacific trough and cuts under and east and the AO continues to drop as it's starting too it could only be a week away from a better look and that would still only be about Jan 21. But there are a lot of ifs in there. 

[Ralph Wiggum]

When the models are struggling this severely and bouncing every run, in my experience this is the sign of a major pattern change on the not too distant horizon. There will be a major change but will it be beneficial? I believe it will but obviously just speculatuon and tbd irt specifics. 

[nj2va]

Euro’s continued mishandling of the MJO throws caution to the wind with relying on the LR EPS.  That view seems backed up by some pros too.  

[Ralph Wiggum]

In addition I believe we are in or just entering a period of time where some major changes are starting to pop up right under our noses. MJO is moving, SOI is negative, PV split is starting to show in the med range. We have gotten into looking too far into the future for the 'full pattern change' when things are happening now that are affecting the LR and this is generally when something pops up and catches us by surprise. Just my $.02

[MJO812]

HM

"By the end of week 1 into week 2, we will see things flip. Arctic high over the pole with a ring of subpolar lows. This high forms between the splitting vortices. Crazy to think that this vortex split/chaos up above creates a rather textbook pressure appearance (z-cells)"

[mattie g]

1 hour ago, LP08 said:

I know one thing...I’m tired of seeing this look in the extended....

 

 

Nothing’s cutting to Mexico City with that look.

[Bob Chill]

10 minutes ago, psuhoffman said:

Yes but we can't be 100% sure the mjo is all of the problem or that the gefs is correct. I believe the gefs is more right...but I won't feel great about it until the euro gets on board and it starts moving closer in time. 

On the other hand it's also possible the euro is right but that look is only temporary. As awful as it looks if the trough in the west splits off from the Pacific trough and cuts under and east and the AO continues to drop as it's starting too it could only be a week away from a better look and that would still only be about Jan 21. But there are a lot of ifs in there. 

Exactly. Weather can just be weather regardless of all indices and teles. The pac appears to be crapping the bed for a month straight. Its entirely possible that it continues much longer. We've wasted entire winters due to persistence before. Things could easily still flip but it has the persistence feel right now. The last time the eps spit out the same pattern it did today it ended up being right. Seeing a carbon copy of how we just lost the last 2 weeks is unnerving. 

[Ralph Wiggum]

1 hour ago, LP08 said:

I know one thing...I’m tired of seeing this look in the extended....

 

 

Then stop unicorn hunting in the extended. 

I dont mean that disrespectfully because I am as guilty as anyone here. But there are signals showing up in the medium range which were/are the steps we were expecting headed into  January. With such large changes coming if model A misjudged something in the short range then its errors will be exponential in the long range. That kind of goes without saying...I know. But my point is we have seen this happen before and 9 out of 10 times many of us get caught looking at 384 ens means and seeing the major differences and overanalyze when what we really need to see of importance is happening right in front of us. I am extremely optimistic moving forward and while I dont think the GEFS are 100% correct I do think this modeling system has a better grasp on what is occurring.

[Bob Chill]

We're losing the GEPS. Not a furnace but close enough. Gefs stands alone...

[aldie 22]

Until things change they don't 

[Bob Chill]

Just now, Ralph Wiggum said:

Then stop unicorn hunting in the extended. I dont mean that disrespectfully because I am as guilty as anyone here. But there are signals showing up in the medium range which were/are the steps we were expecting headed into mid January. With such large changes coming if model A misjudged something in the short range then its errors will be exponential in the long range. That kind of goes without saying...I know. But my point is we have seen this happen before and 9 out of 10 times many of us get caught looking at 384 ens means and seeing the major differences and overanalyze when what we really need to see of importance is happening right in front of us. I am extremely optimistic moving forward and while I dont think the GEFS are 100% correct I do think this modeling system has a better grasp on what is occurring.

Dude, right now the short and med range look terrible. Like shutout terrible. There is literally nothing good going on right now. I applaud optimism and hope my pessimism will be proven to be a grand waste of time but I'd be flat out lying if i said there was anything encouraging to be found at any lead other than twitter posts explaining why all of the best wx models in the world have the entire northern hemispheric pattern backwards wrong.

[LP08]

5 minutes ago, Ralph Wiggum said:

Then stop unicorn hunting in the extended. 

I dont mean that disrespectfully because I am as guilty as anyone here. But there are signals showing up in the medium range which were/are the steps we were expecting headed into  January. With such large changes coming if model A misjudged something in the short range then its errors will be exponential in the long range. That kind of goes without saying...I know. But my point is we have seen this happen before and 9 out of 10 times many of us get caught looking at 384 ens means and seeing the major differences and overanalyze when what we really need to see of importance is happening right in front of us. I am extremely optimistic moving forward and while I dont think the GEFS are 100% correct I do think this modeling system has a better grasp on what is occurring.

No disrespect taken.  We are all looking at the same data and trying to make educated guesses on what and why is happening.  Taking the EPS run, I don’t really see much in the medium range that gives any confidence in things changing.  North America is flooded with pac air so even with transient blocking, there is just zero cold air anywhere.  Take a look at Tuesday’s event, pretty awesome H5 pass and it’s a rainstorm for the entire coast.  Now if it’s the MJO, SSW or whatever that is causing issues then someone who is much smarter than me can assess that.

 

[CAPE]

22 minutes ago, Bob Chill said:

We're losing the GEPS. Not a furnace but close enough. Gefs stands alone...

The CFS weeklies have looked pretty  gross lately too. I am resigned to the pattern remaining crappy overall through mid month at least. I have not been posting here much and will continue that until I see some clear and conclusive evidence of a pattern change. The EPS might be off somewhat in the LR, but it is rarely completely off base. I advise anyone who is in near panic mode to avoid looking at the weeklies this evening. 

[Bob Chill]

1 minute ago, C.A.P.E. said:

The CFS weeklies have looked pretty  gross lately too. I am resigned to the pattern remaining crappy overall through mid month at least. I have not been posting here much and will continue that until I see some clear and conclusive evidence of a pattern change. The EPS might be off somewhat in the LR, but it is rarely completely off base. I advise anyone who is in near panic mode to avoid looking at the weeklies this evening. 

Nah, weeklies have been terrible with week 3. Hasnt got it right in weeks. Weeks 4-7 are useless if week 3 is wrong. I really dgas what they show tonight. Until we break out of the pac assault we're screwed no matter what any model says.

[WEATHER53]

Until we can get some Mongolian high pressure we are going to stay in the now dominant pattern of  lows  into the lakes. Even worse it’s the central and western lakes and not eastern .

Early November snows do not translate well for winter.  The only high we got that set up right was a 30.60 crushing monsters. The 30.25s just can’t  get set up and that must change. Looking for that Mongolian high far more than MJO or SSW

[cbmclean]

Just read a post from NittanyWX in the New York forum saying that actually it's the Euro which has been getting the mjo correct and the gas which has been whiffing.  Something g about how the RMM plots don't show the real story.   

He also feels that AAM is really running the show and there will be no sustained cold until that changes.

I wish I knew how to link to posts.