Evidence for global regime shift mounting

[Isotherm]

Yep I made the same observation. Several runs of the gfs have show the same thing. Temporarily higher hgts progressing into Greenland only to be squashed.

It's a step in the right direction for sure - better than severely low heights over the pole.

[TheTrials]

Yep I made the same observation. Several runs of the gfs have show the same thing. Temporarily higher hgts progressing into Greenland only to be squashed.

to be expected, but i do think it won't take too much of a relaxation in the AO to let the nao loose so to speak

[bmc10]

Yep all the components are on the field there is just a disconnect currently preventing a more favorable pattern from evolving. I hope it is not long before things change for the better. I love watching a snowstorm unfold.

[Isotherm]

If blocking never develops this winter, then I'm going to have to seriously re-examine the methods I've been using to forecast the NAO/AO. Hopefully, the worst does not occur and we end up with a 10" winter like Don is expecting on the main board. For mother nature to do that to us after 2 consecutive historic winters is a pretty low blow - would be nice to step us down easily, maybe to a normal winter first. But mother nature is known for being a sadistic biatch so we shall see what we shall see.

[tornadojay]

what's up with the CPC's AO, NAO and PNA forecast graphics.. they all look like they are flatliners... looks like someone is dying or something.. are these legit forecasts?

[TheTrials]

what's up with the CPC's AO, NAO and PNA forecast graphics.. they all look like they are flatliners... looks like someone is dying or something.. are these legit forecasts?

I never use them, so cannot comment.

[Isotherm]

what's up with the CPC's AO, NAO and PNA forecast graphics.. they all look like they are flatliners... looks like someone is dying or something.. are these legit forecasts?

No, some sort of malfunction, it's happened numerous times before; I'm sure it'll be fixed by tomorrow.

[earthlight]

Yep all the components are on the field there is just a disconnect currently preventing a more favorable pattern from evolving. I hope it is not long before things change for the better. I love watching a snowstorm unfold.

This is currently looking like less of a SSW and more of a gradual change. However, these things can change fairly rapidly as far as forecasts with a 5-10 day lead or so. The Euro stratospheric warming maps are fairly impressive (or were when I last checked them) but still don't support a SSW. This is not to say that the pattern can't change without a SSW propagating into the troposphere, but it would be much easier done if it did happen that way. In that case we could erode the polar vortex's current positioning and begin to build back some high latitude ridging.

Currently the Euro is forecasting a warming event that probably would be best defined as moderate. There is some pretty notable warming at 240hr at 1mb...but if you were to look at the 30mb charts you would still see that the pattern remains generally in place or is changing slowly. Essentially what we are seeing is a slow or delayed stratospheric warming event that probably won't appear to most as a SSW. There could be future waves that could be the SSW we are looking for...but I would think they would come near or after the holidays.

This is supported by the 30mb 240 hr Euro maps which, over the last week, have become continually more robust. This suggests that the Euro is forecasting a more delayed or gradual warming as we move through the end of December. The GFS has another wave towards the very tail end of its run which may be the one we were looking for -- and the one I talked about above.

This probably puts us in a 3-6 week time frame before we start to feel the effects of the warming event. The AO is very stubborn right now -- the next 3 weeks are likely to be a bit of a disaster as far as snow goes. This pattern is really going to test many snow lovers patience. Below is the Euro 240hr 1mb showing the warm zone that is yet to propogate.

[earthlight]

If blocking never develops this winter, then I'm going to have to seriously re-examine the methods I've been using to forecast the NAO/AO.

We are already beginning to see the stratospheric changes that you and I were talking about in our winter outlooks/discussions from October or earlier. So although we aren't seeing SSW indications yet -- I think the general idea is that we will begin to move at least slightly in the right direction by the end of the month. Depending on how this propagates/develops we could be talking high latitude blocking be either mid or late January.

[Dsnowx53]

But does a slow, gradual warming really have that much of an effect? I'm not sure a slow warming can disrupt the PV - I'd think a rapid increase in temperature is much more important than temperature in itself.

[TheTrials]

You can see the other side of the globe warming, so that's something,

It may be enough to put the core of the cold air over eastern canda and if we keep the PNA spiking that could really help out January

[Alpha5]

[TheTrials]

Here is what I was talking about with "warmth" showing up on the other side of the globe. Looks to me it helps to displace the PV just enough to push things south and help us be on the right side of the gradient.

[Weathergun]

Here is what I was talking about with "warmth" showing up on the other side of the globe. Looks to me it helps to displace the PV just enough to push things south and help us be on the right side of the gradient.

It would be better if that cut-off block in the AO region was further SW, north of Alaska. We would see the heights potentially connect to it, from the EPO and NAO regions.

[TheTrials]

It would be better if that cut-off block in the AO region was further SW, north of Alaska. We would see the heights potentially connect to it, from the EPO and NAO regions.

Beggers can't be choosers, its a start, the rest will come.

[Isotherm]

Beggers can't be choosers, its a start, the rest will come.

If you build it, it will come.

[Isotherm]

I think we'll eventually see those higher heights in W Canada hook up w/ the arctic ridge, by early January. Then we can get some arctic air into the picture.

[Alpha5]

If you build it, it will come.

Which is why I'm starting to build my backyard rink this weekend....the cold air will now come

[Hailstorm]

It looks as if the Euro Ensembles wants to amplify the Aleutian ridge more so than what the GEFS are depicting on the maps above. If we can get the Aleutian ridge to amplify a good amount just west of Alaska, that can develop a severe -EPO. Also, the colder anomalies in Northeastern Asia may produce a -WPO which can help to direct Western Canadian cold to the US East Coast.

[Isotherm]

Very impressive drop-off in solar parameters. We'll see if that will do its dirty work down the road.

Geomag activity is nearly non-existant right now.

[HM]

There is still a high TSI currently in progress, lagging the recent swell of activity:

http://www.leif.org/research/TSI-SORCE-Latest.png

This in combination with the lingering +QBO has made the lower stratosphere (particularly at 50mb) pretty warm across the Tropics:

I think this is temporarily keeping tropical forcing unorganized at the moment (CHI anomalies aren't too anomalous with widespread convection).

The good news is that the IMF is heading downward again (top line in graphic) and the TSI will likely follow suit as solar activity continues to trend toward a long-term relative min.

[Hailstorm]

There is still a high TSI currently in progress, lagging the recent swell of activity:

http://www.leif.org/...ORCE-Latest.png

This in combination with the lingering +QBO has made the lower stratosphere (particularly at 50mb) pretty warm across the Tropics:

I think this is temporarily keeping tropical forcing unorganized at the moment (CHI anomalies aren't too anomalous with widespread convection).

The good news is that the IMF is heading downward again (top line in graphic) and the TSI will likely follow suit as solar activity continues to trend toward a long-term relative min.

Thanks for your very great discussion.What is a "TSI" and how does it affect solar activity? I also thought that a -QBO (instead of a +QBO) causes the stratosphere to warm, especially if it is a west-based -QBO. East-based -QBOs are sufficient enough to warm it if there is already low solar activity; whereby a west-based -QBO is needed if there is a spike in solar activity. In addition, I thought that the MJO was the primary factor in tropical forcing, unless the QBO also plays a role? Can you describe the "IMF" please?Your feedback to these questions would be greatly appreciated.

[Alpha5]

There is still a high TSI currently in progress, lagging the recent swell of activity:

http://www.leif.org/...ORCE-Latest.png

This in combination with the lingering +QBO has made the lower stratosphere (particularly at 50mb) pretty warm across the Tropics:

I think this is temporarily keeping tropical forcing unorganized at the moment (CHI anomalies aren't too anomalous with widespread convection).

The good news is that the IMF is heading downward again (top line in graphic) and the TSI will likely follow suit as solar activity continues to trend toward a long-term relative min.

I think Isotherm pointed this out in another thread, but lower solar activity is more conducive of blocking, right?

[NorEaster27]

This was a total fail, pattern is reloading with a huge +AO, dt has given up on the pattern changing in Jan

[BxEngine]

This was a total fail, pattern is reloading with a huge +AO, dt has given up on the pattern changing in Jan

Stay classy.

[Isotherm]

This was a total fail, pattern is reloading with a huge +AO, dt has given up on the pattern changing in Jan

The word "was" implies the forecast time frame has passed. My original post called for a crappy Nina regime through Christmas, transitioning into New Years, with the potential pattern change occurring in early January. So if by January 7th, nothing has changed for the better, then you can come in here and tell me I'm not worth the paper I'm printed on, I'm less valuable than donkey crap, then throw eggs at my house, destroy my mailbox, and send me hate mail for 3.5 years, but until that time, you can't.

Revisiting the first post, the stratospheric warming is still happening and is forecast to get fairly far east, near Greenland by D 10. It likely won't be a major warming, but as I said before, I still think this in conjunction with the downwelling easterly QBO transition and low solar, will be enough to perturb the stubborn vortex and at least get some height rises over the pole by the second week of January. I'm certainly not ready to abandon the idea of a pattern change although right now I'm thinking it would likely occur slightly later than I mentioned in the original post (second week of Jan rather than first).

[Isotherm]

Initial 5hpa

D 10 5hp, note the warming across the pole, Canada, AK, inching close to greenland

10 hpa

1 hpa we have the warming nosing across the pole

[Absolute Humidity]

Agreed, and winter is just beginning thus to say a pattern change is a total fail is surely premature. DT's update did not cancel writer either, he eluded to the exact QBO transition here with detailed ayalisis of the polar shift from S to N now rotating clockwise SW to NE and how this needs to contune to propagate until the western transition is complete with a 50 50 probability of this happening by Jan 10th.

Also, true that most winters that don't have major pattern changes by 1 st week of Jan do fail, however not all - 1985 being one example. With out the particulars, I suspect we could have a delayed shift due to the lag of last 6 weeks or so of quiet sun and the slow transition of QBO. Feb and March may be quite interesting.

[RUNNAWAYICEBERG]

the MJO just cant seem to progress into favorable phases. its been incoherent the past week. for those looking to understand the MJO better, scroll down to "expert dicussion" on the following page, very informative to novices like myself:

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

[Hailstorm]

The word "was" implies the forecast time frame has passed. My original post called for a crappy Nina regime through Christmas, transitioning into New Years, with the potential pattern change occurring in early January. So if by January 7th, nothing has changed for the better, then you can come in here and tell me I'm not worth the paper I'm printed on, I'm less valuable than donkey crap, then throw eggs at my house, destroy my mailbox, and send me hate mail for 3.5 years, but until that time, you can't.

Revisiting the first post, the stratospheric warming is still happening and is forecast to get fairly far east, near Greenland by D 10. It likely won't be a major warming, but as I said before, I still think this in conjunction with the downwelling easterly QBO transition and low solar, will be enough to perturb the stubborn vortex and at least get some height rises over the pole by the second week of January. I'm certainly not ready to abandon the idea of a pattern change although right now I'm thinking it would likely occur slightly later than I mentioned in the original post (second week of Jan rather than first).

Good post. HM in the main thread believes that a major mid-winter warming may be coming into the works for January. The EP flux will lessen the zonal flow and winds in the stratosphere. This could also be the result of an increase in ozone up there. Let's hope the warming gets transferred down to the troposphere.