weatherjunkie

Yeah, I remember quite a few cases where there was a significant Asian MT/Siberian blocking event followed by -AO/-NAO. Thank you for the response.

What would some signs be of wave breaking? I know we have to look at geopotential waves 1 and 2, but what other sources can we look at to determine the possibility of wave breaking?

Wouldn't that signal a +NAO in the future? Or is this still one of those elephant trunk tornado scenarios?

Strong west based -NAO? Looks like the eastern US will be fair game starting around the third and lasting for quite a while. GL to you guys in Europe. I hope the second half of winter provides snow for all.

0z GEFS NAO Outlook Similar to the 18z run, and a little more robust than the 12z run.

This should probably go into the other model thread, but I thought some would enjoy it with all the talk of going back into the icebox. 18z GEFS NAO Outlook 12z similar but not as robust around the 2/6-2/12 time period. It gets as high as -0.4 SD around the 3rd and then dips to around -2.25 SD on the 10th.

Nothing much. I thought that the graphic would be something people would like to see given predictions about high lat blocking in late Jan-mid February.

0z GEFS NAO Outlook Predominately east based.

12z GEFS NAO outlook It is predominately west based though, which I have no problem with in the U.S . Keep the stratospheric updates coming. They are much appreciated.

Today's AO chart.

AyO this looks interesting (please excuse my poor pun). Perhaps another situation where the troposphere counteracts the stratosphere? Or will this change to reflect the strengthening vort and positive mean zonal winds downward propagation?

Any concerns regarding the positive zonal winds propagating downward?

I'll take whatever we can get if it produces a weaker and displaced vortex and hopefully renewed potential for high latitude blocking. Looks like a +NAO and neutral AO from the images you posted and based on what I think you're trying to say. It likes like from those images that there also appears to be potential for -PNA and some ridging along the eastern US. Ew... Thank you both for the continued input. OT: Does anyone know of a website that contains the GME model and its prediction for North America?

Thank you for the reply. I also see heat fluxation at 30hPa that coincide with the slowing down of the winds. That appears to be a good sign as well, but it's probably expected given what's happening. The ECM seems to want to weaken the wave 2 activity in the upper stratosphere and "downwell" it to the lower stratosphere as it propogates poleward, do you have any thoughts about this? Your input is greatly appreciated and here's hoping the GFS hops onto the warming trend and hopefully the ECM will too.

I wish a happy, healthy, and wealthy new year to all. In reference to the bolded, is the stratosphere likely to play an important role down the road given how significantly low the -AO is? To me it appears that the troposphere will not be seriously affected by the potential strengthening stratospheric vortex in the next 1 to 2 weeks. There are signs that both the -NAO and -AO will lose their grip a bit, but would you expect a pattern reversal come the latter half of January? I've seen Don Sutherland's post on Eastern which had the mean composite chart for when the AO reached -6 SD, but I'm curious to know how the stratosphere looked in year's with a similar -AO, and whether or not the stratosphere will be much of a factor. Here in the US, the active subtropical jet and combined forces of strong -AO and -NAO has many people in the eastern third of the country in love with the pattern and reflecting back to how it compares to the 70s. I would love for this to continue and to hear some good news related to the stratosphere. I guess it's a mostly wait and see situation.

MT spiking earlier this month to +4 SD. It has since come back down a bit to +2 SD and it appears to be continuing it's decline at a fairly decent pace. There is word on the street that would could see another spike. I would imagine that this would somehow play a role regarding the PV splitting, even if it's minimal.

So there's potential to see more warming?

Delicious Thanks for the update. On a side note, I wish you a speed recovery Chi, and I appreciate the information you have given to me.

Word on the street is that the ONI trimonthly peak for NDJ may reach the strong category. Sub-surface indicates continued warming under Nino 3. and 3.4. With the upcoming MJO expected to move into a favorable location for Nino strengthening, I think an ONI peak for NDJ that qualifies as strong won't be out of the question (+1.7C).

Oh I see I also believe that there is a greater impact with an easterly QBO. Only time will tell though.

I believe this should answer your question. BDC Basically when the Mountain torque tanked it indicated that Rossby Wave Dispersion was taking place in the mid-latitudes in the N. Hemisphere. The Rossby wave eventually propagated into the stratosphere (may still be propagating into the stratosphere), decelerated the westerly jet stream, and allowed for stratospheric warming to take place. I believe the reason that both Asia and N. America are seeing the strongest warming is because both areas had Mountain Torques that dropped rapidly below -1 standard deviations multiple times. Seems reasonable no?

Source Sub-surface shows cooler water creeping in. With the MJO expected to be stuck in phase 3 for quite some time and perhaps retrograde back into phase 2, I think the easterlies in the W Pac should upwell cooler waters in the western Nino regions. Even a phase 4 of the MJO would result in a similar regression of ENSO SSTA. I suppose this would be mother nature's way of evening things out after the Kelvin Wave. QuikSCAT If one was to look at the NOAA/NESDIS charts, it's clear that the PDO has become more negative. Warmer waters near Japan and south of the Aleutian Straits. Cooler waters hugging N. America. Here's what we generally get to look forward to assuming the MJO remains in phase 3 for the next week or so, and since the signal is weakening and easterly winds are somewhat decent, why wouldn't it take a while to propagate east? MJO Composites

Well, I've taken a look at some of the temperatures and geopotential heights at 10hpa , 30 hpa, and 50hpa and it looks like to me that that there is potential for high pressure to build near or to the west of Greenland and low pressure over the NE Atlantic in the long term. Taking a look at the 100hpa level, it looks like high pressure will build into eastern Europe, low pressure over the northeast Atlantic and central/eastern Europe. MJO is in phase 3 and is sort of expected to lollygag in that octant in the week or so. After that a possible jump to phases 7/8 is possible. Combining those things, would a reasonable forecast for the next 1-2 weeks be a +NAO with a wet western/northern Europe with some reprieve as the MJO is in a favorable phase for dryness? After that in weeks 3-4, a -ve NAO and continued wetness into eastern/northern Europe with some dryness as MJO phases 7/8 by December would favor such a pattern? MJO Composites Thank you all for your input. I'm tring to get a feel for all things named "stratosphere". Thank you for the clarification and information.

Thank you.

The pattern I was referring to was the Western US ridging and Central and Eastern US troughing. It was my belief that stratospheric warming occuring in Western Canada would favor such a pattern. The response you gave to me was: What am I to look for with the troposphere profiles in order to see if there is transmission from the stratosphere to favor the blocking?