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Medium Range Discussion Winter 2011-12


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The objective analogs centered around 2/12 indicate that the East could be colder than normal.

ObjAnalogs02012012-11day.gif

Should the PNA remain positive and the AO negative, that solution would be reasonable. At this time, my guess for the 2/8-15 period (#806 in this thread) appears to be on track. It should be noted that the 2/1 18z GFS is warmer, but we'll see what happens.

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The objective analogs centered around 2/12 indicate that the East could be colder than normal.

ObjAnalogs02012012-11day.gif

Should the PNA remain positive and the AO negative, that solution would be reasonable. At this time, my guess for the 2/8-15 period (#806 in this thread) appears to be on track. It should be noted that the 2/1 18z GFS is warmer, but we'll see what happens.

That's the best news i have heard all winter! Hope it verifies and thanks Don for all your info and hard work.

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Unfortunately, I suspect that the cold probably won't lock in.

This Winter Fall sucks. 2012-13 ftw.

December and January and now February. Bring on spring, I've had a enough of this.

Observing the models back in early January which looked to good to be true towards mid month, mid month rolls in and nothing happens and now they look good beyond Day 8. I'll believe it when I see it. Until I see the complete destruction of that AK Vortex there's no hoping in trying to revie this Winter.

Its interesting how the ECMWF brings the MJO into phases 7,8 and perhaps 1 before the end runs show it trying to retreat back into the circle, unbelieveable. We finally have a decent -AO anomaly but the Pacific is overwhelming the Atlantic signal flooding the country with mild Pacific Air locking the cold air towards Alaska and Siberia. Just sad.

Any thoughts on March Don? I had initially thought March may end up cooler across the consensus but I may change my mind if this continues.

Lets see what evolves over the next few weeks.

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Any thoughts on March Don?

My initial thinking is that there will be colder than normal weather in much of Canada, including southern Ontario and southern Quebec (Toronto, Ottawa, and Montreal included). Parts of eastern Canada might be warm if there is a lot of blocking. Much will depend on the evolution of the ongoing La Niña, which could be fading fairly quickly in March.

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Some thoughts regarding the MJO.

On February 1, the MJO remained locked in Phase 6. Although the ECMWF ensembles have suggested that the MJO will progress through Phases 7 and 8 and possibly into Phase 1 by mid-February, I believe a slower and unsteady progression is more likely. By unsteady progression, I mean that the MJO could revert back to an earlier phase rather than pushing steadily forward. The last steady progression of the MJO occurred back in November.

Since December, the MJO has been predominantly in two phases:

December: Phases 4 and 5 on 29/31 days (94% of the time)

January: Phases 5 and 6 on 28/31 days (90% of the time)

MJO02022012.jpg

If the stickiness one has witnessed in December and January persists, February could see the MJO predominantly in an area that would include Phases 6, 7, and 8. Composite anomalies for those phases are below:

MJOPhasesJFM.jpg

Such a situation would likely lead to widespread warm anomalies for February for a large part of North America despite some transient cold that cold perhaps lead to short periods of cold anomalies.

As for the guidance on the MJO, already the Canadian ensembles with a slower progression than the ECMWF ensembles are performing better relative to the recent movement of the MJO:

MJO02012012.jpg

This recent superior performance by the Canadian ensembles might be offering a hint that the lack of progression one has witnessed in December and January could persist for at least part of February.

Hence, at this time, I have increased confidence in my February idea (laid out in message #703 in this thread):

Feb2012.gif

Finally, if the MJO continues to behave as it has through February, March might see the MJO spend more time in Phases 8, 1, 2, and 3 than in the other phases. If so, that could lead to a colder outcome in areas that have witnessed an abundance of warmth this winter. It could also be consistent with the start of meteorological spring following a number of La Niña winters. That's not cast in concrete and, perhaps has an indication of that uncertainty, the early CFSv2 forecasts for March have a lot of warm anomalies.

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Some thoughts regarding the MJO.

On February 1, the MJO remained locked in Phase 6. Although the ECMWF ensembles have suggested that the MJO will progress through Phases 7 and 8 and possibly into Phase 1 by mid-February, I believe a slower and unsteady progression is more likely. By unsteady progression, I mean that the MJO could revert back to an earlier phase rather than pushing steadily forward. The last steady progression of the MJO occurred back in November.

Since December, the MJO has been predominantly in two phases:

December: Phases 4 and 5 on 29/31 days (94% of the time)

January: Phases 5 and 6 on 28/31 days (90% of the time)

MJO02022012.jpg

If the stickiness one has witnessed in December and January persists, February could see the MJO predominantly in an area that would include Phases 6, 7, and 8. Composite anomalies for those phases are below:

MJOPhasesJFM.jpg

Such a situation would likely lead to widespread warm anomalies for February for a large part of North America despite some transient cold that cold perhaps lead to short periods of cold anomalies.

As for the guidance on the MJO, already the Canadian ensembles with a slower progression than the ECMWF ensembles are performing better relative to the recent movement of the MJO:

MJO02012012.jpg

This recent superior performance by the Canadian ensembles might be offering a hint that the lack of progression one has witnessed in December and January could persist for at least part of February.

Hence, at this time, I have increased confidence in my February idea (laid out in message #703 in this thread):

Feb2012.gif

Finally, if the MJO continues to behave as it has through February, March might see the MJO spend more time in Phases 8, 1, 2, and 3 than in the other phases. If so, that could lead to a colder outcome in areas that have witnessed an abundance of warmth this winter. It could also be consistent with the start of meteorological spring following a number of La Niña winters. That's not cast in concrete and, perhaps has an indication of that uncertainty, the early CFSv2 forecasts for March have a lot of warm anomalies.

AM19PSU also pointed out, that on the OLR Hovmoller charts which I saw for myself, the Euro ensembles indicate convection returning into the IO, despite what those phase diagrams say. The GEFS as of the 31st of Jan showed little convection in the IO.

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AM19PSU also pointed out, that on the OLR Hovmoller charts which I saw for myself, the Euro ensembles indicate convection returning into the IO, despite what those phase diagrams say. The GEFS as of the 31st of Jan showed little convection in the IO.

Thanks for that info. It will be interesting to see how things ultimately unfold.

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AM19PSU also pointed out, that on the OLR Hovmoller charts which I saw for myself, the Euro ensembles indicate convection returning into the IO, despite what those phase diagrams say. The GEFS as of the 31st of Jan showed little convection in the IO.

Based on the MJO charts, wouldn't convection returning to the IO mean that the MJO actually progresses into Phases 2-3, and wouldn't that, in turn, mean colder weather for the CONUS? I'm knew to this so any help is appreciated.

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Don, historically the Canadian ensembles are one of the worst performers among the dynamical models regarding the MJO...it always looks like a squashed spider, even during relatively strong MJO events... I have seen members in all phases in the longer range while in the circle of death. The Euro and Ukie ensembles are 1st and 2nd with the GEFS a little distant third, I think. I have little doubt about the MJO wave progressing towards phase 7, with what I'm a little less confident is that it can go thru phases 8-2... my guess is that it won't, or it will be a very low amplitude event during those phases.

Also, even with the forecasted -EPO, the models are not too enthused about any arctic blast, which is a bit rare in model world in the medium/long range...usually with heights>546dm north of AK we see 1050+mb highs entering NA, at least in model world...but not this time around.

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Don, historically the Canadian ensembles are one of the worst performers among the dynamical models regarding the MJO...it always looks like a squashed spider, even during relatively strong MJO events... I have seen members in all phases in the longer range while in the circle of death. The Euro and Ukie  ensembles are 1st and 2nd with the GEFS a little distant third, I think. I have little doubt about the MJO wave progressing towards phase 7, with what I'm a little less confident is that it can go thru phases 8-2... my guess is that it won't, or it will be a very low amplitude event during those phases.

Also, even with the forecasted -EPO, the models are not too  enthused about any arctic blast, which is a bit rare in model world in the medium/long range...usually with heights>546dm north of AK we see 1050+mb highs entering NA, at least in model world...but not this time around.

Is this wrong then?

http://www.daculawea...ast_anomaly.php

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Don, historically the Canadian ensembles are one of the worst performers among the dynamical models regarding the MJO...it always looks like a squashed spider, even during relatively strong MJO events... I have seen members in all phases in the longer range while in the circle of death. The Euro and Ukie ensembles are 1st and 2nd with the GEFS a little distant third, I think. I have little doubt about the MJO wave progressing towards phase 7, with what I'm a little less confident is that it can go thru phases 8-2... my guess is that it won't, or it will be a very low amplitude event during those phases.

Also, even with the forecasted -EPO, the models are not too enthused about any arctic blast, which is a bit rare in model world in the medium/long range...usually with heights>546dm north of AK we see 1050+mb highs entering NA, at least in model world...but not this time around.

I thoght at one time the GFS was progging some uber high to make it into the CONUS, but I tried to find that e-mail (which of course I can't).

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Don, historically the Canadian ensembles are one of the worst performers among the dynamical models regarding the MJO...it always looks like a squashed spider, even during relatively strong MJO events... I have seen members in all phases in the longer range while in the circle of death. The Euro and Ukie ensembles are 1st and 2nd with the GEFS a little distant third, I think. I have little doubt about the MJO wave progressing towards phase 7, with what I'm a little less confident is that it can go thru phases 8-2... my guess is that it won't, or it will be a very low amplitude event during those phases.

Also, even with the forecasted -EPO, the models are not too enthused about any arctic blast, which is a bit rare in model world in the medium/long range...usually with heights>546dm north of AK we see 1050+mb highs entering NA, at least in model world...but not this time around.

Jorge,

It isn't often that I use the Canadian ensembles to any degree. However, at least over the past few days, the Canadian Ensembles seem to have done better with respect to the MJO (keeping it longer in Phase 6). Hence, I like the idea of a blend that favors a slower progression of the MJO.

The persistent lack of progression seen in December and January may also offer insight until there is strong evidence that the MJO has again begun to break out of such a situation. It will do so eventually, but it might still take some time before that process commences. Possible triggers might include an accelerating fade of the La Niña, hemispheric changes tied to the changing seasons, etc.

For now, I suspect that a situation where the MJO is predominantly in Phases 6, 7, or 8 for February is more likely than one where the MJO progresses steadily into the colder phases. Toward the end of the month, it would not surprise me if there were a few days that fell into Phases 1 or 2, but I expect perhaps more than two-thirds of the days to fall into Phases 6, 7, or 8.

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How often are those Hovmoller OLR charts updated on the CPC site? Still has the 31st.

Not sure what chart you are referring to since there are a variety of Hovmoller plots, but the latest Wheeler/Hendon RMM plots are available as of today. Both the GFS and ECMWF ensembles forecast a progression of the MJO into phase 8, although the GFS continues to be significantly stronger in magnitude. It is still important to realize that both models have a substancial amplitude in both phases that has yet to have been witnessed this winter.

qo9f87.gif

Don is actually right... the Canadian ensembles actually have the most skill out of any model ensemble suite when it comes to forecasting the MJO. This is mainly because the Canadian ensembles are unique for the fact that in addition to having different analyzed perturbations for each model in the ensemble suite, the actual physics of each model is slightly different than the operational run. Unfortunately, I think its "skillful" forecast is more of a play on the fact that most models give very poor MJO forecasts and since the Canadian ensembles often has the most spread (the squashed spider as Jorge was alluding to) its more likely to be right merely based on the fact that its ensemble members go in every which direction.

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Not sure what chart you are referring to since there are a variety of Hovmoller plots, but the latest Wheeler/Hendon RMM plots are available as of today. Both the GFS and ECMWF ensembles forecast a progression of the MJO into phase 8, although the GFS continues to be significantly stronger in magnitude. It is still important to realize that both models have a substancial amplitude in both phases that has yet to have been witnessed this winter.

Don is actually right... the Canadian ensembles actually have the most skill out of any model ensemble suite when it comes to forecasting the MJO. This is mainly because the Canadian ensembles are unique for the fact that in addition to having different analyzed perturbations for each model in the ensemble suite, the actual physics of each model is slightly different than the operational run. Unfortunately, I think its "skillful" forecast is more of a play on the fact that most models give very poor MJO forecasts and since the Canadian ensembles often has the most spread (the squashed spider as Jorge was alluding to) its more likely to be right merely based on the fact that its ensemble members go in every which direction.

Agree. Hence, it probably has one of the highest SD among it's members...that alone would bring my confidence for it down.

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Not sure what chart you are referring to since there are a variety of Hovmoller plots, but the latest Wheeler/Hendon RMM plots are available as of today. Both the GFS and ECMWF ensembles forecast a progression of the MJO into phase 8, although the GFS continues to be significantly stronger in magnitude. It is still important to realize that both models have a substancial amplitude in both phases that has yet to have been witnessed this winter.

qo9f87.gif

Don is actually right... the Canadian ensembles actually have the most skill out of any model ensemble suite when it comes to forecasting the MJO. This is mainly because the Canadian ensembles are unique for the fact that in addition to having different analyzed perturbations for each model in the ensemble suite, the actual physics of each model is slightly different than the operational run. Unfortunately, I think its "skillful" forecast is more of a play on the fact that most models give very poor MJO forecasts and since the Canadian ensembles often has the most spread (the squashed spider as Jorge was alluding to) its more likely to be right merely based on the fact that its ensemble members go in every which direction.

Look at that tiny spread on the GEFS...

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Yeah, big differences, but looks like the GEFS has better continuity between verified and forecasted...ie. look at ~160E

Yeah I brought that up yesterday. The EC goes right from blues to yellows which looks incorrect, although as far as the IO convection...it could have the right idea, but that's more of a forecast. The continuity in the near term is a little weird.

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