Medium Range Discussion Winter 2011-12

[wxmx]

Yeah exactly. When people imagine this whole thing in their heads, they should think of a giant conical tornado and at its base are multiple vortices. These multiple vortices are the tropospheric circulations which are more chaotic / fast. The stratospheric tornado with descending mesospheric NOx etc will be over our polar vortex, enhancing the u-component at most layers.

This is why our vortex isn't modeled to be lobed etc. like the rest in the NH. At least not yet anyway....

Wow, people usually use analogies to dumb down concepts... I still needed a quick search, but I love it anyway

[HM]

Wow, people usually use analogies to dumb down concepts... I still needed a quick search, but I love it anyway

Jackpot! Check out the video on this page:

http://lpc2e.cnrs-or...iched/news.html

It'sa twista

Oh and LMAO at the analogy / concept attempt by me.

[CoastalWx]

I think people know the regime is changed across the globe. The MJO, AO..all these things are different from 3 weeks ago. I guess the question is why models like the EC were showing the pattern in the East, like it was up until 12z today. We know the MJO isn't everything, but some of the models were in serious disagreement and the question was why. With the euro showing what is showed even with the phase charts, I think it made things a lot easier for the PAC jet to cut under the big ridge north of AK. GEFS were exploding convection into the dateline and built PAC ridge up, thus cutting down the PAC jet. Throw in that tight PV in both Kamchatka and Hudson Bay and it can cause some model chaos.

[QVectorman]

Jackpot! Check out the video on this page:

http://lpc2e.cnrs-or...iched/news.html

It'sa twista

Oh and LMAO at the analogy / concept attempt by me.

great link. That is just like the link that use to be on the columbia stratospheric website which is still not operational. Too bad there isn't something like that in real time

[Met1985]

Great stuff on here guys. Learning a lot!

[brad1551]

When the +NAO is running close to neutral or close, it makes me think Blocking might be on it's way, then I see the pattern and along with the teleconnection on out, looks like it could go anywhere. 50/50 shot after 1 more week of above avg temps for the Mid-Alantic. I hope we all on the east coast can say soon, let the games begin. Some people just don't realize what it takes for a snow storm. If they only new that there is just more then precip & cold air envovled.

[TNE]

That 8-10 day time frame is looking like a very crucial period that may make or break this pattern chance.

lmao. It is February, what are you expecting? Are you expecting spring to come in a little early?

There is no cold air, we might see opportunity for snow like we saw on October 29 or January 21st. Overall it has been warm--Nights have been near freezing and less dry, days have been mostly in the 40s/50s. Last year we had the NAO/AO tank in early December and by Mid-December we were talking 30/20s for most of the winter.

I think most people would agree, it is either snow or warm-spring like temperatures....spring has already peaked multiple times this winter. Btw, when are 70s possible across our area based on climo? Late Feb., Early-Mid March?

[phil882]

There continues to be huge differences, relating to what kegg and Gibbs are saying. The EC is still a little suspect with the analysis, but I mean the difference in the IO is astounding. Looks like some other models are also putting convection in the IO as well. Clearly the GFS is going balls to the wall with the convection and potential TC developing east of the Indo. I would guess both models may be going to hard in either direction, but who will be right? Right now, there are two massive clusters of convection, like Phil pointed out. EC is loving the IO and GFS is loving the area near Coral Sea into Fiji. I think evidence right now points in the EC direction, but both clusters of convection are pretty solid right now.

I'm gonna play the devil's advocate here (even though I was harping on the signal yesterday ) and also point out that OLR is only one of the three predictors most use when diagnosing the MJO. I had a nice conversation with another colleague who is far more knowledgeable about the MJO, and he suggested that OLR was a poor predictor of future MJO performance. In fact, he recommended looking at 200 hPa winds over both OLR and 850 hPa winds since the latter two fields are very noisy and strongly influenced by convection which is admittedly poorly forecasted by the models. Fortunately we have hovmollers of 200 hPa winds, and the results are even more astonishing than the OLR plots, with a point in the GFS's favor.

I'm really starting to wonder if the ECMWF maps are longitudinally correct... there is no way the Euro is that far off with the 200 hPa anomalies. The GFS while overdone over the Indian Ocean and Indonesia, seems to make much more sense, especially with proper MJO propagation.

[CoastalWx]

Huh, that's interesting Phil. Although, I guess all three variables are probably not the easiest to predict. I suppose 200mb divergence might be the easiest, but it doesn't always guarantee convection underneath. But yeah I agree....some of the progs are just weird looking and not quite sure why. The thing that suprised me, is that if you look at the MJO RMM phase states, teleconnection indices etc. you just would not expect a blow torch 11-15 day east, like it was showing. Obviously there are many other variables at work, but I'd say >90% of the time..we would never have an 11-15 day blowtorch like the EC was showing. It was just weird looking.

[Rainshadow]

Huh, that's interesting Phil. Although, I guess all three variables are probably not the easiest to predict. I suppose 200mb divergence might be the easiest, but it doesn't always guarantee convection underneath. But yeah I agree....some of the progs are just weird looking and not quite sure why. The thing that suprised me, is that if you look at the MJO RMM phase states, teleconnection indices etc. you just would not expect a blow torch 11-15 day east, like it was showing. Obviously there are many other variables at work, but I'd say >90% of the time..we would never have an 11-15 day blowtorch like the EC was showing. It was just weird looking.

I would agree too just because you have divergence doesn't mean you'll get convection. I can understand how it would be a more accurate variable to outlook.

It does seem like a disconnect in there somewhere, you would think based on those phases that even if it doesn't average cold, there would be a pretty cold shot in there. The images that Phil posted, it does give the appearance of someone who did not scotch tape the two pieces of paper in the correct location.

[Ginx snewx]

Euro is an outlier

[NorEaster27]

Looks like the GFS MJO forecast is now caving to the Euro as we hit a brick wall into the COD before phase 1.

[BxEngine]

Looks like the GFS MJO forecast is now caving to the Euro as we hit a brick wall into the COD before phase 1.

Can you link the gfs mjo forecasts that had it strongly in phase 1? The differences seemed to be in the strength of the wave in 7&8.

[DaculaWeather]

Haven't seen a strong P1

http://www.daculaweather.com/mjo_phase_forecast.php

[Isotherm]

Can you link the gfs mjo forecasts that had it strongly in phase 1? The differences seemed to be in the strength of the wave in 7&8.

I posted this in the NYC thread a couple days ago, illustrating the differences b/t the ECMWF and GFS.

Many ensemble members going into p1.

Latest forecast has caved to Euro, which isn't unexpected given the progression of this winter's MJO:

Rapid weakening in octant 8, spiraling toward the COD

As a result, the D 6-10 pattern should be a predominately cool/dry one in the Northeast US for phase 8 MJO, before moderating/warming temps thereafter.

[SnowGoose69]

I think its pretty safe to say the Euro is no longer the model it was prior to the upgrade a few years ago, at least not for the U.S....I don't know if its improved since then for Europe. But the fact it had 2 runs the last 5 days bringing the PV into Michigan while the GFS has never really wavered on the idea of seasonal temps really speaks volumes. It still may be a superior model as far as grasping the idea of the storm track day-5-8 but it can throw way more stinkers on the pattern overall now than it did during the 2002-2007 period when it seemed to hit just about everything.

[Rainshadow]

I think its pretty safe to say the Euro is no longer the model it was prior to the upgrade a few years ago, at least not for the U.S....I don't know if its improved since then for Europe. But the fact it had 2 runs the last 5 days bringing the PV into Michigan while the GFS has never really wavered on the idea of seasonal temps really speaks volumes. It still may be a superior model as far as grasping the idea of the storm track day-5-8 but it can throw way more stinkers on the pattern overall now than it did during the 2002-2007 period when it seemed to hit just about everything.

Last winter aside, the Euro seems to suffer from a -nao bias in nina winters in the far end of its deterministic run. I remember 2007-8 winter when Chuck started threads about changes pointing toward this Euro type solution, never happened. At least the Euro's ensemble runs the last two 12z runs were way more subdued than the op run. I just think all of the models in general have been shakier beyond day 4 or 5 than they were the last two winters, might be a by product of having a nina that is behaving more like a nina? IDK.

[usedtobe]

Last winter aside, the Euro seems to suffer from a -nao bias in nina winters in the far end of its deterministic run. I remember 2007-8 winter when Chuck started threads about changes pointing toward this Euro type solution, never happened. At least the Euro's ensemble runs the last two 12z runs were way more subdued than the op run. I just think all of the models in general have been shakier beyond day 4 or 5 than they were the last two winters, might be a by product of having a nina that is behaving more like a nina? IDK.

I think the nina pattern is a big factor and the euro has always liked negative nao regimes more than it should in the extended. However, the last two years have been negative noa years so it's looked pretty good. Now we're in a positive nao year and it doesn't look as rosey.

[donsutherland1]

Today, the GFS ensembles delivered an AO forecast that has differed markedly from recent ones. The earlier ones suggested a negative and perhaps strongly negative AO would persist over the next 15 days. The new forecast shows many ensemble members taking the AO positive.

Although it is too soon to know whether this forecast is a blip, it does signal that opportunities for the cold to lock in across much of North America may be limited. At this time, I still believe that odds are against such a scenario where the cold locks in anytime soon. Instead, cold shots will likely remain transient. This scenario also reinforces the argument that February will experience widespread warmer than normal anomalies across North America. Even worse, should the AO be signaling the return of an AO+ regime beyond February, that could have implications for March/early spring.

[CoastalWx]

Last winter aside, the Euro seems to suffer from a -nao bias in nina winters in the far end of its deterministic run. I remember 2007-8 winter when Chuck started threads about changes pointing toward this Euro type solution, never happened. At least the Euro's ensemble runs the last two 12z runs were way more subdued than the op run. I just think all of the models in general have been shakier beyond day 4 or 5 than they were the last two winters, might be a by product of having a nina that is behaving more like a nina? IDK.

Yeah the op run can do whatever it wants in the 6-10 day, but if the ensembles don't agree..it's usually a good sign that it's out to lunch. Personally, since we have ensembles, it doesn't bother me if the GFS or Euro op have kooky solutions in the 6-10 day. If anything, if the ensembles and the op run agree on an anomalous warm or cold pattern...I may take the op runs as showing the potential magnitude of how strong the cold or warm shots may be..since they aren't a smoothed out mean.

[DaculaWeather]

Yeah the op run can do whatever it wants in the 6-10 day, but if the ensembles don't agree..it's usually a good sign that it's out to lunch. Personally, since we have ensembles, it doesn't bother me if the GFS or Euro op have kooky solutions in the 6-10 day. If anything, if the ensembles and the op run agree on an anomalous warm or cold pattern...I make take the op runs as showing the potential magnitude of how strong the cold or warm shots may be..since they aren't a smoothed out mean.

This is a VERY helpful insight when looking at the op and ensembles. Thanks!

[ORH_wxman]

I think its pretty safe to say the Euro is no longer the model it was prior to the upgrade a few years ago, at least not for the U.S....I don't know if its improved since then for Europe. But the fact it had 2 runs the last 5 days bringing the PV into Michigan while the GFS has never really wavered on the idea of seasonal temps really speaks volumes. It still may be a superior model as far as grasping the idea of the storm track day-5-8 but it can throw way more stinkers on the pattern overall now than it did during the 2002-2007 period when it seemed to hit just about everything.

The Euro has never been particularly distinguished beyond D6...I recall seeing a verification chart back in 2008-2009 for the last 12 month period and it was almost exactly the same as the GFS at day 8....I think more than ever we have everyone looking beyond day 6 so people start remembering what it showed at day 8 or day 9 now whereas in the past we never even really looked at those panels...or certainly never took them with an ounce of credibility.

So when we see it show a b ig cold outbreak or a snowstorm at 216 hours and it doesn't materialize....we get the impression that the model stinks, when it used to do this all the time in the past, but we just had less data publically available to see it.

[Ottawa Blizzard]

I'm guessing from the tone of this discussion that a cold snap no longer seems likely in February? JB and Joe D'Aleo spoke too soon?

[Weathergun]

Looking at how poor it's handle the MJO recently, the ECMWF operational/ensemble 500mb forecasts beyond day 5 should be questionable. It's been trying to stall the MJO in phase 6, since Jan 31st.

This forecast from Jan 31st. It had:

Today, the MJO pulse is now strong entering phase 7. But ECMWF is still forecasting to collapse back into phase almost immediately again in phase 6:

[DaculaWeather]

In the last 30 days, very few (CAN) have a decent record for forecasting the MJO http://www.daculaweather.com/mjo_phase_forecast_anomaly.php

[Nic]

I'm guessing from the tone of this discussion that a cold snap no longer seems likely in February? JB and Joe D'Aleo spoke too soon?

To be honest I don't think anyone knows anything. We just have to wait and see.

[HM]

The Euro has never been particularly distinguished beyond D6...I recall seeing a verification chart back in 2008-2009 for the last 12 month period and it was almost exactly the same as the GFS at day 8....I think more than ever we have everyone looking beyond day 6 so people start remembering what it showed at day 8 or day 9 now whereas in the past we never even really looked at those panels...or certainly never took them with an ounce of credibility.

So when we see it show a b ig cold outbreak or a snowstorm at 216 hours and it doesn't materialize....we get the impression that the model stinks, when it used to do this all the time in the past, but we just had less data publically available to see it.

Great post. Perception doesn't make verification but unfortunately that is about 75% of the active meteorological community.

[HM]

Looking at how poor it's handle the MJO recently, the ECMWF operational/ensemble 500mb forecasts beyond day 5 should be questionable. It's been trying to stall the MJO in phase 6, since Jan 31st.

I don't think any model's verification of MJO prediction is worth the time that this forum has put into it. The basic 200mb structure has and continues to suggest that the eastern wave is legitimate and will alter the N PAC.

I don't really care if it nose dives in phase 8-1 to the COD. It doesn't mean anything because the damage has been done at that point. It isn't until the forcing reemerges in phases 4-5-6 again when we go back to winter 11-12 "default"...

[QVectorman]

In the last 30 days, very few (CAN) have a decent record for forecasting the MJO http://www.daculawea...ast_anomaly.php

The performance of the CAN based on that chart was baffling many of us. We dug to the bottom of it in another thread the other day and realized it was because a majority of the time the CAN has such a large spread between its ensemble members (looks like a squashed spider) it has a higher verification score. When you cover as much space on the phase diagram as the CAN does with its ensembles you're bound to "get it right"

[Geos]

To be honest I don't think anyone knows anything. We just have to wait and see.

I think the cold snap is coming true this week. The EURO; I feel, is out to lunch lately. Isn't handling the MJO well and didn't handle the last system well. I would follow the GFS through D6 and that's about it. Too much guess work and variance this winter to accurately predict D7 and beyond!