2013 Fall Medium Range Discussion

[DaculaWeather]

Thanks Don!

How much more warming do you think it will take at 30hPA to reach the level you're talking about?

[QVectorman]

I don't know what's wrong with the forum but I can't quote stuff correctly anymore. Anyways just wanted to give a POP up to this point. I chose Albany NY as the verification point since it's center to most posters. I added numeric labels into the old posts to keep track of the dates.

 

Event 1 temps drop from mid 40's to upper 30's during the week to a 4 pm temp of 30 on Sat.

Event 2 temps drop from low 30's previous days to 3 pm high of 24 on Dec. 30

Event 3 temps drop from mid 30's on Jan 1 to a high of 18 on Jan 3...coldest air of season so far. (good shot of cold)

Event 4 temps warm from a high of 18 on Jan 3 to a high of 39 on Jan 6. Stated a 15-20F warm up....21F warm up

Event 5 temps drop from high of 39 previous day to fct high of 32 today (Jan 7). -7F colder...bust on magnitude of temp fall. 

 

'QVectorman', on 13 Dec 2012 - 14:48, said:

With the MJO going into phase 1 and the 5-7 day lag for MJO induced waves to traverse the eastern US it would set us up for a wave to arrive in the east between Dec. 18-20 which is progged on the 180hr GFS and Euro moving across the upper Midwest or Great Lakes. The same wave also ushers in relatively "colder" air and plays nicely into the idea I spoke of the other day in my post about the pocket of relatively "colder" air arriving during the 1) Dec. 21-23 time frame based off of GWO analogs for the eastern US.Using that same concept for the GWO I expect another batch of 2)colder air Dec. 27-30. And Following the spike in the 10 and 30 mb temps that peaked back on Dec. 6 seems we should see a 3)good shot of colder air Dec 30-Jan 3.

'QVectorman', on 14 Dec 2012 - 16:54, said:

With the newest GWO numbers today the latest analogs indicate a 4)15-20F warm up in sfc temps Jan 3-Jan 6 compared to prior days highs across Midwest or NE (the Dec. 31-Jan 3 cold episode) and analogs suggest a stair stepped 15-20F temperature fall behind the warm up 1-2 days after that, meaning another 5) spell of colder air Jan 5-8.

 

'QVectorman', on 21 Dec 2012 - 12:37, said:

I extended my outlook through Jan 8 on Dec. 14. I still feel comfortable with those dates and with the newest GWO analogs and latest 10 and 30 mb temp forecast it appears the time frame between Jan 8-10 will see a warm up over the east 

 

[QVectorman]

Nice disco from Buffalo on long range pattern coming up.

 

 

000FXUS61 KBUF 080253AFDBUFAREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE BUFFALO NY953 PM EST MON JAN 7 2013

 

THE SECOND PATTERN CHANGE WILL BEGIN TO SHOW ITS CARDS BY THE MIDDLEOF THE MONTH. A MAJOR SUDDEN STRATOSPHERIC WARMING EVENT IS UNDERWAYAND NEARING COMPLETION. SUDDEN STRATOSPHERIC WARMING EVENTS AREFAVORED TO OCCUR DURING AN EASTERLY PHASE OF THE QUASI-BIENNIALOSCILLATION /QBO/...WHICH IS THE PHASE THE STRATOSPHERE IS IN THISWINTER. THE SUDDEN STRATOSPHERIC WARMING CAUSES A DRAMATICWEAKENING...AND SOMETIMES ENTIRE BREAKDOWN OF THE STRATOSPHERICPOLAR VORTEX...AND A GREAT WEAKENING OR EVEN REVERSAL OF THESTRATOSPHERIC POLAR NIGHT JET. THE GFS FORECASTS THIS TO OCCUR OVERTHE NEXT WEEK AT THE 2MB LEVEL.THE RESULT OF ALL OF THIS IS THE GENERATION OF STRONG HIGH LATITUDEBLOCKING AS THE DRAMATIC CHANGES IN THE STRATOSPHERE FEED DOWN INTOTHE TROPOSPHERE. HIGH LATITUDE BLOCKING FORCES THE COLDEST AIR SOUTHOUT OF THE HIGH ARCTIC AND TOWARDS THE MID LATITUDES...AND ALSOFAVORS LASTING STRONGLY NEGATIVE EPISODES OF ARCTIC OSCILLATION /AO/AND NORTH ATLANTIC OSCILLATION /NAO/. THIS TYPICALLY BEGINS TO TAKEPLACE 10-15 DAYS AFTER THE SUDDEN STRATOSPHERIC WARMING EVENT. HOWLONG IT LASTS CAN VARY...BUT TYPICALLY THE COLD PATTERN LASTS FOR ATLEAST A FEW WEEKS...AND OCCASIONALLY CAN PERSIST THROUGH THE REST OFWINTER.AS ALL OF THIS IS OCCURRING...THE MJO IS FORECAST BY THE GEFSENSEMBLES TO WEAKEN AND FADE AWAY IN ABOUT 10 DAYS. THE PACIFICNORTH AMERICAN PATTERN /PNA/ IS FORECAST TO REMAIN NEGATIVE OVER THENEXT 10 DAYS...WHICH WILL DIRECT THE FIRST BATCHES OF COLD INTO THEWESTERN AND EVENTUALLY CENTRAL UNITED STATES. GEFS ENSEMBLE MEMBERSSUPPORT A TREND TOWARDS A NEUTRAL OR POSITIVE PNA BY THE MIDDLE OFTHE MONTH...WHICH SHOULD ALLOW THE GROWING COLD TO SPREAD EASTWARD.WHAT ALL OF THIS TECHNICAL JARGON MEANS IS THAT THERE IS MODERATE TOHIGH CONFIDENCE IN A PATTERN CHANGE TOWARDS MUCH COLDER WEATHER FORTHE CENTRAL AND EASTERN UNITED STATES STARTING AROUND THE MIDDLE OFJANUARY...WITH COLD LIKELY PEAKING IN LATE JANUARY INTO EARLYFEBRUARY. THERE IS THE POTENTIAL FOR THE COLDEST AIR WE HAVE SEEN INAT LEAST SEVERAL YEARS DURING THIS PERIOD. WHAT SNOW POTENTIAL THISWILL BRING IS MUCH MORE UNCERTAIN DUE TO UNKNOWN DETAILS WITHSYNOPTIC STORM TRACK AND LAKE EFFECT POTENTIAL.

[DaculaWeather]

Beginning to feel the mojo... 

[donsutherland1]

Thanks Don!

How much more warming do you think it will take at 30hPA to reach the level you're talking about?

 

Probably not too much. I'd like to see the warming propagate down. Right now, it appears that we had a sudden stratospheric warming event but probably not a major one. Nonetheless, it could boost blocking prospects down the road.

[blizzard1024]

Nice disco from Buffalo on long range pattern coming up.

 

 

000FXUS61 KBUF 080253AFDBUFAREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE BUFFALO NY953 PM EST MON JAN 7 2013

 

THE SECOND PATTERN CHANGE WILL BEGIN TO SHOW ITS CARDS BY THE MIDDLEOF THE MONTH. A MAJOR SUDDEN STRATOSPHERIC WARMING EVENT IS UNDERWAYAND NEARING COMPLETION. SUDDEN STRATOSPHERIC WARMING EVENTS AREFAVORED TO OCCUR DURING AN EASTERLY PHASE OF THE QUASI-BIENNIALOSCILLATION /QBO/...WHICH IS THE PHASE THE STRATOSPHERE IS IN THISWINTER. THE SUDDEN STRATOSPHERIC WARMING CAUSES A DRAMATICWEAKENING...AND SOMETIMES ENTIRE BREAKDOWN OF THE STRATOSPHERICPOLAR VORTEX...AND A GREAT WEAKENING OR EVEN REVERSAL OF THESTRATOSPHERIC POLAR NIGHT JET. THE GFS FORECASTS THIS TO OCCUR OVERTHE NEXT WEEK AT THE 2MB LEVEL.THE RESULT OF ALL OF THIS IS THE GENERATION OF STRONG HIGH LATITUDEBLOCKING AS THE DRAMATIC CHANGES IN THE STRATOSPHERE FEED DOWN INTOTHE TROPOSPHERE. HIGH LATITUDE BLOCKING FORCES THE COLDEST AIR SOUTHOUT OF THE HIGH ARCTIC AND TOWARDS THE MID LATITUDES...AND ALSOFAVORS LASTING STRONGLY NEGATIVE EPISODES OF ARCTIC OSCILLATION /AO/AND NORTH ATLANTIC OSCILLATION /NAO/. THIS TYPICALLY BEGINS TO TAKEPLACE 10-15 DAYS AFTER THE SUDDEN STRATOSPHERIC WARMING EVENT. HOWLONG IT LASTS CAN VARY...BUT TYPICALLY THE COLD PATTERN LASTS FOR ATLEAST A FEW WEEKS...AND OCCASIONALLY CAN PERSIST THROUGH THE REST OFWINTER.AS ALL OF THIS IS OCCURRING...THE MJO IS FORECAST BY THE GEFSENSEMBLES TO WEAKEN AND FADE AWAY IN ABOUT 10 DAYS. THE PACIFICNORTH AMERICAN PATTERN /PNA/ IS FORECAST TO REMAIN NEGATIVE OVER THENEXT 10 DAYS...WHICH WILL DIRECT THE FIRST BATCHES OF COLD INTO THEWESTERN AND EVENTUALLY CENTRAL UNITED STATES. GEFS ENSEMBLE MEMBERSSUPPORT A TREND TOWARDS A NEUTRAL OR POSITIVE PNA BY THE MIDDLE OFTHE MONTH...WHICH SHOULD ALLOW THE GROWING COLD TO SPREAD EASTWARD.WHAT ALL OF THIS TECHNICAL JARGON MEANS IS THAT THERE IS MODERATE TOHIGH CONFIDENCE IN A PATTERN CHANGE TOWARDS MUCH COLDER WEATHER FORTHE CENTRAL AND EASTERN UNITED STATES STARTING AROUND THE MIDDLE OFJANUARY...WITH COLD LIKELY PEAKING IN LATE JANUARY INTO EARLYFEBRUARY. THERE IS THE POTENTIAL FOR THE COLDEST AIR WE HAVE SEEN INAT LEAST SEVERAL YEARS DURING THIS PERIOD. WHAT SNOW POTENTIAL THISWILL BRING IS MUCH MORE UNCERTAIN DUE TO UNKNOWN DETAILS WITHSYNOPTIC STORM TRACK AND LAKE EFFECT POTENTIAL.

 

The 00Z euro and even GFS 8-10 day mean heights are beginning to show this. It's trying..... 

[DaculaWeather]

Looking well below normal for Feb in the east

 

[Mike.Ventrice]

Hi all,

The time-longitude plot of unfiltered 850 hPa velocity potential with GFS 7-day forecast indicates we may be seeing a coherent MJO signal develop. The active phase of the MJO will be over the Indian Ocean, with suppression over the Pacific (~Real-time multivariate MJO phases 1-3). An Indian Ocean MJO is commonly associated with a cold air outbreak over the US, which is suggested in the GFS forecast. While the GFS forecast damps the eastward progressing VP850 anomaly signature and holds it stationary, the GFS occassionally struggles with correctly representing MJO or Kelvin waves (even though this year has been quite good), and therefore will stop progressing these disturbances eastward in the forecast.

The real-time multivariate MJO indices suggest there has been a weak MJO signature over the past 2 weeks:

Most dynamical models suggest a noisy evolution of the MJO signal in the upcoming 1-2 weeks: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

The partial fraction contribution of the RMM for today is as follows for OLR, U850, U200: (0.1422979, 0.1796938, 0.6780083). U200 is driving the show, and therefore taking a look at the time-longitude plot of U200 could provide some information with regards to interpreting the MJO-forecast in week 1-2.

The upper-level easterly wind phase is located over the Indian Ocean in the analysis, however in forecast mode, it damps out and switches to westerlies east of 120E. The primary easterly wind anomaly is in the form of a CCKW over east Africa (2.0 sigma event). You can see in the GFS forecast this eastward propagating CCKW become stationary at 60E (don't buy it!).

While we might enjoy winter in the early half of Janaury, if this MJO signal evolves into a coherent event, we might experience some anomalous warmth over the US somewhere down in week 3-4. Not great news for snow lovers... but the current state in the tropics would support potential for a snowy February... but then again, this is just one piece of the puzzle.

 

 

Agree Mike. We have a three week shot of winter in the cards from Christmas through Jan 15 before the tropics turn unfavorable again. Also of note is the generally unfavorable upper stratosphere, which means the general winter base state is likely what we saw in December and that we'll need significant forcing elsewhere (like the upcoming MJO wave) for winter on the east coast.

 

 

Nice disco from Buffalo on long range pattern coming up.

 

 

000FXUS61 KBUF 080253AFDBUFAREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE BUFFALO NY953 PM EST MON JAN 7 2013

 

AS ALL OF THIS IS OCCURRING...THE MJO IS FORECAST BY THE GEFSENSEMBLES TO WEAKEN AND FADE AWAY IN ABOUT 10 DAYS. THE PACIFICNORTH AMERICAN PATTERN /PNA/ IS FORECAST TO REMAIN NEGATIVE OVER THENEXT 10 DAYS...WHICH WILL DIRECT THE FIRST BATCHES OF COLD INTO THEWESTERN AND EVENTUALLY CENTRAL UNITED STATES. GEFS ENSEMBLE MEMBERSSUPPORT A TREND TOWARDS A NEUTRAL OR POSITIVE PNA BY THE MIDDLE OFTHE MONTH...WHICH SHOULD ALLOW THE GROWING COLD TO SPREAD EASTWARD.

 

 

This was a great discussion! I'm glad to see this in a NWS WFO discussion. This discussion is in agreement with what Adam and I spoke about on this forum in December. The only thing that concerns me is the discussion of the weakening of the MJO event... Most dynamical and statistical models will always show a weakening of the MJO when it tranverses around the Western Hemisphere. In this case, the dynamical models hold onto this MJO signal, but statistical approaches like Paul Roundy's will show a weakening of the MJO over the Western Hemisphere. This weakening is not a true weakening, and is a biproduct of the MJO speeding up over the Western Hemisphere, taking the shape of a strong convectively-coupled Kelvin wave. Therefore, space-time filtering techinques (like Paul's) will weaken MJO filtered anomalies and replace them with Kelvin filtered anomalies.

 

Something that comes to mind is the sudden stratospheric warming.. The Buffalo NWS allude to the easterly phase of the QBO favoring sudden stratospheric warming, which research shows to be a common relationship. However, the timing of the warming appears to align well with recent amplification of MJO convection over the Indian Ocean moving eastward over the Maritime Continent. Without the knoweldge of the sudden stratospheric warming event, Adam and I felt that we would still see a cold spell towards the end of Jan-February. Is this sudden warming event just a biproduct of extratropical Rossby wave dispersion from tropical convection associated with the amplified MJO towards the poles, disrupting the polar vortex?

 

With intraseasonal patterns in the tropics aligning with stratospheric variability, a cold spell over the US only seems inevitable in two-to-three weeks!

[wxmx]

Probably not too much. I'd like to see the warming propagate down. Right now, it appears that we had a sudden stratospheric warming event but probably not a major one. Nonetheless, it could boost blocking prospects down the road.

 

Oh, it's definitely a major one, as winds @60N 10hPa and above turned easterly, with the warming centered at 10hPa. Signals are mixed about it being a propagating event, so I'd follow your advice and be cautious about prolonged and very cold outcomes...but it appears that cold is just around the corner for the east for the last week of January.

 

[blizzard1024]

Looking well below normal for Feb in the east

 

 

The CFSv2 was showing below normal for almost the entire CONUS for January back in December. Unless the last week of January turns historically frigid, that forecast will be a bust.

[donsutherland1]

Oh, it's definitely a major one, as winds @60N 10hPa and above turned easterly, with the warming centered at 10hPa. Signals are mixed about it being a propagating event, so I'd follow your advice and be cautious about prolonged and very cold outcomes...but it appears that cold is just around the corner for the east for the last week of January.

 

ecmwfzm_u_a12.gif

 

Jorge,

 

On further inspection, you're right. It is a major event. Whether it's a propagating event remains to be seen and that's reason for some caution, particularly when it comes to the issue as to whether February will be a blocky month as was the case in 2010.  

 

I agree with the colder outlooks for the closing 10 days of January in the eastern half/two-thirds of North America (except northern Quebec, Labrador, parts of Atlantic Canada). There are still some questions about the magnitude, but my early thinking is the cold should be more severe than what many of those areas witnessed from late December into early January.

[wxmx]

Jorge,

 

On further inspection, you're right. It is a major event. Whether it's a propagating event remains to be seen and that's reason for some caution, particularly when it comes to the issue as to whether February will be a blocky month as was the case in 2010.  

 

I agree with the colder outlooks for the closing 10 days of January in the eastern half/two-thirds of North America (except northern Quebec, Labrador, parts of Atlantic Canada). There are still some questions about the magnitude, but my early thinking is the cold should be more severe than what many of those areas witnessed from late December into early January.

 

I fully agree with your thoughts Don. I just want to add that the strong MJO wave currently near Indonesia might also help get things blockier/colder/wetter for the eastern 2/3s in the time frame you point out.

[am19psu]

This was a great discussion! I'm glad to see this in a NWS WFO discussion. This discussion is in agreement with what Adam and I spoke about on this forum in December. The only thing that concerns me is the discussion of the weakening of the MJO event... Most dynamical and statistical models will always show a weakening of the MJO when it tranverses around the Western Hemisphere. In this case, the dynamical models hold onto this MJO signal, but statistical approaches like Paul Roundy's will show a weakening of the MJO over the Western Hemisphere. This weakening is not a true weakening, and is a biproduct of the MJO speeding up over the Western Hemisphere, taking the shape of a strong convectively-coupled Kelvin wave. Therefore, space-time filtering techinques (like Paul's) will weaken MJO filtered anomalies and replace them with Kelvin filtered anomalies.

 

Yup, I'm saying the same thing in the Philly subforum (but with less science!)

[am19psu]

 

With intraseasonal patterns in the tropics aligning with stratospheric variability, a cold spell over the US only seems inevitable in two-to-three weeks!

 

Agree with this, too. Provided nothing goes wrong with the MJO forecast (like late Nov-early Dec), this should be a fairly straightforward pattern flip.

[tacoman25]

The CFSv2 was showing below normal for almost the entire CONUS for January back in December. Unless the last week of January turns historically frigid, that forecast will be a bust.

 

 

There is still a very decent chance that much of the CONUS could end up below normal for January...even after the warmer temperatures this week for the East. The next 7-10 days looks cold for the West and then Central parts of the country, and then after that a lot is up in the air but we could be looking at more widespread cold spreading east.

 

 

[QVectorman]

Mike Ventrice...is there any PS diagram on your page you recommend over another that handles all these issues you have been talking about with weak MJO signal over western hem. but also filters out the CCKW's to avoid false MJO signals like we had the last 2 weeks of Dec?

 

Also is there another x-t RWT developing at 135E 20N or is that the CCKW expanding??

[wxmx]

The impressive Greenland ridge is back on the Euro. My guess is that there's a relationship between it and how the model handles the MMW.

[Mike.Ventrice]

Mike Ventrice...is there any PS diagram on your page you recommend over another that handles all these issues you have been talking about with weak MJO signal over western hem. but also filters out the CCKW's to avoid false MJO signals like we had the last 2 weeks of Dec?

 

Also is there another x-t RWT developing at 135E 20N or is that the CCKW expanding??

 

The prefiltered 850 and 200 hPa Velocity Potential indices are the only indices that successful (for the most part) removes Kelvin waves. However, these indices are problematic during amplifying MJO events due to the padding with zero at future times technique. 

 

The Velocity Potential MJO (VPM) indices that just remove ENSO and are not prefiltered captures the MJO over the Western Hemisphere better than the Real-time Multivariate MJO (RMM) indices. However like RMM, Kelvin waves will project onto these indices. A future goal of mine is apply a time extended EOF on the prefiltered VP850/VP200 MJO indices to get around the padding with zeros at future times technique and not worry about amplitude issues. 

 

I cannot comment on the 6-variable MJO index. I have not done any research on this index, it is just running in real-time. Hopefully I will have some time to look at it in more detail down the road.

 

There does appear to be a new Rossby wave train developing over the Northern Hemisphere. This Rossby wave train times well with the active convection associated with the MJO translating over the West Pacific.

[Isotherm]

There is still a very decent chance that much of the CONUS could end up below normal for January...even after the warmer temperatures this week for the East. The next 7-10 days looks cold for the West and then Central parts of the country, and then after that a lot is up in the air but we could be looking at more widespread cold spreading east.

 

 

MonthTDeptUS.png

 

 

 

Agree taco. I think most of the Central/West region is pretty much a lock for a colder to potentially very cold January. Portions of New England still have decent negatives now, which will reverse over the next 5 days, but they have a better shot at a cold January than the Mid-Atlantic/Southeast US. I could see a situation where most of the US finishes cold except for the Southeast US if we can get a very cold pattern for the 20th-30th. I'd like to see guidance trend stronger w/ the MJO wave into phase 7-8. They've backed off today w/ more a spiral back toward the COD/phase 6. Often there are difficulties in MJO amplitude so that could change going forward, and there's no doubt this is the strongest wave we've seen this winter so far.

 

The NAO blocking is the other key for getting the East Coast cold. There will be resistance initially w/ higher heights due to the SE ridge. The -EPO and -AO send the cold into the Plains, but the NAO needs to bring it to the coast since we'll have the PNA fighting us as well. The 12z ECMWF looks a bit better w/ building the NATL block westward. We'll see, but Jan definitely looks like a more wintry month nationwide than December. And February could feature more of the same if the renewed -AO episode can persist 30-40 days.

[QVectorman]

The prefiltered 850 and 200 hPa Velocity Potential indices are the only indices that successful (for the most part) removes Kelvin waves. However, these indices are problematic during amplifying MJO events due to the padding with zero at future times technique. 

 

The Velocity Potential MJO (VPM) indices that just remove ENSO and are not prefiltered captures the MJO over the Western Hemisphere better than the Real-time Multivariate MJO (RMM) indices. However like RMM, Kelvin waves will project onto these indices. A future goal of mine is apply a time extended EOF on the prefiltered VP850/VP200 MJO indices to get around the padding with zeros at future times technique and not worry about amplitude issues. 

 

I cannot comment on the 6-variable MJO index. I have not done any research on this index, it is just running in real-time. Hopefully I will have some time to look at it in more detail down the road.

 

There does appear to be a new Rossby wave train developing over the Northern Hemisphere. This Rossby wave train times well with the active convection associated with the MJO translating over the West Pacific.

 

You rock Mike! Can't thank you enough for taking the time to share your research over the past few months with all of us here! 

 

Can solely CCKW's induce xt RWT's? Or is this xtRTW a product of both MJO and the CCKW?

[das]

The tropical-extratropical interface is currently one of the hotest topics in meteorology. I recommend going to AMS's journals and searching the Madden Julian Oscillation (MJO). You will find numerous topics of teleconnections, etc.

 

A recent paper I read with regards to boreal winter MJO event during an El Nino year impacting the 2009-2010 North East snow event: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00033.1

 

There are other indices that investigate the extratropical-tropical connection, such as Klaus Weikmann's and Ed Berry's Global Wind Oscillation: http://journals.ametsoc.org/doi/abs/10.1175/2008MWR2686.1?prevSearch=Global+Wind+Oscillation&searchHistoryKey=

 

Heather Archambault, an old friend and alumni from the University at Albany, did a lot of the 'pioneer' work on recurving West Pacific Typhoons and their potential impact on extratropical circulation. You can find her webpage and examples here: http://www.met.nps.edu/~hmarcham/

 

Most of the ground breaking research is still debatable in the meteorology community, and will not be released to the public for some time. For example, the MJO was discovered in 1972 by Madden and Julian, however we are only now starting to see hints of discussion of the MJO here and there. I recall during my stint for HS3 this past September, I watched the Weather Channel, for the first time, talk about the MJO and potential for tropical cyclogenesis over the Atlantic in week 3. Just in 2010, Dan K. (Accuweather's lead hurricane expert) came up to one of my posters at the AMS trop. conference and told me that people would laugh at me if I presented my poster (MJO + African easterly wave activity + tropical cyclogenesis over the MDR) if it were 5 years earlier. Another example is the recognition of convectively coupled Kelvin waves on tropical cyclogenesis. It took me 4 years of persuading and talks to get the National Hurricane Center to acknowledge these waves over the Atlantic (Tropical Storm Florence)... it all depends on if the mets who have been there for x amount of years approves, or better yet, believes in it. There are many more instances I've seen or experienced that toot the same type of tune... it's all part of the process of a growing science.

 

Excellent discussion.

 

If anyone is interested in some of the research project web pages for the research that is feeding into those AMS papers, the links to many are sprinkled throughout this small thread:  http://www.americanwx.com/bb/index.php/topic/29064-joint-mjo-task-force

[Met1985]

Great info again on here guys! Thanks for taking the time to post stuff and chime in on the upcoming pattern.

[DaculaWeather]

Really great stuff guys, thanks for all you do for us!

[GaWx]

Oh, it's definitely a major one, as winds @60N 10hPa and above turned easterly, with the warming centered at 10hPa. Signals are mixed about it being a propagating event, so I'd follow your advice and be cautious about prolonged and very cold outcomes...but it appears that cold is just around the corner for the east for the last week of January.

 

 

wxmx,

 This shows a positive anomaly of ~20C. Do you think this has maxed or is it still rising? Several of the major SSW's got to near or above +28C at 10 mb per this link:

 

 http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/

 

 Brown and gray anomalies are +28C+. Note the major SSW's that got there at the 10 mb level since 1979: 1/2009, 12/2001, 12/1998, 1/1992, and 1/1985. 1/1985 was near +30 C, for example. I'm leaving off those which exceeded +28 C but only at altitudes higher than the 10 mb level such as 1/2006, 12/2003, 12/2002, and 12/2000. Also, your chart's gray line showing the max. for 1979-2008 shows something similar. So, I think it would be good to know whether this one is stalling near +20 C or if it is still rising? If it stops here (near +20C), that's pretty strong but still not all that impressive vs. pretty recent history anomalywise. OTOH, it has risen ~30C anomalywise from ~-10 C to ~+20 C (and even more in absolute terms due to the seasonal rise of the mean, ~36 C). January of 1985 actually rose only ~30 C, itself, anomalywise.

[Mike.Ventrice]

You rock Mike! Can't thank you enough for taking the time to share your research over the past few months with all of us here! 

 

Can solely CCKW's induce xt RWT's? Or is this xtRTW a product of both MJO and the CCKW?

 

It is more commonly accepted that MJOs can initiation extratropical rossby wave trains. The relationship between CCKWs and extratropical Rossby wave trains has not been well established yet. That doesn't mean they can't intiation one, it is just no one has ever looked at it

[wxmx]

wxmx,

 This shows a positive anomaly of ~20C. Do you think this has maxed or is it still rising? Several of the major SSW's got to near or above +28C at 10 mb per this link:

 

 http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/

 

 Brown and gray anomalies are +28C+. Note the major SSW's that got there at the 10 mb level since 1979: 1/2009, 1/2001, 12/1998, 1/1992, and 1/1985. 1/1985 was near +30 C, for example. I'm leaving off those which exceeded +28 C but only at altitudes higher than the 10 mb level such as 1/2006, 12/2003, 12/2002, and 12/2000. Also, your chart's gray line showing the max. for 1979-2008 shows something similar. So, I think it would be good to know whether this one is stalling near +20 C or if it is still rising? If it stops here (near +20C), that's pretty strong but still not all that impressive vs. pretty recent history anomalywise. OTOH, it has risen ~30C anomalywise from ~-10 C to ~+20 C (and even more in absolute terms due to the seasonal rise of the mean, ~36 C). January of 1985 actually rose only ~30 C, itself, anomalywise.

 

It looks like it's probably the max temp it will reach, tomorrow's update may be similar.

[griteater]

Just wondering what impact the current solar flux and sunspot spike would have on the ongoing SSW. The sunspot spike is higher than what occurred back in mid-Nov.

[Ottawa Blizzard]

The 0z and 6z GFS runs really backed down and both the severity of the upcoming cold, as well as its duration. I hear the 0z Euro did as well. Could this be a general backing down of the models as we saw with the New Years cold shot?

[tnweathernut]

The 0z and 6z GFS runs really backed down and both the severity of the upcoming cold, as well as its duration. I hear the 0z Euro did as well. Could this be a general backing down of the models as we saw with the New Years cold shot?

 

Sure................................ but it could also just as easily be that the models are in complete chaos and flipping like a fish out of water trying to figure out which general solution is correct.

[vortmax]

The 0z and 6z GFS runs really backed down and both the severity of the upcoming cold, as well as its duration. I hear the 0z Euro did as well. Could this be a general backing down of the models as we saw with the New Years cold shot?

 

When looking at the long term, I think it's more valuable to focus on the trends/signs that the overall pattern is showing as opposed to how the operational models are handling it on a day-to-day basis. If there is a major pattern change coming (or two - which there appears to be), then the op models are going to have a hard time settling in for the next couple of days at least...