Medium Range Discussion Winter 2011-12

[donsutherland1]

In another ominous indication, the ECMWF ensembles forecast that the MJO could move into Phase 4 around 1/25, though with a low amplitude.

For those who are curious, the following are the North American temperature anomalies for all January cases when the MJO was in Phase 4, amplitude < 1 during La Niña conditions (ENSO R3.4 anomaly of -0.50°C or below).

The composite map looks a lot like the GFS ensemble temperature anomalies for the extended range (Message #500). It's not the only possible outcome. Some things can still change.

[NCMET]

Very true. Thanks for posting. Here is a look at the GEFS Ensembles for comparison. They look TOTALLY different and this could have profound implications on what happens down the road. Looks like the model dissension continues...

In another ominous indication, the ECMWF ensembles forecast that the MJO could move into Phase 4 around 1/25, though with a low amplitude.

For those who are curious, the following are the North American temperature anomalies for all January cases when the MJO was in Phase 4, amplitude < 1 during La Niña conditions (ENSO R3.4 anomaly of -0.50°C or below).

The composite map looks a lot like the GFS ensemble temperature anomalies for the extended range (Message #500). It's not the only possible outcome. Some things can still change.

[CoastalWx]

MJO forecasting is bad enough anyways, but iirc....the GEFS really have been too aggressive with going towards or hanging around P8-P1.

[donsutherland1]

Very true. Thanks for posting. Here is a look at the GEFS Ensembles for comparison. They look TOTALLY different and this could have profound implications on what happens down the road. Looks like the model dissension continues...

I agee about the model disagreement. I believe the Canadian ensembles also have an MJO forecast that is reasonably close to that on the ECMWF ensembles. I'll try to run the numbers based on the GFS ensemble forecast later tonight or tomorrow. It is possible that the temperature anomalies during a La Niña may not necessarily match the January-March composite for Phase 2.

[BethesdaWX]

Are the GEFS MJO ensembles usually more tightly clustered than the ECM MJO ensembles?

I've been thinking something more in between with a return in the 8-2 or 1-3 octants in February.

[am19psu]

MJO forecasting is bad enough anyways, but iirc....the GEFS really have been too aggressive with going towards or hanging around P8-P1.

The GEFS is terrible at forecasting the MJO. If you want to forecast the MJO using models, the ECMWF ensemble and weekly models are the only ones that have shown any skill beyond 1 week.

[donsutherland1]

As promised, here's a temperature composite map for January La Niña cases when the MJO was in Phase 2 and had an amplitude between 1 and 2:

It differs markedly from the composite January-March Phase 2 anomalies.

[CoastalWx]

The GEFS is terrible at forecasting the MJO. If you want to forecast the MJO using models, the ECMWF ensemble and weekly models are the only ones that have shown any skill beyond 1 week.

That's what I've noticed. I think the UK from time to time is ok too, so I like to look at that as well.

[am19psu]

I think the UK from time to time is ok too, so I like to look at that as well.

Yeah, it's the next best after the EC, though last I time I saw a talk on the subject (Apr 2010), it still didn't have skill beyond 10 days.

[Srain]

Looking ahead to the medium range forecast, the only agreement is that the Pacific NW and N California are headed toward a very active period. The -WPO is allowing Pacific storms to take aim on that region that has been suffering from extremely dry condition since fall. The encouraging news is that badly need moisture returns to those areas as the Pacific 'fire hose' floods the region. Warmer temps are on tap for the Southern tier of the CONUS while a battle zone of air mass clashes sets up for the N Plains and intrusions into the Central Plains. A noisy sub tropical jet and Pacific zonal flow should keep our rain chances coming in the days ahead.

The longer range remains murky with little agreement via the PNA/NAO/EPO regimes and will need to be monitored. The late January time frame continues to advertise a potent storm crossing the S Plains with 'cold' air lurking to our N. My hunch is yet another severe weather event is possible during that time frame.

[donsutherland1]

As predicted by the ensembles, both the PNA and AO are declining. However, in a big change from yesterday's ensemble guidance, the GFS ensembles are no longer tanking the AO. Instead, there is considerable division, with some members keeping it slightly positive in the extended range and other members keeping it slightly negative. Just a few members show a much larger decline. This change in the forecast AO is probably consistent with the fact that no (Sudden Stratospheric Warming (SSW) events have occurred to date and none appear imminent on the modeling. Instead, some moderate stratospheric warming events have occurred.

The GFS ensembles continue to point to a negative PNA down the road. That would be consistent with the strong PDO- that is currently in place. At the same time, the guidance is forecasting a significant rise in the EPO. This setup raises prospects that the final week of January will be warmer than normal. It also heightens the prospects that the 2-3-week "cool" period will wind up milder than normal, though closer to normal than December or the first half of January.

In short, the pattern has shifted somewhat, allowing for somewhat more frequent cold shots. However, a dramatic pattern change or flip has not occurred.

The ongoing La Niña remains relatively stable. Region 1+2 has actually cooled a little in the past week. Region 3.4 continues to hold steady at -1.0°C. Coupled with the guidance on ENSO conditions, it appears to be a reasonable bet that the La Niña probably won't fade rapidly in February.

If that is the case and if the predominant winter 2011-12 pattern of AO+, PNA-, and EPO+ prevails, the stage could be set for a warm February. The evolution of the La Niña and state of the teleconnections will play an important role in determining if the warmth is focused on the Eastern third to half of North America or is much more widespread.

[donsutherland1]

Looking ahead to the medium range forecast, the only agreement is that the Pacific NW and N California are headed toward a very active period...

The longer range remains murky with little agreement via the PNA/NAO/EPO regimes and will need to be monitored. The late January time frame continues to advertise a potent storm crossing the S Plains with 'cold' air lurking to our N. My hunch is yet another severe weather event is possible during that time frame.

I agree with you. The active period will be a big meteorological story for the medium-range. It will be interesting to see if some snow/snowflakes will be seen in the greater Seattle area during the weekend. It will be a close call, as the air mass could be marginally cold enough for a time on Sunday. Another opportunity might exist at midweek.

[bluewave]

It's interesting that it was almost a year ago to the day that the massive ridge up in that region maxed out.

While the rest of the pattern is different now, it's always impressive to see such strong positive 500 mb

height anomalies.

[wxmx]

-NAO to the rescue? The 0z op Euro has a nice omega ridge developing over Greenland past day 7, but it has not much support from it's own ensembles, as they portrait more of a NW ridge. Even with the strong -NAO, the East is torching by day 10, but that would be temporary if the -NAO came to fruition. Since there's little support from any other model, I would disregard, for the time being, the op Euro solution. If MJO/Strato teleconnections change, then I would reconsider this.

[usedtobe]

-NAO to the rescue? The 0z op Euro has a nice omega ridge developing over Greenland past day 7, but it has not much support from it's own ensembles, as they portrait more of a NW ridge. Even with the strong -NAO, the East is torching by day 10, but that would be temporary if the -NAO came to fruition. Since there's little support from any other model, I would disregard, for the time being, the op Euro solution. If MJO/Strato teleconnections change, then I would reconsider this.

The euro has had a bias of over overrdeveloping ridges which may account for its negative nao.. Like you, I'd wait as it doesn't have much support from the ens. When they come on line, then I'll give it some love.

[dtk]

The GEFS is terrible at forecasting the MJO. If you want to forecast the MJO using models, the ECMWF ensemble and weekly models are the only ones that have shown any skill beyond 1 week.

This is a good point (re the GEFS). I know people won't believe it, but the time-lagged ensemble from CFS (v2), which is a coupled atmosphere/ocean DA system and model, actually does have some skill. I don't think anyone is creating the phase diagrams on a regular basis though. I'll try to dig up some examples (or figure from our paper) if interested.

[usedtobe]

This is a good point (re the GEFS). I know people won't believe it, but the time-lagged ensemble from CFS (v2), which is a coupled atmosphere/ocean DA system and model, actually does have some skill. I don't think anyone is creating the phase diagrams on a regular basis though. I'll try to dig up some examples (or figure from our paper) if interested.

It would be interesting to see. What is the CFS saying about the mjo right now for 10 to 15 days down the road?

[dtk]

It would be interesting to see. What is the CFS saying about the mjo right now for 10 to 15 days down the road?

Comparison here:

There is a nice page with links here (all credit to Qin Zhang):

http://www.cpc.ncep.noaa.gov/products/people/wd52qz/mjoindex/MJO_INDEX.html

If you look around, keep in mind that some of the stuff under the dynamical model links labelled CFS are likely still CFSv1 (which we are still running unfortunately)....which is a very old version of the model, much lower resolution, and uncoupled.

[wxmx]

No love for the Canadian ensembles MJO forecast? At least one of it's member is probably right

[usedtobe]

The CFS2 nd most canadian members seem to like the circle of death. That doesn't inspire much confidence in using the mjo as a forecast tool going forward.

[QVectorman]

I always lean towards the ECMWF on the MJO but I have to say, the GEFS for the past week has been more accurate than the ECMWF forecasting the little loop it's doing right now on the edge of the COD. the ECMWFs kept taking it straight into the COD towards phase 4.

[CT Rain]

MJO forecasting is bad enough anyways, but iirc....the GEFS really have been too aggressive with going towards or hanging around P8-P1.

Euro ens/weeklies have been insisting on a low amplitude wave heading back toward P4 toward end of the month. GEFS have consistently been wrong with their MJO forecasts over the last month.

[QVectorman]

I have some thoughts that back up the GEFS forecast for taking the MJO through 8/1/2. Since relative AAM is positive that it should help pull the MJO back into phase 7/8 (although amplitude would be a question) and relative dAAM/dt is now negative it should aid the MJO into phase 1/2 after that. Also since we have negative frictional & mountain torque it will favor phase transition from 8 to 1 of the GWO which correlates to S. American/African convection transitioning to Indian Ocean convection which coincides with phase 8/1 transitioning to phase 2/3 of the MJO. Forecasting the amplitude of the MJO during these phases would be the fly in the ointment to these thoughts though.

If my interpretations are wrong someone please correct me

[donsutherland1]

A look at this morning's forecast teleconnection indices is almost like having to endure another round of water torture. The GFS ensembles are even more strongly pointing to a PNA- for the extended range. They are moving away from forecasting a period with a strongly AO- to one with a more neutral AO for that same period. The EPO is expected to be positive to strongly positive. The MJO remains locked in the so-called "circle of death" with the ECMWF ensembles still taking it to Phase 4 in the long-range. The GEFS has taken a step toward the Euro's MJO idea.

Consistent with the above teleconnections, the GFS ensemble objective analogs paint a warm picture for areas of North America that are weary of this winter's warmth. Even if one rolls the objective analog dates foreward 3-5 days, there is no real relief from the above normal readings.

All said, despite some transient cold shots, including two fairly strong but short-lived ones over the next 7-10 days that should lead to the second half of January being colder than the first half in much of the East, the period should still wind up milder than normal as a whole. None of the major cities from New York City southward are likely to see single-digit lows during either cold shot. Overall the non-Winter of 2011-12 looks to persist for the most part.

In the Pacific Northwest, recent mild weather has given way to some colder but not severely cold weather. The past two mornings saw the mercury dip to 29° in Seattle. The normal low is 37°. The PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday). The coldest anomalies are likely to remain locked away in an area running from Alaska into western Canada.

Finally, farther south, the active weather pattern might well produce some severe weather across the Plains States.

[okie333]

A look at this morning's forecast teleconnection indices is almost like having to endure another round of water torture. The GFS ensembles are even more strongly pointing to a PNA- for the extended range. They are moving away from forecasting a period with a strongly AO- to one with a more neutral AO for that same period. The EPO is expected to be positive to strongly positive. The MJO remains locked in the so-called "circle of death" with the ECMWF ensembles still taking it to Phase 4 in the long-range. The GEFS has taken a step toward the Euro's MJO idea.

Consistent with the above teleconnections, the GFS ensemble objective analogs paint a warm picture for areas of North America that are weary of this winter's warmth. Even if one rolls the objective analog dates foreward 3-5 days, there is no real relief from the above normal readings.

All said, despite some transient cold shots, including two fairly strong but short-lived ones over the next 7-10 days that should lead to the second half of January being colder than the first half in much of the East, the period should still wind up milder than normal as a whole. None of the major cities from New York City southward are likely to see single-digit lows during either cold shot. Overall the non-Winter of 2011-12 looks to persist for the most part.

In the Pacific Northwest, recent mild weather has given way to some colder but not severely cold weather. The past two mornings saw the mercury dip to 29° in Seattle. The normal low is 37°. The PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday). The coldest anomalies are likely to remain locked away in an area running from Alaska into western Canada.

Finally, farther south, the active weather pattern might well produce some severe weather across the Plains States.

Not going to happen. No way the S Plains get a storm strong enough to produce severe weather without bringing the cold air down as well behind it... -70F anomalies don't like to remain in one place very long... big time bomb pattern and big potential for someone to bust warm if you ask me.

[Srain]

A look at this morning's forecast teleconnection indices is almost like having to endure another round of water torture. The GFS ensembles are even more strongly pointing to a PNA- for the extended range. They are moving away from forecasting a period with a strongly AO- to one with a more neutral AO for that same period. The EPO is expected to be positive to strongly positive. The MJO remains locked in the so-called "circle of death" with the ECMWF ensembles still taking it to Phase 4 in the long-range. The GEFS has taken a step toward the Euro's MJO idea.

Consistent with the above teleconnections, the GFS ensemble objective analogs paint a warm picture for areas of North America that are weary of this winter's warmth. Even if one rolls the objective analog dates foreward 3-5 days, there is no real relief from the above normal readings.

All said, despite some transient cold shots, including two fairly strong but short-lived ones over the next 7-10 days that should lead to the second half of January being colder than the first half in much of the East, the period should still wind up milder than normal as a whole. None of the major cities from New York City southward are likely to see single-digit lows during either cold shot. Overall the non-Winter of 2011-12 looks to persist for the most part.

In the Pacific Northwest, recent mild weather has given way to some colder but not severely cold weather. The past two mornings saw the mercury dip to 29° in Seattle. The normal low is 37°. The PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday). The coldest anomalies are likely to remain locked away in an area running from Alaska into western Canada.

Finally, farther south, the active weather pattern might well produce some severe weather across the Plains States.

I agree, Don. The 25th, +/- a couple of days suggest a potent storm crossing the Plains. The warm sector suggests a severe weather threat much like we experienced on January 9th, but on a larger scale. Guidance is suggesting a strong 5H low trekking E which is a pattern we look for in the S Plains for a possible significant severe weather event.

[donsutherland1]

... big time bomb pattern and big potential for someone to bust warm if you ask me.

Two quick points:

1. I suspect that the January 16-23 timeframe could prove colder than normal in the Northern Plains. A colder outcome there would not be a big surprise. The map from Message #424 shows just such an outcome:

2. The kind of vigorous upper low that is shown on some of the guidance might well be capable of producing severe weather in its warm sector.

[donsutherland1]

Guidance is suggesting a strong 5H low trekking E which is a pattern we look for in the S Plains for a possible significant severe weather event.

Thanks Steve. That's exactly the feature I'm referencing.

[mempho]

Two quick points:

1. I suspect that the January 16-23 timeframe could prove colder than normal in the Northern Plains. A colder outcome there would not be a big surprise. The map from Message #424 shows just such an outcome:

2. The kind of vigorous upper low that is shown on some of the guidance might well be capable of producing severe weather in its warm sector.

I still think we need to torch more. Honestly, this has been the first winter I can remember when the normal was... normal.

We can't get snow nor ice nor severe nor real warmth nor real cold. Today's high is 39-41 here.... which is really nothing.... except this year its a really cold day.

X

[blizzardof09]

A look at this morning's forecast teleconnection indices is almost like having to endure another round of water torture. The GFS ensembles are even more strongly pointing to a PNA- for the extended range. They are moving away from forecasting a period with a strongly AO- to one with a more neutral AO for that same period. The EPO is expected to be positive to strongly positive. The MJO remains locked in the so-called "circle of death" with the ECMWF ensembles still taking it to Phase 4 in the long-range. The GEFS has taken a step toward the Euro's MJO idea.

Consistent with the above teleconnections, the GFS ensemble objective analogs paint a warm picture for areas of North America that are weary of this winter's warmth. Even if one rolls the objective analog dates foreward 3-5 days, there is no real relief from the above normal readings.

All said, despite some transient cold shots, including two fairly strong but short-lived ones over the next 7-10 days that should lead to the second half of January being colder than the first half in much of the East, the period should still wind up milder than normal as a whole. None of the major cities from New York City southward are likely to see single-digit lows during either cold shot. Overall the non-Winter of 2011-12 looks to persist for the most part.

In the Pacific Northwest, recent mild weather has given way to some colder but not severely cold weather. The past two mornings saw the mercury dip to 29° in Seattle. The normal low is 37°. The PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday). The coldest anomalies are likely to remain locked away in an area running from Alaska into western Canada.

Finally, farther south, the active weather pattern might well produce some severe weather across the Plains States.

there really isnt much hope for us in the northeast the remainder or january even into february. the pattern changed, yes, but did it in no way help us in getting a more prolonged cold pattern for the northeast. the se ridge now has the muscle to really flex itself and looks like were heading for a month 2-5 degrees above average.