February Medium/Long Range Discussion Thread

[psuhoffman]

5 minutes ago, das said:

Yes, but...

It's been a while since I read this but, if I remember right, MJO spikes to a high amplitude typically fall back into the COD instead of propagating to the next phases.  If I have time to peruse the UMD AOSC archives this evening, I'll try to find the paper.

That fits the longer range projections but most slide into 1 before fading into the COD

[RitualOfTheTrout]

15 minutes ago, psuhoffman said:

So we may need to wait and hope the wave makes it into 1. 

I don't think it really adds much clarity to the situation... Phases 6-7 are low significance too, but by ending up being much stronger than originally forecast still managed to throw a wrench into what looked like a decent setup several days ago. I think it goes back to whatever other factors are influencing the pattern the MJO just enhances or mutes this year. You would think if we manage a strong wave in phases 8-1 it could enhance or extend a window of opportunity, but like you mentioned a sustained 2-3 week "good" pattern is not likely. That being said, it wouldn't surprise me if models just flipped to a better look seemingly out of nowhere given the -AO and incoming favorable MJO phase.

[WinterWxLuvr]

What did the euro show?

There were a couple of gfs members that gave us a pretty good storm next week.

[Maestrobjwa]

23 minutes ago, Amped said:

The 8-1 Boundary is where storms normally occur. It won't be there until the 18th-20th.

Hey look! Right near President's Day week...lol I think we need to label that the hail mary week! 

[psuhoffman]

2 minutes ago, Maestrobjwa said:

Hey look! Right near President's Day week...lol I think we need to label that the hail mary week! 

I don't think we're going to get this right by then. If we do get a favorable look for a big storm it might be more feb 25 into march. 

[Amped]

2 minutes ago, Maestrobjwa said:

Hey look! Right near President's Day week...lol I think we need to label that the hail mary week! 

Thats every week for the rest of this winter. It's go for broke time.

[MAG5035]

50 minutes ago, das said:

Have to remember, Statistical Significance in JFM for Phase 8 is not terribly strong.  20-25% chance that anomalies rise above random chance in our area.  Way below the significance for Phases 1&2.

 

Agreed on Phase 8 significance... however don't those significance percentages work in reverse in effect? I was always under the impression that the significance maps reflected the percent of time that the actual anomalies exceeded the anomalies generated on the various three month maps for each phase. For instance you see less than 2.5% for the entire eastern seaboard on Phase 6.. a phase that is usually a surefire eastern torch if the MJO pulse has a reasonable magnitude. So I would interpret that as being very few times that the east had a below normal (or even normal) temperature pattern in that phase. If that's the case, I'm actually surprised at the amount of what would be uncertainty with phase 1&2 in JFM. 

From CPC site

Quote

Assessing significance:
Significance of these �raw anomalies� composites are tested with a Monte Carlo test:

(a) A large number (800) of randomly generated composites are created for each season. The composites are created from randomly sampling the entire historical record (with replacement). The number of degrees of freedom remains consistent between the observed MJO composites and the randomly generated composites (for example, if there are 7 consecutive days in Phase 8 in the MJO composite than the random sampling will extract 7 consecutive days somewhere in the full record). 

(b) Significance maps are created by calculating the percent (%) of times the anomaly in the observed MJO composite is exceeded by the anomalies in the 800 randomly generated composites.

 

[showmethesnow]

19 minutes ago, WinterWxLuvr said:

What did the euro show?

There were a couple of gfs members that gave us a pretty good storm next week.

Nothing to speak of. Though if you squint real hard you could probably make a case for something right after day 10. 

[Bob Chill]

49 minutes ago, showmethesnow said:

Nothing to speak of. Though if you squint real hard you could probably make a case for something right after day 10. 

Euro control run blasts us pretty good d12. Good squint job. 

[heavy_wx]

19 minutes ago, MAG5035 said:

Agreed on Phase 8 significance... however don't those significance percentages work in reverse in effect? I was always under the impression that the significance maps reflected the percent of time that the actual anomalies exceeded the anomalies generated on the various three month maps for each phase. For instance you see less than 2.5% for the entire eastern seaboard on Phase 6.. a phase that is usually a surefire eastern torch if the MJO pulse has a reasonable magnitude. So I would interpret that as being very few times that the east had a below normal (or even normal) temperature pattern in that phase. If that's the case, I'm actually surprised at the amount of what would be uncertainty with phase 1&2 in JFM. 

From CPC site

 

Yeah I think you're correct; the significance they plot is the p-level significance, basically the probability that the composite anomaly over a particular region is just a coincidence in the data. So the 15-25% values over the mid-atlantic for the phase 8 composite suggests that there is a 15-25% chance that there is no connection between negative temperature anomalies and the MJO being in phase 8.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/readme.shtml

The widespread low significance values in those composites is a result of the complex interaction between the extratropics and the MJO. For one thing, the extratropical response to the MJO signal depends on the extratropical pattern itself. Rossby waves excited by the MJO can either destructively or constructively interfere with the longwave pattern, which could cause an existing pattern over North America to break down or strengthen.

For example, if you look at the 200 mb wind and height forecast from the GFS, you can see that the East-Asian jet is perturbed poleward, perhaps due to the forecast location of the MJO in phase 6-7 (central-western Pacific).

Downstream of the enhanced jet, you can see that trough south of the Aluetians amplifies; if you click through the rest of the run, you can then see the ridge amplifying over the west coast, before breaking and driving another trough into the Northeast. Of course throughout this extratropical pattern progression, the MJO continues to propagate eastward and excite Rossby waves poleward. I think the question for when the MJO propagates into phase 8 is how does it interact with the western Pacific jet and how does this interaction influence the downstream pattern.

[WinterWxLuvr]

7 minutes ago, heavy_wx said:

Yeah I think you're correct; the significance they plot is the p-level significance, basically the probability that the composite anomaly over a particular region is just a coincidence in the data. So the 15-25% values over the mid-atlantic for the phase 8 composite suggests that there is a 15-25% chance that there is no connection between negative temperature anomalies and the MJO being in phase 8.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/readme.shtml

The widespread low significance values in those composites is a result of the complex interaction between the extratropics and the MJO. For one thing, the extratropical response to the MJO signal depends on the extratropical pattern itself. Rossby waves excited by the MJO can either destructively or constructively interfere with the longwave pattern, which could cause an existing pattern over North America to break down or strengthen.

For example, if you look at the 200 mb wind and height forecast from the GFS, you can see that the East-Asian jet is perturbed poleward, perhaps due to the forecast location of the MJO in phase 6-7 (central-western Pacific).

Downstream of the enhanced jet, you can see that trough south of the Aluetians amplifies; if you click through the rest of the run, you can then see the ridge amplifying over the west coast, before breaking and driving another trough into the Northeast. Of course throughout this extratropical pattern progression, the MJO continues to propagate eastward and excite Rossby waves poleward. I think the question for when the MJO propagates into phase 8 is how does it interact with the western Pacific jet and how does this interaction influence the downstream pattern.

This is an awesome post.

My goodness, do we have knowledgeable people in here or what?

[WinterWxLuvr]

Not completely convinced next week is a done deal yet.

Separate that little chunk of energy coming down out west from the black hole over the ne, slow it down a hair, get it to dig a little and we might get the look of the ens members that pop a storm.

Did the eps have any members show a storm.

[mitchnick]

Too little,  too late, but it looks like the qbo has peaked per January's reading.

https://www.esrl.noaa.gov/psd/data/correlation/qbo.data

[Bob Chill]

26 minutes ago, WinterWxLuvr said:

Not completely convinced next week is a done deal yet.

Separate that little chunk of energy coming down out west from the black hole over the ne, slow it down a hair, get it to dig a little and we might get the look of the ens members that pop a storm.

Did the eps have any members show a storm.

EPS has been fading every run. Down to maybe 3-4 members showing anything worth talking about. It may not be a done deal but it's definitely pulled off the grill and resting under foil. 

[WinterWxLuvr]

1 minute ago, Bob Chill said:

EPS has been fading every run. Down to maybe 3-4 members showing anything worth talking about. It may not be a done deal but it's definitely pulled off the grill and resting under foil. 

You love to relate stuff to food and sports! I believe you and I could hang out and have a good time.

[NorthArlington101]

About half the EPS members lay a dusting down at DCA... almost all of them give some snow to somewhere in the area (NE MD) in the next 54 hours.

Maybe VDOT knows what its doing. 

[Bob Chill]

58 minutes ago, WinterWxLuvr said:

You love to relate stuff to food and sports! I believe you and I could hang out and have a good time.

Yep, food and sports go together like food and sports! I've been a basketball addict this year. Between the terps and wiz and random sweet ncaa matchups like the Baylor KU game I've been watching a game a night. We'd definitely get along. 

I'm not mad at the ridge/trough alignment and progression on the 18z gefs d10-13. We may have another window before things go downhill. Maybe we pull off a miracle next week before that but the trend has certainly not been friendly last few days. 

[CAPE]

5 minutes ago, losetoa6 said:

Enough Gefs members with the follow up wave to keep me watching. A good handful.

Yeah there are about 6 that look decent and a few more that have "something" close by, but pretty weak.

[paulythegun]

Too little,  too late, but it looks like the qbo has peaked per January's reading.

https://www.esrl.noaa.gov/psd/data/correlation/qbo.data

[Maestrobjwa]

34 minutes ago, paulythegun said:

 

 

So...Is it overly simplistic to say that the QBO has been the main problem?

[mitchnick]

18 minutes ago, Maestrobjwa said:

So...Is it overly simplistic to say that the QBO has been the main problem?

Yes. I'm certainly not saying that.

[Bob Chill]

12 minutes ago, mitchnick said:

Yes. I'm certainly not saying that.

Yea, let's be honest at this point. It's not just the QBO. It's the QBO, AO, NAO, PNA, EPO, ENSO, MJO, AMO, and Strat that have been against us.

The simplistic view is the WDI was due to give us a big FU. 

[kurtstack]

This winters WDI tells me we have a decent shot at hitting the inside straight draw on the river next week.

[Bob Chill]

I'm rooting for a snowless Siberia next October. I can accept 2 years in a row failing as an anomalous statistical fluke but 3? And the way Cohen has been doing his blog the last 3 years reminds me a little of JB's style. He can never come out and just call a huge bust what it is. The SAI is dead to me. 

[PDIII]

5 hours ago, heavy_wx said:

Yeah I think you're correct; the significance they plot is the p-level significance, basically the probability that the composite anomaly over a particular region is just a coincidence in the data. So the 15-25% values over the mid-atlantic for the phase 8 composite suggests that there is a 15-25% chance that there is no connection between negative temperature anomalies and the MJO being in phase 8.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/readme.shtml

The widespread low significance values in those composites is a result of the complex interaction between the extratropics and the MJO. For one thing, the extratropical response to the MJO signal depends on the extratropical pattern itself. Rossby waves excited by the MJO can either destructively or constructively interfere with the longwave pattern, which could cause an existing pattern over North America to break down or strengthen.

For example, if you look at the 200 mb wind and height forecast from the GFS, you can see that the East-Asian jet is perturbed poleward, perhaps due to the forecast location of the MJO in phase 6-7 (central-western Pacific).

Downstream of the enhanced jet, you can see that trough south of the Aluetians amplifies; if you click through the rest of the run, you can then see the ridge amplifying over the west coast, before breaking and driving another trough into the Northeast. Of course throughout this extratropical pattern progression, the MJO continues to propagate eastward and excite Rossby waves poleward. I think the question for when the MJO propagates into phase 8 is how does it interact with the western Pacific jet and how does this interaction influence the downstream pattern.

What is the mjo?

[WinterWxLuvr]

19 minutes ago, PDIII said:

What is the mjo?

Madden Julian Oscillation 

Plenty of research articles available.

[BTRWx]

7 hours ago, heavy_wx said:

Yeah I think you're correct; the significance they plot is the p-level significance, basically the probability that the composite anomaly over a particular region is just a coincidence in the data. So the 15-25% values over the mid-atlantic for the phase 8 composite suggests that there is a 15-25% chance that there is no connection between negative temperature anomalies and the MJO being in phase 8.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/readme.shtml

The widespread low significance values in those composites is a result of the complex interaction between the extratropics and the MJO. For one thing, the extratropical response to the MJO signal depends on the extratropical pattern itself. Rossby waves excited by the MJO can either destructively or constructively interfere with the longwave pattern, which could cause an existing pattern over North America to break down or strengthen.

For example, if you look at the 200 mb wind and height forecast from the GFS, you can see that the East-Asian jet is perturbed poleward, perhaps due to the forecast location of the MJO in phase 6-7 (central-western Pacific).

Downstream of the enhanced jet, you can see that trough south of the Aluetians amplifies; if you click through the rest of the run, you can then see the ridge amplifying over the west coast, before breaking and driving another trough into the Northeast. Of course throughout this extratropical pattern progression, the MJO continues to propagate eastward and excite Rossby waves poleward. I think the question for when the MJO propagates into phase 8 is how does it interact with the western Pacific jet and how does this interaction influence the downstream pattern.

Thanks for the technicalities! Anyone know what we want the 200mb heights to look like over the Pacific for favorable winter wx ioby?

[pasnownut]

1 hour ago, kurtstack said:

This winters WDI tells me we have a decent shot at hitting the inside straight draw on the river next week.

I'm still waitin on the turn.....

Nut

 

[Wonderdog]

Maybe, just maybe the 60 it's starting to bring back next weekend storm!

[showmethesnow]

For those that know no quit. That draw to the inside straight expecting to win. That go that extra mile even though their car is running on fumes. That put half their paycheck into the lottery saying this time I will win. That expect the winter of 16/17 to actually produce....

I SALUTE YOU! You are one of the few, the proud, and an absolute depraved masochist. 

That being said. Overnight runs still suck. According to the models the slim chances of a followup low Thur/Fri have gotten even slimmer. And any chances of a post day 10 storm are slipping away as both the GEFS and the EPS now seem to want to hold the energy back in the southwest instead of ejecting all or part of it eastward.

One positive note though. Phil says six more weeks of winter.