December Pattern Disco- 2013

[weathafella]

It will do a Tippy constructive and destructive interference. Yeah, it could enhance the signal near the dateline down the road. The basic idea is that the RMM graphics will sort of falsely think the MJO is in one spot when it's just the CCKW enhancing convection and then once that leaves..all of the sudden the RMM progs change in a matter of a few days. So, the RMM progs may do a bad job at MJO forecasting.

So the false signal will mess up a lot of what we look towards such as the weeklies right?

[CoastalWx]

So the false signal will mess up a lot of what we look towards such as the weeklies right?

 

Well the ECMWF stuff seems to do the better of all guidance. I wouldn't always look at it and treat it as being wrong...it's just that the signal will get muddled. One of the parameters in measuring MJO activity is outgoing long wave radiation with the idea being the more convection you have..the more radiation bounced back from the clouds. These disturbances called convectively coupled Kelvin waves that are not MJO related can cause convection and sometimes these MJO charts will falsely think this enhancement of outgoing longwave radiation is the MJO when it's really not. I certainly don't fully comprehend all this CCKW and MJO stuff, but I do know that..lol.

[toronto blizzard]

Well the ECMWF stuff seems to do the better of all guidance. I wouldn't always look at it and treat it as being wrong...it's just that the signal will get muddled. One of the parameters in measuring MJO activity is outgoing long wave radiation with the idea being the more convection you have..the more radiation bounced back from the clouds. These disturbances called convectively coupled Kelvin waves that are not MJO related can cause convection and sometimes these MJO charts will falsely think this enhancement of outgoing longwave radiation is the MJO when it's really not. I certainly don't fully comprehend all this CCKW and MJO stuff, but I do know that..lol.

So the idea of Retrogression to the pattern is still not set in stone?

[CoastalWx]

So the idea of Retrogression to the pattern is still not set in stone?

 

No, but it is possible. There are still signs of that.

[Clinch Leatherwood]

It'll be interesting to see which direction this goes:

 

Cohen says warmer by mid-month/holidays.

Those relying on the ensembles/weeklies are looking at a much more favorable pattern. 

 

Two totally different approaches, one that looks more at what's already occured in how it influences upcoming weather and one that relies on computer forecasts of what's to come compared to previous known patterns.  Chaos FTW?

[CoastalWx]

It'll be interesting to see which direction this goes:

 

Cohen says warmer by mid-month/holidays.

Those relying on the ensembles/weeklies are looking at a much more favorable pattern. 

 

Two totally different approaches, one that looks more at what's already occured in how it influences upcoming weather and one that relies on computer forecasts of what's to come compared to previous known patterns.  Chaos FTW?

 

Well actually some models try to bring in warmer wx mid month which is what he probably looked at.  Chances are if we have a cold two week period..it may relax anyways, but Siberian snow cover is not going to give you those details of weekly patterns.

[CoastalWx]

That gyre of low pressure and some subtle height rises may try to keep heights lower over the east next week. The pinwheel of low pressure off the Atlantic will have a say.

[KEITH L.I]

Well actually some models try to bring in warmer wx mid month which is what he probably looked at.  Chances are if we have a cold two week period..it may relax anyways, but Siberian snow cover is not going to give you those details of weekly patterns.

He also said late November would be warm along with many other Mets at the beginning of the month..There is really know way to know after a few weeks,basically it's all guessing..A few days ago..Monday Tuesday of next week were supposed to be warm..doesn't look that way now

[Tropopause_Fold]

That gyre of low pressure and some subtle height rises may try to keep heights lower over the east next week. The pinwheel of low pressure off the Atlantic will have a say.

yeah maybe it ends up as a rather short-lived mild period as heights rise late week. difficult to say but it's trending that way. doesn't look overly "cold" early in the week but even the GFS now is significantly cooler. 

[Damage In Tolland]

I just called..to say..I love you.

 

Next week even yetserday was showing signs of not being that mild..cold air to north is powerful

[N. OF PIKE]

I just called..to say..I love you.

Next week even yetserday was showing signs of not being that mild..cold air to north is powerful

Go bliz go

[CoastalWx]

I just called..to say..I love you.

 

Next week even yetserday was showing signs of not being that mild..cold air to north is powerful

 

Well the reason isn't what you are inferring. Thank the cluster you know what in the western Atlantic. Also, the trough out west is slower to dig, thus s/w in the Plains can dig some more over the east. Also, offshore low is closer to the coast. It's still a rather bland look, but we have time to swing either way.

[Damage In Tolland]

Go bliz go

Someone told me that dreams can come true..they can happen to you.

 

Well i guess they just might

[CoastalWx]

Someone told me that dreams can come true..they can happen to you.

 

Well i guess they just might

 

I wouldn't spike the ball..lots to be worked out.

[Damage In Tolland]

I wouldn't spike the ball..lots to be worked out.

Guess and just might don't sound like balls spiking

[CoastalWx]

The "cheap" cold is something we talked about. A 6" storm would be hard to come by.

[Typhoon Tip]

As long as the EPO domain remains negative (and apparently more so in magnitude than the other teleconnectors are opposing...) it would be a bad course to predicted any period of warming for our latitude that goes beyond briefer interludes.   May not be excessively cold, either... but there's likely to be lower tropopsheric interference exerted from the N.

 

The baser flow construct as the higher latitude deep layer flow circumvents the ridge node up in and around Alaska puts confluence in the mean in central-E Canada, and that means tendencies for +PP astride the Can/U.S. border.  

 

Yes there can and in this case probably will be some at least modest positive geopotential heights in the SE U.S. (+NAO notwithstanding...) but these polar high tendencies over a rich Canadian snow anomaly, being back built in the mid levels by -EPO -related cold continental conveyor is highly likely to cause cool thicknesses to cleave under the westerlies, and make it colder relative to what the heights may look like at any given time. 

 

Having said that ... -EPO is your only hope.  The other teleconnectors really put the acrimony on winter weather enthusiasts with panache. ...at least for the time being.  Things may change with those toward mid December.  But,  we observed recent neutralized PNA, now going forward it settles back into -2SD -type anomaly.  The NAO is sort of weakly committed to being positive, and the AO appears destined to another 10 days where it exceeds +2SD.  Basically, without the aforementioned -EPO influence?  We'd be talking an extended Indian Summer complex until further notice with these other teleconnector layout.   And there is no guarantee (if you want "snow" specifically...) that the -EPO would serve as the elixir.  The trouble is, look at today's event.  It's snowing in western NC while Boston gets to be butt-sore at 63F.   'Course, today was all about "threading the needle," as some like to call it, so perhaps we merely missed the eye -- better luck next time.   And ... it does seem somewhat paradoxical to the discussion above, that the -EPO could not supply enough confluence this time to create some blocking that might have helped a wintry cause.  However, if you observe the various models initialization presently we notice the the EPO domain is bit relaxed -- westerly shifted as well ... That's not the same thing as what this looks like in the D8-10 mean from PSU:  

 

  

 

Granted ... the appeal over eastern Canada leaves much to be desired ... But the dominating features are really the ginormous ridge in the Alaska air space, and it's giant negative couplet down stream over western N/A.   Ooh rah for the Rockies and glacier production!   But, despite that eastern Canadian odd-ball quasi Red Block set up, that's not really conducive overall to flaming hopes for early season winter fair.   In fact, operaionally, there is contention in the Euro and GFS re the beginning of next week.

 

The Euro wants to make a discerned coastal out of it; whereas the GFS is laboring through what bears some semblance to Norlun sort of set up/potential.   The Euro is slightly too warm in the critical thickness.  The GFS is cold enough.  It's beyond D5 so one would be unwise to hang their hats on the Euro.  Contrasting, the GFS' native progressivity bias should give one pause when observing how it runs the westerlies so far out into the west Atlantic before curving back north.  The ensemble mean of both is probably the course of least regret, and given to aforementioned reasons to suspect there could be more cold around, it may not be completely hopeless for wintry aspects to the Mon-Wed time frame.   

[CoastalWx]

 Agree John, we'll have to watch if that ridge retros because that would not be a good thing. At all. However for now I haven't noticed a distinguished trend in a westward movement so that's good. In fact, everything I see shows the ridge more or less staying put. Little wobbles and nuances witht he SE ridge are going to play havoc with models, but we won't see that on an ensemble mean...only can infer what the consequences are and let people know the stakes are high. But, I do like the overall look from afar. Will it mean 3" or 30" of snow..I don't know..but I'd take the look as is.

[radarman]

As long as the EPO domain remains negative ..

 

Really good post

[Heisy]

Does EURO show a snowstorm today for Day 6-7? The GGEM was close, seems the models trended colder. 850's look good, not sure about surface & precip on EURO. 

[Snow_Miser]

Does EURO show a snowstorm today for Day 6-7? The GGEM was close, seems the models trended colder. 850's look good, not sure about surface & precip on EURO. 

 

Looks like a moderate snowstorm for Eastern New England on the Euro. 

[Damage In Tolland]

Seems like pieces are falling into place

 

 

Joe Bastardi ‏@BigJoeBastardi18s

ECWMF continues to insist on ne snow/cold in 6-10 says no above normal ne and the arctic hound on way w to e week 2 pic.twitter.com/dV79jtMHUK

[8611Blizz]

Noyes seems to be onboard.

Matt Noyes: Broadcast Meteorologist

NECN set up an hour of Twitter questions & answers with me from 10-11 AM. One of the more common questions: What does the winter look like/when can we expect snow? Seasonal forecasts from even the experts who've devoted their lives to seasonal prediction run only slightly better than a coin toss in the Northeast, so take it all with a grain of salt...but what I can reliably tell you is the nation has been seeing big storms last few weeks. Many areas have seen big snow, not most of New England...so far. That won't last in this pattern. After the incoming cold shot Thanksgiving through the weekend, Sunday to Tuesday is a bit unsettled - a mix of raindrops/snowflakes - with showers of rain/snow Sunday to Tuesday part of a transition to warmer-than-normal temps middle/end of next week. By *next* weekend, I expect next shot of cold to be ready for New England, back to colder than normal pattern we'll go. As a jet stream trough sets up near the Great Lakes mid-December, the potential for cold and storms goes up, which equates to a higher than normal snow potential. In short, the atmosphere is giving plenty of signals it's ready to get the Northeast US winter party started early on this year.

[Tropopause_Fold]

12z ensembles are pretty tasty. as soon as things start to flatten over the aleutians you see more ridging start to build back. pretty consistent signal too that the core of the PV is going to park itself in Canada.

 

and kevin gets a bit of holiday-wish-come-true-but-it-doesn't-really-matter as next week's mild up is looking fairly unimpressive. We may get a brief "torch" if the LP coming out of the plains in response to the trough out west really goes to town...but trend, at least as of today, would be to flatten that a bit. 

 

then it's off to the races perhaps?

[ORH_wxman]

12z ensembles are pretty tasty. as soon as things start to flatten over the aleutians you see more ridging start to build back. pretty consistent signal too that the core of the PV is going to park itself in Canada.

 

and kevin gets a bit of holiday-wish-come-true-but-it-doesn't-really-matter as next week's mild up is looking fairly unimpressive. We may get a brief "torch" if the LP coming out of the plains in response to the trough out west really goes to town...but trend, at least as of today, would be to flatten that a bit. 

 

then it's off to the races perhaps?

 

 

Yeah behind the potential cutter looks to set us up pretty nice. Its a very classic SWFE gradient setup for us with the +NAO and the cold dump via EPO/WPO. Obviously no guarantees and each pattern has nuances. But I'd think we'll have some opportunities.

[CoastalWx]

Looks good to me. That is a strong signal for a ridge that potent so far out.

[ORH_wxman]

Stilla nice gradient setting up for the 2nd week of December on the ensembles. Even week 1 has gotten colder...the mild temps are really just confined to a day or so ahead of the potential storm system on 12/6.

 

Ensembles guidance has the EPO ridge breaking down around Dec 10th but reloading to the west as more of a WPO ridge (quite amped at that too)...which will threaten a bit warmer beyond mid-month, but the gradient theme is still there as long as the cross polar flow is.

[CoastalWx]

Stilla nice gradient setting up for the 2nd week of December on the ensembles. Even week 1 has gotten colder...the mild temps are really just confined to a day or so ahead of the potential storm system on 12/6.

 

Ensembles guidance has the EPO ridge breaking down around Dec 10th but reloading to the west as more of a WPO ridge (quite amped at that too)...which will threaten a bit warmer beyond mid-month, but the gradient theme is still there as long as the cross polar flow is.

 

The euro ensembles were actually a bit weaker with the SE ridge this go aorund, but obviosuly the intensity will probably wax and wane a bit with each run. That ridge is real amped up, hopefully it holds into mid month because I do think we will threaten to turn a bit milder, but as you say........I think we'd be ok if the ridge remained strong.

[Damage In Tolland]

Chilly week next week as some circles surmised. Let's hope the coastal can get us with a nice hit

[CoastalWx]

Chilly week next week as some circles surmised. Let's hope the coastal can get us with a nice hit

 

It's still going to be a bit mild late week. That cluster fook in the Atlantic is helping to keep heights lower  Mondaya and Tuesday with the storm threat. Actually, if that moves OTS, it may be milder like models had a few days ago.