January 2019 Medium/Long Range Pattern Discussion

[John1122]

Virtually all current disco pertains to January at this point, so it's time to fire up the January pattern thread. The Euro weeklies say the potential is there. The cold Nov/cold January is a pretty consistent match. So game on as we move into the heart of winter in the valley. Which I consider our prime winter frame to be Jan 15th-Feb 15th. Our coldest temps and most snow will usually fall in that window. Let's hope the pattern gets right as we head towards prime time.

[John1122]

All the globals have some winter potential in about a week for the forum. The Euro is the most suppressed right now. The Canadian is the furthest North and west with wintery weather. The FV3 has a major ice storm and heavy snows in the South and far Eastern areas of the forum. The GFS is almost as suppressed at the Euro. Prefer to be NW of the modeled precip 90 percent of the time, but last year the deep south cashed in several times while we were too far N/W.

[tnweathernut]

Good posts, John.  I generally agree we need to keep an eye on the final piece of energy out of the gulf between 120-144.  It’s being picked up on all modeling and this is the type of system that will very likely end up northwest of modeling.  With the 850 line nearby, we (at least) are in the game for something wintry before transitioning to a new pattern.

[Carvers Gap]

Definitely going to be a test of the Weeklies....As noted before, the Weeklies have not been infallible for at least a couple of months.  They initially missed the eastern trough amplification in mid-November.   They have pushed back the upcoming cold by at least a week or two...may end up being even more.  I will give the Weeklies a pass in November as they are generally inconsistent during shoulder seasons.  Yesterday was a great set of model runs.  I am not, however, seeing a strong continuation of the positive trend today.  And that may be up for debate and is not unexpected.  I don't have the d10-15 EPS as WxBell's did not load last night....but the d15 that I did see was a bit of a change.  Now, to paraphrase Sutherland from a post that I quoted in the other thread.  We have an SSW, a potential pattern change as signaled by the MJO, and an SOI that reversed(in 48 course) some really good gains.  I noticed after scrolling through Twitter that the SOI has bounced strongly positive after a brief dip into negative territory.  It is now again in La Nina territory.  Now, obviously I don't think we are in a La Nina.  The never ending rain pattern IMBY tells me this is El Nino.  But, this index likely signals that there might be some La Nina characteristics to the upcoming pattern.  It might also signal that January's cold look on the Weeklies is not a slam dunk(also reference to Twitter...can't remember who posted it).  So with so many things "up in the air" (I know...ha ha) it is understandable that there is plenty of uncertainty as to how this unfolds.  So, I am just rolling with Nino climatology which is a backloaded winter.   I think the Weeklies might have been a tad quick...but I do like a transition timeframe of Jan 1-20 regarding an evolution to an ever increasingly cold pattern.   I would rate my confidence in the Weeklies cold look as low to moderate, only because the noted uncertainties above have not been resolved.  I think our best chance for winter is in the time frame that John mentioned above.  Anyway, just trying to add some balance to an excellent Weeklies run last night.  Hopefully, the EPS will again provide it some support.  The SOI referenced below is from the Long Paddock SOI dashboard.

 

[Carvers Gap]

I also agree that any time that we get a system tracking to our south that it needs to be watched....so I am on board with keeping an eye on that feature. 

[Carvers Gap]

Switching gears from LR to under 10 days...to echo tnweathernut and John, the 12z ICON and GFS do show wintery precip over the forum area around Jan 2.  The ICON is a paste job!

Edit:  GFS is quite a similar look to the ICON.

[Carvers Gap]

The 12z FV3 can be added to the mix for the Jan 2-3 potential.

[Holston_River_Rambler]

Here's 0z EPS H5 mean from last night (for longer term)

 

I don't think it looks too bad for a 10 day+ mean, especially toward the end.

Just thought about something for the SOI. I wonder if the SOI is being affected by the SSW. As I understand it, the SSW, aside from it's other effects, causes increasingly favorable conditions for tropical convection (thus MJO amp): 

 

Now, since the SOI involves measurement of pressures between Darwin and Tahiti and that is the region where the convection is now associated with the MJO, maybe once the convection/ MJO gets further east, the SOI will lower again?

[Holston_River_Rambler]

Here's the 12z UKMET for the Jan 3-5th storm at the end of it's run, hour 144.

Hopefully this leads us to fine 12z Euro run

 

[Carvers Gap]

Here is a excellent LR nugget that was shared w me that donsutherland posted in the NYC forum.  It talks about the rarity of the positive December SOI during a Nino event and what happened the following January(turned negative and had episodes of high latitude blocking).  Just another reason to like AmWx...

 

 

[Carvers Gap]

Here is a graphic from TT that shows the 48 hour trends of heights in the LR.  While I don't look at it for specifics at this range, I do look to see how various teleconnection regions are fairing in terms of trends.  Heights are dropping in Greenland and Alaskas while rising over much of the rest of NA.  Terribly difficult forecast time from during the mid-month w plenty of conflicting signals.  I think there is more chaos than normal in the system w the aspects discussed above.  While the teleconnection regions below are not trending well today, I might add that it is very common for models to bounce around before major changes in the atmospheric pattern both in NA and PV areas.  That said, I remain somewhat conflicted in that the 94-95 analog that I shared earlier this month has been a decent fit, though not perfect, in relation to the current warm-up structure.  Just throwing out various pieces of the puzzle this afternoon in hopes that maybe they can be fitted together in order to form some ideas about where the pattern may go after the first 1/3 of January.

[Holston_River_Rambler]

I decided to do some digging of my own into MJO/ SOI. Tried copying my MS Word doc, but apparently it just ends up as an image Figured it out:

I was wondering how rare it is to have this sort of MJO amplitude/ SOI forecast in a Nino, so I went through and looked at the times in El Nino conditions (1974 – present accessed from BOM dataset) winters (defined for me as Dec – March) when the MJO amplified above 2.0 in phases 5/6, with the assumption that it would tell me when convection was as intense in phase 5/6 tropical areas as it is now and then maybe offer some insight into where we are going. I added SOI for comparison. 

 

I’m sure I missed some dates and the BOM dataset of MJO only goes back to 1974, but for fun here is a quick list.

 

Months/ years with + ENSO conditions as defined by CPC which also had 2.0 or higher amplitude of MJO in phase 5 or 6. All SOI numbers are monthly and taken from Long Paddock SOI site:

 

Dec 1976 (SOI = -20.0)

Feb 1978 (not technically still a Nino, but the last 3 month period was. ENSO was transitioning to Nina; SOI = -26.90)

Dec 1987 (SOI = -1.5)

Feb 1988 (really amped up from 6 through phases 7-8-1; SOI: - 6.2)

March 1995 (SOI : +1.10)

Feb 2005 (SOI: -28.68)

Dec 2014 (SOI: -5.77)

Jan 2015 (highest sustained amplitude over the course of a week or so of all years I looked at in mid winter) (2.95; SOI= -7.80)

March 2015 (3.13, highest overall amplitude in any part of winter months; SOI -11.28)

Dec 2015 (SOI = -5.77)

Feb 2016 (SOI = -19.27)

 

Some overall thoughts: The MJO just doesn’t get to an amplitude of > 3.0 in phases 5/6 in Ninos outside of March in the years I looked at. I suspect this is tied to the typical breakdown of the SPV and the Brewer-Dobson circulation plus seasonal enhancement of tropical convection in the places it is enhancing it now. Looking beyond Nino years, Nina years are, 90% of the time, favored for high amplitude phase 5 or 6. I should also add that in the Nino months/ years above (outside of 2015), just getting the phase 5/6 MJO above around 2.1 was really, really rare. Most of the months/ years above were 1.9-2.1.

 

I was also going to compare this to SSWEs (to see if the Brewer-Dobson circ. Mentioned above contributed to high MJO values) but with the gov’t shutdown, those lists are unavailable.  

 

Seems to me some of the strat. damage may already be done, no matter what outcome of the actual SPV, in the tropical convection it is aiding. If the MJO gets to phase 6 in early January, in even a > 2.5 amplitude, we will be in some pretty unique territory. 

 

[Holston_River_Rambler]

Euro looks ok for 6 days out for the Jan. 3-5th storm (in that it is still there), but for this run anyway, just not enough cold air outside of elevation for most of TN. For any Arkansas folks who may be around though: https://imgur.com/a/2Xgulse 

[BullCityWx]

1 hour ago, Holston_River_Rambler said:

Euro looks ok for 6 days out for the Jan. 3-5th storm (in that it is still there), but for this run anyway, just not enough cold air outside of elevation for most of TN. For any Arkansas folks who may be around though: https://imgur.com/a/2Xgulse 

Yeah, Little Rock got pasted

[Will (little rock)]

1 hour ago, Holston_River_Rambler said:

Euro looks ok for 6 days out for the Jan. 3-5th storm (in that it is still there), but for this run anyway, just not enough cold air outside of elevation for most of TN. For any Arkansas folks who may be around though: https://imgur.com/a/2Xgulse 

lock it in! LOL

[John1122]

November 84 was -3.5

December 84 was +9 after being cold/snowy early in the month, temps warmed significantly to close the month (sound familiar?)

January 85 was warm the first couple of days. Then the bottom fell out the rest of the month. 

84-85 was a weak La Nina. But the atmosphere in some respects, as Carves has pointed out, is acting like a weak La Nina right now.

There was a SSW in mid to late December 1984. (December is early for SSW events to happen) This led to the January of 85 cold waves that lasted for just over a month.

I don't know that we will get anything remotely like 1985, but there are similarities this year. The fact that the PV is being disturbed so early is a potentially very good scenario.

 

[Holston_River_Rambler]

One thing that has been interesting about the Jan 3-5 potential storm is the tropical connection it may have.

I know. More precip. Who'd a thunk it?  

But there is an unusual upper cutoff low east of Hawaii that looks like it is going to transport maybe even more moisture than normal up from the Eastern Pacific:

 

 

[Carvers Gap]

Quick thoughts on the afternoon's EPS runs.   The control gets west TN twice w snow I think...very Nina-esque and similar to last winter's tracks.  The EPS would imply that week two on the Weeklies is a bust if the EPS verifies.  The 12z EPS is seasonal to slightly AN, and again pushes back the cold to the very last two days of its run.  One positive is that at the end of the run the EPS does plop that trough in the East in what looks like a stable, non-transient look.  Maybe the Weeklies were just a bit too quick?  Of note, there were a handful of tracks that support snow in western areas.  Overall, the EPS did not look as poorly as the 12z GEFS did.  One final note, the EPS control did have some similarities to the Weeklies last night as it developed a huge eastern trough late in the run with a legit Arctic outbreak.  So, I think today's ensemble runs probably tell us to pump the breaks on a quick, sustained return to cold(but not to give up on it either)....but leave the door open for cold later on.  But I will say, there are two things that nag at me on this...when cold keeps getting pushed back, there are reasons for that.   The other is that 94-95 analog.  While there are plenty of great, notable winters that did not begin until after Jan 15, there are plenty of winters that were also ho-hum.  I still like my original winter ideas of a slightly AN Dec, normalish January, and BN February for temps.  I had slightly AN for snow.  I still like that as well, though NE TN has a shot to exceed even that prediction.  I know it sounds a bit counterintuitive, but the MJO is a real headache right now.  Where it has gone high amplitude into warm phases is going to make it tough to reset winter, and that is assuming that it does not rotate back through there any time soon.  My gut tells me that we will like where we are by late January, but it will take some time to get there.  I can also see a scenario where the Weeklies are indeed correct if the strat split happens in a clean enough manner where it induces blocking.

[Carvers Gap]

Just now, Holston_River_Rambler said:

One thing that has been interesting about the Jan 3-5 potential storm is the tropical connection it may have.

I know. More precip. Who'd a thunk it?  

But there is an unusual upper cutoff low east of Hawaii that looks like it is going to transport maybe even more moisture than normal up from the Eastern Pacific:

 

 

Very similar to the early December event, but warmer.  Basically points a firehose at the southern Apps.

[Carvers Gap]

2 minutes ago, Holston_River_Rambler said:

One thing that has been interesting about the Jan 3-5 potential storm is the tropical connection it may have.

I know. More precip. Who'd a thunk it?  

But there is an unusual upper cutoff low east of Hawaii that looks like it is going to transport maybe even more moisture than normal up from the Eastern Pacific:

 

 

Speaking of the early December storm, the 18z GFS takes a similar track.  

[Carvers Gap]

I think for now, I am taking a break this weekend from the LR analysis until this straightens out a bit.  I think there are so many variables and moving parts, it is a mess.  If forced to make a call for January I would go w slightly BN temps(choosing BN partly due to the Weeklies and mostly due to deference to John's Nov/Jan correlation research).  But there is plenty of room for that to bust high or low w the MJO being a potential thorn or power-up.  Oddly, January sort of has the same feel as this past November.  We may get a warm start, but there is room for those early AN departures to be erased.  Also, it has the same feel as last February when it took the actual occurrence of the strat split before things shook loose into a discernible pattern.   Going to enjoy some CFB playoffs this weekend and keep an eye on the Jan 2-3 feature and the potential strat split.  

 

[BNAwx]

Like most here, I think the models in general are struggling at long-leads due to the uncertainty on two pretty big factors.  MJO progression and the SSW event.  It' simply going to take a while longer to get a clearer picture of what is going to transpire as we get into what I consider to be the "peak" of winter which is roughly January 15th - February 15th.  Simply looking at the MJO progression, perhaps it's best to pick a blend of the Euro and GFS at this point.  I'm not sure.  If that's the case, I do think we'll have a 3 to 4 weeks stretch of true winter with several opportunities to cash in.  If the SSW pans out favorably and leads to more sustained blocking, maybe this back-loaded el nino will be one to remember.   I guess patience is the moral of the story...

[jaxjagman]

29 minutes ago, BNAwx said:

Like most here, I think the models in general are struggling at long-leads due to the uncertainty on two pretty big factors.  MJO progression and the SSW event.  It' simply going to take a while longer to get a clearer picture of what is going to transpire as we get into what I consider to be the "peak" of winter which is roughly January 15th - February 15th.  Simply looking at the MJO progression, perhaps it's best to pick a blend of the Euro and GFS at this point.  I'm not sure.  If that's the case, I do think we'll have a 3 to 4 weeks stretch of true winter with several opportunities to cash in.  If the SSW pans out favorably and leads to more sustained blocking, maybe this back-loaded el nino will be one to remember.   I guess patience is the moral of the story...

GEFS has been to amped with the MJO,but like you mentioned the best thing is to use a blend.It's possible the euro could be more right than wrong.Take the CFS out the MJO looks stronger than the Euro into week2 of Jan and beyond that the MJO could be suppressed WEST of the IDL and more active east of the IDL later on,even into wk 3

[jaxjagman]

The euro looks alot better compared to last night,the daughter on our side looks much colder than last night

[jaxjagman]

Just saying compared to yesterday the daughter on our side looks much better than yesterday using the 5th of Jan

[Holston_River_Rambler]

Overnight Euro/ EPS weren't kind to the Jan 3 storm for central/ eastern areas. Even though the 500 mb mean looks ok, the individual MSLPs look yucky for middle and eastern areas: https://imgur.com/a/lyVsSZM. Far western areas, especially Arkansas, are still in the game even if the more amped/ NW trend continues. 

Everything else, except the ICON and UKMET, is still further south, so there's some hope for more of us.  I have seen the Euro do this then back off, but the opposite has also happened. I've always thought this one was more of a cutting danger than suppression, but you never know. The overall trend over the past few runs has been slower and more amped, so I guess we hope for a well timed N. Stream wave to help try and suppress it as much as possible. If it can slow down so much that it misses the first suppressive wave, maybe it can eventually slow down enough to be influenced by another? If we get a low-road-taking, rolling cutoff, January's got to be good for dynamic cooling...............right? 

On the bright side the Euro gives me 2-3 more inches of rain over the next from the Jan 3 storm, so my dream of kayaking downtown may come true! 

 

 

[Carvers Gap]

13 hours ago, Carvers Gap said:

I think for now, I am taking a break this weekend from the LR analysis until this straightens out a bit.  I think there are so many variables and moving parts, it is a mess.  If forced to make a call for January I would go w slightly BN temps(choosing BN partly due to the Weeklies and mostly due to deference to John's Nov/Jan correlation research).  But there is plenty of room for that to bust high or low w the MJO being a potential thorn or power-up.  Oddly, January sort of has the same feel as this past November.  We may get a warm start, but there is room for those early AN departures to be erased.  Also, it has the same feel as last February when it took the actual occurrence of the strat split before things shook loose into a discernible pattern.   Going to enjoy some CFB playoffs this weekend and keep an eye on the Jan 2-3 feature and the potential strat split.  

 

Not going to add much other than overnight/AM models doubled down on warmth through mid-month.  I will possibly adjust my Jan call back to my original “normal-ish.”   Going to wait a couple of days in order to see if some sort of trough amplification is being missed.  If I update, will likely do so on New Year’s Eve.  Happy football day!  May have to talk some football in banter...

[Carvers Gap]

I think we go somewhat AN for the first part of Jan...but I am waiting until Monday for a final call.  The second half of January could finish very cold, especially that last week.  Makes it especially tough to make a call.  While the models look toasty through mid-month, there is reason to believe that the there might be a terminus to that anomalous warmth during week three. (again, I am always cautious of the cold being pushed back...but it is winter and the cold will likely return at some point)  Read this and you will see why.  Awesome post.  

 

[Holston_River_Rambler]

Amazing how different the Euro and GFS/ Fv3 are with the evolution of the Jan 3rd system. GFS just keeps getting more suppressed and Euro holds onto a bowling ball upper low. I do think the 12z Euro caved a tiny amount toward a less amped solution, but only insomuch that it made the bowling ball roll more east to west than WSW to ENE. Big difference seems to be how they handle a shortwave in the northern stream. Euro progresses it more E-W and GFS drops in down and suppresses and strings out the energy in the southwest as it ejects. Key piece of N. stream energy is going to get slung at us from the big gyre in the N pacific like the Enterprise trying to time travel by using the sun's gravity. It will be blazing down the lee side of the Canadian rockies sometime Monday, so likely more changes ahead. 

EPS looked a little better for central and east TN, but looking at all the members, that just means we are in the 1-2 inch shade on about 1/3 of the members, rather than the no snow shade. As of now Euro holds serve for Arkansas folk, but favors areas NW of Little Rock. 

Throwing this in just for the imagery of how big the N. Pacific thingy is that will be slinging that piece our way: 

 

[PowellVolz]

I’m sure it will change but January isn’t looking good for at least the first half.


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