November Long Range Disco

[Cobalt]

e3 

 

[Cobalt]

I would take this mean any day for November

 

It's a good start 

[mattie g]

4 hours ago, leesburg 04 said:

Ian is laughing

Who is that? And why should we care that s/he’s laughing?

[HKY1894]

AAM forecast to drop big time in the long range

[BristowWx]

9 hours ago, HKY1894 said:

AAM forecast to drop big time in the long range

I had to look this one up atmospheric angular momentum.  I have no idea what it means for us or if it’s good or badI

[eurojosh]

9 hours ago, HKY1894 said:

AAM forecast to drop big time in the long range

 

Had to look that one up! So, a drop in stage 2. Per Noaa ESRL:

The four primary phases of the GWO are described below, along with generally cold season (November-March) probable weather impacts for the USA. The GWO recurrence interval, or "time it takes to make a circuit", ranges from a broad 15-80 days. Two of the stages project strongly on El Nino and La Nina circulation states, which are also characterized by positive (Stage 3 below) and negative (Stage 1 below) global AAM anomalies, respectively.  Stages 2 and 4 are transitional. 

 

Stage 1 (La-Nina like) – the global relative AAM anomaly is negative. The negative anomaly is primarily due to easterly upper level wind anomalies that extend from the Eastern Hemisphere tropics to the Western Hemisphere mid-latitudes. A retracted Pacific Ocean jet stream is a key feature in the total field.  Troughs are probable across the western USA with a ridge over the southeast.  High impact weather is favored across the Plains.

 

Stage 2 – the global relative AAM tendency is positive. This means that negative AAM is being removed from the atmosphere by surface friction and mountains. At the same time, westerly wind anomalies are intensifying in equatorial regions of the Western Hemisphere. Fast Rossby wave dispersion events in both hemispheres are a coherent feature of this stage and Stage 4.  A cold regime is probable across the central USA.

 

Stage 3 (El-Nino like) – the global relative AAM anomaly is positive. Westerly wind anomalies move into the Eastern Hemisphere, broaden in latitudinal extent and link up with deep westerly flow anomalies over the mid-latitude Western Hemisphere. An extended Pacific Ocean jet stream and southward shifted storm track is observed  favoring high impact weather events along the USA west coast.

 

Stage 4 – the global relative AAM tendency is negative. Positive (westerly) AAM anomalies are being removed by surface friction in the Western Hemisphere mid-latitudes and through mountain torques across the Northern Hemisphere topography. The next phase of the oscillation (if there is one) is represented by easterly wind anomalies intensifying over equatorial regions of the Western Hemisphere. This stage has enhanced subtropical jets and closed lows in the subtropics favoring rainfall events over the southwestern USA.

 

[showmethesnow]

On 11/10/2017 at 6:25 AM, showmethesnow said:

The overnight run of the GEFs doesn't look as enticing as earlier runs. Has weakened and shifted north somewhat on the blocking over top earlier on so we are seeing a shifting of the better potential to the north and east towards NY/NE in the earlier part of our window (roughly day 9-12). The look is suggestive of possible clipper/lake effect flurries/squalls for our region, temps cooperating of course. Post day 12-16 sees it dropping the better potential back into our general region and the placement is probably a little better then what we were seeing previously and actually is a good look. EPS for the most part keeps the better potential to our north and east throughout the long range. Gem is in pretty good agreement with the GEFS.

Just one run of the models, at range no less, so I probably wouldn't take it to heart. We are probably going to see fluctuations with the exact placement and strength of the blocking over the coming days which will be the driving force behind the exact placement of the best potential.

Looks as if there may be a wild card thrown in as well in the longer range especially after day 16. Mentioned a week or two ago I thought we would see a flip between the Aleutian ridging and the Alaskan/GOA trough. Models have been hinting on and off for the last couple of days that this may be the case. But the last couple of runs of the GEFS and GEM actually start the process in the longer range. EPS isn't quite there yet but it also is showing some signs as well. If indeed this occurs it would be an somewhat exciting look if we can keep the blocking over top as well. I will say that quite often times that the models try to rush these changes so it would not be surprising to see this delayed somewhat.

Note: The following is just for fun so take it with a grain of salt.

Purely speculation on my part on what would happen if we see a flip but would not be surprised if we see a brief surge (3-4 day) of warm Pacific air overrun the CONUS as well as a temporary breakdown of the -NAO through the process. During the NAO breakdown there would be a good chance we also see a strong east coast storm/noreaster as well. The brief surge of warm air would then be driven out of the CONUS (except for the west, especially the southwest) as we see a surge of well below normal temps dive down into the west/central US progressing towards the east coast. As the warm air is being driven out on the east coast we would then probably see a corresponding re-surging of the -NAO. After that it would hopefully be game on as we move into December.

After looking over the overnight run of the GFS op I thought I would revisit the above. The run matches my thoughts pretty closely on what we might expect to see during a NPAC flip.

-----------------------------------------------------

Below I have posted Day 4+ because it is a good representation of what we have been dealing with in the NPAC. The blue circle below (GOA/Alaska/Pacific NW) is where we have been/will deal with a trough and the continuous energy rotating through that region. Now normally you do not want to see this for hopes of cold and snow in the east. But with the blocking we will see you can skate by this setup all dependent on where that energy rotating through is located at any particular time. But for all general purposes we want that trough feature gone from that location. Now looking just to the right of the blue circle we see earlier energy that has already rotated through and what it has done is knock down the ridging we were seeing in the western US. Again, that is not what we want to see.

Now one other feature (red circle) I want to point out is the strong ridging we see through the Aleutians. This has been a permanent feature for a month, month and a half and was induced by the massive disruptions we saw occurring with the PAC jet as I have mentioned earlier. Now this feature had excellent timing showing up when it did because it is having a huge impact on the winter pattern setting up. It injected large amounts of heat into the upper latitudes which in turn is probably why we are now seeing blocking (-NAO) showing up as well as a disturbed PV (-AO). But now we want it gone. It has served its purpose at helping to establish the winter time pattern (at least for the first half of winter) and now is only becoming a hindrance to our snow chances in the region. What it is now effectively doing is to create a block for the trough (blue circle) as well as to amplify that trough. So we want it to go Kaput at this time. 

 

 

Now below at day 9. We once again see the trough located generally in the GOA with the ridging to its west (red circle) though it has weakened quite a bit from the previous image. The reason I am showing day 9 though is to show the strong ridging we are now seeing in the west (from Mexico to N Canada) which is playing a part in what looks to be a NPAC flip. Now this gets beaten back down somewhat as the trough can't be forced westward because of the ridging to its west so it attacks this west coast ridging. But in the process of all of this the trough does weaken the ridging to its west as it does make an attempt  to move in that direction.

Also wanted to point out the -NAO (red circle over Greenland). At this time we are seeing an extremely strong -NAO but from this point forward we see a rapid breakdown of it as it looks to move to a strong + phase. I bring this up because that is something I expected to see as the NPAC flipped. One other thing I favor on seeing is a strong coastal showing up shortly after this time period as the NAO breaks down and transitions over. As most probably already know this transitional period quite often features strong coastals especially when you see such a drastic flip in the NAO state. And for what it's worth we have been seeing some indications of a coastal in the longer ranges for a couple of days now. Now how that could possibly impact our area (rain, snow, nothing), if one does actually show up, God only knows at this point. Just too far out to guess and it would be fighting climo to boot.

 

 

Below we have day 16 which looks to be in the process of showing the flip in the NPAC from a Aleutian ridge and GOA trough to an Aleutian trough and ridging up the west coast into northern Canada and into Alaska (+PNA). This is what we want for our snow chances in our region. As you notice the trough and associated lower pressures (blue circle) have shifted westward towards the Aleutians. We also see a total breakdown of the very strong persistent ridging to it's west that we have seen since October. Now we also see a re-surging of the ridging in the west (red arrow). As this ridging builds and strengthens into Alaska (post day 16) we will see the trough continue to be forced westward into the Aleutians as it is now no longer being blocked by the ridging to its west.

Two other things I want to point out. Notice the difference we now see in the NAO region (blue circle). We went from a strong -NAO at day 9 to a strong +NAO at day 16. And for those freaking out about losing the NAO. I probably wouldn't. Chances are very good we see this get reestablished in short order. Also notice the red circle (that should actually be shifted south, I put it to far north on the map below), we are seeing a large expanse off of the Mexico and the southwest coast of strong warm SST anomalies. These anomalies have been building over the last few weeks and I think they argue strongly for us to see strong ridging in the west. ***(Quick note while I am thinking about it: The PAC jet is also hinting, fairly strongly now, that we have a change in the NPAC coming up)***

 

 

 

Wanted to show some features temp wise as we see this transition get under way. Notice at day 12 we see  neg temp anoms in the GOA as well as Alaska (two blue circles). We also see warm anomalies to their east (red circle) in western Canada. We also see 2/3'rds of the CONUS engulfed by well below normal temps (blue circle). Now watch what happens to the temp anomalies during the ongoing flip. 

 

 

4 days later from the above map and we see some changes. The temp anomalies have now shifted west in the NPAC. We now see warm anomalies in the GOA and Alaska with the cold anoms now to the west into the Aleutians. We want this (When Alaska sees warm and rain quite often times the east coast sees cold and snow). This is the signature of ridging into Alaska with the trough to its west. Now I also mentioned that during a flip I thought we would see the CONUS get flooded with warm PAC air. And that is actually what we are seeing (bottom red circle) and compare to what we were seeing just 4 days earlier.

Now some of you may freak out when you see all the warmth in Canada and the CONUS on this map. DON"T. What we are seeing in this setup is a cross polar flow getting established that will begin to shortly dump the cold (brrrrrrr) into Canada, then shortly afterwards into the west central US and move it eastward.

 

 

All in all, none of this is a prediction on my part. It is just my thoughts on what the overnight GFS op run is showing. That being said I strongly believe we will see some semblance of what it is showing and the evolution above to actually occur at some point in the next few weeks. Now if in fact we do see a flip in the NPAC and we can see a resurgence of the -NAO as well I think fun times may be ahead for us running into the Holiday season.

[CAPE]

@showmethesnow

Great write up!

I understand the general thinking that its better to have the PV on our side of the pole, but when we get a deep vortex backing that far SW into the GOA and parking there, it becomes a major hindrance overall. You and I have both made posts/discussed the possible reshuffling in the NPac, and while it will coincide with the NAO heading towards neutral/positive for a time, at this point there is no reason to believe we will flip to a raging +AO/NAO regime for the long term.  I am all in on a transition to a more stable +PNA and even a -EPO for a time... get the +heights building again over GL, and we might have a chance at a fun December for a change lol. Have to see how this plays out, but I kinda liked the general h5 look advertised on the Euro weeklies going forward into December. Be interesting to see what the new edition looks like. 

[showmethesnow]

13 minutes ago, WxWatcher007 said:

@showmethesnow is on a roll. Another nice post.

Thank you.

[showmethesnow]

7 minutes ago, C.A.P.E. said:

@showmethesnow

Great write up!

I understand the general thinking that its better to have the PV on our side of the pole, but when we get a deep vortex backing that far SW into the GOA and parking there, it becomes a major hindrance overall. You and I have both made posts/discussed the possible reshuffling in the NPac, and while it will coincide with the NAO heading towards neutral/positive for a time, at this point there is no reason to believe we will flip to a raging +AO/NAO regime for the long term.  I am all in on a transition to a more stable +PNA and even a -EPO for a time... get the +heights building again over GL, and we might have a chance at a fun December for a change lol. Have to see how this plays out, but I kinda liked the general h5 look advertised on the Euro weeklies going forward into December. Be interesting to see what the new edition looks like. 

Thank you.

I can't agree more. Though we may lose 7-10 days, if not a little more during the transition, I think chances are very good we will all be salivating on the pattern presented (Come on -NAO/AO!!!) moving forward into the holidays and hopefully mid-winter. Chances are very good it would be a stable pattern as well. Much better then fighting a GOA/Northwest trough/low which may or may not be in a favorable position. I hate depending on the stars aligning to get a favorable setup in our region because we all know how that generally works out. Here's hoping. 

 

[CAPE]

2 minutes ago, showmethesnow said:

Thank you.

I can't agree more. Though we may lose 7-10 days, if not a little more during the transition, I think chances are very good we will all be salivating on the pattern presented (Come on -NAO/AO!!!) moving forward into the holidays and hopefully mid-winter. Chances are very good it would be a stable pattern as well. Much better then fighting a GOA/Northwest trough/low which may or may not be in a favorable position. I hate depending on the stars aligning to get a favorable setup in our region because we all know how that generally works out. Here's hoping. 

 

Yeah we just endured a winter with a persistent NW trough. The memories are fresh. Despite some decent modeled looks, a bunch of pattern chasing, the resulting ground truth was pretty dismal.

[BristowWx]

25 minutes ago, C.A.P.E. said:

Yeah we just endured a winter with a persistent NW trough. The memories are fresh. Despite some decent modeled looks, a bunch of pattern chasing, the resulting ground truth was pretty dismal.

I think if we double our estimate of how long the transition will take..since it always takes longer than modeled...we would be in pretty good shape. our first test will be if this currently modeled block...late this week into t-day weekend.. comes to bear fruit.  Its been modeled for a while and now its time for it to materialize.  If it fails then we should be rather disappointed.   

[CAPE]

1 minute ago, BristowWx said:

I think if we double our estimate of how long the transition will take..since it always takes longer than modeled...we would be in pretty good shape. our first test will be if this currently modeled block...late this week into t-day weekend.. comes to bear fruit.  Its been modeled for a while and now its time for it to materialize.  If it fails then we should be rather disappointed.   

Not a bad way to look at it I guess. The guidance has been consistently advertising a legitimate west-based block for the period we are about to enter, for quite a while now. We know how that has gone in recent cold seasons. If it does verify at close to modeled strength and position, and is stable for a week or so, I would take it as a good sign for at least the first half of winter.

[frd]

1 hour ago, showmethesnow said:

Now if in fact we do see a flip in the NPAC and we can see a resurgence of the -NAO as well I think fun times may be ahead for us running into the Holiday season.

Great write up ! I love the use of content and maps !

You are in good company too,  as Isotherm and Benchmark have a wintery December in their Winter outlooks.

The progression looks possible, and it would be awesome to have a snowy and cold holiday period. Also, if this plays out the way you are thinking we will have the cold,  and snow :-)   right around the Winter Solstice on December 21 st.  I have seen that happened only few times in my life that I can actually remember . I would love to see it again.   

[frd]

Looks like a cold Thanksgiving Day morning, a cool map by Ryan using the Euro ensembles.   

 

 

[WxUSAF]

Looks like chance for scattered snow showers/flurries on Sunday if GFS to be believed.  

[showmethesnow]

1 hour ago, frd said:

Great write up ! I love the use of content and maps !

You are in good company too,  as Isotherm and Benchmark have a wintery December in their Winter outlooks.

The progression looks possible, and it would be awesome to have a snowy and cold holiday period. Also, if this plays out the way you are thinking we will have the cold,  and snow :-)   right around the Winter Solstice on December 21 st.  I have seen that happened only few times in my life that I can actually remember . I would love to see it again.   

Thank you.

I have 40+ years invested in this region (most down around Baltimore and the last 13 here in Hanover) and I can tell you that white and/or wintry Christmas' have been hard to come by. Would be nice to have one this year.

[BristowWx]

6 minutes ago, losetoa6 said:

Yep...and our Turkey day storm is a little further south with some  light snow northern tier.

seems like some of the conditions are there for it to perhaps dig and develop further south.  trough looks mostly positive.  The date is problematic being Nov but as long at 11/11/87 happened then you never know.  mood flakes would be great.  certainly no massive warm up on tap that weekend

 

[showmethesnow]

Much better and stronger look showing up on the GEFS for the possible post 10 day coastal storm.

[Cobalt]

GEFS coming in colder and wetter by day 10, which must mean that it's picking up a bit of consensus for the Tday storm. I'll post pics of the GEFS once it's through day 16

[NEWeatherWx]

EURO EPS suggesting a cold end to November. Exciting times ahead!


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[clskinsfan]

Looks somewhat likely that those of us to the west should see our first mood flakes of the season over the next week. But that is really pretty normal timing wise for out here. I do like the look of the blocking be modeled. Hopefully it can be a persistent pattern this winter.

[Eskimo Joe]

Someone refresh my memory...was the 2010 - 2011 winter a La Nina winter?

[clskinsfan]

2 minutes ago, Eskimo Joe said:

Someone refresh my memory...was the 2010 - 2011 winter a La Nina winter?

Yes it was. Or are you just trolling us/me

[Eskimo Joe]

2 minutes ago, clskinsfan said:

Yes it was. Or are you just trolling us/me

No I'm serious.  The Jan 26-27, 2011 event was my second favorite winter storm.  I'm hoping for a few of those this winter and if we get enough blocking it isn't out of the realm of possibilities.  The only thing that kept it from being #1 was it's speed...if it were slower post-changeover to snow then it'd be my bench mark winter event.

[mitchnick]

27 minutes ago, NEWeatherWx said:

EURO EPS suggesting a cold end to November. Exciting times ahead!


Sent from my iPhone using Tapatalk

yesterday's 12z run fwiw

[clskinsfan]

3 minutes ago, Eskimo Joe said:

No I'm serious.  The Jan 26-27, 2011 event was my second favorite winter storm.  I'm hoping for a few of those this winter and if we get enough blocking it isn't out of the realm of possibilities.  The only thing that kept it from being #1 was it's speed...if it were slower post-changeover to snow then it'd be my bench mark winter event.

http://ggweather.com/enso/oni.htm

And I still think we have a chance at a neutral this winter. When I said it couple of month ago I got discouraged because of the forecast. But we will see where it ends up. I would definitely prefer a neutral though. Especially out here.

[Heisy]

Bit of a step back from the 12z EURO, but the OP seemingly flips back and forth each run. 

Eskimo Joe, I am a Philly guy of course, but the Jan 26-27 2011 is in my top 5 fav storms. The initial WAA snows overachieved here and was a surprise during the morning (got like 3-5" i believe) then Part II had some of the heaviest snowfall of my life. You could almost see it accumulating in front of you. Think I got a foot from part 2 in only a few hours. Love that storm. 

[osfan24]

We missed out on Part I down here but Part II was so much fun. Just snowed like crazy for 4 hours or so. Picked up like 6-10 area-wide.

[Bob Chill]

28 minutes ago, Eskimo Joe said:

No I'm serious.  The Jan 26-27, 2011 event was my second favorite winter storm.  I'm hoping for a few of those this winter and if we get enough blocking it isn't out of the realm of possibilities.  The only thing that kept it from being #1 was it's speed...if it were slower post-changeover to snow then it'd be my bench mark winter event.

That nina was a lot stronger than anything we're going to see this year regardless of the numerical indices. This panel says it all:

 

 

The interesting thing about the Jan 11 storm was it was pretty much a classic Archambault event which marked the flip to a +AO/NAO and the end of winter for the most part. This is the AO graph for the year but the NAO flipped at the same time: