Winter 2017-18 Disco

[North Balti Zen]

Reminiscing about snow that screwed the beltways. And preluded a disastrous winter. Par for course.

[mitchnick]

1 minute ago, North Balti Zen said:

Reminiscing about snow that screwed the beltways. And preluded a disastrous winter. Par for course.

Well, on a completely different topic, I see the GEPS have been advertising a persistent trough in the east starting to build around 198 hours then establishing it nicely through the end of the recent runs. If everyone recalls, last year the GEPS were always painfully lousy vs. GEFS and even the EPS at times, and the GEPS always prevailed.  Hopefully this year it can prove to be correct when it calls for cold and/or stormy periods. 

[Bob Chill]

48 minutes ago, mitchnick said:

Well, on a completely different topic, I see the GEPS have been advertising a persistent trough in the east starting to build around 198 hours then establishing it nicely through the end of the recent runs. If everyone recalls, last year the GEPS were always painfully lousy vs. GEFS and even the EPS at times, and the GEPS always prevailed.  Hopefully this year it can prove to be correct when it calls for cold and/or stormy periods. 

You know what mitch? I'm actually pretty encouraged with what I'm seeing to close this month out. It's more like a nino pattern so I doubt it hangs for weeks but the -epo/+pna couplet along with AN heights around GL and the pole is a welcome sight. 

As we go into Nov, the 2 things I don't want to see is a big AK vortex pumping pac air into NA or a big blue ball of BN heights around the ao/nao region. Looks like we enter Nov with none of that. 

[uncle W]

to bad we weren't entering December with a plus pna and neg ao/nao...in six weeks the game begins and I'd like to see a fast start for a change...

[WVclimo]

1 hour ago, mitchnick said:

I could be mistaken, but wasn't that the storm that dumped around a foot at Camp David? I recall driving up there around 5 years ago and talking to  Park Ranger about an early season snow that gave them that and whining I got only a coating.

That sounds about right.  A spotter in Sabillasville, just north of Camp David, reported 11.5"

[Eskimo Joe]

On 10/14/2017 at 7:14 PM, WxUSAF said:

I think Oct 2011 did with that cold Halloween nor'easter that gave hoffman like 6".  

I was in PA at the time finishing my masters at Millersville.  We got 4-8" in the county and it was highly dependent on elevation.  Some parts of Parrs Ridge into lower York County picked up 9" IIRC.

[LoveSN+]

22 minutes ago, SimeonNC said:

I've posted this more in detail over at another board but the cold pool south of Greenland that has been around during the past few winters has disappeared. I don't how much this will affect things this year though.

I think I saw ORHman mention this as well. Could we finally see some blocking this year? It has been many years since we have had sustained blocking. 

[mitchnick]

3 hours ago, Bob Chill said:

You know what mitch? I'm actually pretty encouraged with what I'm seeing to close this month out. It's more like a nino pattern so I doubt it hangs for weeks but the -epo/+pna couplet along with AN heights around GL and the pole is a welcome sight. 

As we go into Nov, the 2 things I don't want to see is a big AK vortex pumping pac air into NA or a big blue ball of BN heights around the ao/nao region. Looks like we enter Nov with none of that. 

Yeah, I like the look too. I just hope it's a taste of the winter to come and not a feeble attempt that comes too early for any "real" event, only to switch back to warmth and meh. Not that that ever happens around here of course. 

[showmethesnow]

Thought I would look into the forecasted Jet stream to see if there may be any clues as to what we might expect moving into winter. 

*** Note: Would have preferred to use the GEFS but the look gets somewhat muddied in the longer ranges. Also any conjecture on my part is not a forecast but instead speculation on if what is forecasted by the GFS Op run actually comes close to verifying which as we all know is never etched in stone.***

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First pic below shows what the configuration of PAC jet is currently (The strip of yellows, reds, purples). Notice it is straight as an arrow from west to East, from Asia across the Pacific into the northwest. What this configuration does is flood Canada and the CONUS with warm Pac air, bottling up any potential cold far to the north. It is a typical look during a La Nina and one we do not want to see for any hopes of winter in our region.

 

Here we are at day 5+ and though there is a little waviness across the Pacific with this feature it is still a bad look with flooding North America with Pac air and bottling up any potential cold far to the north..

 

 

Now look what happens with the PAC jet at day 8 as a deep low rotates into Alaska. The jet has now been disrupted as we see large waves form in its configuration over the Pacific. For any hopes of winter weather in our region we need to see this disruption for it will allow cold air intrusions southward into the CONUS.

 

 

Now from day 8 until day 12+ (shown below) we see the Pac Jet attempt to move back to a state seen both currently and at day 5. The straight as an arrow west to east look. But look what happens once again at day 12+. We are once again seeing a large disruption of the PAC jet. Which, again, is what we want to see for our winter hopes. Now not shown after day 12 is that we don't see another attempt by the PAC jet to strengthen as seen from day 8-11 but instead we see a continuation of the disruption with a weak and convoluted jet left in place.

 

 

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Now left unsaid so far is another implication of the continual disruptions to the PAC jet. As we all know by now, our hopes this winter will revolve around high latitude blocking (-NAO, -AO). What plays a key factor in this is the state of the polar vortex, which is now currently in the process of setting up for the early part of winter. A strong polar vortex is normally associated with a +AO and +NAO and conversely a weak and disrupted PV is normally associated with a -AO and -NAO. The strong west to east jet configuration seen currently and at day 5 is a look associated with a strong undisturbed PV setting up (+AO). The current pic below shows this quite well. Except for the large disturbance in Europe, the polar jet forms is strong and an almost perfect concentric circle around the globe. This look typically bottles up all the cold in the polar regions with only occasional and brief intrusions southward. 

 

 

Now look at the polar jet in the longer range after repeated disturbances. This is the look typically seen with a weak and disturbed PV. Notice the polar jet has weakened substantially and is now snaking all over the place. This is the type of look we need to hope for through most of the winter.

 

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Now there was one other feature I wanted to point out while discussing Jets. It is still somewhat early to know if this might be a player this coming winter but I thought I would mention it anyway. Look what is popping up off of Baja at day 3. If I am not mistaken I believe that is the sub tropical jet nosing into the scene. 

*** Note: The subtropical jet is better depicted on the 200mb then the 250mb but the 250 was the one I had available to show. ***

 

 

Now look at day 9. Once again we see what looks to be the subtropical jet popping up in the gulf states in the eastern us. 

 

 

And at day 16? I believe we are seeing the phasing of the polar and subtropical jet over the east coast. 

 

 

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Not a prediction by any means, but if what we see currently forecasted on the GFS comes close to verifying I think we would like the implications it presents leading into the beginning of winter. The continual disruptions to the PAC jet weakening it suggest that there is a good possibility that we head into the winter with a weak and disturbed PV and the -AO and high latitude blocking associated with it. I also like seeing the sub tropical jet showing up at this time though whether we see it during the winter is another story.

All in all I have for the most part liked what I have seen these last few weeks for the first half of winter. If you were to twist my arm at this point to make a prediction on what to expect for the first half of winter I would be somewhat bullish. I think the first half will present quite a few opportunities (whether that would equate to snow, you know how that works in our region) and I think the onset will be early, possibly quite early. I would not be surprised whatsoever if we were discussing realistic snow chances as early as mid to late November.

 

 

[SnowLover22]

3 hours ago, showmethesnow said:

Thought I would look into the forecasted Jet stream to see if there may be any clues as to what we might expect moving into winter. 

*** Note: Would have preferred to use the GEFS but the look gets somewhat muddied in the longer ranges. Also any conjecture on my part is not a forecast but instead speculation on if what is forecasted by the GFS Op run actually comes close to verifying which as we all know is never etched in stone.***

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

 

First pic below shows what the configuration of PAC jet is currently (The strip of yellows, reds, purples). Notice it is straight as an arrow from west to East, from Asia across the Pacific into the northwest. What this configuration does is flood Canada and the CONUS with warm Pac air, bottling up any potential cold far to the north. It is a typical look during a La Nina and one we do not want to see for any hopes of winter in our region.

 

Here we are at day 5+ and though there is a little waviness across the Pacific with this feature it is still a bad look with flooding North America with Pac air and bottling up any potential cold far to the north..

 

 

Now look what happens with the PAC jet at day 8 as a deep low rotates into Alaska. The jet has now been disrupted as we see large waves form in its configuration over the Pacific. For any hopes of winter weather in our region we need to see this disruption for it will allow cold air intrusions southward into the CONUS.

 

 

Now from day 8 until day 12+ (shown below) we see the Pac Jet attempt to move back to a state seen both currently and at day 5. The straight as an arrow west to east look. But look what happens once again at day 12+. We are once again seeing a large disruption of the PAC jet. Which, again, is what we want to see for our winter hopes. Now not shown after day 12 is that we don't see another attempt by the PAC jet to strengthen as seen from day 8-11 but instead we see a continuation of the disruption with a weak and convoluted jet left in place.

 

 

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

 

Now left unsaid so far is another implication of the continual disruptions to the PAC jet. As we all know by now, our hopes this winter will revolve around high latitude blocking (-NAO, -AO). What plays a key factor in this is the state of the polar vortex, which is now currently in the process of setting up for the early part of winter. A strong polar vortex is normally associated with a +AO and +NAO and conversely a weak and disrupted PV is normally associated with a -AO and -NAO. The strong west to east jet configuration seen currently and at day 5 is a look associated with a strong undisturbed PV setting up (+AO). The current pic below shows this quite well. Except for the large disturbance in Europe, the polar jet forms is strong and an almost perfect concentric circle around the globe. This look typically bottles up all the cold in the polar regions with only occasional and brief intrusions southward. 

 

 

Now look at the polar jet in the longer range after repeated disturbances. This is the look typically seen with a weak and disturbed PV. Notice the polar jet has weakened substantially and is now snaking all over the place. This is the type of look we need to hope for through most of the winter.

 

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

 

Now there was one other feature I wanted to point out while discussing Jets. It is still somewhat early to know if this might be a player this coming winter but I thought I would mention it anyway. Look what is popping up off of Baja at day 3. If I am not mistaken I believe that is the sub tropical jet nosing into the scene. 

*** Note: The subtropical jet is better depicted on the 200mb then the 250mb but the 250 was the one I had available to show. ***

 

 

Now look at day 9. Once again we see what looks to be the subtropical jet popping up in the gulf states in the eastern us. 

 

 

And at day 16? I believe we are seeing the phasing of the polar and subtropical jet over the east coast. 

 

 

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

Not a prediction by any means, but if what we see currently forecasted on the GFS comes close to verifying I think we would like the implications it presents leading into the beginning of winter. The continual disruptions to the PAC jet weakening it suggest that there is a good possibility that we head into the winter with a weak and disturbed PV and the -AO and high latitude blocking associated with it. I also like seeing the sub tropical jet showing up at this time though whether we see it during the winter is another story.

All in all I have for the most part liked what I have seen these last few weeks for the first half of winter. If you were to twist my arm at this point to make a prediction on what to expect for the first half of winter I would be somewhat bullish. I think the first half will present quite a few opportunities (whether that would equate to snow, you know how that works in our region) and I think the onset will be early, possibly quite early. I would not be surprised whatsoever if we were discussing realistic snow chances as early as mid to late November.

 

 

Great post. Surprised you don’t have a red tag. Your contributions are greatly appreciated.

[showmethesnow]

12 minutes ago, Philadelphia Snow said:

Great post. Surprised you don’t have a red tag. Your contributions are greatly appreciated.

Thank you. While I appreciate the red tag reference all I can say is that I am no where near the level of the red taggers that grace these boards. I am nothing more then a hobbyist that finds he has to go back far too often to reread things he has forgotten (getting old sucks  ). But thanks none the less.  

[RDM]

25 minutes ago, showmethesnow said:

Thank you. While I appreciate the red tag reference all I can say is that I am no where near the level of the red taggers that grace these boards. I am nothing more then a hobbyist that finds he has to go back far too often to reread things he has forgotten (getting old sucks  ). But thanks none the less.  

Agree with PA Sn.  Great post showme...  

     In the case of the jet, at least the PAC jet, laminar flow is a bad thing, so it appears.  We want some non-laminar mixing in there (wrt the flow around the pole) with some appropriately placed troughs to link up with the STJ to promote phasing.  One observation and don't mean to be nitpicking here...  the map for 01 Nov shows a STJ out of the gulf (originating off the coast of Baja) with a low off the coast of SC.  It appears the cold is too far North, no?  Or is perhaps that map on 01 a precursor for the ridge in PAC Jet to phase with with the STJ and spin up something decent?  (not predicting MECS or HECS here, but that setup does look enticing).  Wish we could see what's going on at the same time IVO 50/50 to help drive the cold down and/or generate some blocking.  Or, maybe it's there and my weenie eyes are to blind to see it.

[BTRWx]

1 hour ago, RDM said:

Agree with PA Sn.  Great post showme...  

     In the case of the jet, at least the PAC jet, laminar flow is a bad thing, so it appears.  We want some non-laminar mixing in there (wrt the flow around the pole) with some appropriately placed troughs to link up with the STJ to promote phasing.  One observation and don't mean to be nitpicking here...  the map for 01 Nov shows a STJ out of the gulf (originating off the coast of Baja) with a low off the coast of SC.  It appears the cold is too far North, no?  Or is perhaps that map on 01 a precursor for the ridge in PAC Jet to phase with with the STJ and spin up something decent?  (not predicting MECS or HECS here, but that setup does look enticing).  Wish we could see what's going on at the same time IVO 50/50 to help drive the cold down and/or generate some blocking.  Or, maybe it's there and my weenie eyes are to blind to see it.

I'll bite after in-range ensembles show it.

eta: within a week out

[Bob Chill]

50 minutes ago, BTRWx said:

I'll bite after in-range ensembles show it.

They already do. The aleutian trough/pna ridge is a pretty standard feature in a Nino. That's why I don't think the pattern will hold for long. But it's nice to see either way. 

5 day mean looks like a Nino:

 

 

250mb jet shows a nice split flow with the pac splitting with the northern branch riding up and over the PNA ridge and the southern branch riding underneath from HI and across the soutern tier of the country. 

 

 

The 2 branches could phase and spin up a nice storm for someone down the line 10+ days. Not a snowstorm for us obviously. But I wouldn't be surprised if a nice Oct synoptic event like the one on the 12z gfs starts showing up off and on going forward. The 12z gfs is a pretty classic NS/STJ phase coastal. 

 

You can see the branches getting ready to phase right here with a decent NS vort diving down:

 

 

And  then this bad boy spins up:

 

 

[BTRWx]

56 minutes ago, Bob Chill said:

They already do. The aleutian trough/pna ridge is a pretty standard feature in a Nino. That's why I don't think the pattern will hold for long. But it's nice to see either way. 

5 day mean looks like a Nino:

 

 

250mb jet shows a nice split flow with the pac splitting with the northern branch riding up and over the PNA ridge and the southern branch riding underneath from HI and across the soutern tier of the country. 

 

 

The 2 branches could phase and spin up a nice storm for someone down the line 10+ days. Not a snowstorm for us obviously. But I wouldn't be surprised if a nice Oct synoptic event like the one on the 12z gfs starts showing up off and on going forward. The 12z gfs is a pretty classic NS/STJ phase coastal. 

 

You can see the branches getting ready to phase right here with a decent NS vort diving down:

 

 

And  then this bad boy spins up:

 

 

Day 15 nina chaos...

[showmethesnow]

1 hour ago, RDM said:

Agree with PA Sn.  Great post showme...  

     In the case of the jet, at least the PAC jet, laminar flow is a bad thing, so it appears.  We want some non-laminar mixing in there (wrt the flow around the pole) with some appropriately placed troughs to link up with the STJ to promote phasing.  One observation and don't mean to be nitpicking here...  the map for 01 Nov shows a STJ out of the gulf (originating off the coast of Baja) with a low off the coast of SC.  It appears the cold is too far North, no?  Or is perhaps that map on 01 a precursor for the ridge in PAC Jet to phase with with the STJ and spin up something decent?  (not predicting MECS or HECS here, but that setup does look enticing).  Wish we could see what's going on at the same time IVO 50/50 to help drive the cold down and/or generate some blocking.  Or, maybe it's there and my weenie eyes are to blind to see it.

Thanks. After looking over Nov 1'st again you may be right. Didn't look to deeply into it initially and just assumed it was a very sloppy phase from just looking at 250 mb progression. See what you mean about a precursor. If that setup were to get into the shorter range I think we would see some excited people from the lakes into NE. 

[RDM]

22 minutes ago, showmethesnow said:

Thanks. After looking over Nov 1'st again you may be right. Didn't look to deeply into it initially and just assumed it was a very sloppy phase from just looking at 250 mb progression. See what you mean about a precursor. If that setup were to get into the shorter range I think we would see some excited people from the lakes into NE. 

   You're welcome.

I didn't look too deeply either.   However, after last Winter and the gloom, despair and agony that came with it, I'm probably grasping at straws too far out, but can't help myself.  I'm just anxious to chase models for something tangible, anything....   just hope in due time it will be something less than 5 days out like we had in Jan 2015 when we had strong model consensus nearly a week out.  If this early Nov potential does develop into anything, even a MA rainstorm, it will be good to see models hold serve.  Last year we were constantly teased with something 10 days to 2 weeks out only to have it evaporate and leave us hanging.  After 30 years in the MA I realize the variables that come into play for us to get a shellacking are complex.  If just one gets out of whack, then we typically loose. 

[poolz1]

Still a long ways to go but both eps and gefs seem primed to keep the end of oct pattern going into the first week of nov.  On both ens,  day 12-15 look ripe.  Always a concern that the nina base state rules the roost but an encouraging sign nonetheless.  Would love to see this pattern the first week of dec but a few leaf stripping nor'easters to start the month of nov would be a welcome sight and help set the mood for eyeing real potentials down the road...  

[CAPE]

3 minutes ago, poolz1 said:

Still a long ways to go but both eps and gefs seem primed to keep the end of oct pattern going into the first week of nov.  On both ens,  day 12-15 look ripe.  Always a concern that the nina base state rules the roost but an encouraging sign nonetheless.  Would love to see this pattern the first week of dec but a few leaf stripping nor'easters to start the month of nov would be a welcome sight and help set the mood for eyeing real potentials down the road...  

EPS. GEFS, GEPS all very consistent and similar at h5 towards the end of the month into Nov with +PNA and east-based -NAO. CFS weeklies are pretty much there too. Yeah lets hope this is an indication of what lies ahead.

[WxUSAF]

Cold Novembers are Nina climo though,right? Not that I’ll complain about it, but I’d just caution that a chilly November isn’t necessarily a sign that the pattern is behaving non-Nina.

[poolz1]

24 minutes ago, WxUSAF said:

Cold Novembers are Nina climo though,right? Not that I’ll complain about it, but I’d just caution that a chilly November isn’t necessarily a sign that the pattern is behaving non-Nina.

You know, I'll be honest...I lack the chops to do the research that a lot folks do on here....Not that I dont want to learn ...but kids, job , life bla bla bla

So, I did the poor man's version of climatology research and looked at last year's winter thread in mid oct as we headed into a nina...it's almost a carbon copy of the current discussion.  Ive been watching the pv lately and have been encouraged by it's failure to get it's act together but....this time last year there was already talk of a split happening.  A lot of hope being thrown around and where did we end up???  My only hope is that this nina doesnt have the force to overwhelm the entire winter like last year. 

[BTRWx]

1 minute ago, poolz1 said:

You know, I'll be honest...I lack the chops to do the research that a lot folks do on here....Not that I dont want to learn ...but kids, job , life bla bla bla

So, I did the poor man's version of climatology research and looked at last year's winter thread in mid oct as we headed into a nina...it's almost a carbon copy of the current discussion.  Ive been watching the pv lately and have been encouraged by it's failure to get it's act together but....this time last year there was already talk of a split happening.  A lot of hope being thrown around and where did we end up???  My only hope is that this nina doesnt have the force to overwhelm the entire winter like last year. 

[Bob Chill]

2 hours ago, WxUSAF said:

Cold Novembers are Nina climo though,right? Not that I’ll complain about it, but I’d just caution that a chilly November isn’t necessarily a sign that the pattern is behaving non-Nina.

Nothing really means much in Oct or Nov right?

I remember ens and the weeklies showing a good pattern for Dec during Thanksgiving weekend. Even into early Dec there was a big Aleutian ridge pushing poleward on guidance and we thought big cold was incoming. Lol. Then it all flipped....Dec cansips saw it first but none of us wanted to believe it. God last winter sucked. 

[mitchnick]

2 hours ago, WxUSAF said:

Cold Novembers are Nina climo though,right? Not that I’ll complain about it, but I’d just caution that a chilly November isn’t necessarily a sign that the pattern is behaving non-Nina.

Doing a quick review of recent Nina Novembers and there is a wide variety,  both AN and BN, so I don't think November temps are like December with "typical" Nina climo.

[psuhoffman]

10 hours ago, poolz1 said:

You know, I'll be honest...I lack the chops to do the research that a lot folks do on here....Not that I dont want to learn ...but kids, job , life bla bla bla

So, I did the poor man's version of climatology research and looked at last year's winter thread in mid oct as we headed into a nina...it's almost a carbon copy of the current discussion.  Ive been watching the pv lately and have been encouraged by it's failure to get it's act together but....this time last year there was already talk of a split happening.  A lot of hope being thrown around and where did we end up???  My only hope is that this nina doesnt have the force to overwhelm the entire winter like last year. 

The Nina was pretty weak last year. Our problem was almost everything lined up wrong. It wasn't just one thing. 

[psuhoffman]

10 hours ago, BTRWx said:

Your a ray of sunshine 

[Bob Chill]

Hmmm.... Cohen's blog yesterday had a blurb that said pretty much the same thing that I posted a few days ago....lol

"I would conclude that the three factors that I consider favorable for severe winter weather increased atmospheric blocking in the fall, more extensive Siberian snow cover and low Arctic sea ice have become the norm more than the exception over the past decade.  I do believe that the lack of variability in these three factors, likely reduces their utility in winter predictions"

 

I do like this though:

"The latest plot of the tropospheric polar cap geopotential heights (PCHs) shows cold/below normal PCHs in the stratosphere but normal PCHs in the troposphere (Figure 10).   The forecast is for renewed warm PCHs in the troposphere, which would favor an increase in high latitude blocking to close out the month. This could also be signaling a pattern change to seasonable to seasonably cold temperatures across Northern Asia, Europe and/or the Eastern US at the end of October and the beginning of November. Also the longer the warm PCHs persists in the troposphere the more likely is troposphere-stratosphere coupling to become active, which favors a weak PV".

 

We've had nothing but a strong trop and strat PV to kick off met winter since basically 2010 but the last 3-4 years have been really bad. We're still a full month away from getting a bead on how the trop/strat is going to look to kick off met winter. Anything that happens in Nov that favors a weaker PV will be very welcomed. 

[midatlanticweather]

I am sure this means nothing..

 

 

[BTRWx]

The following map will be a key indicator for what happens after next month!

 

[SnowGoose69]

19 hours ago, mitchnick said:

Doing a quick review of recent Nina Novembers and there is a wide variety,  both AN and BN, so I don't think November temps are like December with "typical" Nina climo.

Cold Novembers are more a classic mod-strong Nino head fake tendency before things usually begin to torch December onward.  Ninas as you found are usually all over the place.  I thnik some of the stronger La Ninas have shown tendencies for cold Octobers in the East.