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Mid to Long Term Discussion 2017


buckeyefan1

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5 minutes ago, packbacker said:

Phase 8 FTW...Feb may end up AN but think after this big cold shot day 10 we will see a period that gives chances. We can't suck forever.  

As painfull as it is to say...I agree with Jon's post above.  

Yeah, we can and this winter is how! The good look after day 10, will look like hot doo-doo tomorrow! :(

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9 minutes ago, packbacker said:

Phase 8 FTW...Feb may end up AN but think after this big cold shot day 10 we will see a period that gives chances. We can't suck forever.  

As painfull as it is to say...I agree with Jon's post above.  

Probably the best look we have had all winter. Too bad it's 13 days away.

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Ok, so here is something where I'm out of step here with some of you.  I hope you can help get me back in line.  We talk about blocking all winter long and I'm not sure we're all taking about the same thing.  Our idea of what blocking is translates directly to our expectations of its (blocking's) effects on weather patterns.  When I think about and look for blocking, I look at the 500 mb height pattern.  Others of you tend to use the 850 temp anomaly charts to illustrate blocking.  I never do that and am wondering if I have not been thinking about it correctly??

My thinking is this:  Blocking, by nature, alters the jet stream pattern.  In the AK region, it promotes cross-polar flow.  In the NAO region, it allows the jet to buckle, cold air to penetrate into the SE, and storms to really crank up.  These things are visible at 500 mb.  The 850 mb temp anoms are a product of lower/higher heights (and it's true that you'll typically find warmer 850s under upper level ridging or blocking).  But in my mind, it's not a useful map to illustrate jet stream, flow-altering blocking.  Here's the example I will use to illustrate my point:

Today's EPS 500 mb 240 map:

ecmwf-ens_z500_mslp_nhem_11.png

 

The only real block I see is over in Russia, circled.  There is ridging into the Pole (outlined), which should cause the AO to drop.  But I don't see any blocking in the NAO space or the EPO space (although there is some ridging over central/eastern Greenland, which may cause the NAO to dip (maybe a slight east-based -NAO?)).  The circled block over Russia and the highlighted ridging over the Pole are the only real evidential elements of blocking/ridging that I see that would alter the flow.  The way I see how they would do so would be this:

The Russian block would act to stretch the already stretched PV in an east-west fashion, keeping the EPO positive and eliminating cross-polar flow.  Ridging over the Pole, if it's strong enough would press the elongated PV into Canada.  Since the PNA is somewhat positive and the NAO is positive or neutral (or at best slightly negative east-based), the flow into the SE would have a slight NW trajectory.  So, beyond 240, I would expect an elongated quasi east-west PV in north-central Canada with semi-zonal flow over the US, with maybe a bit of a NW component, which would yield temps near normal around here.

Now, if you look at the 850 anom map, you get a different picture:

ecmwf-ens_T850a_nhem_11.png

 

It looks like the highlighted area exemplifies extreme blocking, which would trap very cold air in the eastern half of the country for an extended period, causing a run on sleds and shovels.  It's quite a different picture than you get by examining the 500 mb map.  What I see when I look at both maps is that the 850s appear warmer than you would think they would, given the 500 mb depiction.  Just looking at the 850s, I'd expect to see huge, multi-contoured circles over extreme eastern Siberia, again over Greenland, and again over Newfoundland at 500.  But you don't.  The ridging at 500 that results in the torching 850s over Greenland and down through Newfoundland looks anemic.

Anyway, I'm just trying to make sure I'm on the same page as others and wondering if I've been looking at this the wrong way.  Please advise!

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^CR I've always used the 5h anomaly to look for blocking, not 850.  Verbatim EPS looks pretty cold but again with the +EPO Alaska vortex I dunno how cold it's going to get.  Especially at a 10 day lead.  The pattern is for blockiness this year is to fade, fade away...unless it's in Siberia.  Plus the trough is too far east, won't let anything pop IMO. NW flow. 

  ecmwf-ens_z500a_nhem_11.png

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Good point, SN.  I was going to mention the 500 mb Anom chart too, but I forgot.  To me, the anoms are misleading a bit, just as the 850s are, although that map does show heights.  But I honestly don't know which is the best map to look at for blocking.  I always thought heights were, but more and more people are using anom charts to illustrate it.  I dunno.

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51 minutes ago, Cold Rain said:

Ok, so here is something where I'm out of step here with some of you.  I hope you can help get me back in line.  We talk about blocking all winter long and I'm not sure we're all taking about the same thing.  Our idea of what blocking is translates directly to our expectations of its (blocking's) effects on weather patterns.  When I think about and look for blocking, I look at the 500 mb height pattern.  Others of you tend to use the 850 temp anomaly charts to illustrate blocking.  I never do that and am wondering if I have not been thinking about it correctly??

My thinking is this:  Blocking, by nature, alters the jet stream pattern.  In the AK region, it promotes cross-polar flow.  In the NAO region, it allows the jet to buckle, cold air to penetrate into the SE, and storms to really crank up.  These things are visible at 500 mb.  The 850 mb temp anoms are a product of lower/higher heights (and it's true that you'll typically find warmer 850s under upper level ridging or blocking).  But in my mind, it's not a useful map to illustrate jet stream, flow-altering blocking.  Here's the example I will use to illustrate my point:

Today's EPS 500 mb 240 map:

ecmwf-ens_z500_mslp_nhem_11.png

 

The only real block I see is over in Russia, circled.  There is ridging into the Pole (outlined), which should cause the AO to drop.  But I don't see any blocking in the NAO space or the EPO space (although there is some ridging over central/eastern Greenland, which may cause the NAO to dip (maybe a slight east-based -NAO?)).  The circled block over Russia and the highlighted ridging over the Pole are the only real evidential elements of blocking/ridging that I see that would alter the flow.  The way I see how they would do so would be this:

The Russian block would act to stretch the already stretched PV in an east-west fashion, keeping the EPO positive and eliminating cross-polar flow.  Ridging over the Pole, if it's strong enough would press the elongated PV into Canada.  Since the PNA is somewhat positive and the NAO is positive or neutral (or at best slightly negative east-based), the flow into the SE would have a slight NW trajectory.  So, beyond 240, I would expect an elongated quasi east-west PV in north-central Canada with semi-zonal flow over the US, with maybe a bit of a NW component, which would yield temps near normal around here.

Now, if you look at the 850 anom map, you get a different picture:

ecmwf-ens_T850a_nhem_11.png

 

It looks like the highlighted area exemplifies extreme blocking, which would trap very cold air in the eastern half of the country for an extended period, causing a run on sleds and shovels.  It's quite a different picture than you get by examining the 500 mb map.  What I see when I look at both maps is that the 850s appear warmer than you would think they would, given the 500 mb depiction.  Just looking at the 850s, I'd expect to see huge, multi-contoured circles over extreme eastern Siberia, again over Greenland, and again over Newfoundland at 500.  But you don't.  The ridging at 500 that results in the torching 850s over Greenland and down through Newfoundland looks anemic.

Anyway, I'm just trying to make sure I'm on the same page as others and wondering if I've been looking at this the wrong way.  Please advise!

Oops...looks like I posted the wrong image above.  Fixed that.  An area of higher heights can be called a block but some may disagree.  Image I posted above shows Newfoundland ridge to Scandinavian block.  The Scandinavian/Russia block probably registers as -AO as its close to the AO region. 

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31 minutes ago, packbacker said:

Oops...looks like I posted the wrong image above.  Fixed that.  An area of higher heights can be called a block but some may disagree.  Image I posted above shows Newfoundland ridge to Scandinavian block.  The Scandinavian/Russia block probably registers as -AO as its close to the AO region. 

I wasn't trying to call you out...hope it didn't come across that way.  I was just curious what peoples' thoughts were.  I guess both the height maps and the 500 anom maps can be effective here.

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1 minute ago, Cold Rain said:

I wasn't trying to call you out...hope it didn't come across that way.  I was just curious what peoples' thoughts were.  I guess both the height maps and the 500 anom maps can be effective here.

LOL...I read you post and I thought to myself, what dummy is posting temp maps to demonstrate blocking....I was the dummy.  :facepalm:

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2 minutes ago, packbacker said:

LOL...I read you post and I thought to myself, what dummy is posting temp maps to demonstrate blocking....I was the dummy.  :facepalm:

Haha you had too many maps open at the same time!  But in all seriousness, you would expect the upper level heights to be really high if you just look at those 850 departures.  The 500 anom you posted matches up pretty well with the 850 map, so in a sense, it kinda works.  For me, visually, it's hard to get a sense of how strong the blocking is by looking at the 500 anom maps.  They usually look like they're showing much more robust blocking than there really is.  Like that big orange circle over Newfoundland, for instance.  If that's really a block, it wouldn't be in such a hurry to break down....kind of like the AK block we've seen set up....and you should get a building PV reflection in SE Canada.  I don't have the LR EPS, so I don't know what it goes on to show, but I'll bet that the big red blob over NF, doesn't sit there like that through the balance of the run.

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4 minutes ago, Cold Rain said:

Haha you had too many maps open at the same time!  But in all seriousness, you would expect the upper level heights to be really high if you just look at those 850 departures.  The 500 anom you posted matches up pretty well with the 850 map, so in a sense, it kinda works.  For me, visually, it's hard to get a sense of how strong the blocking is by looking at the 500 anom maps.  They usually look like they're showing much more robust blocking than there really is.  Like that big orange circle over Newfoundland, for instance.  If that's really a block, it wouldn't be in such a hurry to break down....kind of like the AK block we've seen set up....and you should get a building PV reflection in SE Canada.  I don't have the LR EPS, so I don't know what it goes on to show, but I'll bet that the big red blob over NF, doesn't sit there like that through the balance of the run.

It's weird not having access to WB anymore and not being able to see more in depth EPS.  Had it for years and hasn't gotten me anymore snow so figured why flush away that money.  If it's good it will be plastered all over the forums and twitter.

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