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Hoosier

Winter 2017-18 Medium/Long Range Disco

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Thread is for discussion of the pattern and longer range storm threats that are too far out for a separate thread.

Obviously most areas are not seeing consistent winter yet, but at least there are/will be shots of it.  

As mentioned in the November thread, there is a potential system for the 11th-12th that may be of some interest.  There will be a cold shot prior to that and it may hold on long enough for snow (or at least snow changing to rain) for a lot of folks.  

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The current Bering Sea Ridge/Aleutian Ridge, which is quite common in La Nina's, looks to continue over the next 10 days. This key player is a major influence on our pattern here in the East. Now a Bering Sea Ridge, usually centers the coldest anomalies in the West and in the Plains, which is what were seeing right now, with transient cold shots in the East. However, seeing a continuing Bering Sea Ridge is ideally better than having a big AK vortex, which practically killed the 2011-12 winter. 

 

ecmwf-ens_z500a_nhem_11.thumb.png.6a4c94300a92d773a15441368be6abd7.png

For now, having the coldest anomalies centered in the West will allow for a solid snowpack to establish itself, which would aide us down the line come December and beyond. Below is the latest EPS at Day 15 and one of the key things that stuck out to me was; 1) the Bering Sea Ridge and 2) the development of ridging around Greenland which maybe the development of some blocking (-NAO/AO). This coupled with the Bering Sea Ridge, will allow us in the East, especially the Great Lakes, to be on the colder side of the gradient. I wouldn't be surprised if many of us in the lower Great Lakes area see our first real snow event beyond the 10th, and further increasing chances beyond the 18th, should this pattern unfold.

59ff953f2d7f0_ScreenShot2017-11-05at5_39_51PM.png.5e581eb8847f051616fd2271e63190c3.png

Its certainly a positive sign, so let's see! 

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2 hours ago, Snowstorms said:

The current Bering Sea Ridge/Aleutian Ridge, which is quite common in La Nina's, looks to continue over the next 10 days. This key player is a major influence on our pattern here in the East. Now a Bering Sea Ridge, usually centers the coldest anomalies in the West and in the Plains, which is what were seeing right now, with transient cold shots in the East. However, seeing a continuing Bering Sea Ridge is ideally better than having a big AK vortex, which practically killed the 2011-12 winter. 

 

ecmwf-ens_z500a_nhem_11.thumb.png.6a4c94300a92d773a15441368be6abd7.png

For now, having the coldest anomalies centered in the West will allow for a solid snowpack to establish itself, which would aide us down the line come December and beyond. Below is the latest EPS at Day 15 and one of the key things that stuck out to me was; 1) the Bering Sea Ridge and 2) the development of ridging around Greenland which maybe the development of some blocking (-NAO/AO). This coupled with the Bering Sea Ridge, will allow us in the East, especially the Great Lakes, to be on the colder side of the gradient. I wouldn't be surprised if many of us in the lower Great Lakes area see our first real snow event beyond the 10th, and further increasing chances beyond the 18th, should this pattern unfold.

59ff953f2d7f0_ScreenShot2017-11-05at5_39_51PM.png.5e581eb8847f051616fd2271e63190c3.png

Its certainly a positive sign, so let's see! 

Sounds great. Bring on winter!

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Better not be a torch Dec/backloaded winter. The east trough west ridge regime we've seen each spring since 2012 is REALLY starting to get old. 

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53 minutes ago, cmillzz said:

Better not be a torch Dec/backloaded winter. The east trough west ridge regime we've seen each spring since 2012 is REALLY starting to get old. 

Last couple springs haven't been that bad really.  You act like it's been wall to wall trough/cold weather.

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That is an impressive surface high coming down from Canada later in the week (especially for this time of year) and it's what will give that weekend system a chance to be wintry, even though it looks to be retreating.  If it ends up at that strength in that position, I wouldn't be surprised if the low level cold air bleed is more efficient than progged, which would then result in it taking longer to dislodge.  

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Really strong PNA relaxes, EPO loses steam though. This should allow some cold shots the next few weeks. No sustained cold/blocking in the foreseeable future. The Euro/GFS actually has a piece of the PV heading into the Northeast on Friday. Looks like an arctic front in the beginning of November.

4indices.png

ecmwf-ens_T850a_us_6.png

 

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1 hour ago, Hoosier said:

That is an impressive surface high coming down from Canada later in the week (especially for this time of year) and it's what will give that weekend system a chance to be wintry, even though it looks to be retreating.  If it ends up at that strength in that position, I wouldn't be surprised if the low level cold air bleed is more efficient than progged, which would then result in it taking longer to dislodge.  

Looks like a January arctic front. I don't remember seeing those temps on Nov 10th in forever. 

gfs_T850_us_17.png

gfs_mslp_pcpn_frzn_us_16.png

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Any explanation for that ginormous trough next week? With a neutral EPO and -PNA/+NAO, why would we be seeing a trough at all. Is there some kind of SSW event about to take place that would cause that? 

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2 hours ago, Hoosier said:

Last couple springs haven't been that bad really.  You act like it's been wall to wall trough/cold weather.

That's just what it seems like to me. I remember May this year being extremely foul though, that's probably why.

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52 minutes ago, cmillzz said:

That's just what it seems like to me. I remember May this year being extremely foul though, that's probably why.

Do you remember April?  

Apr17TDeptUS.png.c68871883344107e363db6fa107083b4.png

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56 minutes ago, cmillzz said:

Any explanation for that ginormous trough next week? With a neutral EPO and -PNA/+NAO, why would we be seeing a trough at all. Is there some kind of SSW event about to take place that would cause that? 

EPO is still negative for a while, though rising.  Troughs do occur with unfavorable alphabet soup indices, it's just that they will have a harder time locking in on a consistent basis.

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Potential cold shot later this week is impressive for mid-November, but it lifts out quickly and the long range looks milder and meh.

With that said - still too early to be concerned about the pattern. We’ll see how things look in about 10 days - to get a good sense of Thanksgiving and beyond. Would like to keep building up the snow in southern Canada, but the 7-10 day period looks mild even up there. 

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1 hour ago, beavis1729 said:

Potential cold shot later this week is impressive for mid-November, but it lifts out quickly and the long range looks milder and meh.

With that said - still too early to be concerned about the pattern. We’ll see how things look in about 10 days - to get a good sense of Thanksgiving and beyond. Would like to keep building up the snow in southern Canada, but the 7-10 day period looks mild even up there. 

I'm definitely not seeing anything at all that would hurt buildup of Canadian snowpack.

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12 hours ago, cmillzz said:

Any explanation for that ginormous trough next week? With a neutral EPO and -PNA/+NAO, why would we be seeing a trough at all. Is there some kind of SSW event about to take place that would cause that? 

I'm no expert, but there was this from the GEFS for the period:

 

20171024 6z gfs-ens_10mb_trend_namer_d14.png

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2 hours ago, michsnowfreak said:

I'm definitely not seeing anything at all that would hurt buildup of Canadian snowpack.

Of course I hope you’re correct. North of 50N seems ok, but far S Canada and the far northern tier of the US will probably lose snow cover as fairly mild temps (30s and 40s) arrive in 7-10 days. 

Not a big deal and not too unusual for mid-November...but would like to see the + snow cover anomaly continue as much as possible. 

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5 hours ago, beavis1729 said:

Of course I hope you’re correct. North of 50N seems ok, but far S Canada and the far northern tier of the US will probably lose snow cover as fairly mild temps (30s and 40s) arrive in 7-10 days. 

Not a big deal and not too unusual for mid-November...but would like to see the + snow cover anomaly continue as much as possible. 

Me too. Trust me, like a switch, when November 1st arrives I am ready for snow. However I'm also realistic, and building up snowpack in Canada is the most important thing at this early date. It's very common for us to see measurable snow in November, but it's very uncommon for us to see a lot of it. December through March is another story, especially with a niña brewing. I have no problem with how the upcoming pattern seems to be shaping up.....SO FAR.

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Winter is a funny commodity. Sometimes it never shows anything worth its investment. Other times, it doubles in value overnight. This season looks to have a good promise now its just up to time. I do like the snowpack/cold building to the north plus the continual plumage of temp over the past 3 weeks. In perspective the kids were swimming in the lake St. Claire just 4 weeks ago..

If you want sustained cold, its all about the baby steps in getting there. A quick transition to cold will flip back to warmth in the same fashion.

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4 hours ago, Hoosier said:

Euro is still colder with the weekend system.  

Euro's been pulling the cold wagon lately. Those who can remember the contrast between Christmas of '82 and the following one know what contrasts are possible in just a single year.

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I'm going to be in Door County this weekend, so the weekend system definitely has my attention.  Looks very borderline, might be changing precip types depending on time of day and rates as well.  Maybe a 'snow island' kind of scenario for some up there.

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3 hours ago, Hoosier said:

AO is progged to fall off a cliff.  NAO pretty negative too, which is not a surprise given the correlation between those two.

Yeah, but due to the screamer off the pacific, that is just a reaction. The question is whether it can last long enough to create anything afterwards. Ensembles of course in that range are all over the place.

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Ok, what about this?  A very cold month that was rather active and of course featured the Dec 11 storm.

 

5a1e32b5ccc6b_cd2607fb901d9d5c96049ad7fe101_331_20_39_15_prcp.png.faa6f6766ed7be132f84120083b06730.png

 

Bringing up December 2000 is an excellent example to disprove the frequent assumption that an amplified +PNA/-EPO ridge automatically means cold and dry away from the lake effect belts. Another example of this is January 2014. Comparing the 500 mb composites for December 2000 and January 2014 with day 15 of the 12z 12/28 European ensemble, they're strikingly similar.

 

This isn't to say that we're headed for a historic stretch of snow outside the lake belts, but that northwest flow implied on the ensemble mean is not a guaranteed mainly dry pattern. The position of the ridge axis is important, with farther west as in December 2000 and January 2014 and by extension what's shown on the EPS prog one that can be quite favorable for an active pattern with clippers/hybrids from polar jet. Also, if the progged -NAO block trends weaker as shown on today's EPS, that gives a better chance of favorable storm tracks from phased waves due to influence of southeast Ridge/WAR.

 

So, moving forward, we need to watch for the position of the +PNA/-EPO ridge axis in terms of attaining a more active pattern vs being drier with moisture starved clippers. Overall, I'm fairly optimistic for at least some opportunities for light-moderate events outside of the lake belts, because temperatures correlate pretty well with snow and it's less common to get largely shut out in very cold patterns than it is to cash in with at least somewhat near normal snow. With all this being said, obviously possible that we do end up in a very cold but mainly dry pattern. 47e34d07641b02ae1edd5b83b5e26942.jpg6c55225399be3bf3e6dd10071fac2c0b.jpg7dbcf7cfaab7e929302b37d917530d53.jpg

 

 

 

 

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17 minutes ago, RCNYILWX said:

Bringing up December 2000 is an excellent example to disprove the frequent assumption that an amplified +PNA/-EPO ridge automatically means cold and dry away from the lake effect belts. Another example of this is January 2014. Comparing the 500 mb composites for December 2000 and January 2014 with day 15 of the 12z 12/28 European ensemble, they're strikingly similar.

 

This isn't to say that we're headed for a historic stretch of snow outside the lake belts, but that northwest flow implied on the ensemble mean is not a guaranteed mainly dry pattern. The position of the ridge axis is important, with farther west as in December 2000 and January 2014 and by extension what's shown on the EPS prog one that can be quite favorable for an active pattern with clippers/hybrids from polar jet. Also, if the progged -NAO block trends weaker as shown on today's EPS, that gives a better chance of favorable storm tracks from phased waves due to influence of southeast Ridge/WAR.

 

So, moving forward, we need to watch for the position of the +PNA/-EPO ridge axis in terms of attaining a more active pattern vs being drier with moisture starved clippers. Overall, I'm fairly optimistic for at least some opportunities for light-moderate events outside of the lake belts, because temperatures correlate pretty well with snow and it's less common to get largely shut out in very cold patterns than it is to cash in with at least somewhat near normal snow. With all this being said, obviously possible that we do end up in a very cold but mainly dry pattern. 47e34d07641b02ae1edd5b83b5e26942.jpg6c55225399be3bf3e6dd10071fac2c0b.jpg7dbcf7cfaab7e929302b37d917530d53.jpg

 

 

 

 

Nice post.  As far as the -NAO, we'll see how that sets up.  With the most recent -NAO, I believe it ended up being weaker/more east based than models had been suggesting.  

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1 hour ago, snowlover2 said:

Don't I wish.

gfs_mslp_pcpn_frzn_us_44.png

gfs_mslp_pcpn_frzn_us_45.png

This is where the trough needs to setup, just far enough west to open up the door for stuff to slide northeast and phase with the northern stream vs being crushed by it or phasing on the east coast.

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The 12z GFS has a lot of clippers of varying intensities from about FH200+, several runs prior also had clippers, but nowhere near as many as the 12z. Maybe RC was on to something? I hope. I'm optimistic for this upcoming pattern.

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