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Long Term Disco


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No Alaskan vortex is a good start, that damn thing ruined last winter.

Jon

^This

+100

That would be a great start without that! A near neutral NAO and a weak SE ridge would be really good for a lot of us.

I was just looking at the November before December of 2000; the snowiest month I've/most of us ever experienced, it featured more warmth then we've had now and just a little snow! So it could be in the 50s every day next week, but it doesn't mean winter won't set in a week later.

If the AO and NAO do go negative, then the models have some readjusting to do.

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^This

+100

That would be a great start without that! A near neutral NAO and a weak SE ridge would be really good for a lot of us.

I was just looking at the November before December of 2000; the snowiest month I've/most of us ever experienced, it featured more warmth then we've had now and just a little snow! So it could be in the 50s every day next week, but it doesn't mean winter won't set in a week later.

If the AO and NAO do go negative, then the models have some readjusting to do.

That's true, but I would not want to bet on history repeating itself in this manner. It does seem likely that, like many years, wintry weather will be ushered in abruptly when it does, whether that be late November, mid December, or even early January or something.

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Looks like 2001-02 may end up being a good analogue for this winter. That's the only year I can recall where the ENSO petered out to this extent. If this turns out to be true, it may be case of the cold & snow always being fifteen days out.

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Looks like 2001-02 may end up being a good analogue for this winter. That's the only year I can recall where the ENSO petered out to this extent. If this turns out to be true, it may be case of the cold & snow always being fifteen days out.

We are off to an excellent start on that analogue, since November 2001 was one of the, if not THE all-time, warmest Novembers on record in this region, and currently the region sits at 3 to 6 degrees below normal for November 2012.

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I smell a 1976-77 redux, if that happens hopefully its a somewhat milder/snowier version. I saw that analog tossed around a lot in the summer and early Fall, and this November is behaving quite similarly to November 1976, albeit somewhat milder. Nov 1976 was much colder than normal (a brief bout of Indian Summer late-month) and VERY boring. Gales of November? Pshhh, a few dustings of snow and ONE rainy day was all that November mustered here. Also, the now-antiquated stat of % of possible sunshine had DTW at 51% that November (normal is near 30%).

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Looks like 2001-02 may end up being a good analogue for this winter. That's the only year I can recall where the ENSO petered out to this extent. If this turns out to be true, it may be case of the cold & snow always being fifteen days out.

03-04? Although we were coming off a Nino instead of Nina.

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03-04? Although we were coming off a Nino instead of Nina.

I've seen 03-04 thrown around a lot in terms of analogues, and I think that was a pretty average winter both in terms of temperatures and precip/snowfall. It seems to make sense that this could be an overall pretty average winter, so it seems to be a decent analogue to me.

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A bit of an interesting find.

216 hr GFS:

P1_GZ_D5_PN_216_0000.gif

240 hr GEM:

P6_GZ_D5_PN_240_0000.gif

Once again I think the GFS is to progressive. I know this is fantasy land until the ECMWF picks this up....but at least we can hope

I know, but even the GEM cuts it off. I too think some amplification of a system may occur, and who knows where the low will track, but my early thought is it would be a Western Lakes cutter or tracking through Minnesota if a system does amplify along the leading edge of some arctic air.

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I think the Euro is starting to hint at something If I'm reading these maps correctly.

00zeuro500mbHeightAnomalyNA240.gif

Thoughts anyone?

This map shows ridging pushing eastward into Alaska. GoAK low pushed out. Looks like some blocking returning to the east side of Greenland.

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Good news, but id be careful using those "off" runs 6z and 18z. They tend to suck.

off runs of the GFS are some what helpful in showing trends as it moved closer to the last nights run of the gem. For support, the GEM,GFS and UKMET are showing the MJO moving into phase 1, and some of the ensemble members of the Euro are as well Way to early to have a lot of confidence, but signals seem to be pointing that way.

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Looking at the models and ensembles, I don't like the chances for any decent cold for our sub-forum until the last few days of November, and I'm not sure how long lasting the cold would be when it occurs...

post-525-0-14150400-1353010294_thumb.png

It's more or less a forgone conclusion at this point that the next 7-10 days, through the holiday and probably the holiday weekend, will feature a dry zonal and boring pattern across much of the eastern 2/3rds of the US. As we fast forward to day 10 (240 hr 0z Euro ensembles, 228 hr 12z GFS ensembles) there are some changes beginning to occur with the pattern shown on the models that will make things more likely to become colder and potentially snowy across the eastern US:

1. Both ensembles show the NAO beginning to take on a more negative look. However, the European ensembles on the right are more agressive in developing the -NAO and show more troughing along the east coast at day 10.

2. Both ensembles show nice ridging extending into Alaska with a cross polar flow developing into northwest Canada. The GFS suite is more agressive than the European suite in developing this feature however, resulting in stronger troughing along the west coast and more ridging in the central part of the country.

While the look still isn't particuarly good if you live in the Lakes/Ohio Valley and want to see copious amounts of snow in the 9-10 day timeframe, things are improving.

Sticking with the Allan's model plots, the 11-15 day GFS ensembles continue to show blocking stregnthening near Greenland and Alaska through the end of the model run, as they have been doing for a few days:

post-525-0-97722600-1353010677_thumb.gif

However, the 12z GFS suite doesn't really attempt to dislodge the troughing along the western US coast, which continues to try to maintain higher heights from the Rockeyes east into the Plains, which isn't what we want to see if we are looking for a synoptic snowstorm. Given that no modeling has yet to show the western US troughing trying to break down through the end of the month, I really don't think our chances of seeing a major synoptic snowstorm are good through the end of the month, despite what the op GFS has occasionally shown. Given the persistent -NAO and active sub-tropical jet this pattern could well end up yeilding another Nor' Easter and potential snowstorm for the eastern US. Either way though assuming the NAO does go negative in 8-10 days as has been persistently shown I don't think we torch, but I think the best chance we have for snow is for a clipper type system diving into the eastern US trough and dropping light snows across the lakes and upper Ohio Valley and maybe some lake effect downwind of the lakes.

Another factor to consider is the fairly strong stratospheric vortex that has developed over the North Pole. Thus far we haven't seen this translate into a monstor polar vortex, however the GFS and Euro haven't really shown any signs of the vortex becoming disrupted for the forseeable future, and this makes the AO forecast more uncertain more than a week out. There have been some attempts to develop a -AO in the extended range on the models, but the GFS ensembles show much divergence with the AO forecast near the end fo the run and the op Euro continues to show a dominating polar vortex developing in 8 days or so near the North Pole, resulting in a very positive AO and making it difficult to get the flow to buckle and let the arctic air south...anyways, here is the most recent ECM run avalable showing the stratospheric vortex alive and quite well 9 days from now...until we get the vortex to break down it may be hard to sustain cold air and a -AO/-NAO combo may be hard to come by:

post-525-0-11427600-1353011327_thumb.gif

So, the news isn't all bad, but I think we are still a few weeks away from anything sustained winter wx wise in our area, and the threat for major synoptic snows remains low through the end of the month in the Lakes/Ohio Valley.

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