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Countdown to Winter 2018 -2019


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16 minutes ago, Typhoon Tip said:

Fwiw - according to the Climate Diagnostic Center's cross-correlation table...  their linear correlations between indices -

The PNA and NAO have close to an N/S ...noisy correlation starting Dec...but... it gets a bit brighter toward February's, when negative correlation coefficient becomes fairly robust around -.25. 

In straight up stat definitions, that's weakly correlated... however, we are dealing in atmospheric analysis, and with its intrinsic noisy domain of various arguing mass-fields at all times, I almost wonder if that ".25 ness" might be more significant than the standard paradigm.  Either way, there is semblance there that they tend to move opposite of one another as the winter gets into its wheel-house 45 days ...which I consider to be about Jan 15 to March 1 for snow barring nit picky neurotic decomposition of the data to somehow extend winter indefinitely...  

Back handed snark aside... the NAO and PNA are spatially not very similar (I know you know this simple schit I'm prepping the reader here...)  The PNA being 3X's the areal girth of the NAO (or whatever it is) means it takes bigger forcing to get it to motivate...etc..etc...

Contrasting, the NAO can become modal in intra-weekly time scales, only to return to the previous dynamic...merely because some wayward bomb happened to ripple through and transiently knock it off kilter.  The PNA is so massive that you could fit a couple bombs in there and it may not even register much on the nightly EOFs... So, that's proooobably related to why the index correlations are ho-hum at best, too.  

Point being, if the PNA is moving positive or negative, the NAO may or may not be responding to its own headaches and either needs to catch up ...or even can't and is muted. 

That all said ...there is still a residue of negative movement there though.  

My personal findings are that you need a modest rising PNA with a neutral negative NAO, in a gradient that is not overall "too" saturated for big snow/winter storm events.. (otherwise, shearing starts negation if the gradient is too steep)  The statistical sciences I've read on the matter, from H. A. to J.B. and everyone in between, they seem to only skim the surface of these index correlations/comparisons and don't plumb very deep into their actual anomaly ranges - which is where the story of 1978 and 1992 and 1993 and 1996 and 2015 is told. 

Not to gloss eyes any more than this probably already has ... but, I think of the atmosphere as having a total 'torque budget' if you will... If the flow is too hostile and fast, with uber compression and 510 heights over Jame's Bay while 588 over Dallas to Miami latitudes... that "looks" delicious...but it's those red berries they warn you about as a kid...  Ha.  seriously, with torque budgeting...all the angular momentum in that circumstance is quantifiably (perhaps) gobbled up in the planetary wave scales... However, a weaker gradient can still give you the same actual numerical index numbers ... but, there is a lot of torque on the playing field and sure enough...shearing becomes less and the torque gets expressed at smaller scaled bombs.   Think +.5 PNA --> while <-- -.5 NAO, sans the extraordinarily tall subtropical Dallas wall towering above the grand canyon in Canada. 

This conjures a much better visual vs a Canadian girdle.

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13 minutes ago, weathafella said:

This conjures a much better visual vs a Canadian girdle.

Mmm...yes, right - the locals don't respond as well to metaphoric/poetic reference in the use of the language.. 

I realize ur just bustin' balls but the formal Webster (for what that's worth) definition of girdle begins with: ": something that encircles or confines: "   ... not sure what to say man - ya gotta learn to process information via symbolic inference too. 

 

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14 hours ago, Hoth said:

"Cold and white" doesn't necessarily describe snow. It could just describe the demeanor of New England's historically pale-skinned and puritanical natives during those months.

That phrase nails 2002-03 up here, way BN temps and way BN snowfall, as all but one (Jan 4) of the good storms were suppressed.  DJFM that season were all BN for temps, with only 2013-14 doing the same since 1998-99, our 1st winter here.

ENSO ranging from weak nino thru neutral to moderate nina have been good for Maine snow, using CAR, PWM and Farmington as representative.  Strong nino is actually the best, but sample size is only 3 and both moderate and very strong nino show significantly BN snow for their 9 winters combined.

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3 hours ago, 512high said:

Your last sentence the words "early ideas"......on another swamp *ss day, we want more "ideas"! Good write up .....

Just look at Will's last post...idk how you could be unhappy with weak el nino climo in sne...especially east.

Of course, there are exceptions, and I'll do my best to hit every nuance as we progress through fall.

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11 hours ago, MarkO said:

Any idea how ski country/NNE does?

I grabbed the Mt. Mansfield snow depth data for the seasons people seem to have been taking about in this thread (except ’51-’52 which doesn’t appear to be available on the SkiVT-L Mt. Mansfield Weather Data Page).  Snowpack seems decent in those seasons as far as I can tell – there’s really not much below the mean.  I’m sure PF will comment if he gets a chance.

Mansfieldweakelninosnowpack.jpg

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GW is an article of religious faith (and scientific fact, at least for the time being). The fact side is fine, the ideological assumptions are not. Sometimes I wonder if the latter gets in the way of the science. Granted, a super nino would paint us in the CFC orange all winter, but it seems a bit dumb to make the assumption on the eve of what looks like a weak nino. 

Of course, the Old Farmers Almanac has already cancelled winter, so maybe the CFC is taking its cues from them.

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2 minutes ago, J Paul Gordon said:

GW is an article of religious faith (and scientific fact, at least for the time being). The fact side is fine, the ideological assumptions are not. Sometimes I wonder if the latter gets in the way of the science. Granted, a super nino would paint us in the CFC orange all winter, but it seems a bit dumb to make the assumption on the eve of what looks like a weak nino. 

Of course, the Old Farmers Almanac has already cancelled winter, so maybe the CFC is taking its cues from them.

Larry Cosgrove, in one of his recent newsletter mentioned something along the lines of taking GW into account when making a long range forecast. 

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Sure, but what is the formula for that? Do we just add a couple of degrees C/F? Do we multiply by certain factor? Is there an agreed upon norm?

If we are doing science, we need the numbers. If we are doing ideology/religion we can simply invoke the creed "I believe in Climate Change".

Of course the climate is changing (it does us well to remember that 15,000 insignificantly short years ago a kilometer of ice covered the place I live in) and currently it is warming. Human beings very likely have an affect on this. Precisely what effect and how long the warming will continue is open for debate. There are other factors at play, too, including solar activity, etc. that may mitigate or enhance GW/CC.

It worries me when GW is thrown into predictions without further qualification. It would help if there was a standard value being added to predictions and those predictions were checked against what actually happens.

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1 hour ago, J Paul Gordon said:

Sure, but what is the formula for that? Do we just add a couple of degrees C/F? Do we multiply by certain factor? Is there an agreed upon norm?

If we are doing science, we need the numbers. If we are doing ideology/religion we can simply invoke the creed "I believe in Climate Change".

Of course the climate is changing (it does us well to remember that 15,000 insignificantly short years ago a kilometer of ice covered the place I live in) and currently it is warming. Human beings very likely have an affect on this. Precisely what effect and how long the warming will continue is open for debate. There are other factors at play, too, including solar activity, etc. that may mitigate or enhance GW/CC.

It worries me when GW is thrown into predictions without further qualification. It would help if there was a standard value being added to predictions and those predictions were checked against what actually happens.

Maybe instead of calling it global warming just think of it more generically as bias. If someone bet you that a month was going to be above or below normal, which way would you lean without looking at anything?

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15 hours ago, Great Snow 1717 said:

Above.

If you always leaned warm in the energy industry, you’d do well. Obviously exceptions like winter in the Midwest and northeast 13-14 and 14-15...but that’s how it’s been. But, it’s inpoetant to realiE the small scall patterns and how that is the big driver. Nobody has talked about how chilly Canada has been. We’ve been warm because of s persistent trough in the NW territories into the PAC NW.

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1 hour ago, CoastalWx said:

If you always leaned warm in the energy industry, you’d do well. Obviously exceptions like winter in the Midwest and northeast 13-14 and 14-15...but that’s how it’s been. But, it’s inpoetant to realiE the small scall patterns and how that is the big driver. Nobody has talked about how chilly Canada has been. We’ve been warm because of s persistent trough in the NW territories into the PAC NW.

9 out of 10 times it's AN though it feels like the winter months are more likely to register BN when it's the easiest time to go above. 

BN weather has become very rare. In fact even during normal months people have complained that it was too cold/cool. This June was a prime example. 

Maybe that's why people think GW isn't happening, because AN feels normal and normal feels cold. 

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There’s no doubt we’re in a warm regime but keep in mind the holy grail-snow-has been above normal by a significant margin vs historical averages over the past 25-30 years.  At some point the warmth will mute that if it keeps happening.  Losing the Greenland ice shield would be a game changer and it could trigger a fairly rapid reversal.

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Winter months have been easier to go below normal recently than other seasons. In fact, the middle latitudes as a whole have seen almost no winter warming in the past 25-30 years....it's been confined to the high latitudes which may be part of our lack of winter warming recently. Even last winter we had 3 out of 4 months below normal. Granted it was offset by a nuclear torch February....

 

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7 hours ago, ORH_wxman said:

Winter months have been easier to go below normal recently than other seasons. In fact, the middle latitudes as a whole have seen almost no winter warming in the past 25-30 years....it's been confined to the high latitudes which may be part of our lack of winter warming recently. Even last winter we had 3 out of 4 months below normal. Granted it was offset by a nuclear torch February....

 

This is a good point. Winters are actually more harsh now in many northern areas than they were in the middle of the 20th century. Actually, here 6 of the past 10 winters have been colder than normal and 7 of the past 10 have been snowier than normal (2 of the other 3 were only slightly below normal snow). Essentially there has been 1 ratter winter here the last decade 

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On 8/30/2018 at 5:09 PM, J Paul Gordon said:

Sure, but what is the formula for that? Do we just add a couple of degrees C/F? Do we multiply by certain factor? Is there an agreed upon norm?

If we are doing science, we need the numbers. If we are doing ideology/religion we can simply invoke the creed "I believe in Climate Change".

Of course the climate is changing (it does us well to remember that 15,000 insignificantly short years ago a kilometer of ice covered the place I live in) and currently it is warming. Human beings very likely have an affect on this. Precisely what effect and how long the warming will continue is open for debate. There are other factors at play, too, including solar activity, etc. that may mitigate or enhance GW/CC.

It worries me when GW is thrown into predictions without further qualification. It would help if there was a standard value being added to predictions and those predictions were checked against what actually happens.

Adding about 2 deg F to long-term temperature averages for monthly guesses beats just about all other prediction methods for long-term temp forecasting at most mid latitude locations.  For mountainous and urban locations, the additive factor should be higher.  For some continental locations that radiate well (important for daily mins), the factor is a little lower.  

Most forecasters are not scientists.  Climatologists can model and predict increases in global average temperatures.  But meteorologists cannot predict short-term regional forecast temperatures in the same way.  It is well understood that weather does not equal climate.  But because warming has been so significant in most locations, adding a constant factor actually does out-predict most regular forecasts in most places (on average).  It does not work every month... just over the long term (like 12 consecutive months averaged).

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17 hours ago, ORH_wxman said:

Winter months have been easier to go below normal recently than other seasons. In fact, the middle latitudes as a whole have seen almost no winter warming in the past 25-30 years....it's been confined to the high latitudes which may be part of our lack of winter warming recently. Even last winter we had 3 out of 4 months below normal. Granted it was offset by a nuclear torch February....

 

The long-term temperature trend in winter is clearly increasing.  If you plot a relatively short duration dataset that starts with a relatively warm period, you might get a near horizontal trend.  But that's a bit of a statistical fluke.  Most places are warming in winter and in summer.  Of course there are significant fluctuations in this warming and the changes are inhomogeneously distributed spatially.  High latitudes and high elevation areas are warming faster than low elevation, mid-latitudes.  

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1 hour ago, eduggs said:

The long-term temperature trend in winter is clearly increasing.  If you plot a relatively short duration dataset that starts with a relatively warm period, you might get a near horizontal trend.  But that's a bit of a statistical fluke.  Most places are warming in winter and in summer.  Of course there are significant fluctuations in this warming and the changes are inhomogeneously distributed spatially.  High latitudes and high elevation areas are warming faster than low elevation, mid-latitudes.  

This doesn't refute what I said though. As warming has increased overall, the winters have actually had more trouble warming in the middle latitudes and this may not be coincidence. The effect is most obvious in Asia where there has been a steep cooling but we've seen basically zero trend since about 1990 across NA. The exception may be the far southwest. 

The warming will resume at some point but it shows that temporal and spacial trends are not very well understood.  

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1 hour ago, CoastalWx said:

Too big for me to post, but I forgot I had the entire loop of 3/13 on my laptop. What a classic loop. Interesting the little BOS-Scooter screw zone relatively speaking too. However, if 16" is screwed..I'll take it. But man...gorgeous evolution.

Amazing fronto band over E MA and RI/E CT in that. 

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17 minutes ago, CoastalWx said:

That final band gave me almost 4” of see through fluff. Some of the best growth I’ve ever seen. 

Yeah I had nearly 2 feet and the final 12-14" was like lake effect. It was funny because the first 2-3" was really wet and greasy and I'm thinking "oh man, are we gonna have a repeat of 5 days earlier?" Even though I knew aloft was definitely colder. I was still worried it would take too long to turn drier. But it did very quickly once the really good lift got in here...temp plummeted into the 20s and the snow went fluffy. But yeah, that last few hours was like 20-25 to 1 stuff. 

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2 hours ago, ORH_wxman said:

This doesn't refute what I said though. As warming has increased overall, the winters have actually had more trouble warming in the middle latitudes and this may not be coincidence. The effect is most obvious in Asia where there has been a steep cooling but we've seen basically zero trend since about 1990 across NA. The exception may be the far southwest. 

The warming will resume at some point but it shows that temporal and spacial trends are not very well understood.  

I only pop over to this thread for some pre-Winter discussion, but there has been some interesting talk in here. I don't get into any of the specifics regarding average global temperature, climate change, etc. But a few observations I can make locally; winters in this area arent warming, there is minor warming in the other seasons, but the main factor of that warming is increasing minimum temperatures (UHI?). Average high temperatures do not seem to be changing much.  And this is most notable summer nights. 

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