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Winter 2015-2016 speculation and discussion


AlaskaETC

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Could be somewhat boring making a winter forecast this year given how similar the +QBO/Niño years tend to be. They're almost always +NAM/warm during December/January then flip around to -NAM/cold for February/March, though some of older analogs like 1957-58 don't follow that train of thought.

My hunch is we end up something like a mix of 2006-07 and 1982-83, pattern wise.

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A lot of talk about the potential for the epo to continue it's negative base state this winter. Mostly because of the persistent warm pool in the NE Pac. I'm personally skeptical of the connection between the 2. Those warm anomalies can change fast. A partial reversal happened in Oct of last year.

Nino climo almost always includes low height anomlaies and SLP in the N Pac. Persistence varies from just south of the aleutians to just off the NA coast. Obviously the former is much much preferred. And would support better odds at having +pna and or -epo periods during winter. If we don't get any help from the Atlantic, we'll have to hang out hopes on the Pac...again...

Going under the assumption that the current Nino will end up a top 5 event, I made some quick epo graphs for DJF for the previous top 5 ninos (excuse the crude graphs. I did them quickly). Not very encouraging for a persistent negative state during winter. Which shouldn't be much of a surprise given what the LW pattern should look like in the N Pac during Ninos. Overall, the small data set is basically a coin flip across the board with a + state being favored.

97-98

97-98 epo.JPG

82-83

82-83 epo.JPG

72-73

72-73 epo.JPG

65-66

65-66 epo.JPG

57-58

57-58 epo.JPG

Great post Bob. Isotherm posted about this in the NYC forum but strong and super ninos strongly favor +EPO and displacement east of the Aleutian Low. In 1997 the north pac ssts looked similar until October then a massive goa vortex developed, big time upwelling and it was goodbye warm goa and ne pac and hello +EPO. In July, the Aleutian Low was actually well east of its normal position. If this is any indication of what is to come this fall it's not good: https://twitter.com/strawn_04/status/627361127505104896
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I'm sick of back-loaded winters. Nothing worse than waiting for Feb / Mar snow, only to watch it vaporize the next day. I'd gladly trade AN JFM for a -3F Dec.

.. of course that is predicated on whether one actually believes this winter offers the possibility of Feb/Mar snow....

December isn't really a snow month anyway, especially during Niños (relatively speaking). I could care less if it torches so long as there's at least some semblance of storminess in the pattern, and we flip cold later in the winter, as Niños usually do.

I'd much prefer a backloaded winter, which tend to deliver the most snow, most impressive cold, and generally lead to nicer summers thereafter, statistically speaking.

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December isn't really a snow month anyway, especially during Niños (relatively speaking). I could care less if it torches so long as there's at least some semblance of storminess in the pattern, and we flip cold later in the winter, as Niños usually do.

I'd much prefer a backloaded winter, which tend to deliver the most snow, most impressive cold, and generally lead to nicer summers thereafter, statistically speaking.

I actually have come to like back loaded winters, especially since March has been so impressive the last few winters. And you are right, Decembers generally dont produce in most years for the cities and the coastal plain. 

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I actually have come to like back loaded winters, especially since March has been so impressive the last few winters. And you are right, Decembers generally dont produce in most years for the cities and the coastal plain. 

I agree. I don't mind to be a little patient if it means ending strong. A good start to winter seems like fool's gold more than not.

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I'm sick of back-loaded winters.  Nothing worse than waiting for Feb / Mar snow, only to watch it vaporize the next day.  I'd gladly trade AN JFM for a -3F Dec.

 

 

.. of course that is predicated on whether one actually believes this winter offers the possibility of Feb/Mar snow....

 

We had snow cover from Feb 16th till Match 8 or so-- not great, but impressive for the time of year. 

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We had snow cover from Feb 16th till Match 8 or so-- not great, but impressive for the time of year. 

 

Well, the snow cover was mostly in areas out of direct sun light, but that stretch last year was impressive.

 

December isn't really a snow month anyway, especially during Niños (relatively speaking). I could care less if it torches so long as there's at least some semblance of storminess in the pattern, and we flip cold later in the winter, as Niños usually do.

I'd much prefer a backloaded winter, which tend to deliver the most snow, most impressive cold, and generally lead to nicer summers thereafter, statistically speaking.

 

Now, that is the best argument I've ever heard for a back-loaded winter.

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Well, the snow cover was mostly in areas out of direct sun light, but that stretch last year was impressive.

 

 

Now, that is the best argument I've ever heard for a back-loaded winter.

HUH?? I averaged 6-10 inches during that period.

02/15/2015   0.07 1.1 0.07 1.0 0.05 02/16/2015   T T T 0.5 0.03 02/17/2015   0.78 8.5 0.78 8.5 0.80 02/18/2015   0.00 0.0 0.00 6.5 0.71 02/19/2015   0.02 0.4 0.02 6.5 0.69 02/20/2015   T T T 6.0 0.66 02/21/2015   0.04 0.5 0.04 6.0 0.65 02/22/2015   1.62 10.5 1.55 15.0 2.35 02/23/2015   T 0.0 0.00 9.5 2.02 02/24/2015   0.00 0.0 0.00 9.0 1.93 02/25/2015   0.01 0.1 0.01 8.5 1.90 02/26/2015   0.14 2.0 0.14 9.5 1.99 02/27/2015   T T T 8.0 1.86 02/28/2015   0.00 0.0 0.00 8.0 1.88 03/01/2015   0.02 0.1 0.01 8.0 1.88 03/02/2015   0.02 T T 7.5 1.79 03/03/2015   0.00 0.0 0.00 4.5 1.54 03/04/2015   0.08 0.0 0.00 4.0 1.56 03/05/2015   0.87 T T 1.5 0.90 03/06/2015   1.07 6.0 0.77 7.5 1.63 03/07/2015   0.00 0.0 0.00 7.0 1.60 03/08/2015   0.00 0.0 0.00 4.0 1.35 03/09/2015   0.00 0.0 0.00 0.5 0.38

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It is subject to bias, but mine was legit :P

 

Well, I started typing that snow cover reports are suspect, but wanted to change that it was "subject" to bias as a more PC description, but I didn't catch the correction.

 

I don't doubt your measurements.  However, my point is that while maybe 50% of the ground is covered with 6" of snow and the other 50% is not, is that really "snow-covered"?  

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Well, I started typing that snow cover reports are suspect, but wanted to change that it was "subject" to bias as a more PC description, but I didn't catch the correction.

 

I don't doubt your measurements.  However, my point is that while maybe 50% of the ground is covered with 6" of snow and the other 50% is not, is that really "snow-covered"?  

That's why I don't really keep track of snow cover. Up in the woods snow can stay a week longer than the exposed south-facing yard and hills, so the snow is never well-balanced. In that case what do I report?

 

Too much trouble lol...

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That's why I don't really keep track of snow cover. Up in the woods snow can stay a week longer than the exposed south-facing yard and hills, so the snow is never well-balanced. In that case what do I report?

 

Too much trouble lol...

 

Exactly.  I would think the problem is even worse in an urban environment where 80% of the land is concrete or asphalt.  I don't live there (and rarely visit), but I have a hard time believing these surfaces stay snow-covered very long under Feb and Mar sun.  I know that they don't here, even with an additional 500' in elevation.

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December isn't really a snow month anyway, especially during Niños (relatively speaking). I

could care less if it torches so long as there's at least some semblance of storminess in the pattern, and we flip cold later in the winter, as Niños usually do.

I'd much prefer a backloaded winter, which tend to deliver the most snow, most impressive cold, and generally lead to nicer summers thereafter, statistically speaking.

I much prefer a front loaded winter. That's when I most look forward to it plus I would settle for a white Christmas every year and be done.

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Although a connection seems to be there, such a small set is full of caveats. But fun to look at nonetheless. I like gridded #'s better than scatters:

 

post-2035-0-71610100-1438814712_thumb.jp

 

 

Looks good until you get below -.600 for July then the wheels come off. 4 out of the top 5 on the list had -AO Augusts as well. Off to a good start there. 

 

This could be better than the SAI/SCE! Dr. Cohen should be scared.

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HM just ran the correlation and posted it on twitter.  

 

.@DTVaWeatherman top -AO 1/3 (n=63) with range -0.397 to -1.356 has r=0.76 for DJF. +AO r=0.14 or 0.19 depending on range.

 

 

r=0.76 is pretty good.

he updated after that post and found top 10 to have a .86 correlation and top 5 have .89

since this year is #2, well, ahh.... :weenie:

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Exactly.  I would think the problem is even worse in an urban environment where 80% of the land is concrete or asphalt.  I don't live there (and rarely visit), but I have a hard time believing these surfaces stay snow-covered very long under Feb and Mar sun.  I know that they don't here, even with an additional 500' in elevation.

No one is using paved surfaces to compile snow-cover-days data. No one is suggesting that paved surfaces "stay snow-covered very long under Feb and Mar sun." 

 

This whole conversation resulted from your personal-experience-post after someone challenged you about your back-loaded winter comment. Snow-cover is a stat that climate and 'official' stations collect, and it's always been interesting to compare DCA vs. IAD in terms of snow depth and snow-cover days. No one is trying to change your mind about what you experienced in your back yard-- Yes, your property has different exposures so snow is gone from one side but not the other. Why you would use that personal experience to diminish others' data about February and March days is what I don't understand......

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Not sure about any one else's, but the majority of my snow cover during that stretch was in areas away from direct sunlight.  Soon after the storms, the usual areas were pretty quickly exposed.  My south and southwest (unprotected) facing yard was pretty much snowless, while protected areas had a nice snow pack.

 

 

Well, it is flat here, and Stephens City was basically built on graze-land and old orchards, so there are about 19 trees in the whole town.  However, I also suspect snow cover "estimation" is highly suspect subject to bias.

 

 

Well, I started typing that snow cover reports are suspect, but wanted to change that it was "subject" to bias as a more PC description, but I didn't catch the correction.

 

I don't doubt your measurements.  However, my point is that while maybe 50% of the ground is covered with 6" of snow and the other 50% is not, is that really "snow-covered"?  

 

 

That's why I don't really keep track of snow cover. Up in the woods snow can stay a week longer than the exposed south-facing yard and hills, so the snow is never well-balanced. In that case what do I report?

 

Too much trouble lol...

 

 

Exactly.  I would think the problem is even worse in an urban environment where 80% of the land is concrete or asphalt.  I don't live there (and rarely visit), but I have a hard time believing these surfaces stay snow-covered very long under Feb and Mar sun.  I know that they don't here, even with an additional 500' in elevation.

Here you go, it is NOT difficult......

http://cocorahs.org/media/docs/measuringSnow2.1.pdf

I use two snowboards during the winter to get the most accurate that I can get, yes my yard also has a W to WSW facing slope that snow disappears of off before the rest, it is an AVERAGE. If you have 10 inches in the shade and 2 inches on the full sun WSW slope, it is a 6 inch average. I usually take 4-6 sample measurements to get my average snow depth. Yes, I am a 'stickler' for accuracy.

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Here you go, it is NOT difficult......

http://cocorahs.org/media/docs/measuringSnow2.1.pdf

I use two snowboards during the winter to get the most accurate that I can get, yes my yard also has a W to WSW facing slope that snow disappears of off before the rest, it is an AVERAGE. If you have 10 inches in the shade and 2 inches on the full sun WSW slope, it is a 6 inch average. I usually take 4-6 sample measurements to get my average snow depth. Yes, I am a 'stickler' for accuracy.

Thanks for the good info.

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No one is using paved surfaces to compile snow-cover-days data. No one is suggesting that paved surfaces "stay snow-covered very long under Feb and Mar sun." 

 

This whole conversation resulted from your personal-experience-post after someone challenged you about your back-loaded winter comment. Snow-cover is a stat that climate and 'official' stations collect, and it's always been interesting to compare DCA vs. IAD in terms of snow depth and snow-cover days. No one is trying to change your mind about what you experienced in your back yard-- Yes, your property has different exposures so snow is gone from one side but not the other. Why you would use that personal experience to diminish others' data about February and March days is what I don't understand......

 

 

Thanks, I realize that no one is using concrete surfaces for snow measurements.  However, if 80% of the surface area is made from that material, then that likely leaves a lot of exposed area.  According to the cocorahs manual wxdude linked, anything less than 50% ground coverage is reported only as a trace. Call me crazy if I think the process people use to estimate % coverage might be prone to bias and/or errors.  I mean it's not like the actual depth measurements (something that should be easily quantified) of new snow are not constantly called into question around here. 

 

I'm not trying to diminish anyone's experience, I simply cast doubt on the process that one attempts to quantify "snow cover."  Does a "T" count as a snow cover day?  My personal experience can't possibly be too different than most, seeing that we share similar latitude and climate.  

 

 

Here you go, it is NOT difficult......

http://cocorahs.org/media/docs/measuringSnow2.1.pdf

I use two snowboards during the winter to get the most accurate that I can get, yes my yard also has a W to WSW facing slope that snow disappears of off before the rest, it is an AVERAGE. If you have 10 inches in the shade and 2 inches on the full sun WSW slope, it is a 6 inch average. I usually take 4-6 sample measurements to get my average snow depth. Yes, I am a 'stickler' for accuracy.

 

Great info.  This explains the process nicely.  You're obviously very thorough. It still seems prone to bias to me, however.  Imagine, if you will, that the ground is 40% covered (in the shade) with 6 inches of snow, and 60% of the ground is bare (in the sun... and/or concrete/pavement).  Officially this is a "trace".  Now, if you deem that the ground is 51% covered, then this snow cover measurement is suddenly 3".  I hope this illustrates the point that I'm trying to make.  I realize the sticklers for detail, like yourself, will report the range of measurements with the "trace", but - again - does a "T" count as a snow-cover day?  That's not rhetorical, I really don't know the answer to that question.

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