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Author Topic: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs  (Read 11166 times)

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #100 on: December 03, 2019, 04:19:08 PM »
Anyone would think winter had arrived.
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #101 on: December 05, 2019, 07:21:51 PM »
https://ccin.ca/ccw/snow/current - 4 Dec

But how much melt before the next blast ?
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #102 on: December 09, 2019, 11:58:03 AM »
https://ccin.ca/ccw/snow/current - 4 Dec

Qu: But how much melt before the next blast ?
_____________________________
https://ccin.ca/ccw/snow/current - 8 Dec

A:  Quite a lot (North America and Eurasia)

My speculation that belongs to me (mostly stolen from real scientists) - for North America especially ↠↠
Global heating ↠ Weak Polar Vortex
↠ ↠ large slow-moving Rossby Waves 
↠ ↠ influx of cold & snow from the North
↠ ↠ followed by influx of warmth from the South

= record snowfall & storms followed by strong melt = overall average snow cover.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Shared Humanity

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #103 on: December 09, 2019, 10:42:10 PM »
47F and raining in Chicago.

Shared Humanity

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #104 on: December 15, 2019, 03:07:30 PM »
Generally, over recent years, snow cover extent has lagged snow water equivalent in the NH.

https://www.ccin.ca/index.php/ccw/snow/current

If we look at the current map for snow depth anomalies, it is clear what is happening. Positive anomalies are generally occurring at higher elevations and latitudes while negative anomalies are occurring at lower elevations and latitudes. Kind of expected, IMHO.


gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #105 on: December 18, 2019, 02:37:34 PM »
https://ccin.ca/ccw/snow/current as at 17 December

New snow in North America, but wunderground.com say temperatures will rise in the US Lower 48. A thaw coming?

In Eurasia only modest new snowfall.

Overall snow cover extent for the Northern Hemisphere very much average.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #106 on: December 23, 2019, 06:12:10 PM »
https://ccin.ca/ccw/snow/current as at 22 December

Interesting contrast between Snow Cover Extent (SCE) and Snow Water Equivalent (SWE).

In North America (NA) SCE is a average after a thaw at low latitudes, relatively low compared with the last 2 years. But SWE is above average.

Eurasia (EU) SCE is very much below average, mainly due to an absence of snow cover in Europe. But SWE is well very much above average.

In other words, where there is snow its thickness and therefore mass is very much above average.

We are also getting close to the maxima of SCE and SWE for the northern hemisphere, though from now to March or even April large snowfalls can happen.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #107 on: January 04, 2020, 08:26:48 PM »
https://ccin.ca/ccw/snow/current Snow Cover Extent and Mass as at 3 January 2020

The situation as described below on 22 December has not changed. i.e. Snow Cover Extent at or below average, Snow Water Equivalent well above average, meaning average snow thickness (where it is lying) very much above average.

https://ccin.ca/ccw/snow/current as at 22 December

Interesting contrast between Snow Cover Extent (SCE) and Snow Water Equivalent (SWE).

In North America (NA) SCE is at average after a thaw at low latitudes, relatively low compared with the last 2 years. But SWE is above average.

Eurasia (EU) SCE is very much below average, mainly due to an absence of snow cover in Europe. But SWE is well very much above average.

In other words, where there is snow its thickness and therefore mass is very much above average.

From now to March or even April large snowfalls can happen.

ps: Snowfall on Greenland is also a bit below average.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Janne Hietalahti

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #108 on: January 17, 2020, 09:44:21 AM »
Im from Finland and I was amazed about inaccuracies on snow cover data. We have 1/4 country, about 80 000 km^2 snow free, and in nooa and rutgers it seem all snow here.

Shared Humanity

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #109 on: January 17, 2020, 03:21:43 PM »
The Snow Cover Extent and Snow Water Equivalent metrics are getting a little crazy.

(I miss having bbr2314 here saying it is heralding a new ice age.)

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #110 on: January 17, 2020, 04:23:37 PM »
And so it goes on
https://ccin.ca/ccw/snow/current Snow Cover Extent and Mass as at 16 January 2020

The situation as described in the quotes below has not really changed. i.e. Snow Cover Extent at or below average, Snow Water Equivalent well above average, meaning average snow thickness (where it is lying) very much above average.

The snow drought in much of Europe is impressive (see next post)
Snowfall on Greenland is somewhat below average (see next post)

https://ccin.ca/ccw/snow/current Snow Cover Extent and Mass as at 3 January 2020

The situation as described below on 22 December has not changed. i.e. Snow Cover Extent at or below average, Snow Water Equivalent well above average, meaning average snow thickness (where it is lying) very much above average.

https://ccin.ca/ccw/snow/current as at 22 December

Interesting contrast between Snow Cover Extent (SCE) and Snow Water Equivalent (SWE).

In North America (NA) SCE is at average after a thaw at low latitudes, relatively low compared with the last 2 years. But SWE is above average.

Eurasia (EU) SCE is very much below average, mainly due to an absence of snow cover in Europe. But SWE is well very much above average.

In other words, where there is snow its thickness and therefore mass is very much above average.

From now to March or even April large snowfalls can happen.

ps: Snowfall on Greenland is also a bit below average.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #111 on: January 17, 2020, 04:24:55 PM »
The snow drought in much of Europe is impressive
Snowfall on Greenland is somewhat below average
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

SimonF92

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #112 on: January 17, 2020, 04:40:24 PM »
An interesting paper on modelling changes in Arctic precipitation over time

https://www.nature.com/articles/s41598-018-34450-3

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #113 on: January 22, 2020, 06:27:55 PM »
https://www.wunderground.com/article/storms/winter/news/2020-01-21-persistent-winter-storm-track-not-favorable-snow-south-east-us

illustrates ice deficit at lower latitudes, ice surplus at higher latitudes - the dividing line very much according to the average storm track largely determined by the track of the polar jet stream.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #114 on: January 23, 2020, 02:09:16 PM »
And so it goes on
https://ccin.ca/ccw/snow/current Snow Cover Extent and Mass as at 22 January 2020

North America
Despite storms and headlines about Newfoundland under a record blanket of snow,
North America Snow Cover Extent (SCE) is back to within +1SD of average, while Snow Water Equivalent (SWE) remains very high

Eurasia
The snow drought in much of Europe and lower latitudes in Asia  is impressive, resulting in SCE at more than 1SD below average.
Even more impressive is SWE, steeply increasing and at a guess +2SD above average.

In other words, where there is snow its thickness and therefore mass is very much above average.

From now to March or even April large snowfalls can happen.
________________________________________________
(Snowfall on Greenland to date is also somewhat below average)
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

be cause

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #115 on: January 23, 2020, 07:32:27 PM »
Is it reasonable to assume that high SWE relates to deeper snow ? Could it not be wetter snow ? b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 
 (phew)

kassy

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Re: Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs
« Reply #116 on: January 23, 2020, 11:03:05 PM »
Could be. That is why they do SWE in the first place.

To determine snow depth from SWE you need to know the density of the snow. The density of new snow ranges from about 5% when the air temperature is 14° F, to about 20% when the temperature is 32° F. After the snow falls its density increases due to gravitational settling, wind packing, melting and recrystallization.

https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2_046155

Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.