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Author Topic: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs  (Read 43936 times)

Tom_Mazanec

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Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« on: August 22, 2020, 03:20:18 PM »
Here is the new thread, Oren.
« Last Edit: August 25, 2020, 07:10:29 AM by oren »

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Re: 2020-2021 winter snow northern hemisphere
« Reply #1 on: August 25, 2020, 06:29:50 AM »
Can naming conventions stay the same year to year. Please. It makes things so much easier.

Northern Hemisphere Winter 2019-2020 Snowcover / Misc Obs

to

Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
And, given a story to enact in which the world is a foe to be conquered, they will conquer it like a foe, and one day, inevitably, their foe will lie bleeding to death at their feet, as the world is now.
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #2 on: August 25, 2020, 07:10:41 AM »
Fixed.

Tom_Mazanec

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #3 on: August 25, 2020, 12:23:26 PM »
Yeah, I did this from my iPhone. Thanks for renaming.

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #4 on: August 25, 2020, 12:48:08 PM »
snow is accumulating on the ice ?
 https://modeles.meteociel.fr/modeles/gfs/run/gfsnh-16-6.png?6  .. b.c.
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #5 on: August 25, 2020, 12:52:04 PM »
so they don't get lost again .. from tealight ..

Some time ago I posted regional snow extents, but the topic is kind of lost in the depth of the forum. After some minor improvements and adding two new regions in Asia I created a seperate webpage for the data. It makes it easier to analyse than several different forum posts.

On the snow-cover webpage, featuring snow maps I added the long term NOAA data since 1967. The low 200km resolution looks terrible compared to the new 24km, but the longer timespan is better to judge changes over time.

https://cryospherecomputing.tk/Snow-Cover
https://cryospherecomputing.tk/snow-regional
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #6 on: August 26, 2020, 12:27:31 AM »
Lots of bright new snow has fallen over Axel Heiberg and the Ringnes Islands in the CAA.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #7 on: August 27, 2020, 09:04:43 PM »
Yikes. I anticipate a record or near-record September advance in North America.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #8 on: August 27, 2020, 10:48:50 PM »
Yikes. I anticipate a record or near-record September advance in North America.



I hold against it and if it's only for the sake of you saing "I expect" in relation to the fact that this forecasts like more or less most of your snow forecasts, just to make points that never are going realize, are and have been 10 days out over many years.

Using forecasts 10 days out is a nice tool to hype anything that never happens, exactly like i can tell that those forecasts almost never become true.

<Removed judgemental part. Clarified snow not general forecasts. O>
« Last Edit: August 28, 2020, 03:09:42 AM by oren »

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #9 on: August 27, 2020, 11:49:28 PM »
I thought of bbr when I found a new paper - Severe Cold Winter in North America Linked to Bering Sea Ice Loss

I posted it here...
https://forum.arctic-sea-ice.net/index.php/topic,596.msg283603.html#msg283603
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #10 on: August 28, 2020, 12:26:25 AM »
Yikes. I anticipate a record or near-record September advance in North America.



I hold against it and if it's only for the sake of you saing "I expect" in relation to the fact that this forecasts like more or less most of your forecasts, just to make points that never are going realize, are and have been 10 days out over many years.

Using forecasts 10 days out is a nice tool to hype anything that never happens, exactly like i can tell that those forecasts almost never become true.
My posts in the melt thread this season have been spot on. Your personal attack comes with no analysis and is not positive to generating analytical discourse.
« Last Edit: August 28, 2020, 03:10:28 AM by oren »

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #11 on: August 28, 2020, 03:17:44 AM »
It's true that 10-day forecasts are not worth much, and that bbr has posted his share of them in the past. It's also true that their use has gone down sharply this year after re-registration. Igs and all, please avoid attacking users for past behavior, and for well-known behavior as well.
bbr - if you want to continue posting 10-day forecasts in the snow thread, that is less of an issue compared to the melt season thread where it's a big no no. However, I would strongly recommend following up 10 days later and reporting whether said expectations were fulfilled or not. This will greatly increase the value of such postings. In addition, maybe we will discover that for continental snow the 10-day is more reliable than for Arctic ocean weather.

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #12 on: August 30, 2020, 12:46:40 AM »
Yikes

The d8 forecast is pretty similar to what i posted before, but the d10 output....





It looks like snows should really begin in force imminently across the highest Rockies, the Mackenzie Range, Alaska, and much of the Canadian tundra.

The GFS offers a somewhat diff look (and is probably the most incorrect of them all) but is still frigid.



I am beginning to become very concerned about potential agricultural impacts. The CMC is IMO the best for North America this time of year, EURO also good. But CMC is good at ice and snow dynamics, esp advance (IMO) which is why it is ideal for September / October / November (altho globally it may still underperform, it is designed for Canada, so.....)



Note the attached EURO snowfall from weather.us is through D10 and not just D10!

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #13 on: September 01, 2020, 09:00:38 PM »
Yikes. I anticipate a record or near-record September advance in North America.


The 120hr forecast is remarkably consistent to the D10 forecast! And today's 12z EURO shows more potent Greenland airmasses mixing into the Arctic waiting to descend into North America as well, with more energy from recurving typhoons pumping a PIG ridge into Bering / Chukchi...


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #14 on: September 01, 2020, 09:05:24 PM »
PS,

Day 8, the 12z EURO has a major snowstorm in the lower Rockies, with snows into Denver and accumulations all the way into the TX panhandle. That would be fairly unprecedented for September 8th, I believe, Denver's earliest on record is actually about 4" on 9/3/1961, but its #2 was on 9/8/1962 and that was under an inch.

https://weather.us/model-charts/euro/colorado/acc-precipitation-snow-total/20200911-1200z.html

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #15 on: September 02, 2020, 08:38:06 PM »
Major blizzard now D5-6 in Rockies, amounts much higher, and over the more "normal" center of cold anomalies as of late (Montana and vicinity).

https://weather.us/model-charts/euro/2020090212/usa-west/acc-precipitation-snow-total/20200909-0000z.html

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #16 on: September 02, 2020, 08:56:25 PM »
So, it is worth noting --

The EURO has done WELL with cold forecasting in North America so far this week or two. The D10 forecast posted previously is going to come pretty close to verifying (not perfect, but the overall look was very accurate).

The EURO is now hinting at another vortex of Greenland air rotating into the Arctic and down into North America by day 10 or so. At D9 you can see it here still over Beaufort.
 


You can also see the atmospheric trace of event #1 still extant in the Rockies. It is more obvious when looking at 2M temps, but the snow is so deep from the first blizzard that a good portion would PROBABLY survive til the next wave arrives (around the 13th or so?). This would accrete to what has already fallen in many areas, further dropping the snow line in the Rockies, and establishing a firm foothold for winter 2020-21 to take root on the North American continent.

Finally, this early and anomalous mid-latitude albedo event is likely going to evacuate an enormous amount of heat from the Pacific and Gulf of Mexico poleward in varying directions (IMO) and these evacuations will worsen as the anomaly grows in area and extent. Prepare for heat blasts into the Arctic from all directions, aided significantly by this potentially widespread appearance of snowfall around 40-45N in North America (which, interestingly, is proximate to my post in the ice age thread re: the Rockies matching the Himalayan anomaly.... but that is another subject).

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #17 on: September 03, 2020, 01:47:40 PM »
The 00z EURO was worse than the 12z, IMO. The Rockies blizzard in the D5 period is now forecast to produce 4"+ in Denver and 2"+ in Albuquerque. At 00z yday, amounts were substantial over highest Rockies, at 12z yday, amounts increased and spread to MT / WY, at 00z today, amounts increased further but switched from MT + WY + CO to CO + WY + NM (primarily).

New Mexico is..... SOUTH. I think such a September event would be unprecedented (or almost unprecedented, certainly with currently +oceanic heat content) for the Lower High Rockies.

https://weather.us/model-charts/euro/usa-west/acc-precipitation-snow-total/20200913-0000z.html

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #18 on: September 03, 2020, 06:45:29 PM »
Yikes for agriculture....

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #19 on: September 04, 2020, 06:15:47 PM »
Now creeping into the Plains. I am very worried about this September.




The 00z EURO might have been even worse.

https://weather.us/model-charts/euro/usa-west/acc-precipitation-snow-total/20200914-0000z.html

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #20 on: September 04, 2020, 08:55:39 PM »
Long range modeling is looking.... COLD

The Bering Sea connection has to be a major factor here but I guess this year maybe Laptev, ESS are aiding (???)





All the polar air keeps draining into North America, but by the end of the period it is also happening again over Kamchatka and NE Siberia. Meanwhile, it looks like the advected heat from the Rockies blizzard (now D4) arrives on the ATL front by day 8-10 on the 12z CMC, and accompanies a GAAC that is almost 1050MB (!!!). The extreme WARMTH dominates the entirety of the CAB by D10 and for mid-September, that would be very impressive, though it is Day 10 and the CMC.

I do think with the Rockies event now drawing near, we can consider such a scenario more LIKELY than it would be if depicted otherwise.

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #21 on: September 04, 2020, 09:01:37 PM »
The next major Rockies snow event arrives D10 on the North Slope of the Yukon / NWT. Wow. I think this will also end up more impressive than modeled and could also possibly arrive sooner. This would probably be a Rockies storm by D12ish.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #22 on: September 06, 2020, 06:24:28 PM »
As depicted, I would now call the upcoming event "unprecedented" in its scope, depth, and duration for areas impacted given the time of year. We are now seeing snows forecast to spread well into the High Plains, all the way to the middle of Nebraska and Kansas...








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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #23 on: September 06, 2020, 10:31:30 PM »
The CMC shows major areas of >32F daytime temps developing by D10 across AK, the NW Territories, Yukon, and Quebec. As well as parts of the Shield and the elevated Rockies. Snowfalls by D10 are overspreading increasingly broad areas of North America though their duration remains tenuous outside of areas of greatest depth and elevation (for now).



I think the EURO is shunting too much cold towards Siberia in the extended and it is probably going to fall into the Rockies. We will see if it adjusts but it is also cold along North Facing-slopes of the NW continental areas, as well as Quebec and the Shield.

With the impending airmass around 9/15 looking to be substantially below 32F even during daytime, if it arrives overtop the Rockies a few days thereafter, the snows could be even larger than round 1, and much more geographically uniform (i.e. across the entire High Plains and maybe the Upper Midwest). We will see what happens but I think there is a good chance North America sees one of its snowiest Septembers ever.

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #24 on: September 09, 2020, 12:09:23 PM »
GFS says its damn cold in that patch of the USA this morning, but by Saturday.....

Meanwhile still plenty of warmth over most of North America.
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #25 on: September 12, 2020, 09:19:30 PM »
While some snows will fall over Canada through D10, melting in some spots and starting to stick in favored elevations, the big story today is an event shown on the 12z EURO around D8-10. Snows begin in Maine and New England by D10 on the NW side of the phasing hurricane / polar vortex and it is backing into the coast at that hour.

The solution will probably disappear, but the EURO has a knack for major cyclonic events in this season (it was the first to show Sandy) so it will be interesting to watch its evolution over the next few days and this may bear watching.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #26 on: September 13, 2020, 01:41:47 AM »
72F in Denver as I type so that snow melted rather quickly. There was one disaster as a result of the freeze and snow. Millions of dollars of marijuana crops were destroyed.

https://mjbizdaily.com/early-freeze-in-colorado-could-cost-marijuana-hemp-growers-millions-in-losses/

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #27 on: September 13, 2020, 11:29:36 AM »
.. while those in Mendocino , California go up in smoke ...
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #28 on: September 24, 2020, 05:22:58 PM »
https://ccin.ca/ccw/snow/current

North America - the snow came, it melted. It does that in September.

Eurasia - almost zero new snow.

Early days - climate scientists suggest a long-term trend of later snow and more of it.
And a winter Al Nina is supposed to mean a cold North America - at least above 40? 45? 50? North.
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bbr2315

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #29 on: September 26, 2020, 12:47:07 AM »
Through D10 modeling is now showing major SWE accreting in elevated areas of Quebec as well as the Rockies and Alaska. By D10, many models are now showing extreme 500MB blocking developing across much of the Arctic, centered atop the greatest oceanic heat anomalies derivative of the melt season. This is extremely concerning, IMO, and while extended guidance from the GFS posted below *should not be taken at face value* I think that combined with the looks being printed by ECMWF / CMC, alarm bells are ringing for possible anomalous snowfalls and severe October cold spells in the mid-latitudes.


gerontocrat

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #30 on: October 02, 2020, 06:47:36 PM »
So far this year's snowfall is more in Eurasia than North America, where snowfall is very much at average.

But it is very early days as yet.
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Niall Dollard

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #31 on: October 04, 2020, 02:05:31 PM »
Day 277 compared with last year. (needs a click)

Very little yet in eastern Siberia.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #32 on: October 13, 2020, 01:37:17 AM »
The snowfall response this year, surprisingly and contrary to my thoughts, has so far been anemic -- or it had been before about yesterday. Looks like accretion and spread of the snowpack begins substantially over the next week over both Eurasia and North America.

I guess the record warm Laptev et al have overwhelmed the Eurasian snowfall response until this point (?) due to high latitude blocking? But perhaps as the snowfalls actually begin the depths will accrete more than normal and do so quite rapidly, who knows!

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #33 on: October 16, 2020, 03:56:13 PM »
How average can you get? https://cryospherecomputing.tk/ from Nico Sun
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #34 on: October 21, 2020, 03:11:32 AM »
Welp, here we are, the cascade is happening in force again it seems.



North America is up to +2SD suddenly and looks like it should end the month at a record high (IMO).

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #35 on: October 27, 2020, 03:17:36 PM »
How average can you get? https://cryospherecomputing.tk/ from Nico Sun

Until it's not average any more - at least in North America.
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #36 on: October 27, 2020, 03:39:25 PM »
October might end at a massive all-time record for North America. The animated Canuck maps are a day ahead of the graphs. The uptick today was again.... absolutely insane, and occurring across MANY of the elevated areas of the continent.

https://weather.gc.ca/saisons/animation_e.html?id=month&bc=sea

Winter is most definitely here.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #37 on: October 27, 2020, 10:29:24 PM »
Very much not average. Record breaking cold across the center of the U.S. with a lot of snow and ice storms as far south as Oklahoma. Miserable weather in Chicago with lows around 0C.

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #38 on: October 28, 2020, 02:18:09 PM »
Very much not average. Record breaking cold across the center of the U.S. with a lot of snow and ice storms as far south as Oklahoma. Miserable weather in Chicago with lows around 0C.
This is insane.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #39 on: October 28, 2020, 02:20:39 PM »
If the winter weather continues for another week, it will suppress the vote a little.  On one hand, 'they are used to it'; on the other, 'it's early.'  Several of the most affected states have competitive federal office races.  There will also be competitive state and local offices, and some 'interesting' ballot initiatives.
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #40 on: October 28, 2020, 03:33:50 PM »
winter will have forgotten it's visit to the states by election day ...
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #41 on: October 28, 2020, 03:34:46 PM »
The positive snow anomaly in North America of 4.430 million km2 is very close to the record anomaly. On 11th and 12th October 2009 had an anomaly of +4.533 million and +4.715 million respectively. The only other close year was 2014 with +3.956 million on November 15th.

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #42 on: October 28, 2020, 04:19:20 PM »
winter will have forgotten it's visit to the states by election day ...

In the lower 48 snow starts to melt tomorrow and Nov 3rd looks like a really pleasant day
"Para a Causa do Povo a Luta Continua!"
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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #43 on: October 29, 2020, 04:26:58 AM »
Please don't go OT re elections.

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #44 on: October 29, 2020, 02:54:23 PM »
The positive snow anomaly in North America of 4.430 million km2 is very close to the record anomaly. On 11th and 12th October 2009 had an anomaly of +4.533 million and +4.715 million respectively. The only other close year was 2014 with +3.956 million on November 15th.
Did we pass 2009's anomaly today? The numbers are up again... we may have a new record here!

It should be noted 09-10 and 14-15 were both El Nino winters (moderate, and weak). We are in Nina-ish conditions now.

It should also be noted that the NHEM snow anomaly (+3.781M KM^2) is now larger than the sea ice deficit (-2.1M KM^2). By a decent margin, to boot. Who says the Earth-climate-system doesn't have built in resiliency measures....? It just so happens that the resiliency of the planet comes at the cost of most of our civilization. Oh well!

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #45 on: October 31, 2020, 03:19:02 PM »
The freshwater flux is now well underway in North America and I would say the melting of this extremely anomalous event is giving us our first meltwater pulse of the season. Though it is not substantial compared to the spring melt it is still an important process in lowering ambient temperatures of rivers, lakes, and adjacent saltwater bodies when runoff does arrive. SSTs are now cooling rapidly in the Gulf of St. Lawrence and parts of Hudson Bay, with shore ice also forming along much of Hudson Bay.

Given the extended forecast I anticipate a relatively early Hudson refreeze this year with most of the Bay frozen by 11/20 - 12/1. I wonder how this will act in concordance with the latest-ever-open areas of the Siberian-adjacent seas re: atmospheric impacts come December and onwards (and also in sync with what will probably be +SWE and +SCE anomalies).

bbr2315

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #46 on: October 31, 2020, 05:11:26 PM »
Central Park and the rest of the reporting stations in NYC recorded a trace of snow yesterday, setting the record for the shortest length of time between measurable snowfalls, coming on the heels of our last T on May 9th. Five months, and three weeks. !

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #47 on: October 31, 2020, 06:32:38 PM »
What goes very impressively up may go as equally impressively down.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
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bbr2315

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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #48 on: November 03, 2020, 02:17:24 AM »
While SCE is only now stabilizing, SWE rebound is already well underway and it dipped much less (relatively). This shows how potent albedo can be as an insolation modifier early / late in the winter season -- it takes barely any relative precipitation to cover a HUGE continental area to massive deflection of proportional insolation. Even if these incursions of snowfall are short-lived for the time being, their scale makes them quite effective at dissipating sunlight (and heat).

Simultaneously, their OCCURRENCE is a dissipation of heat (from the Arctic Ocean) so they are doubly advantageous. Or perhaps even more efficacious than Arctic Sea Ice at resolving +OHC when the sea ice peels back even further. Oh dear. Let's hope not.


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Re: Northern Hemisphere Winter 2020-2021 Snowcover / Misc Obs
« Reply #49 on: November 03, 2020, 02:31:19 AM »
Also, if the EURO is correct it looks like Foxe Basin will be totally iced over by D10 and much of Hudson will be following suit at a rapid pace. There is a chance most of Hudson Bay will ice by 11/15-20, which would be very early. 11/25 is more reasonable which is still 1980s ish.

This would probably anchor a -500MB area in North America accompanied by associated negative temp anomalies, I think this would also advect a major amount of heat into both PAC and ATL fronts but esp the ATL fronts as Baffin is also icing over very quickly while Laptev, Kara, and Barentz are not. They will probably bear the brunt of poleward heat transport derivative of the continental and sea ice anomalies impending in aforementioned regions (IMO) as these anomalies are upwind of an Atlantic Ocean that has a LOT of heat to send poleward.