<![CDATA[Snow depth oddity]]>Snow depth in Europe is shown as 3m deep in sharp-edged blocks
windy snow.jpg

]]>https://community.windy.com/topic/18280/snow-depth-oddityRSS for NodeSun, 13 Sep 2026 12:26:00 GMTWed, 20 Oct 2021 09:15:07 GMT60<![CDATA[Reply to Snow depth oddity on Mon, 25 Oct 2021 11:42:19 GMT]]>@idefix37 said in Snow depth oddity:

past accumulation + the predicted snowfalls.

Snow depth is layer indicating depth of a laying snow, it is based on snow density and amount of water in precipitation.

]]>https://community.windy.com/post/90623https://community.windy.com/post/90623Mon, 25 Oct 2021 11:42:19 GMT<![CDATA[Reply to Snow depth oddity on Fri, 22 Oct 2021 17:40:06 GMT]]>@korina
So the ‘Snow depth’ is the past accumulation + the predicted snowfalls.
More information here:
https://apps.ecmwf.int/webapps/opencharts/products/medium-snow-sic?base_time=202110220000&projection=opencharts_europe&valid_time=202110220000

This map shows the same ‘blocks’ as in Windy over the Alps.

]]>https://community.windy.com/post/90451https://community.windy.com/post/90451Fri, 22 Oct 2021 17:40:06 GMT<![CDATA[Reply to Snow depth oddity on Fri, 22 Oct 2021 13:58:26 GMT]]>@idefix37 @Chris-Bolton Detailed description - https://apps.ecmwf.int/codes/grib/param-db/?id=141

]]>https://community.windy.com/post/90439https://community.windy.com/post/90439Fri, 22 Oct 2021 13:58:26 GMT<![CDATA[Reply to Snow depth oddity on Thu, 21 Oct 2021 11:55:47 GMT]]>@korina said in Snow depth oddity:

Snow depth is not historic accumulation, but snow density/depth in the next days.

Please could you confirm that the ‘Snow depth’ forecast is the accumulation of old snow ie before the forecast date plus the next falls and the natural compacting of the snow cover.

]]>https://community.windy.com/post/90337https://community.windy.com/post/90337Thu, 21 Oct 2021 11:55:47 GMT<![CDATA[Reply to Snow depth oddity on Thu, 21 Oct 2021 08:09:32 GMT]]>@chris-bolton Furthermore, Snow depth is not historic accumulation, but snow density/depth in the next days. New snow layer is total snow accumulation in next hours or days.

]]>https://community.windy.com/post/90320https://community.windy.com/post/90320Thu, 21 Oct 2021 08:09:32 GMT<![CDATA[Reply to Snow depth oddity on Wed, 20 Oct 2021 16:46:18 GMT]]>@idefix37 - thanks, understood.

]]>https://community.windy.com/post/90253https://community.windy.com/post/90253Wed, 20 Oct 2021 16:46:18 GMT<![CDATA[Reply to Snow depth oddity on Wed, 20 Oct 2021 16:55:11 GMT]]>@chris-bolton
Global models, even ECMWF model with 9 km resolution, are quite bad in mountains. The 9km distance between grid points and the interpolation between them cannot give a realistic view of weather in these areas. In addition the topographic model that global models use is very coarse. For example the temperature shown at top of Mont-Blanc 4800m is almost the same as that in the valley, at Chamonix 1100m.
Anyway I agree with you the Snow depth layer gives strange pictures. I don’t remember to have seen that in the past. We will see later in the season.

]]>https://community.windy.com/post/90252https://community.windy.com/post/90252Wed, 20 Oct 2021 16:55:11 GMT<![CDATA[Reply to Snow depth oddity on Wed, 20 Oct 2021 14:34:31 GMT]]>@korina
Thanks - if you're happy with it, OK. I thought 'new snow' was forecast (and the display shows how many days accumulation), and 'snow depth' was historic accumulation in the model, as there's no timescale on the display. It is in the general area of the Alps, but the patches cover the valleys as well as the mountains so I though it was a modelling artifact.

Happy to close it out as bug, if you wish.

]]>https://community.windy.com/post/90240https://community.windy.com/post/90240Wed, 20 Oct 2021 14:34:31 GMT<![CDATA[Reply to Snow depth oddity on Wed, 20 Oct 2021 14:25:37 GMT]]>@chris-bolton Hello, as you can see on the screenshots, the snow patches are located on the top of Swiss Alps, therefore the snow depth makes sense. Furthermore, the layer shows forecasted values, actual snow depts might be influenced by many factors like orography, cities and so on.

]]>https://community.windy.com/post/90237https://community.windy.com/post/90237Wed, 20 Oct 2021 14:25:37 GMT<![CDATA[Reply to Snow depth oddity on Wed, 20 Oct 2021 13:24:50 GMT]]>@korina

As I read that display, it's showing clearly defined patches of lying snow, 3m deep, with quite sharply defined and sometimes straight edges that don't follow the terrain. That's not what I expect to see at this time of year, snow should be mostly on the mountains and with the depth tapering off gradually. If it showed 3cm of snow like that, fine, but 3m is a typical winter accumulation. So I think there's an error.

]]>https://community.windy.com/post/90230https://community.windy.com/post/90230Wed, 20 Oct 2021 13:24:50 GMT<![CDATA[Reply to Snow depth oddity on Wed, 20 Oct 2021 10:49:31 GMT]]>@chris-bolton Hello, would you like to report any issue? You can change the units by clicking on "cm" unit.

]]>https://community.windy.com/post/90221https://community.windy.com/post/90221Wed, 20 Oct 2021 10:49:31 GMT