Snowfall24-parameter, do we need it?

[sutne]

I am very interested in knowing the snowdepth at my Rjoand station.
I have ordered a LDS01 and hopefully I will have automatic measuring of the snowdepth.
At the momennt I am using the Diary to fill in data every morning.
In the new diary there is a new parameter Snowfall last 24 h. How do we measure/calculate that and what is the reason for having it?
At the moment I get the snow data from the nearest official meteorological station which is an indication of the depth at my station. But to find the snowfall for the last 24h I have to look at several charts and then make an assumption.
And now I ask: Why, what is the use of this parameter?

And when we will have automated measuring of snowdepth, we will not have this parameter. LDS01 cannot know anything of snowfall.

Of course I can just drop filling in this parameter if I do not need it, but I am a bit curious why it is there.

[Dador]

Personally, I miss the yes or no "Snowall" box from the old journal.
I have an example from yesterday that this 3rd parameter would be useful to me.
I measure snow once a day at 06:00 UTC. Today's measurement will not record snow cover or 24-hour snow increase, which was not measured on an ongoing basis. However, yesterday around noon there was a lot of snow, which created a cover of about 3 cm, which had completely melted by this morning. So in my new diary it will appear that I had a day without snow, which is not true. All that remains is to enter the comment that it was snowing.

[sutne]

Dador,
I think we agree, a tick-off box would be more usefull than a number for snowfall.
If you had about 3cm snow on the ground and melting, what would you put in the Snowfall24 box? 3 cm, 10cm?

[PaulMy]

My reply got lost because of the new post...
@Dador,
I disagree. The Previous Snow lying "Yes" had no value with it. I have always entered 0.1 new snow if there was a noticed trace of snow in the 24 hours 8:00 am. And if there was more snow observed during the 24 hours but not lying at 8:00 am I would enter that amount as snowfall. I think this is as good, or better, than a "Yes" comment.

@surtne,
In the new diary there is a new parameter Snowfall last 24 h. How do we measure/calculate that and what is the reason for having it?
At the moment I get the snow data from the nearest official meteorological station which is an indication of the depth at my station. But to find the snowfall for the last 24h I have to look at several charts and then make an assumption.
And now I ask: Why, what is the use of this parameter?

The amount of new snow is a measurement just like rain. The snow depth is a good measurement but it does not allow for snow melt or compression. The amount of new snowfall and snow on the ground are both important.

Snow recording has been part of Cumulus since its beginning, but had little visibility other than looking at the Snow Index for the year. The new diary has improved that, and the charts are great.

I have been collecting snow amounts for nearly 13 years as part of the CoCoRaHS program.
https://www.komokaweather.com/weather/snowindex.html
https://dex.cocorahs.org/stations/CAN-ON-784

I also look forward to the LDS01. Hopefully there will be some calculations on new snowfall over a period of time.

Enjoy,
Paul

[HansR]

I have rarely snow here where I live, but when there is snow it is for one or two days and often pretty intense (lots of snow, 10cm and more melting fast).

I could do with only snowDepth and would not need a tick box. What would the tick box tell me and how should I work that into report and chart? Nothing I guess. The only objective valid number is the total snowdepth, measured at a fixed moment of the day (the morning, so before the melting).

That could be automated, the other fields could/should be optional (and if filled in, can be reported/charted).

[HansR]

@Paul: Yes, that is how I understood and what has been implemented now. But for the future snow24h could be made optional. Actually both numbers already are, so in a way @sutne's remark what to do with it is a bit superfluous: if you do not need it, don't use it.

And with automatic measurement, there is only one number. In my view that would be snowDepth.

[sutne]

PaulM: And if there was more snow observed during the 24 hours but not lying at 8:00 am I would enter that amount as snowfall. I think this is as good, or better, than a "Yes" comment.

That is only possible if you are at the station and manually observing. Most of the time I am not there, so there are different needs.
An optional box is ok with me.

[HansR]

PaulM: And if there was more snow observed during the 24 hours but not lying at 8:00 am I would enter that amount as snowfall. I think this is as good, or better, than a "Yes" comment.

An optional box is ok with me.

As I said: it is already optional, if you do not fill in snow24h it remains null.
But maybe the visibility of the field could be configurable

[sutne]

I removed all 24h data and it is Null, but the table present it as 0.
With the previous discussion I think it should be dash.

[sutne]

Paul,
I ask once more: how do you really observe snowfall?
If it is -5 or colder, it is quite easy, but if the tempetatur is around 0 and all kinds of precipitation falls from the sky, what do you note then?

[HansR]

I removed all 24h data and it is Null, but the table present it as 0.
With the previous discussion I think it should be dash.

I think you are right, already said I will review but that will be much later today if not tomorrow

[PaulMy]

by HansR » Sat Dec 07, 2024 2:29 am
@Paul: Yes, that is how I understood and what has been implemented now. But for the future snow24h could be made optional. Actually both numbers already are, so in a way @sutne's remark what to do with it is a bit superfluous: if you do not need it, don't use it.

And with automatic measurement, there is only one number. In my view that would be snowDepth.
Hans

I think no reporting should be null or shown as dash --- as there was no observation, and reporting zero 0 as 0.0 as that is what is observed.

by HansR » Sat Dec 07, 2024 3:27 am
sutne wrote: ↑Sat Dec 07, 2024 3:08 amI removed all 24h data and it is Null, but the table present it as 0.
With the previous discussion I think it should be dash.
I think you are right, already said I will review but that will be much later today if not tomorrow

I agree with the current/new diary, it is optional. And for me beneficial.
I don’t know how often CMX would pick up the LDS01 and log it, and I thought/hoped it will be some times during the day, then current measurement minus previous measurement would give the amount of New Snow during that period.

by sutne » Sat Dec 07, 2024 2:38 am
PaulM: And if there was more snow observed during the 24 hours but not lying at 8:00 am I would enter that amount as snowfall. I think this is as good, or better, than a "Yes" comment.
That is only possible if you are at the station and manually observing. Most of the time I am not there, so there are different needs.
An optional box is ok with me.

It is an observation… When home it is easy to determine if there is/was snow falling, so if that is the case then put something in at normal reading time even though there may be nothing visible at reading time due to snow melt. If you see no snow then reporting 0 would be correct. But if someone dependable tells you there was snow at your place then report it to your best determination.

by sutne » Sat Dec 07, 2024 3:13 am
Paul,
I ask once more: how do you really observe snowfall?
If it is -5 or colder, it is quite easy, but if the tempetatur is around 0 and all kinds of precipitation falls from the sky, what do you note then?

The same holds true on snow depth!
As part of the CoCoRaHS program I manually read the precipitation collected in the CoCoRaHS approved gauge (4”) every morning around 8:00 am. Above freezing time it is all rain water, and during freezing time it could be rain or snow. If snow, then this is melted and the snow-water-equivalent (SWE) is reported as precipitation.
During snowing the CoCoRaHS 4” gauge will accumulate with snow and that can then be melted for the SWE, or using a scale to weigh the snow to determine the amount of SWE. However, not all snow is collected in the 4” gauge so CoCoRaHS guidelines is to have a snow board, a white wood board of about 3 feet square placed in an area of least drifting and best location for collecting snow amounts. One board is used for the new snow during the previous 24 hours, and cleared after the reading so this gives daily snowfall (but would not include any new snow that may have melted during the day). Melting the new snow on the snow board and comparing that the SWE in the CoCoRaHS 4” gauge is a good comparison but can vary quite a bit with higher temperatures. Another board is used for the ongoing accumulation of snow which is not cleared. My rear deck is a good location for the snow measurements.
My entry in the diary comments includes if there was new snow, the amount, and whenever possible the SWE. For snowfall24hr I use the amount on the snow board that is cleared each day. For depth I use the amount on the other snow board that is not cleared every day. My Excel spreadsheet that I have used since 2011 also displays the number of days of snowing, and the amount on the ground. I had used this to compare to the Environment Canada 30-year average of snowfall but unfortunately EC has stopped adding this to their latest 30-year report 1990-2020.
It is quite involved but I enjoy the reporting to CoCoRaHS, and then the added benefit that I can share that data in Cumulus. And now display it in Charts – thanks Mark and Hans!
Enjoy,
Paul

[HansR]

It is quite involved but I enjoy the reporting to CoCoRaHS, and then the added benefit that I can share that data in Cumulus. And now display it in Charts – thanks Mark and Hans!

Thanks @Paul; and now to discuss on how to improve and continue with automatic measurements. I expect this not to be the last remark on how to and what to measure in different methods. It would not surprise me if we develop a technique able to support more than one method (a Canadian and a Norwegian ).

[PaulMy]

It would not surprise me if we develop a technique able to support more than one method (a Canadian and a Norwegian

As in hockey, Norway and Canada are often tied!

Not a lot of snow but very wet as temperature is rising https://www.komokaweather.com/pictures/sebec/image.jpg

Enjoy,
Paul

[sutne]

Paul, I was quite impressed of the way you measure snowfall.
But I think you are wrong about Norway and hockey. I think we are way behind Canada.

I don’t know how often CMX would pick up the LDS01 and log it, and I thought/hoped it will be some times during the day, then current measurement minus previous measurement would give the amount of New Snow during that period.

According to the datasheet the LDS01 offers realtime monitoring, each 20 sec.
Then it could be possible to calculate some snowfall (before it melts.

Edit: Ecowitt has different pages with specification for the LDS01.
This page gives 1 min interval:
https://shop.ecowitt.com/products/lds01

While this says 79.75sec (!) or 10 sec:
https://www.ecowitt.com/shop/goodsDetail/338