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BMC Idwal Winter Conditions Sensors

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Good news, our contractor has in the last few minutes managed to get access to the National Park servers and offices at Ogwen and has rebooted the sytem. This is required to recieve the radio signal from the sensors on the hill and send it on to the webpage we see.  We lost access to the system due to Covid and the National park changing their set up at Ogwen, but the good news is that the sensors seem to be working as they should and the batteries should survive at least until well into next spring. 

So as of midday today, these are now live again. Unfortunately the system hasn't recorded anything in the time the system was down so we don't have the latest historical data. 

https://www.thebmc.co.uk/idwal

Cheers

Elfyn Jones 

BMC Access & Conservation Officer (Wales)

 galpinos 07 Dec 2020
In reply to Elfyn Jones BMC Cymru/Wales:

This is great news. Is there any info to help equate the sensor data to conditions on the ground?

1
 John Kelly 07 Dec 2020
In reply to Elfyn Jones BMC Cymru/Wales:

Lakes next????

 ianstevens 07 Dec 2020
In reply to galpinos:

If they’re above zero at 5cm, the turf is not frozen. Don’t touch it with anything pointy. About all there is too it! 
 

p.s snow is a great insulator, so early in the season big snow dumps are very unhelpful for getting turf into good nick.

Post edited at 20:52
 galpinos 07 Dec 2020
In reply to ianstevens:

> If they’re above zero at 5cm, the turf is not frozen. Don’t touch it with anything pointy. About all there is too it! 

I was wondering if it was that simple or if there was anything more to it? Seems a bit unnecessary to have the 15cm and 30cm probes if so.

> p.s snow is a great insulator, so early in the season big snow dumps are very unhelpful for getting turf into good nick.

I was assuming this was why the 5cm @ 850m is warmer than the 5cm @ 600m.

 ianstevens 07 Dec 2020
In reply to galpinos:

Almost certainly re: elevation. Snow is bad at conducting thermal energy, and if it’s fresh it has an incredibly high albedo (c. 0.8) so reflects most radiative stuff. Plus water within the snowpack is well, water, so above 0, and will percolate down into the groundwater in the turf beneath. 

Edit: don’t know the exact location of the snow line at present, social media seems to suggest 700m?

In my experience that’s been the case. Turf on proper mixed routes seems solid when the 5cm is below zero - can’t speak as much for gullies as I’ve not bothered to any since the sensor went in... I’d suspect that exposed patches of turf probably freeze before that of the sensor, but I don’t know where the sensor is actually placed for comparison.

Post edited at 21:18
 Marek 07 Dec 2020
In reply to galpinos:

> I was wondering if it was that simple or if there was anything more to it? Seems a bit unnecessary to have the 15cm and 30cm probes if so.

> I was assuming this was why the 5cm @ 850m is warmer than the 5cm @ 600m.

Perhaps not in this case, but higher is not always colder. Coldest places in still weather in the Cairngorms are quite often in the bottom of the valleys (cold air is heavier than warm air).

 ianstevens 07 Dec 2020
In reply to Marek:

Temp inversions tend to be a morning phenomenon - air in the valleys is shaded and warms slower, plus as you say the colder air will sink down too

In reply to ianstevens:

A number of times I seen it in the Lakes in recent years that low down in the valley bottoms that the turf is iron hard, obviously days of un-snow-covered ground in quite hard frosts only to fine that 700 mtrs higher, on Red Tarn Face that the turf wasn't particularly frozen except on more wind exposed areas where snow wasn't built up.

 galpinos 08 Dec 2020
In reply to Marek:

That's true. I was going on the snow insulating hypothesis as the turf temp was warmer @ 850m despite the air temp being colder.

 Tom the tall 08 Dec 2020
In reply to John Kelly: Great end sensors also now up and running and displaying on bmc website. 

https://www.thebmc.co.uk/lake-district-winter-conditions

 John Kelly 08 Dec 2020
In reply to Tom the tall:

Great, just Helvellyn to go 

Post edited at 17:54
 static266 09 Dec 2020
In reply to ianstevens:

In my experience winter climbing in north wales since the monitors were installed that’s not necessarily true. In previous years the turf sensors have taken an age to get down to freezing when there’s well frozen turf and plenty of ice. In fact one year I don’t think it went below freezing at all but plenty of mixed turfy routes were climbed in good nick. This could have been due to the location of the probes and maybe the ground had a large snow covering etc. 

 ianstevens 09 Dec 2020
In reply to static266:

> In my experience winter climbing in north wales since the monitors were installed that’s not necessarily true. In previous years the turf sensors have taken an age to get down to freezing when there’s well frozen turf and plenty of ice. In fact one year I don’t think it went below freezing at all but plenty of mixed turfy routes were climbed in good nick. This could have been due to the location of the probes and maybe the ground had a large snow covering etc. 

Depends on the turf - exposed patches will freeze faster than those being measured (which must be somewhere with at least 30cm of soil, so probably in a gully) and ice is a different ball game to groundwater. (It'll freeze way faster, soil is also a fantastic insulator!). SO like you say; location is key But if you're travelling any distance and want "guaranteed" good mixed conditions, better to be safe IMO.  

 galpinos 15 Dec 2020
 galpinos 15 Dec 2020
In reply to ianstevens:

Ian, as you seem more knowledgeable than me on this, could you answer this..... 

using the @600m graph, showing air and turf temps, it's quite clear that the 5cm depth temp follows air temp. That makes sense to me. Then we have the 15cm Turf temp which is a pretty flat curve, which also makes sense, as, in my head, the deeper you go the less prone the temp will be and the longer the air temp will need to be at a temp to affect the turf temp.  What I'm baffled by is the 30cm Turf temp which I thought would be an even flatter curve (it is at 800m) but it's jumping around like the air temp/5cm turf temp. Why is this?

Any ideas?


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