UKC

Hi, in the last 6 days the Cwm Idwal turf temperature at 850m has been consistently around the 0.05 to 0.5°C at all three depths. In the last few years has the turf temp actually dropped below 0 °C?

If not, why not?

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

Because turf is slow to respond to changes in temperature, especially if it receives an input of groundwater. I suspect that the sensor is in such a location. In contrast, turf on the crag (no groundwater supply to small exposed patches) *tends* to be frozen, even when the sensor is reading 0.05 - 0.2C. As for below 5cm, it doesn’t really matter IMO, and even if it did it would take some exceptional weather in the UK to get turf to freeze down to 30cm!

I agree! I went climbing up brown cove crag the other weekend and got grief because the sensors didnt say it was frozen. Well i found plenty frozen turf! 

I'll give it two more seasons before all these sensors are removed - waaay too many anomolies for them to be of any use in assessing frozen turf on routes (see other Lakes threads on similar).

It’s a pretty useful indication though. The air sensor is also important. 

It's like most data it needs interpretation, if you want a 'climb now/don't climb now ' sensor this isn't it, doesn't mean it's not helpful, it will become more helpful as we see how conditions corrolate with the numbers 

Had the exact thoughts and conversation about these on the great end thermometers in a orevious thread

Indeed. I'm assuming that everyone who has complained on here about the sensor accuracy has filled in the feedback form, to help with correlation?

Didn't know there was one. Interesting though I will use it. Using the data of temperature will only work if it is correlated with real climbing experience. Problem is who would ever want to take the time to do that.

Realistically the only way to know is to put an axe in and see if your stick is good, if its not and your route climbs through sensitive areas then back off, individuals judgement in the moment will always be key. Unfortunately all climbing damages the rock/turf, luckily most climbers are perceptive to this as they have a greater affinity to rock than the general public.

If there are no heavy frosts before snow, the snow can then insulate the earth below and freezing takes significantly longer. 

The lowest I’ve seen 5cm turf go is 0.00 which has been on a few occasions including Friday Saturday last week. I had frozen turf and ice above 800m then. I have started looking at turfy routes when the sensor goes to around 0.20 degrees and yes the air temperature is really useful. 

If the turf on your route is exposed to the wind it will freeze way faster than a sensor thats not in the wind.

Perfect task for an undergraduate geography dissertation.