As part of an ongoing effort to gather weather data to enable a climatic research study into the future potential for snow making and other optimisation strategies for snow management and snowsports on CairnGorm Mountain, I today took delivery of a Technoline WS2350 AWS (automatic weather station).  Which I’m setting up for use on the lower slopes of CairnGorm Mountain to gather temperature, wet-bulb temperature and wind speed data specifically from the beginner runs served by the Sheiling Trainer Tow.

This AWS will when set up (during the Autumn) give specific data from a mid-point of the lower slopes as well as being configured through a computer data logger to upload data on-line to Winterhighland to give a real-time data feed of weather conditions on the lower mountain.

To both log the data for future research and to enable the on-line provision of weather data in real-time the AWS requires to be connected to a PC. Though the Technoline weather stations come with their own Windows software called ‘Heavy Weather’, Winterhighland is using re-furbished second hand P3 computers operating Ubuntu Linux and an open source suite of applications called ‘Open2300′. Open2300’s apps provide the direct interface between the Winterhighland data processing scripts and the AWS console.

This use does not require particularly powerful computers, thus Winterhighland has chosen to buy and re-use second hand small form factor P3 computers as previously used for the Loch Morlich AWS and the SSC Hut webcams.

Adding RAM and hard drive to second hand small form factor P3 PC.

Unlike the WS3600 model of weather station which has been used for the past 2 winter seasons at the Scottish Ski Club Hut adjacent to the mid-station on CairnGorm Mountain, the WS2350 model does not have a slatted radiation shield for the thermo-hygro sensor, only a solid plastic rain cover. This makes it susceptible to ‘over heating’ at times of the day when it’s exposed to direct sunlight. Despite the best efforts to place the temperature sensor in the shade, this problem has been evident with our Loch Morlich unit during sunny mornings at the height of summer.

To alleviate this issue I’ve been experimenting with a home made fan aspirated radiation shield, driven by a small fan powered when the sun is strong by a solar panel designed for a small ornamental fountain! Lacking the solid bottom plate when the photo was taken, this screen has shown a temperature as much as 5°c lower than the WS2350 sensor in standard housing when exposed to direct sunlight, showing a significant improvement in temperature accuracy on warm sunny days.

Experimental Fan Asspirated Radiation Screen for WS2350

One final photo shows the rebuilt P3 computer running Ubuntu Linux set up as a temporary work station in the garden shed where it was easy to provide a cable connection to the WS2350 sensors.  With a cabled connection the update frequency is greatly increased which will help provide more accurate gust wind speed figures.

Rebuilt P3 hooked up to the WS2350 in a shed for testing.

Now up and running in the shed and online using PCI WiFi cards with external antenna connector, this computer will ultimately upload data to the internet through Winterhighland’s GPRS router in the SSC Hut at 2500ft on CairnGorm by WiFi link to the SSC Hut.