Later this year hill walkers and climbers on Snowdon will be able to find out with new confidence the answers to what can be life-saving questions. The Snowdonia Weather Stations Project will install the first "hole-in-the-wall" weather information system at the Pen-y-Pass warden centre this spring, fed with data from a unique solar-powered, telemetered, automatic weather station installed on the highest peak in England and Wales.
The project is the work of the University of Wales, Bangor, and its principal collaborator, the Meteorological Office. It addresses the classic predicament facing anyone who ventures on to Britain's mountains: the weather can deteriorate alarmingly fast,especially in winter, and there may be big differences between valley and summit conditions. These factors contribute to more than 1,000 emergencies and 50 fatalities each year.
The Met Office has long had summit weather stations in Scotland - on Cairn Gorm, for example - but these get their power from the ski lifts. It has none on the Welsh or English mountains.
Jeremy Williams, who leads the Snowdonia project, says that Snowdon is a hostile site for any weather station. But the real technical challenge has been the lack of a power supply. (Snowdon's summit cafe is closed from November to May.) In its first winter (1993), a pilot station had to endure winds gusting up to 140mph miles per hour, temperatures as low as minus 10 degrees Centigrade and rime ice to a depth of 30cm.
At other sites with mains power, the rain gauges, anemometers and sensors are electrically heated in such conditions, but the Snowdonia project has had to develop a new approach.
Power consumption has been minimised, and the station's instruments and its cellular telephone link to the university's computers are driven by two 40W solar panels.
The station is fitted with aerospace de-icing technology. As the temperature drops, it triggers the release of stored gas; this inflates a silicon rubber balloon which covers the sensors and breaks off ice as it forms.
At the moment the station is interrogated by telephone every hour (information could be collected as often as every 15 minutes). From this spring the data will be available by phone from the Met Office's Mountain Call weather information service and directly to the public at new information displays at Pen-y-Pass and Betws-y-coed.
Dr Williams says his team is now working on graphical representations of the weather data for vandal-proof "hole-in-the-wall" computer displays. "The Snowdon massif gets 500,000 visitors a year - walkers from all over the world. We hope to describe the weather through language-independent icons," he said.
The summit weather information will be married up to Met Office forecasts, National Park warden advice - ice hazards on paths, for example - and even flora and fauna sightings. In the longer term, Dr Williams hopes to install stations on other Welsh summits, and, at intermediate sites, to build a complete mountain weather picture.
The Met Office has linked the Snowdon station to its Siesaws (Severe Icing Environment Semi-Automatic Weather Station) network, and is considering the same type of station in England.
As well as supplying weather information, the Snowdonia project has research applications. In effect, it will compile the first complete set of summit weather statistics for any mountain-top in England or Wales.
"Almost nothing is known scientifically about winter conditions in the mountains, beyond anecdotes," Dr Williams said.
The project will also help with research into global warming. Snowdonia is one of the last refuges of Arctic-alpine plants in Britain. Scientists believe changes in this vegetation will provide evidence of climate change. In particular, the station is equipped with a range of sensors measuring total solar energy, as well as photosynthetically active and ultra-violet radiation reaching the summit.Reuse content