I would think that, in view of global warming and how rarely any of Snowdonias winter features come in to condition these days, that Welsh Winter Mountaineering Equipment now comprises a wetsuit and flippers!
When I think back on the winters I lived and worked in Outdoor Persuits it was glorious - you went from endless sunny days of Spring and summer to crisp frosts of Autumn to ice climbs and corniced ridges overnight! I am suprised that there was enough water to keep the rivers in prime condition as it never seemed to rain in those days...
Seriously - get to Pen y Pass and "if there is snow - don't go" unless you have the gear and training. Equally "if theres rain - its a pain" and "if there is sun - you will get it done" - but get a good forcast as mountain weather is a tricky thing and I too have had my epics in Snowdonia (and I am suppost to know what I am doing!)
Stay safe but have fun!
Spot on about the weather John. I remember years ago you would find ice and bits of snow even around Easter time. Many a happy weekend was spent there in the winter, and you could have some glorious cold but sunny days walking the hills. Back then, when younger, fitter and more foolish, we would think nothing of camping up in the Carnedd's in winter


