Long range snow forecasts?

My bush says you should be fine :)

I recall my boss, head instructor Franz, saying, "Yes, this morning, I saw three crows flying upside down. This means it will start to snow at 10.00am on Wednesday"
(This was on the preceeding Friday)
Yeah, so it came to pass, at 10.00am on the Wednesday morning, snowflakes formed, and down it came, a huge dump.

Should I wish to check the possible outcomes of particular resorts, I use J2ski snow reports/snow history. This gives a good guide, and has been 100% when I have relied on it.

We have a place in Switzerland and I'd echo that you just can't be sure. We've cancelled a trip out one week because of it being warm with thin snow cover, and then 10 days later my daughter went out and it was one of her best ski trip in terms of conditions. We tend to go out end Jan/start Feb and seen it -19°C one year and +18°C another. It can be great in SW Alps and terrible in NE Alps, and vice-versa.

So if you can go in term-time, then the advice to leave it 'till late is sound and if you rent an apartment, then I'd say that there are always places available outside of school hols. Going to the Tourist Office or direct to agencies in your chosen resort will usually be successful. This is what a lot of mainland Europeans seem to do - I suppose they just jump in their cars and drive down - no Eurotunnel/ferry or flight/carhire to worry about.

Having a place over there, I always found that the biggest problem in leaving it late was finding the time off work. Between the two of us, there'd always be something in the diary that meant we ended up going for less time than we'd like. Nowadays, we put a 2-week holiday slot in the diary end Jan./start Feb., but only take 5-6 work days out and travel weekday-to-weekday across the middle Weekend. This means that we don't take an entire week off work; air fares are much cheaper than on Saturdays; and we have some leeway to accommodate important work appointments.

Obviously, we have the luxury of our own place and a weekday-to-weekday booking is difficult for a TO and can be tricky even for apartment rentals. However, as owners we're often approached by our agency to accommodate a weekday booking and we're happy to do so. In fact, I suspect that most agencies have someone like us on their books who actively accommodates weekday bookings and who is their first port of call when someone enquires.

Everywhere will be fine by January. I wouldn't say the same for December. Although the weather can, and will, change quickly at this time of year, its still summer in most parts of Europe at the moment.