Dan’s right – there are traps, and even what looks like beautiful weather can be treacherous. Experiencing a strong downdraft can be a real eye-opener.
No one wants to say “ah, just go fly, it will be fine” and then read about you in the next day’s newspaper.
Clouds are of course something to be aware of but clear windy days require experience both to handle the turbulence and to ensure you are always in the rising air.
The “bible” is a great book, and any pilot flying in mountains will learn something from it.
If the day is clear and calm, temps are not too high, you have an aircraft of decent performance, you have a clear understanding of the terrain on the route, and nothing goes wrong, you’ll be fine.
Local knowledge from someone like Dan that’s probably made more “quick trips” around the Matterhorn than many of us have landings will help you find the right places to cross depending on conditions. The GAFOR is also helpful – if you get anything other than O/O/O then take care.
Only go when the gafors are green all the way up. Make sure you really understand Vx and in particular Vx at altitude on a warm day. Always cross ridges at 45 degrees. Never fly in the middle of a valley. Practice box canyon turns. That’s about the long and short of it. If you want to land anywhere funky, then you need a mountain rating anyway, which, by the by, is about as much fun as you’ll have with your clothes on. Just start on an easy route and bear in mind the penalty for poor planning is severe. The only real problem is jamming in the alps is addictive.
Oh and forget flying in the afternoons. Unless you like seeing your lunch twice.
Well, I feel a bit foolish now for sounding so flippant in the OP.
In the older threads I linked, there were a lot – most? – posters who seemed to give off the vibe of “yeah, it’s not that hard, just keep the side of the valley and crosses ridges at an angle etc., follow the GAFOR routes you’ll be fine”. Is that a difference of opinion, or am I misunderstanding what kind of flying is being talked about?
Re. my comment about IMC – emphatically, I was not proposing to cruise down valleys with 0 vis! 
Oh and forget flying in the afternoons
That is one main problem with flying down there from London/Paris, things gets clogged in the valleys and weather may change a lot by the time you arrive on a bumpy afternoon: don’t be a hero, just admit it’s too late and turn back (or climb in safe area if your aircraft has some juice left)
PS: the easy way is to land nearby where you are less likely to do stupid things !
Well, I feel a bit foolish now for sounding so flippant in the OP.
Not at all.
The advice on this sort of thing comes down to specifics. The main challenge is getting people who actually know this stuff to write down the info
And as I said it strongly depends on the aircraft. A C150 can be used on a perfect day and if you start climbing way back. A TB20/SR22 makes light work of it. In between, it varies. What altitude does the Brenner pass need? I have been there but the whole route was flown at 13000ft which is above the terrain anyway.
I think the one bit of advice I would have given to the late jgmusic would be to never turn into a canyon unless already above its floor i.e. not rely on the aircraft having the climb capability to outclimb the terrain ahead. The ability to notice that you won’t, and turning back before it becomes too late, needs more experience. I also strongly suspect that, with a baby on board and no oxygen, he was contrained in altitude and hoped it would just about work. Without oxygen, you are severely constrained.
As regards checking the wx, there are nowadays loads of webcams in the mountains and it is dead easy to check the general picture. You find them online, and on windy.com in the webcams layer.
Last week we did LIDA-LOKL-LOWZ in sunny autumn weather and it was just great. I think that covers the area the original poster asked about. But we had the advantage of real climb power. I would not have been very comfortable in a plane which is performance limited to the valleys only. It also helps if you know the valleys a bit. Some of them are more flyable than they seem on the map and for others its the inverse. For example on this trip we flew the Felbertauern route for the first time and it was quite a bit more hostile than I anticipated. Also the Brenner pass valley north of Bolzano is not as wide as one would expect it from the main automobile route over the Alps.
Just that if a cloud layer suddenly came down and I didn’t have an VFR “out” – which would be bad planning on my part – I wouldn’t have to remain trapped underneath it
That’s the point, unless you have something like an F-16 you will stay trapped. The other option is to bet on your climb rate. Lots of people have done this, and most have lost the bet.
Scotland has some mountains, doesn’t it? Why not do some flying there in low cloud cover and you will experience what it’s like to fly “trapped”.
We still don’t know the aircraft type…
If you are in the Alps at say 9000ft then you are already above most of the terrain, and a climb is usually just fine, assuming you have some sort of topo moving map. The challenge then, if you are doing this to escape IMC, is icing.
Scotland has “hills” The biggest is 6000ft or so.
It would be dumb to fly below low cloud surrounded by terrain, unless you know exactly where and what etc. Even helicopters have frequently crashed doing that. You don’t need the Alps for that – people have done it in the Welsh hills.
Peter wrote:
Scotland has “hills” The biggest is 6000ft or so
That is MSA or TA? I think the biggest is 4.5kft which you can out climb in Turbulents without mixture control and car engines
I think knowing your & aircraft performance are very important: for planning purposes, ceiling = highest altitude you have flown in hot days !
If you always flew TB20 at 3kft under LTMA, don’t expect it to make +FL180 under 15min in the Alps, go and have try yourself over flat lands 
