Winter mountaineering layers

Planning on getting on some winter alpine climbs this season, and I'm curious about my layering system.
I'll be spending time mostly at Yatsugatake in Japan. To give an idea of conditions, the forecast for the next ten days includes temps around -10 to -20 degrees Celsius, with winds 10-30 m/s.

Right now I've got:

Icebreaker 200 weight long-sleeve half-zip baselayer
Outdoor Research Cathode
Arc'teryx Psiphon FL Hoody softshell
Montbell Dyna Action Parka hardshell
Marmot Zeus down jacket (old version with 800 fill power down)

I've never been out in conditions like this, so I'm not really sure what to expect. I've been cobbling this kit together for other uses and I use all these pieces frequently in different combinations in less serious conditions, but does this seem like it'll do the trick in more extreme alpine conditions?

Thanks for the feedback.

You need a proper belay parka for -20C, otherwise probably OK. A fleece midlayer wouldn't hurt, inexpensive and versatile.

Obviously you also need lower body layers. Gloves (more than 1 pair ideally) and mitts. Face protection and goggles if the wind is that bad. Warm boots. 

jdejace wrote: You need a proper belay parka for -20C, otherwise probably OK. A fleece midlayer wouldn't hurt, inexpensive and versatile.

Obviously you also need lower body layers. Gloves (more than 1 pair ideally) and mitts. Face protection and goggles if the wind is that bad. Warm boots. 

The belay jacket was the only thing I was concerned about. I'll be starting out on routes without pitched climbing, so have time to think about picking up one of those. Also have a Montbell fleece hoody that I was thinking might be a good addition. Was only worried about how much space it'll take up in the pack.

For lower body I've got 200 weight merino base, a double weave softshell, and a MH hardshell.

Several pairs of gloves, the warmest being the OR Arete. Probably need to get a pair of mitts.

Balaclava and goggles.

La Sportiva Nepal Evos on the feet.

I have an R1 fleece, and a Sportiva source hoody and I prefer the source hoody for layering in the cold. If you’re in CO or have a buddy there I’d also suggest a melanzana grid fleece over an R1 type too. I bought my girlfriend one and she wears it non stop.  

Pretty reasonable setup if you keep moving.

Aretes are good. I would want to carry the mitts and the belay parka as emergency pieces even if I didn't plan on stopping. I'd bring the fleece along on the trip, you might like it. If it's that cold I'd just put it on in the morning and likely it won't come off. 

At -20C for belays probably you'll enjoy another insulation layer on your legs. And Nepals start to get a little cold for most people sitting still at that temp.

That's a lotta wind. Sounds miserable. Stay in and drink coffee instead?

You need like 3 or 4 pairs of gloves. 2 thinner moving pairs, a warm not moving lots pair and a pair of oh shit mitts if you get into trouble.

Layers seem ok. A bigger puffy is very convenient but throwing all your puffies under your hardshell will be pretty warm.

You can cut up a bit of foam and slip it under the laces of your boots to keep snow from getting stuck under the laces. Helps keep the feet a little warmer.

Nepal's wouldn't be warm enough for me at those temps.

Speaking from plenty of experience in brutally cold temperatures, if you're planning on technical climbing in anything subzero, you will need *at least* a 275-gram down belay jacket and warmer boots.  I use a 300-gram down belay jacket.  Belaying in Nepals in those temperatures will be painful.  Mittens are the key for belays, with several pairs of gloves for active climbing, unless you use a vapor barrier.  Technical climbing in subzero temps are a whole new ballgame - you quickly realize how important it is to keep your hands as warm as possible.  It wouldn't be a bad idea to have chemical hand warmers in your belay mitts.  I promise you, your hands will get frigidly cold.  Do your best to mitigate barfies.