Snowfall line
Climbs briefly to 1000-1200m today, then drops back to 600-900m tonight. Full amounts from 1400-1600m
The quantities
There will be 30-50cm across the entire northern Alps. In the core it will probably be 50-70cm and with perfect nordstau I see potential for surprises upwards, in central Switzerland and other powder holes up to 80 or 90cm. We won't manage that metre, the oracle believes.
Where should I go?
It's going to be socked in all day on Saturday, so head for the alpine meadows that have already had some snow, or if there's enough in the trees somewhere in central Switzerland or on the Arlberg, then head there. As there's already a lot coming tonight, you should be out and about early on Saturday to maximise the fluffiness and beat the daytime warming in spring. (Even with snowfall, the diffuse radiation in April has power).
Sunday will be showery. Season pass holders can speculate on a short break in the clouds at midday, but everyone else should rather stay in the trees.
It should clear up on Monday and at least be suitable for the ski area in the morning, with possible showers in the afternoon and the rest of the days until Wednesday. It will stay cold until Wednesday and those who can take a holiday can still find good powder on the north side in fairly stable conditions. That's the good thing about spring.