In reply to Jake80:
Weather in the mountains is complicated. Resolution is very important (grid density as you say, check our post in that respect:
https://meteoexploration.com/wordpress/index.php/2019/04/11/model-resolutio... ). But also initial conditions and number of weather stations in the direction of the coming weather, which is useful to initialise models. That's why forecasts for Eastern Europe are usually more accurate than for Western Europe, as there are hardly any weather or radiosounding stations in the Atlantic, but there are plenty of them in Western Europe.
Model ensembles (for example
https://meteoexploration.com/forecasts/Monte-Rosa/?module=ensembles ) gives you an idea of how reliable the forecasts are, sometimes the dispersion is such, that forecasts are just a guess, and then local knowledge is crucial. A local, experienced forecaster knows the behaviour of weather systems when they interact with local topography and no freely available model goes to that level of detail.
All weather (and climate) models are of limited resolution and had inherent limitations in simulating the chaotic behaviour of weather, although they do a really good job many times.
In a summary, check resolution, vertical levels and how they interpolate to the altitude of the peaks, which model and model initial conditions they use, and don't trust anything beyond five days (treat everything beyond three days with suspicion).