Here are some resources that we use to check the locations, routes, and weather while planning our trips. Also, avalanche bulletins are very important for understanding the current situation on the slopes.
Resort info and weather
DAV Weather Report, https://www.alpenverein.de/DAV-Services/Bergwetter/
Weather to Ski, https://www.weathertoski.co.uk/
Snow forecast for ski resorts, https://www.snow-forecast.com/maps/dynamic/alps
Maps & routes
Pistehors.com (FR & CH), http://pistehors.com/