Here's the page I have bookmarked:
in the top box on the right titled "SNOW SENSOR INFORMATION" you have access to remote snow sensors giving you real-time snowpack info for a variety of locations in the Sierra. Be aware that these primarily read in inches of water content, not snow depth. But in the late spring when it matters, snow depth is usually fairly close to double the water content number. It takes some time to figure out which sensors are closest to where you are planning to go, but once you have that dialed it is a great resource. I have used this info for years in planning my spring backcountry ski trips.
If you tell me where you are planning to go I can tell you which sensors are closest to your route.