The storm is not quite as strong as initially feared, but the impacts of Hilary on the Sierra are still going to affect travel.
Here's a link to the best info we've found: https://goldrushcam.com/sierrasuntimes/index.php/news/local-news/48878-weather-service-projected-rainfall-totals-for-sunday-through-monday-weather-system-for-the-central-valley-foothills-and-sierra-nevada-yosemite-valley-up-to-1-50
Monday night and Tuesday will be the worst of it, but keep in mind that the rivers and creeks in the Sierra are still running quite high due to snow melt. This will only make things worse. We've already decided against a number of backpacking trips because of the snow levels (first) and now high water levels that are making every creek crossing something between an adventure and suicide.
Please be careful up there, and if you do take a trip, let us now what you find.