This time of year with the heavy snow expect the river to be up and the Mist Trail will be WET, there are some parts of the mist trail where the mist is blowing like a fire hose up hill. Bring rain gear for that part or strip to shorts and get soaked. I prefer the get soaked method if its sunny. I would stay off that section of the JMT and take the mist trail. The JMT is almost just as wet and longer.