We hiked Whitney once in strong winds although I don't think they were as strong as 45 mph. You will need a wind proof outer layer or you will be very cold. Fleece is not windproof. A sudden gust could upset your balance. Be careful next to steep drop offs or at the "windows" on the last stretch of trail. I believe that the trail is doable in winds this strong with care, but it may not be much fun. If you get part way up the trail and start thinking that these conditions are misery, bail out and try again on another day.