According to this map, at least the flight should make GREAT time, with a couple of disturbances along the way that may well push them over 800mph! It will likely also be bumpy. Also remember the pilots are also ON the plane, so they won't fly into something that could kill them too.
Looks like there may well be more storms after this one. What has UA done so far with all the typhoons? Divert elsewhere or just cancel?