The "weather" notice from Taiwan is 2 1/2 hours after the departure scan from Anchorage. So I don't think this is a matter of the plane going to Taiwan instead of Louisville, but maybe Taiwan is a regional command center for flights in the Pacific and all stuff like that is posted from there. Anchorage is currently experiencing heavy snow/rainfall, but I don't think it would affect flights that have taken off (there are several UPS planes flying from Anchorage to Louisville and one to Ontario, CA right now). Now Louisville experienced heavy rain this morning, but it appears to have cleared. Maybe they had flooding that is hampering operations?
Edit: It appears that Flight 63, which normally would have taken off five hours ago, is still on the ground, delayed. At this point, it would not make it to Louisville in time to get its cargo on the planes going out to make deliveries scheduled for Wednesday.