Look at the departure screens at the Boise Airport this morning and next to Seattle, you'll see canceled ... and canceled ... and canceled.
While the Treasure Valley's snowfall has abated, a major ice storm has crippled the Seattle-Tacoma International Airport, with runways completely shut down this morning. As of 10 a.m., 10 planes slated to land at SeaTac were diverted to other cities, and the rest of the planes slated for Seattle have been grounded at their airports of origin.
A quick look at Alaska Airlines' departures from Boise showed a number of Seattle-bound flights (and some heading for Portland) were canceled until further notice. All inbound flights from Seattle have also been canceled until at least early afternoon.