As you can see, tomorrow will be a crapshoot, but it's certainly doable in half an hour. Since it's more likely your luggage will make it, you may want to consider packing more into your checked luggage and having less carry on to drag through the airport if you are on the run. Depends on what you need at your destination.
For more fun reading, here is the Seattle connection time thread:
Minimum Connection Transfer Time at Seattle (SEA): The Definitive Thread