Update Monday evening: Sequim and vicinity might be a possibility.
Tomorrow, from around 3:09 PM to sunset, Venus will move in front of the sun---the famous transit of Venus. This is an extraordinarily rare event that will not occur again for over a century (December 11, 2117).
The problem is that a weather system will pass through the region tomorrow morning and afternoon...but there appears to be a chance that some NW residents will see it.
Bottom line: for Puget Sound residents, head for the southern Washington coast or Oregon coast for maximum chances of viewing. Westport might be the closest location that is viable for Seattle residents. Or head south to Longview/Portland.
I don't have much time right now...but here are some of the model graphics, indicating cloud cover. First, cloud forecasts for 2, 5, and 8 PM.
Portland and northwest Oregon may luck out. There is some uncertainty with these forecasts...lets see what tonight's runs show.
Here is the official National Weather Service sky cover percentages for 5 PM and 8 PM: