I'm not from the PNW but I have a hundred mile round trip commute and ride in all conditions unless there is likely to be ice or snow on the road. The coldest I have commuted to work in a Strom was in the single digit Fahrenheit range. (We get winter here.) I wear a suit and tie to work most days. I ride about 30,000 miles a year.
I left home this morning in the pouring rain with temperatures in the upper 40's. I got home tonight and added an extra 20 or 30 mile side-trip to my commute and it was raining all the way. When I got home it was back to mid 40's again. I was dry and comfortable all the time I was on my bike.
I bought an Aerostich Roadcrafter two-piece in 2009 and after about 200,000 very hard rough miles I replaced it with a new Aerostich Roadcrafter one-piece R3. I was shipped to me about two weeks ago and, since I was on a road trip last week, I have out about 3,500 miles in it.
Apart from the Roadcrafter I only need two pieces of body gear to work for me in commutes down to freezing. A soft shell and a Warn n Safe jacket go over my Street clothes (the heated jacket goes over my shirt (no t-shirt for work) so usually my work suit-jacket goes in my Topcase if I will need the heat.) When it gets at or below freezing I add an Aerostich Fleece liner over my dress pants.
I wear Alpinestar Web-Goretex boots all year round with Tilley Travel dress socks. These work well for me down to the upper ranges of freezing (used to work colder but as I age my feet are getting older.)
I have three pairs of gloves: some light mesh gloves, a pair of intermediate Goretex gloves and pair of Gerbing heated gloves (I would much rather have Warm n Safe gloves but not being able to try them on in Canada makes it difficult.)
The large long pocket in the top right of my Roadcrafter carries my Aerostich three-finger rain overgloves. I can put these on while riding and they are completely waterproof when put on properly.
Road Crafters are designed for commuting and riding in all kinds of conditions. They go an over your street clothes in seconds (literally!) and come off in less time. For someone riding in rain you will appreciate you put the suit on and take it off over your boots. If you are coming in after a ride in the pouring rain you will appreciate the ability to take off the suit without having to stand in your socks on the soaking wet floor!
If have found the Roadcrafter to be a great buy...expensive at first but in the long run much cheaper than the multiple jacket etc I had in the past and the stuff works.
Btw it is supposed to be raining when I leave for work tomorrow morning as well. Of course I'm riding.