1. Don't bring any plastic bags... Plastic bags are illegal... Portlanders pride themselves on caring for the environment so it is best not to be seen using plastic bags. Caring about the environment is assumed, and not doing so (littering, carrying groceries in plastic bags) is really frowned upon.
2. Portland gets and cloudy skies from October through May. Portland's annual average is 40 inches of rainfall, with about 150 days offering at least some rain. Chances are good when you will be moving in the rain. Familiar movers will all be prepared for any rain.
3. Before moving in is your best opportunity to clear the home of any spiders... Portland is notorious for its Hobo Spiders. They're not good at crawling up walls so live in corners, in cracks along the floor, bathrooms, etc. Clean out the cob webs and lay down some of those sticky traps at baseboards and corners. Your unpackers will likely set up the beds just a little away from the walls so the Hobo's can't crawl up on the bed at night and so you have room to place more of those sticky traps.