Western Washington has a few hazards worth planning for. Each one points to the same short list of gear: a ready kit, light and a radio, and a way to keep things dry.
Earthquakes
The region sits above the Cascadia Subduction Zone and other faults. A large quake can cut power, water, and roads for days or longer, so a packed kit, lights, and a radio carry you through the first stretch while you wait for help and information.
Mount Rainier lahars
Lahars follow river valleys, and a warning means moving to high ground right away. A grab-and-go kit by the door or in the car means you leave with supplies instead of nothing.
Winter storms and outages
Wind, snow, and ice can knock out power for days. Flashlights, spare batteries, a battery or crank radio, and a way to charge a phone matter most when the grid is down.
Wildfire smoke
Smoke can settle over the Puget Sound region in summer and fall. Keep well-fitted N95 respirators with your kit, stay indoors on smoky days, and check air quality on AirNow.
Evacuation in the rain
If you have to leave, it will probably be wet. Dry bags keep documents, spare clothes, electronics, and first aid supplies usable in rain, flooding, or a leaky car trunk.