You can have snow - but as you head east you get a lot less. By February, snow is unlikely to be a problem and you have a reasonable chance of being snow free (although this has been a pretty snowy year in Eastern WA). One of the best places to view the channeling is Dry Falls State Park/Visitor Center https://maps.northwestportal.com/outdoors/#12.52/47.605094/-119.395425?search=true&f=namelc&q=dry%20falls%20visitor I also really enjoy Frenchman Coulee - where you can walk along the cliffs carved out above the Columbia River https://maps.northwestportal.com/outdoors/#13.45/47.020855/-119.977526