What a great find! After searching on several weather sites to see the projected weather along our route to pick the best time to leave, I happened across the Weather Underground Road Trip Planner. This lets you put in destinations and departure times, then will show the route and forecast (click for details). It also shows below freezing and precipitation notes.
is the 7-day forecast centered on the I90 pass east of Seattle. Temperatures are adjusted for altitude.
Your link gives a nice overview, but for details I'd suggest using the gov 7--day, including the 'forecast discussion', radar and sat views, and graphical plots.
