Source: Facebook/US National Weather Service Seattle Washington. Residents of Seattle brace for a spate of inclement weather as the National Weather Service in Seattle, Washington, forecasts a series of showers and possible thunderstorms in the coming days. The weather, carrying a 40 percent chance of precipitation, is expected to disrupt the calm that’s held the city in a cool embrace, with temperatures hovering at a comfortable 59°F and overcast skies as of the last 6:05 AM update.