Best source for checking weather over a long route?
 

In late November, I need to drive from near Denver CO to near Seattle WA

Weather is obviously a crapshoot that time of year, and I could basically take one of three routes:

1) I25 north to I90 then west
2) I70 west to Green River UT then cut up to Salt Lake then I84 onwards
3) I70/US 50 west to Ely NV then north to Twin falls then I84 onwards (a good deal longer)

Each route has its winter weather challenges: I70 over the Eisenhower Pass/Tunnel often has chain laws and accidents; I25/I80 in Wyoming can have fierce winds.

I've seen times when the Wyoming/Montana route would have been fine, but the I70 west route terrible, and vice-versa.

What do folks recommend for weather sites that can actually do a decent job (a day or two before travel) of forecasting over such a broad swatch of territory? I find most of the commercial sites to be long on fluff and short on information/usability.

Don't know if it's the best but I've used Accuweather's route weather feature before:

https://www.accuweather.com/en/drivi...ctions-weather

I do a much, much shorter route located further north and two mountain passes in a row (and once you're committed...). I usually check the weather forecast for a couple of towns in the area + the origin/destination in the area (at a lower elevation than the passes) - these bracket the mountain ranges - and then account for likely temperature at the passes. This gives me an idea of whether there will be inclement road conditions or not. If you're familiar with the terrain on the route, you could do the same though it'd be a lot more research for you.

I usually use TAF reports when available from airfields along the route. Otherwise I just stick with METAR data on the day of. AWOS data is very accurate IME.

I like 'Weather Underground' www.wunderground.com - while enroute, the android app can make use of GPS based location, too.

From the horse's mouth: The National Weather Service.

weather.gov/briefing has several links for a good national overview, and if there's a weather event of interest go to the local forecast office's webpage (available at weather.gov by clicking on the map), then go to the forecast discussion under the "Forecasts" dropdown.

Another good resource is the respective states' DOT websites. Speaking for Washington (www.wsdot.gov) and Oregon (www.tripcheck.com), both have pretty useful websites with weather and traffic information, pass cams, weather alerts, etc.

I have spent a bunch of time on I-84, and most of the time it is really good, but when it goes sideways weather wise, the stretch from Ontario, OR to Pendleton (~170 miles) can be brutal if it is open at all. Ice storms and blowing snow frequently close the highway during the winter between Ontario and LaGrande, and the Meacham/Deadman Pass/Cabbage Hill area is something like 4700 feet of elevation.

Other resources:
511.idaho.gov
https://www.codot.gov/travel
https://www.udot.utah.gov/main/f?p=1...0:::1:T,V:1673,
http://www.dot.state.wy.us/home/news...formation.html
http://www.mdt.mt.gov/travinfo/