The W to E winds are likely to be strongest in the spring...summer is when the SW US High builds up and can suppress those winds. If you're doing Donner Pass over the Sierra, that should be open, but wouldn't be my first choice--the ACA chose Carson Pass for the Western Express route to SF for good reasons. Caltrans tries to keep Carson Pass open all year, and it is currently open.
Last edited by stevepusser; 04-30-19 at 02:27 PM.