@crewman59
You defined California as your “tax home“. Do you have any other work for the four weeks out of every six when you live in Washington? If your only work is in California for those two weeks, then I would say that you just have a very long commute with an unusual work schedule, and California is your tax home. And in that case, if this situation is either of indefinite nature, or has lasted, or is expected to last more than one year, then your travel expenses to and from California are not deductible. The fact that your work assignments are only two weeks out of every six weeks is not enough to call the situation a temporary work assignment, if it is your only work, because if it is your only work, that makes California your tax home, and travel TO your tax home is not deductible.
If you also perform work in Washington state, then Washington may be your tax home, and traveling to California would be a deductible expense.
Of course, you may want to have your own specific fact situation reviewed by your own professional expert.
