Traveling from Memphis To San Francisco

[AZBuck]

It is simply too early to give you any precise information about which roads to take in January of next year if weather is a major, or even minor, concern. The fact is that weather forecasts even a few days out are nothing more than educated guesses (WAGs). Both the I-40 and the I-80 route are going to require a minimum of four days to drive so you will have no reliable information on the weather on the western part of your trip when you set out. The lack of knowledge is exacerbated by the fact that you will be traveling west with little knowledge of what is brewing out in the Pacific that will be heading towards you.

So in the end you've really only got one option and that is to keep your options open. As Mark noted in his response to your initial question you'll need to keep your eye on the weather and be ready, able and willing to simply shelter in place if the weather turns against you. I don't know exactly what Mark's reasoning was to suggest I-80, but I can guess. Nebraska, Wyoming, Utah, Nevada and California expect severe winter weather every year along I-80, and are equipped to deal with it. Not so much Texas, New Mexico and Arizona which are responsible for I-10 and I-40.

Again, just to emphasize... You should not make decisions on routing now - you simply don't have enough information. Even on the day you depart you will not know with any surety what the weather will be once you get even into the Mountain Time Zone, let alone the Pacific. Make your best call, based on the most reliable forecast (National Weather Service) available to you. But then be ready to change those plans even en route as conditions change. Perhaps most importantly, plan on the drive taking five days rather than four. Be pleasantly surprised rather than having to press on regardless.

AZBuck