They don't have weather in southern CA. :B. The biggest problem you could have is black ice at night, or early morning, fog, or wind can be a problem. If there is any snow at all just wait a few hours and it will be gone. Assuming you are taking the Pearblossom highway across. BTW, some history, They used to grow fruit in Littlerock until they cut off the irrigation water. Now it is just desert. You can see a few stands of dead trees in the area. Lived in So CA for 40 years. DW lived in Quartzhill. The little town of Shoshone, CA is at about 1600 ft in the Avawatz mountains. However Apple Valley and Victorville are at almost 3000 ft. Pahrump is about 2500 ft. My actual choice of routes would be I-15 to 160 and up to Pahrump.