Weather may affect their travel plans. They should periodically check the weather (for example, the NWS now has interactive forecast equipped with Celsius and Spanish options: http://www.wrh.noaa.gov/forecast/Map...3639&degrees=C) and, if there's weather, more frequently road conditions (CA: 1-800-427-7623 toll free in state, 1-916-445-7623). Because of slippery slopes and that few cars have snow tires, Interstate mountain passes are often closed due to snow with little advanced notice, for example, I-5 between L.A. and Bakersfield, I-15 north of San Bernardino and just south of L.V., all of these over 4000 feet.