Whether you’re heading home after the holidays or heading somewhere nice to celebrate New Year’s Eve, travel is underway for millions of people, and the weather can be a factor. For some, snow, rain and even a little ice can throw a wrench into your plans.

Here’s what you need to know to make your trip as safe as possible.

Thursday and Friday

• South, Midwest: Rain and thunderstorms will spread from the central and southern Plains north into the Mississippi Valley, Ohio Valley and Great Lakes on Thursday. Severe T-storms are possible in the south, but locally heavy rainfall and wet roads appear to be the main travel concern in these areas.

• west: Persistent snow is expected Thursday in the Rocky Mountains from Idaho and Montana to Utah and Colorado. Another windy, wet Pacific storm with rain and mountain snow will hit Washington, Oregon and Northern California late Thursday evening into early Friday. Another system will arrive in the northwest late Friday evening.

• Possible weather-related delays at the airport: Dallas, Houston and Seattle (Thursday); Chicago, San Francisco and Seattle (Friday)

This weekend

• East, Midwest: Rain in the Midwest and South will spread to much of the East on Sunday. T-storms are possible in the south, but locally heavy rainfall and wet roads appear to be the main travel concern in these areas.

• west: Rain and mountain snow will continue from Northern California, Oregon and Washington to parts of the Rocky Mountains. Flooding and landslides are most likely in northern California and southwest Oregon.

• Possible weather-related delays at the airport: Chicago, New Orleans, Seattle and San Francisco (Saturday); Washington, Philadelphia, NYC, Boston, Charlotte, Orlando, Miami, Seattle and San Francisco (Sunday)

Jonathan Belles is a graphic meteorologist and author for Weather.com for 8 years and also helps produce videos for The Weather Channel en español. His favorite weather is tropical weather, but he also enjoys covering severe weather events, news reports, and winter storms. He is a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.