A frontal boundary is stalled out across the Midwest and Central Plains, leading to a multi-day flood threat. Cities like Chicago need to be prepared.

To understand how this monumental El Niño will shape our winter, NOAA has a network of instruments in the Pacific.

El Niño's southern storm track could bring bigger snowfall to Mammoth Mountain, Telluride, Park City, Taos and Flagstaff this ski season.

We have the maps you need to monitor the tropics, including tracks, current weather and other areas to watch.

Clear skies, calm winds and longer autumn nights combine to form dense fog and frost — know what to inspect on your car before that first chilly commute.