Episode Details

Four states are already on the map for significant snow this winter, and the pattern behind it is only getting stronger. Forecasters expect El Nino to build into a Super El Nino by the end of the year, the kind of setup that has historically buried the Sierra Nevada and the mountain Southwest in above-average snowfall. For drivers, the warning has arrived six months early, which is exactly the point.
What a Super El Nino Is

The El Nino weather pattern shows up when sea surface temperatures in the central and eastern tropical Pacific run warmer than average. In a Super El Nino, that warm anomaly exceeds two degrees Celsius. Researchers at the Columbia Climate School say the early warning signs are already in place, with subsurface heat across the equatorial Pacific beginning to rise toward the surface.

For U.S. winters that pattern historically tilts the odds a specific way: milder across the northern tier, wetter across the South. The strong El Nino winter of 1997-98 landed as one of the warmest and wettest on record.

The States Bracing for Snow

Milder does not mean drier where it counts for drivers. The latest predictions single out four states for heavy rain and significant snow this winter: California in the Sierra Nevada, New York, Vermont and New Hampshire. NOAA's Climate Prediction Center meanwhile puts its highest confidence on above-normal precipitation across the Gulf States and parts of the Southeast to Mid-Atlantic, and gives the strengthening El Nino an 81 percent chance of reaching very strong intensity by the end of the year.

Translated to the road, that is a wet Sierra with deep winter snow over Donner Pass and the ski corridors, another loaded winter for the Northeast on the back of last season's cold one, and repeated rounds of rain and cold fronts across southern states where winter driving experience runs thin. These are the corridors where winter snow warning headlines will stack up once the season turns, and where an early forecast is worth acting on rather than reading.

There is a snow map too. NOAA's own analysis of snowfall in El Nino winters shows exactly where the pattern delivers, in inches: more snow than average across the Sierra Nevada and the mountains of the Southwest, from Utah and Colorado through New Mexico and Arizona, and less across the northern tier from the Pacific Northwest through the Great Lakes. For drivers, that is the map that matters.

Where Drivers Will Feel It