Arctic clipper snow and successive atmospheric rivers drench California as New Year arrives
Alberta Clipper strengthens winter conditions in the north
A strong Arctic front known as an Alberta Clipper has reinforced cold air across the northern United States, sustaining lake-effect snow showers and snow squalls from the Great Lakes down through the Ohio Valley into Pennsylvania and western New York. This cold surge is expected to maintain hazardous winter travel conditions into the early days of January, as winds funnel Arctic air over the relatively warmer lake surfaces, generating bands of heavy snow and localized accumulations while temperatures plunge well below seasonal norms.
National Weather Service forecasts highlight the potential for another 1–2 feet (30–60+ cm) of snow in persistent lake-effect bands, especially near Lake Erie and Lake Ontario, with locally higher totals possible where snow bands stall for extended periods.
Additionally, snow showers and squalls are expected to spread into the upper Midwest, Northern Plains and interior parts of New England as the clipper advances eastward.
Southern California braces for heavy rain and flood risks
Meanwhile, the opposite end of the country is dealing with an entirely different winter hazard. Southern California is under the influence of successive **atmospheric rivers**, moisture-rich corridors in the lower atmosphere that transport vast quantities of water vapor inland. These storms have already brought significant rainfall and flooding over the Christmas period, causing flash floods, mudflows, infrastructure strain and multiple evacuations.
Officials in Los Angeles County and other Southern California jurisdictions issued **evacuation warnings for burn scar areas**, where hydrophobic soils and steep terrain make flash flooding and debris flows especially dangerous. These warnings remain active as more rain is forecast around New Year’s Day.
Rainfall totals in this pattern are notable: some mountain and foothill communities have already reported upwards of 250 mm (10 inches) in recent events, prompting states of emergency in multiple counties and extensive deployment of emergency personnel.
Why California is so vulnerable right now
The heightened flood and debris flow risk stems largely from the combination of intense atmospheric river events following a wet Christmas and the presence of wildfire burn scars from previous fire seasons. Burned and hydrophobic soils absorb far less water, increasing runoff and the potential for destructive flows and flash flooding in steep canyons and valleys.
Even where rainfall rates diminish, saturated ground conditions can prolong the hazard, as continued precipitation can quickly translate to stream cresting, slope instability and road washouts.
Forecast into the start of 2026
Forecasters project that the current atmospheric river pattern will persist through the early New Year weekend, with intermittent bursts of heavy rain and mountain snow continuing in California. Heavy snow remains likely at higher elevations of the Sierra Nevada, contributing to winter recreation hazards even as low-land flooding remains the immediate concern.
Across the northern and eastern U.S., the Alberta Clipper is expected to keep temperatures cold and maintain lake-effect snow into the first few days of January, while the transition zone between Arctic air and milder Pacific systems may periodically shift bands of snow farther east toward the Appalachian and northeastern states.
Impacts so far and safety reminders
Heavy snow and winds in the north have already disrupted travel, with icy roads and reduced visibility creating hazardous conditions for motorists and transportation networks. In the west and south, emergency services have conducted numerous rescues and advised residents to heed evacuation warnings, especially in historically flood-prone and burn-scarred areas.
Meteorologists recommend staying abreast of the latest official forecasts, monitoring flood and snow advisories, and avoiding travel in the most affected zones until conditions improve. The combined influence of Arctic air and potent atmospheric rivers underscores the varied and evolving nature of U.S. winter weather as the country enters 2026.
