Fresno, Calif. — Forecasters are increasingly confident that a powerful winter storm will deliver significant snowfall to the Sierra Nevada ahead of Christmas, with a 60% chance of at least 2 feet of snow accumulating above 7,000 feet by Thursday, according to the National Weather Service.
The Weather Service office in Hanford says the highest likelihood of major snow impacts will occur between early Monday, Dec. 23, and Christmas Day Thursday, Dec. 25. While confidence is high that heavy snow will fall in the high Sierra, uncertainty remains regarding when snowfall will begin and when the heaviest rates will occur during the 48-hour period.
Probabilities for two feet of snow exceed 70% near Tioga Pass, Mammoth Mountain, and portions of Yosemite National Park, with chances nearing 60–70% along the crest near Sequoia and Kings Canyon national parks. Lower elevations, including the Central Valley, are not expected to see snow.
Forecasters outline a range of possible outcomes. In a best-case scenario, estimated at a 20% chance, warmer storm temperatures would raise snow levels and limit accumulations. In a worst-case scenario — also about a 20% probability — colder air could drive snow levels down to around 5,000 feet, bringing impactful snowfall farther south into Kern County and affecting mountain passes such as Tejon and Tehachapi.
If the colder scenario develops, travel disruptions could become significant across major Sierra routes, including Highways 120, 168, and 180, with chain controls and temporary closures possible.
Officials urge travelers heading into the mountains for the Christmas holiday to closely monitor forecasts, prepare winter emergency kits, and expect rapidly changing conditions. Additional updates are expected as confidence increases on storm timing and intensity.
