The Western United States is bracing for a historic December cold snap. The temperature nosedived from the West Coast through the Rockies to the Plains early Wednesday. Many spots were seeing 30+° temperature drop in the past 24 hours. The temperature in Denver, CO fell from the 57° to 5° in 18 hours.
The cold plunge will last for several days, and a second surge of Arctic air may be even colder in the Central United States next week. The temperature Friday morning will be 15-45° colder than normal west of the Mississippi. All of Wyoming, Montana, North Dakota, South Dakota, and Minnesota may be below 0°, with parts of the Rocky Mountains reaching -35°! Those same states may not see the temperature get above 10° on Friday afternoon, with most of North Dakota and Montana not making it above 0°.
They will be “bundling up” in Los Angeles where the temperature is not expected to get out of the 50s late in the workweek, despite the usual heavy dose of sunshine. Farmers in California will be taking preventive measures to protect crops as the temperature falls below freezing at night. A storm will develop in the South Central United States late in the workweek. A significant snow/ice event is possible from Texas through Oklahoma to the Ohio Valley.
It will stay very cold through the weekend, and another Arctic blast is likely early next week. It will be centered a bit farther east, with temperatures in Minnesota, Wisconsin, and most of Iowa well below zero Tuesday morning.
Southern New England will not see the worst of the cold weather, with low temperatures falling into the single digits and teens by the middle of next week after a Monday-Tuesday storm departs.