It’s no surprise to anyone that it’s been much colder than normal in much of the country over the last few days, with Arctic air sagging well south of its normal location due to a weak polar vortex. It’s delivered single-digit temperatures as far south as central Texas, with ice the main story through the mid-South and in the Pacific Northwest while temperatures in the northern Plains are as low as -20 Fahrenheit to start the week. Winter storm warnings stretched from New Mexico to Vermont, including the entire state of Texas, on Sunday night, as an ice-bearing system slowly moves east. Another system off the Pacific coast driven by a deep trough is behind the current system, hence its trajectory well south of normal. That system will bring ice in a line from central Texas to Maine, while snow will be likely just north of that line in the next two days. The good news: Arctic oscillation is expected to move back northward, allowing temperatures to warm later this week through early March. A wet pattern in the west, active weather in the Midwest and mid-South and drier conditions in the Plains are likely later next month. See more from the latest forecast.