The dip in the jet stream that brought frigid temperatures, snow and Santa Ana winds to the West over the past few days has broadened out and the atmospheric trough now covers the western two-thirds of the country; this morning, its leading edge extends from south-central Texas to western New York and wintery conditions stretch from this front all the way back to the Pacific Coast.
A reinforcing cold front has also dropped southward through the Rockies, bringing single-digit and below-zero (F) temperatures to the northern parts of that region while low pressure over the Desert Southwest is spinning snow into southern Colorado, New Mexico and West Texas. Light snow is also expected along the southeast edge of the trough, including northeast Texas, northern Arkansas and southeast Missouri. Here in central Missouri, we dodged the precipitation but the temperature at dawn is 27 degrees F and highs are expected to remain in the thirties for the next several days.
Unlike many winter storms that rush in with high winds, heavy snow and ground blizzards, this widespread surge of cold air, not tied to a powerful zone of low pressure, has pushed south and eastward with little fanfare. Nevertheless, it is the first major outbreak of the season and, as it spreads eastward, only South Florida will escape winter's advance.
