In the West, scattered rain and snow showers are most numerous across California, the Intermountain West, and the Northwest. Pre-holiday storms provided a dramatic boost to high-elevation snow packs in parts of the West; for example, the average water content of the Sierra Nevada snow pack climbed to 12 inches (140 percent of normal) by December 24, up from 6 inches a week earlier.

On the Plains, cold, mostly dry weather prevails. This morning’s low temperatures plunged below -10°F as far south as the central High Plains, where only a shallow snow cover exists to help insulate drought-stressed winter wheat. Early today, sub-zero readings were widespread on the northern and central Plains, while temperatures generally ranged from 0 to 20°F on the southern Plains.

In the Corn Belt, a major winter storm is underway in the Ohio Valley, where frozen precipitation (snow, sleet, and freezing rain) is occurring. Blizzard warnings are in effect today from near the mouth of the Ohio River into western Ohio. Meanwhile, cold, dry weather covers the upper Midwest, where the ground remains snowcovered. Current snow depths include 6 inches in Des Moines, Iowa, and 4 inches in Omaha, Nebraska.

In the South, cold, windy weather is spreading into the Gulf Coast States in the wake of a Christmas Day severe weather outbreak that resulted in at least two dozen tornadoes from eastern Texas to southern Alabama. Farther north, snow is ending across the Mid-South, where travel remains difficult and Little Rock, Arkansas, is reporting a current snow depth of 9 inches. Elsewhere, showers and locally severe thunderstorms are sweeping across the southern Atlantic States.

Outlook: An active weather pattern will continue through week’s end, along with mostly below-normal temperatures. Five-day precipitation totals—from two separate storms—could reach 1 to 3 inches in the East. Totals of 1 to 2 inches can be expected in the Pacific Northwest. Late-week snow will occur from the northern Plains into the upper Midwest. The NWS 6- to 10-day outlook for December 31, 2012 – January 4, 2013, calls for near- to belownormal temperatures nationwide, except for warmer-than-normal weather in the western Gulf Coast region. Meanwhile, above-normal precipitation in the lower Great Lakes region and across much of the South will contrast with drier-than-normal conditions from the Pacific Coast States to the northern and central Plains and upper Midwest.