In the West, the last in a week-long series of Pacific storms is pounding central and southern California with heavy precipitation and gusty winds. Precipitation stretches as far inland as the central Rockies, where snow is falling. The stormy pattern favors Western water-supply prospects, but threatens southern California and parts of the Desert Southwest with additional flash flooding and mudslides.

On the Plains, cold weather persists across northern areas, including Montana, where a snow cover continues to insulate winter wheat. Meanwhile, cooler air is returning to the southern Plains, following two days with high temperatures of 80 degrees F or greater in parts of Texas.

In the Corn Belt, dry weather prevails. A snow cover blankets the region, except in the southwestern Corn Belt. Snow depths of 1 to 2 feet exist in the upper Mississippi Valley, where some rural travel remains difficult.

In the South, warm weather continues for a final day in the Gulf Coast region. Meanwhile, cooler air is spreading across the interior Southeast. La Niña-induced drought continues to expand and develop across the Deep South, particularly from central and eastern Texas to Florida and southern Georgia.

Outlook: Following a lull, locally heavy precipitation will return to the Pacific Northwest on Thursday and the remainder of the Pacific Coast States by Christmas Day. Meanwhile, the storm currently affecting California will drift eastward, crossing the southern Plains on December 23-24. Generally light but beneficial precipitation will fall across the southern half of the Plains, while some snow will spread from the western Corn Belt into the middle Mississippi Valley. By December 25, some rain and wet snow will arrive in the Southeast, while cold weather will cover most areas from the Plains to the East Coast. The NWS 6- to 10-day outlook for December 27-31 calls for colder-than-normal weather from the Southeast into southern New England, while near- to above-normal temperatures will prevail along and west of a line from Texas to Michigan. Meanwhile, drier-than-normal conditions across the central and southern Plains and the Southwest will contrast with near- to above-normal precipitation across the remainder of the U.S. Wet conditions will be most likely in the Northwest.