Not much precipitation is expected across the contiguous U.S. A strong but compact coastal low is expected to intensify rapidly off the Carolina coast. There is a great deal of uncertainty regarding the evolution of this system, exacerbated by the compact nature of the system, which means a small change in track could have big implications for precipitation amounts at any given location. The Carolinas and southern Virginia are the most likely regions to receive moderate to heavy precipitation, and given the much below normal temperatures in place, it will likely be mostly or entirely snow. Snow could affect a larger area surrounding this region, but odds for heavy snow drop moving away from the Carolinas and southern Virginia. Later, the strong low pressure system will head northeastward, possibly pushing moderate to heavy snow onto portions of the immediate Atlantic Coast from Maryland northward. In the areas most directly affected, amounts near or exceeding one inch (liquid equivalent) are expected, with several tenths of an inch possible a bit farther away from the storm. Moderate to heavy precipitation is also expected over the western half of Washington and adjacent Oregon. The Washington Cascades and far northwestern Washington are expecting 2.5 to 5.0 inches of precipitation, with totals ranging from near 1.0 to 2.5 inches in the rest of the area. Only light to locally moderate precipitation, if any is forecast elsewhere across the contiguous U.S. Several tenths to an inch may fall on northern Idaho, and a few tenths of an inch are forecast across some of the higher elevations of Wyoming and Colorado, parts of the northern Plains, and portions of the Florida Peninsula. Light amounts at best are expected elsewhere across most of the contiguous U.S. Meanwhile, the pattern featuring abnormally cold weather in the eastern half of the Lower-48 and unseasonably mild temperatures farther west. Subnormal temperatures are expected across a broad area from the central and southern Great Plains eastward and northeastward through the Eastern Seaboard outside northern New England. Temperatures are expected to average 10 or more degrees below normal in much of this area, with isolated sites in the Mid-Atlantic and southern Florida reaching 15 degrees below normal. Farther west, above-normal temperatures are expected to cover most areas from the High Plains to the West Coast. Temperatures are expected to average 10 to approaching 15 degrees above normal across the Great Basin, northern Intermountain West, and the central and northern sections of the Rockies and High Plains.
The 6- to 10-day outlook for February 3-7 depicts an eastward expansion of abnormal warmth into the middle of the Lower-48 while subnormal temperatures persist in most areas from the Lower Mississippi Valley, Lower Ohio Valley, and eastern Great Lakes to the Atlantic Coast, excepting northern New England. Odds for above-normal temperatures increase moving westward, with chances of at least 80 percent in place over parts of the northern High Plains and from the western Rockies to the Pacific Coast. Meanwhile, chances for subnormal temperatures top out above 70 percent across southern Florida, eastern North Carolina, and adjacent Virginia. Warm weather is favored across most of Alaska – especially southeastern sections – and throughout Hawaii. Wetter than normal conditions are also favored across the 49th and 50th states, but increased odds for surplus precipitation in the Lower-48 are limited to the southern Plains. Meanwhile, enhanced chances for subnormal precipitation covers the northern Plains and most areas from the Rockies to the Pacific Ocean. Chances for abnormal dryness exceed 60 percent across the Great Basin and the northern Intermountain West. Meanwhile, Chances for below-normal precipitation are slightly elevated along the Eastern Seaboard, though odds of 40 percent or higher are limited to a swath from central Florida through the eastern half of South Carolina.