The upper air pattern, which drives the movement of air masses and weather systems, will feature a significant onshore orientation of the jet stream in to the Pacific Northwest, a drop southeastward on to the central and southern Plains, with a curl back then to the northeast and into southeastern Canada via the Ohio Valley and Midwest. This in turn should allow rather dominate ridges of high pressure aloft to set-up in the southwestern and southeastern U.S.
As a result, look for warmer- than-average weather in parts of the Southwest and West, as well as far across the southeastern U.S.
Meanwhile, temperatures will average below-normal to occasionally well-below normal throughout the nation's heartland and at times across the Northeast and New England. A wide-range of temperatures will be from the Pacific Northwest to much of the Corn Belt.
A cold, active (wet) weather pattern will persist into mid- spring in many areas of the country.
Active precipitation pattern
The precipitation outlook for early to mid-spring suggests an active pattern for the northern and central Plains, the Midwest, the Great Lakes region, the Northeast, New England and the mid-Atlantic region. Storminess is forecast to build early in the season the Pacific Northwest. Drier-than-usual weather is forecast across much of the Southwest, the central and southern Rockies and parts of the Deep South.
Specifically, across the Pacific Northwest, the northern Rockies and south throughout the inter-Mountain West and Southwest, outbreaks of cold-wave weather will be on the wane early in the season. Temperatures will show an upwards trends toward moderation later in the spring season. As for precipitation, above to well-above normal amounts are expected through mid-Spring in the Northwest and northern Rockies as a dry pattern tightens its hold in the Southwest. At least adequate levels of run-off moisture should finally materialize.