The Nation's Weather 10.15.09

By WEATHER UNDERGROUND (AP)

An Alberta Clipper from southern Canada was forecast to drop into the northern tier of the nation Thursday.
As the system plunged southward, a mix of rain and snow showers was expected to blanket the Northern Plains, the Upper Mississippi Valley and the western portions of the Upper Great Lakes. Showers were expected to spread into the Ohio Valley during the evening hours.

In the East, a wave of low pressure along a frontal boundary in the Southeast would combine with rich gulf moisture to produce scattered showers and thunderstorms along the Gulf Coast. Meanwhile, a low pressure system in the Southeast would kick up cool precipitation and thunderstorms along the coast of the Mid-Atlantic and the Southeast as it jumped across the Georgia coast. Cooler temperatures were expected throughout the southeastern quadrant of the nation, as the system pulled cooler air from the North into the region.

Elsewhere, quiet weather activity was expected to develop in the West as the remnants of the recent Pacific storm shift eastward. Lingering moisture in California would spark showers and high elevation snow showers throughout the morning. Meanwhile, a ridge of high pressure would begin building into the West Coast, bringing drier and warmer weather to the state. To the north, showery weather was expected to persist in the Pacific Northwest as a series of low pressure waves moved through the region. Light to moderate bands of precipitation were expected across Washington and the Cascades as a warm front dropped through the region through the latter half of the day.

Temperatures in the Lower 48 states Wednesday ranged from a low of 13 degrees at Spincich Lake, Mich., to a high of 100 degrees at McAllen, Texas.