Weather Underground Forecast for Thursday, January 12, 2012.
The storm system in the Tennessee Valley will lift northeastward through the Ohio Valley and into the Lower Great Lakes on Thursday. As this system progresses, it will merge with another system dropping in from the Upper Great Lakes. Expect widely scattered showers with periods of heavy rain and thunderstorms to persist ahead of this system in the eastern Tennessee Valley, Ohio Valley, Central and Northern Appalachians and northern Mid-Atlantic. Precipitation will change into a mix of rain, sleet, freezing rain, and snow showers in the Northern Appalachians and the interior Northeast. Another area of low pressure trying to develop along the southern New England coast will enhance precipitation in these regions, allowing for heavy precipitation in the Northeast. Snow accumulations from this system are expected to reach up to 9 inches by the evening. Winter Weather Advisories and Winter Storm Warnings will remain in effect for much of the Northeast through Thursday night.
On the back of this system, blustery northwest wind will usher an arctic airmass over the Upper Midwest, allowing rain showers in the Upper Great Lakes, Mid-Mississippi Valley, and western Ohio Valley to change over into snow showers. Expect 6-10 inches of accumulating snowfall in Wisconsin, about 3-6 inches in northern and central Illinois and Indiana, and light snow accumulations in Iowa, Missouri, southern Illinois, and Kentucky. inter Weather Advisories and Winter Storm Warnings will remain in effect for much of these states through Friday morning.
Elsewhere, high pressure will maintain generally dry weather conditions in the West. Temperatures in the Lower 48 states Wednesday have ranged from a morning low of -19 degrees at Clayton Lake, Maine to a high of 86 degrees at Gainesville, Fla.