Clouds eroded across the metro area on Monday allowing Chicagoans to observe sunshine for the first time in a week. The day offered 45% of possible sunshine bringing the month’s total to a dismal 18%. January, one of our cloudiest months, typically yields 40% possible sunshine. Prospects for a period of partial sunshine, along with light winds, and relatively mild temps will likely make Tuesday the most pleasant of the next 7 days. Satellite imagery late Monday showed a well-developed upper-level low swirling over southern Arizona. This disturbance is forecast to make its way across Texas on Tuesday while ingesting Gulf moisture. By early Wednesday, the storm center will begin moving up the Ohio Valley spreading heavy snow along the I-70 corridor from central and southern Illinois to Ohio. Steady snow can be expected as far north as Chicago with amounts tapering from several inches south and east of the city, to minor accumulations to the west and north. Skies are then likely to remain generally cloudy into the weekend with another chance of snow about Saturday night or Sunday.