Strong low pressure will move from the Mississippi Valley today, into the Great Lakes tonight. A broad and mild southwesterly flow will develop across the region through tonight. Showers and even a few thunderstorms are likely today as the warm air rides up and over the departing cold air. Temperatures will climb to the mid 50s by late this afternoon
It will be breezy and very mild tonight with a few showers possible through this evening. Overnight, a strong cold front will move through the mid west and into lower MI and western OH by daybreak. Showers and thunderstorms will redevelop overnight as that front approaches. Temperatures will fall to the mid 40s early tonight, then rise slowly after midnight.
Showers and thunderstorms, some with very heavy rainfall, will move across the area Wednesday morning as the cold front moves eastward across northwestern PA. It will become windy as well with gusts in excess of 45 mph possible. Temperatures will climb to near 60 degrees during the morning.
After the front passes, showers will become more scattered in nature and temperatures will fall quickly.
Wednesday night, the rain showers will change over to snow showers as very cold air pours southward across the state. The snow showers will be widespread Wednesday night through early Thursday, then transition to lake effect snow and become more confined to the snow belt areas during the day on Thursday.
The lake effect snow will continue into the weekend along with very cold temperatures. There is still some uncertainty regarding the wind trajectory and the amount of available moisture. Some of the favored snow belt areas could pick up some significant accumulations.
A clipper-type system will bring more widespread snow showers to the entire region on Saturday and Sunday.