A storm system developing across the Plains States Monday will move to the mid Mississippi Valley on Tuesday, then to the eastern Great Lakes on Wednesday. Low pressure will develop along the east coast during this time frame, and some phasing of these systems will be possible through mid week, however models disagree on the amount of phasing that will take place.
Rain will spread across the region late Monday night through Tuesday, possibly beginning as a period of snow, sleet, and freezing rain. Some accumulation of ice will be possible.
Mixed precipitation will change to rain across Ohio and most of western Pennsylvania as milder air spreads northward. The rain could be heavy at times. Across western New York, some areas could change to rain, but it is still uncertain how much cold air will remain in place through Tuesday across these areas.
On the northwest side of the primary surface low across far northwestern OH and eastern lower Michigan, precipitation will change to snow. Snow accumulations in excess of 6 inches will be possible across these areas.
As the system moves into the eastern Great Lakes and stalls Tuesday night, colder air will be pulled further south and east changing the rain over to snow across much of the region. The exception will be portions of western New York where some milder air from the Atlantic could cause a mix of wintry precipitation to persist into Wednesday. Many areas across the region could see accumulating snow Tuesday night through Wednesday night.
The system will remain parked over the eastern Great Lakes and northeastern United States through the end of the week with occasional snow or snow showers likely, with additional accumulation likely.
This is a complex weather system. The type of precipitation as well as amounts of each type will be determined by the eventual track and strength of this system.
Stay tuned for additional updates.