Areas of freezing rain, sleet, and snow continue across the eastern Great Lakes at this time. This activity will continue into the afternoon while gradually changing to all rain as temperatures warm. Roads and walkways will continue to be icy for a while this afternoon so use caution if you will be traveling.
The system responsible for the wintry weather is over the Great Lakes. This system will weaken and move northeastward into Ontario tonight. A weak cold front will cross the region late tonight or Saturday morning bringing a few additional rain or snow showers to the area.
All precipitation across the eastern Great Lakes will change back to all snow Saturday night with scattered, mainly light snow showers persisting into Sunday.
High pressure will bring a brief period of fair weather to most of the region on Monday, but it will be short-lived.
Surface low pressure will intensify and move into the Ohio Valley on Monday as a deep upper level trough digs into the Great Lakes. At the same time, low pressure will develop along the southeast U.S. coast. By Tuesday, the upper level trough will dig all the way into the southeastern U.S. The surface low over the Ohio Valley will lift northward into the Great Lakes while the southeast system deepens and moves to the Mid Atlantic coast. The two surface lows will begin to phase by Tuesday night.
Rain or a wintry mix will spread across the region Monday night, then gradually transition to all snow on Tuesday as the systems phase and draw in colder air from the north. Precipitation across the region, be it rain or snow, could be significant, however pinpointing the location and amount of precipitation as well as the type of precipitation is impossible this far out.
The phased system will move northward into eastern Great Lakes or New England late Tuesday and Wednesday with the potential for a widespread, fairly significant snow storm across the region.
The main upper trough will become separated from the westerlies, lingering across the northeastern U.S. and southeastern Canada for several days. This will mean a prolonged period of snow or snow showers for our region.
As expected 4 to 5 days out, there are significant model differences in the evolution of this pattern. Current and forecast telleconnections (negative NAO and positive PNA) would support a deeper and more robust solution. This is something we will have to keep our eye on, with further updates forthcoming as new information becomes available.