What: A wintry mess will move northward tonight into Tuesday.
Timing: Tonight into Tuesday. (Below is HRRR Model precipitation type for 8PM Tonight, 12AM Tuesday, 4AM Tuesday, and 7AM Tuesday respectively)
-Erie: I think it stays all snow in this area and that 4-8″ of snow is expected here. I wouldn’t be surprised to see more than that depending on how far the rain snow line moves north and where that heavy band sets up.
– Oil City/Mercer/Titusville: Area I am most concerned about. Will stay as snow during most of the event, but could transition over to freezing rain by the morning. I think these areas could see 4-8″ of snow with potential for locally more depending on how much warm air advection causes the rain snow line to move north. If could air wins out, I could see up to 12″ of snow in some spots within this area. Snow could be heavy at times. The further north and west you are into western PA and eastern Ohio, the more likely you’ll see higher amounts of snow.
– Butler: Start out as snow before changing over to a rain snow mix and then over to freezing rain/rain for most of the event. I think they could see 2-4″ of snow or so before it washes away. Rain will transition back over to snow before the event ends though.
-Pittsburgh and southward: Looks to start out as a rain and snow mix before changing over to rain overnight into Tuesday. Freezing rain could also cause for slick roadways. Could see maybe and inch or 2 by the end of it.
–East of Pittsburgh in the mountains: More freezing rain expected than anything. Snow and rain could mix in at times though. Could see up to a 0.5″ of ice, which is very significant.
– Icy roads, especially east of Pittsburgh in the mountains and north near I-80
– Snow covered roads
– Heavy snow at times in NW PA
Risks With Forecast:
– More warm air advection could decrease snow totals from Butler County to Venango County
– Colder air could increase totals, which I think is more likely with the timing of this system overnight
What to do:
– Stay off the roads if you don’t have to be on them, mainly overnight into Tuesday morning.
– If you have to drive, take it easy. If you live in the mountains east of Pittsburgh, I suggest staying off the roads.