A front boundary that will move through tomorrow (Sunday) morning will stall to our south. A wave of low pressure riding along the front will move through to our south late Sunday night into Monday morning causing snow to fall in April!
Like similar storms over recent weeks, dynamic cooling will result in enough cold air in the lower levels of the atmosphere for precipitation to turn to snow between 3 AM and daybreak. Current QPF values are in the 0.40 inch range which translates into anywhere from 1 to 3 inches possible on grassy surfaces with some accumulation on roadways in the immediate PHL area and close to 5 inches north in areas around Allentown and Reading!
Temperatures warm during the day on Monday, and whatever falls will quickly melt.
Exact predicted QPF amounts have changed over the day today, so a final handle on this won’t be available until Sunday evening.