The large blocked high pressure system that has given us the unseasonably mild temperatures will move east allowing a frontal boundary to move through.

On Saturday, look for increasing cloudiness with showers by evening.  (The daytime hours should be dry. ) Mild temperatures continue with highs in the low 60s despite the cloudiness.

Update; This morning’s models have the rain today (Saturday) starting as early as 2-3 PM

The models diverge a bit for Sunday, with the GFS having showers ending early morning with just lingering cloudiness and cooler temperatures. The NAM model has the front stalling closer to PHL with showers continuing into early afternoon Sunday.  High 56.

There has been a lack of continuity with the current blocked upper air pattern, so this Sunday’s forecast is lower than usual confidence. I suspect the NAM’s handling of the frontal showers continuing into the day Sunday may be correct.

The latest NAM run is similar to the GFS model– rain ends early Sunday morning and skies clear in the afternoon.