[su_note note_color=”#d9f2da”]Fri Morning Update: The latest models have shifted the showers to late Saturday and most of Sunday into Sunday night.  So Saturday is looking like a better day, especially from PHL and northward. I’ll do an updated weekend forecast Friday evening. [/su_note]

The weather for this weekend is again looking unsettled.  There are huge differences between the NAM and GFS models for Saturday with the NAM being much wetter than the GFS.

Basically, there are timing differences with the disturbances that are expected to move along a frontal boundary. The position of the front is also in question.

Perhaps there’s insight in the fact that the new GFS model under development (referred to as the GFS FV3- “Finite Volume Cubed Sphere” ) has a similar forecast for Saturday as the NAM.  By the way, I’ve been looking at the GFS FV3 more and more.

That would mean that Saturday would be the wettest and Sunday would be dry.  Too soon to be sure.

As for the cool weather so far this season, it’s not been a surprise— the nadir in the solar cycle is known for cool weather.  The secondary effects of a solar cycle nadir results in  a lower solar wind  causing more cloudiness.