A dip in the jet stream will allow cold air to move in behind a front moving through tonight.

Saturday will be mostly sunny, cool and breezy.  High 56.   A weak upper air disturbance will bring in some clouds before sunset.

For Sunday, skies will be mostly sunny but another upper air disturbance will bring cloudiness mid to late afternoon.  Less breezy.  High only 52.

A cold  front moved through this evening (Friday) and cooler, more fall-like temperatures will be apparent Saturday.  Plenty of sunshine will allow temperatures to get into the mid 60s on Saturday.

The pattern will be very progressive and a return flow of milder air will make Sunday (and Monday) beautiful with sunny skies and highs in the 70s.