A ridge of high pressure will provide nice weather for Friday and Saturday. No rain is expected, and temperatures will reach to near 80 F (27 C for our Canadian friends) each day. The ridge weakens on Sunday, and this will allow an upper level disturbance to cross the area. Timing is uncertain at this time so I'm not confident enough to be too specific on that yet, but the afternoon and evening hours appear to have the better rain chances than the morning. One models (GFS) shows most of the rain staying south and west of the track, while another (ECMWF) is slower with the rain, bringing it in Sunday night. I'll start the forecast off with a 40% chance of rain for Sunday.
For our Canadian followers, here's the forecast graphic in Celsius: