Sarah and I have been pretty conservative about the cold air until today. I think we are both sold on the fact of 30s overspreading Region 8 in a few days for overnight lows. Models have been having a tough time handling the solution, which is typical this time of the year.
The above image is the BUFKIT program showing the 06Z GFS. The time stamps go from right to left. The GFS is showing over an inch of rain from tomorrow's system and much cooler air. In fact, Thursday looks cold, wet, and sloppy. Cold air then moves in, leaving highs in the 50s and lows in the 40s and maybe 30s. We may briefly warm on Sunday, but that's still very questionable. I think lows may be a little colder than the GFS is showing, too! We may see our first freeze in some location over the next week!