The ridge is sitting along the West Coast and we will see lots of sun and mild temps through the weekend. A system will move through the Pacific NW tomorrow and then the ridge will amplify further up the coast. Highs will be around 60 degrees at base level through Monday.
By Monday the ridge begins to break down as a ridge builds out around 140-150w to the North of Hawaii by Wednesday. We will see a cold trough that will dig down the West Coast by next Thursday. That should bring us much colder air next Thursday and Friday and some snowfall. It's still early to look at snowfall amounts. It will depend on how much moisture is pulled in off the Pacific.
The long-range runs of the forecast models want to keep the ridge out around 150w in the Pacific through the end of the month. That should allow more shots of cold from the North and possibly some systems coming underneath the ridge from across the Pacific as well. Overall it still looks like an increased chance of cold shots and snow starting next Thursday through the end of the month with the mean ridge staying out in the Pacific.