High pressure will keep the area dry this weekend and into next week with strong valley inversions. Small chance for a few showers later next week. Pattern change possible before the end of the month (details below).
High pressure is dominating the area creating warm and sunny conditions in the mountains with cool and smoggy conditions in the valleys. This will continue through the weekend and into next week.
Over the next week, the ridge is going to continue to amplify along the West coast. While this will keep us totally blocked from systems for now, it may eventually open the door to snow again by the end of the month. While amplification might sound like a bad thing, and it generally is, in this case it is going to cause the the ridge to become stretched as it expands north toward Alaska. As the ridge becomes stretched, it becomes less resilient to systems moving across the Pacific. The systems “pinch off” the ridge and move under the areas of highest pressure. This is called undercutting. It’s been a long time since we’ve had a classic undercutting of the westerlies.
Here is an animated GIF of the ECMWF model that you can actually see the ridge building over the area then elongating and getting stretched over Alaska before finally getting undercut at the end of January….
The first effect we’ll see of this undercutting will be a weak system for next Thursday or Friday (Jan 23/24). At best we’ll just see a few showers from this system and confidence in the first breakthrough systems is always low, but it does show up in all models so we’ll keep an eye on it. The main breakthrough of the westerlies happens after January 27 which is conveniently just beyond the scope of the deterministic model of the EC. However, the EC control run and GFS fantasyland runs all support this idea. This is all very far out and we’ve seen these pattern changes fail to materialize as we got closer, so don’t get too excited yet. However, I’m saying there’s a CHANCE!
…which is more than I could have said the last few days.