It’s about time that the La Nina weather pattern shows up in the Pacific NW. It’s actually not all that uncommon that the ENSO state doesn’t take control of the weather pattern until Winter sets in. The ridge off the West Coast has been keeping the jet stream up into Canada but that is about to end as the storm train arrives with Santa beginning this weekend.

There really doesn’t need to be much discussion in this post because the pattern we have been discussing coming is going to be here. It will be hard to talk about any specific storm next week because the storms will be so close together it will just be almost continuous snowfall for the mountains with varying intensity and rising and lowering snow levels. Above 5000 ft. at Mt. Baker, Mt. Hood, and Mt. Bachelor it should be mostly snow and it could add up to quite a bit over the course of the week. Some of the storms will be cold and could bring snow levels down quite low.

The forecast models vary on the timing and intensity of each storm but let’s just look at the overall trend. The storms start with 2 weaker storms that will affect mainly Washington over the weekend. Here is a look at the 2nd storm which moves in Christmas night.

Now I don’t usually use this many maps but pictures are worth 1000 words so let’s look at the possible storms every other day moving forward. Here is next Tuesday which is a stronger storm and extends further South into Oregon.

Then next Thursday….

Again New Year’s Eve…

Then we move into the 1st week of January. The forecast models are not reliable that far out on specific storms, but they can show a potential pattern and the stormy pattern looks to continue. Let’s look at some of the fantasy charts. Here is 1/2…

and then 1/4….

and 1/6…

etc., etc., etc…..

Right now it looks like that pattern will continue but the PNA is not negative yet or the AO so the ridge could sneak back in. Again, these images were pulled off of one run of the GFS forecast model. There are lots of other models and they are showing varying strengths and timing of the storms. But overall the forecast models agree that we will be going into an active pattern in the Pacific NW at least through the end of the month

Let’s look at potential total precip over the 7 day period starting on Saturday. This is a mix of the GFS and Euro models. The first map is the total precip for this weekend to show that the storms are light and confined to Washington. Upper half of Baker could pick up 6-12 inches.

And then the Monday-Tuesday storm is stronger and further South. These maps continue to add to the previous storms.

And then after the Wednesday-Thursday storm which looks like another strong one…

and then after the Friday storm….

That is 5-6 inches of liquid in the dark red zone which would be around 5-6 feet at elevations of all snow around 30 degrees. In the higher elevations like above 8000 ft. where temperatures average around 20 degrees through the week the snow amounts could much higher and then areas where it goes back and forth rain-snow much less. This is only week number 1 so it definitely looks like we could be back in the game heading into the Winter season. BA