Models are in very good agreement on the big picture over the next two weeks. Take a look at the ECMWF height anomaly maps through the 17th of November…from last night’s run:
What do those pretty pics mean? The large yellow (and red in the 2nd week) area is unusually high upper-level heights in the atmosphere up around 18,000′; a block in the atmosphere with very warm air aloft. Interesting to note the block gets stronger the 2nd week…unusual. The blue areas indicate below average heights over us and then moving slightly offshore during the period. The 850mb (5,000′) charts show very good agreement on the pattern persisting with very few ensemble members showing spikes either high or low:
Here’s what I get out of this: The upper level high is far enough west (160-170W) that cold air (what little we have in early November) will mainly dump out over the eastern Pacific and spin up into storms. If you want an outbreak of cold arctic air here in the Pacific Northwest, you want the high around 150W. So I don’t see a pattern to bring us an unusual early season snowfall to lower elevations. But this pattern can be excellent for building the mountain snowpack.
Looking at this and other models, I think there’s a very good chance we’ll see some skiing within the next 2-3 weeks; before Thanksgiving. It helps that Thanksgiving is the latest it can possibly be this year.
Of course this is no guarantee…what if a warm atmospheric river rain event were to show up just before? You never know.
I don’t see a ton of rain the next week here in the lowlands, but Thursday’s system looks like a good rain and wind producer. Could be some 30+ mph gusts during the day Thursday as a weakening low passes by just to our north.
Chief Meteorologist Mark Nelsen