That was fun eye candy…did everyone see the 18z run of the GFS? Coldest arctic outbreak across the Pacific Northwest since maybe 1989 or 1990. And it’s only 13 days away according to that model. Ha! I’ll believe that when I see it in the more believable 7-10 day range. Here’s the 500mb chart at Day 15:
It’s a massive, sprawling Hudson’s Bay low that shifts westward across Canada, sending cold air down across the northern 1/3 of the USA. As I said, great eye candy, especially if you look at all the 18z ensemble runs:
Each line represents one of the 21 versions of the 18z GFS run out to 16 days. The blue line is the operational run, showing temperature, in Celsius, at about pass elevations. For example this model claims the air temperature would be a few degrees below zero up there!
This run (the maps we see) is out there all alone with the massive surge of cold air. Several other runs are cooler than average, but none to this extreme.
For kicks, here’s the 12 ECMWF ensemble plot:
It’s showing lots of runs a bit cooler than average, but none have a big arctic blast.
To wrap it up; it still appears SOMETHING will change in the 2nd half of January, we just can’t say to WHAT and WHEN and if it even involves anything other than slightly wetter and cooler.
Chief Meteorologist Mark Nelsen