When I last posted a week ago the “anti-Ralph” high pressure on the Siberian side of the Pole was forecast to fade south into Siberia, but it hasn’t obeyed. It refuses to budge, and today’s map looks very much like the map of a week ago. The only excitement has been down in the North Atlantic at the bottom of the maps, where the typical winter gales have roared.
The main inflow to the Pole has seemed to take a long, convoluted path over Europe and then back around the top of these gales, bringing moisture into the Atlantic side of the Anti-Ralph and creating a feeder-band of milder air north of Greenland, though “milder” is a relative term, for the same gales bring the same air around and down their west sides, whereupon it is colder-than-normal further south, swinging over England and then into mainland Europe. Besides this region of outflow, another has poured south over Hudson Bay, and a third into the Pacific from East Siberia.
The Labrador Low (at “7:00” on most recent map) may be of interest, for some models show it could become the first “Ralph” we’ve seen in some time, and jolt us out of the current pattern. Of course, you can’t really trust models all that far in the future, but the suggestion is that the general area of low pressure will take around five days to battle around the south tip of Greenland, (not as a single storm but as a complex collection of secondary and tertiary lows), and then will drift northeast as a collection of North Atlantic gales until it moves into the Arctic Ocean over Svalbard. We’ll see about that.
The Labrador Low is at the far left of the map of Europe. If it can interrupt the flow from the north in the Atlantic it may be a pattern-changer. The flow from the north is starting to cool the above-normal SST south of Greenland and Iceland.
The Labrador low is in the upper right of the map of North America.
The arctic air is pouring south down the west side of this low, but hasn’t been able to push west, and North America is only bitter cold in the northeast.
As long as the anti-Ralph stays anchored on the Pole the arctic outbreaks will be of the lesser sort. The north is so sunless in December cold can be home-grown over tundra, but to really make headlines the flow can’t be zonal, which is what the anti-Ralph encourages at higher latitudes (even as the flow can be meridional further south.) This is fine with me. The Pole can be selfish and keep its cold, as far as I’m concerned. I’m made nervous that the Atlantic side of the anti-Ralph seems to be slowly and quietly bleeding air from Siberia across to Canada.
Here is a map from Joseph D’Aleo’s site at Weatherbell comparing this years SST with last year’s. It is quite different, though both years had La Nina conditions. Last year’s La Nina was weaker, in a sea of mildness. This year the cold water off the entire west coast of South America is impressive. Also note how this map makes the cold south of Greenland look more intense. (2016 left; 2017 right).
Hopefully I can update later, but it seems like the entire staff at work is calling in sick, so today the boss (me) can’t sit back and be a fat capitalist.