Parts of North East Asia are looking at absolutely frigid temperatures combined with some near record breaking high pressures Monday morning. In one location in Northern Mongolia the sea level pressure rose to a stunning 1085.1HPA. (The highest SLP on record over 750m is 1090.1hpa at the same point in 2004.) With a pressure this high and through the overnight hours a massive amount of nocturnal cooling took place combined with a inversion with the cold air and temperatures were pushed down to -40C, so cold that the temperature Celsius temperature was actually lower than the Fahrenheit.
This statistics are pretty impressive but most people are probably thinking unless I live in Northern Mongolia how does this effect me? In fact Siberia is the heart of the North East Monsoon and the general layout of winter weather in North East Asia, and with temperatures so low and the pressure so high all of that cold air is going to want to go somewhere. The high will want to flow towards lower pressure along with cold air moving south over the coming days is what looks to be a fairly potent cold surge. For those in Seoul expect temperatures to drop well below freezing through mid-week as the surge heads south.
Residents of Okinawa the coldest air of the season will move south combined with gusty winds mid-week.
But one of the biggest surprises is Tokyo where temperatures will be near the freezing point overnight Thursday and a weak trough will be pushing over head. This could be just enough to bring some snowfall in the Tokyo area early Thursday morning.
This would be unprecedented if it was to occur and at first glance I would discount that possibility in November. Yet right now we are looking at record breaking cold and high pressure across Siberia, and with a anomaly like that taking place we must consider the possibility of something out of the ordinary taking place elsewhere.
Right now three numerical models. (GFS, JMA and ECMWF) all predict a wet snow accumulation Thursday morning. This of course would be a record early snow fall in the city which typically does not get it until January. For now I would not go ahead and say it will snow, but there is a high enough chance that the cold rain could change over to the white stuff in the Metro area that I think we should continue monitoring it very closely.
The mountains of Japan will see wide spread snowfall as well, maybe even allowing ski resorts in central Honshu to open up this coming weekend.