Why do we care about Snow growth in Siberia?
Good morning everyone ,
So I’m sure you have heard me & others mention the snow growth in siberia. So , why should we care about how much snow siberia has in october? I mean i just care about how much snow my city gets!. Glad you asked , and yes you should most certainly care about it if you live in the mid atlantic & northeast. Think about this , its sunday in october and you are going to the football game and your bringing sandwiches and potato salad. Obviously you must keep this cold so you bring a cooler , OK , good start but you need to add something that will enhance and keep it cold….ahhhh ICE!.
You see the more snow we have develop , the stronger the polar and arctic masses can get.The more snowfall that develops in siberia , the cooler the environment becomes. As the cold air mass builds , higher pressure is established and strong high pressure systems develop in siberia. The building heights in the atmosphere eventually builds up to the point of amplifying the tropospheric jet stream , which means warmer air is transported towards the lower stratosphere. The polar vortex then begins to weaken and break down. The broken pieces of the vortex then propagate down through the troposphere and eventually from the higher lalitudes to the mid latitudes. What this process does is leads to a negative arctic oscillation where higher 500 mb heights are found near the north pole , and lower 500mb heights are found in the mid latitudes. The faster the rate of snow growth , the stronger the influence on the atmosphere and more likely high latitude blocking conditions in the east. The less snow growth you have the opposite occurs , the polar vortex remains strong and therefore kept in place over the north pole.
Now , what we are seeing thus far are areas showing both positive and negative anomalies which pretty much cancel out to average to slightly above. Last year was very near a record matching 1976. All model guidance strongly point to a rather rapid and robust growth coming in the coming weeks. We will continue to watch and monitor!
UPDATE october 24th 2015
Since this post roughly 2 weeks ago the snow growth has really blown up in both depth and coverage. The latest anomalies have most if not all of siberia now with no below normal anomalies. Another observation is the coverage of above normal anomalies have expanded.
This is so crucial as i have mentioned above and when coupled with a more quiet sun it enhances the likelihood of a – AO/-NAO pattern and enhances the arctic air masses by the north pole as the density of the atmosphere increases.