https://twitter.com/NWSCaribou/status/984911627010084865/photo/1It is not coincidental that this is happening at the same time the same records for snow/etc are being set across the entire Canadian Shield...
It is also not coincidental that the Younger Dryas came with the same pattern and with no change/warming over the far SE US. This is exactly what we are now seeing.
I think the CAUSE of the Younger Dryas is what is misunderstood... it was not a shutdown in AMOC, it was an abundance of oceanic heat content and a lack of sea ice that resulted in a temporary period of prolific snows, which THEREAFTER depleted the ocean of its heat content, started sea ice expansion, and pushed the Gulf Stream way S. This did not occur until continental ice sheets began building year-round, which started abruptly (it only takes one year).
My question for everyone here:
We are normally at 1,000 or so KM^3 as of 4/1, in terms of accumulated SWE across North America, according to the Canucks. This takes three months to melt down to zero.
IF we are at 1,250KM^3 as of 5/1 this year (i.e., 250 KM^3+ of ice ABOVE what is normally seen at April, also still more than the seasonal max most years), will it take 3.5 months to melt that ice? Will it take three months? Or will it be unchanged vs normal and all melt out at same time anyways, taking only two months?
I do not think it will be unchanged. An additional month would put melt-out at 8/1 instead of 7/1. Another month and a half would put it at 8/15.
IF we begin to see melt-out extend later in the year, that is when the runaway impact of albedo feedbacks begin to take hold. We are one week away from the same insolation as 8/21, with over 1,500KM^3 of snowpack still accumulated across the continent.
If we can hold onto 1,250KM^3 come 5/1, I think it shows that in the absence of significant Arctic sea ice relative to the 20th Century and in the presence of warmer oceans than ever, weather becomes increasingly stagnant. This is because when sea ice retreats, the "jet stream" falls apart. When this happens in the absence of snowcover, the Hadley Cells deliver heat everywhere. But *if snowcover is still substantial* when the Hadley Cells rear their heads in February and March, the "heads" of the Hadley Cell are much more prone to MAINTAINING cover as massive amounts of heat are advected thanks to the albedo surplus, while the oceanic warmth allows sufficient moisture for near-year-round snows.
This is interesting because as we see more oceanic warming, the Hadley Cells will continue becoming increasingly potent earlier and earlier in the year. This means stagnant weather becomes the norm instead of our old seasons. And this is the natural mechanism that resolves excess oceanic heat content onto the continents in the form of SNOW (i.e. ice sheet expansion). It is not due to the cold that the ice sheets form, it is due to the WARMTH (i.e., MOISTURE).
This year, we are likely to still see full melt-out. It will be late, but it will happen.
But, if next year or in five years, we have 2,000 KM ^3 of SWE across North America on 5/1 -- what happens then? That is a number that would ordinarily take six months to melt under pre-crazy conditions. Will it simply melt faster? Or will enough stay around until August that there is no "summer or fall," with the residual feedbacks of extant snowpack in areas where it normally does not exist during summertime allowing gains to begin again by late August, instead of late October? The act of persistence itself allows the snowpack to build much earlier in the year IF it survives peak insolation....