-40C (850mb temps) is insane! Never personally seen that here...this in (F) -40C upper air temps can translate to similar surface temps
snowstorm with the potential for accumulations of 6+ inches and
strong winds. There is the potential for a foot of snow but too soon
to tell the axis of the heaviest snow band. Models indicate a 50
knot low level jet impinging on a very tight thermal gradient, suggesting very
strong upward motion. The latest run of the GFS/European model (ecmwf) has come in
farther south with the track of the surface low, with the European model (ecmwf)
taking the low across far northern MO. This puts much of the cwa
squarely in a significant snowstorm. Temperatures will moderate with
highs in the teens north and 20s south.
Tuesday through thursday: in the wake of this system (and the much
deeper snowpack that will be in place) this will set the stage for
brutally cold Arctic airmass to plunge southward into the Midwest.
Now the GFS indicates a pocket of -40c 850 mb temps dropping across
the dvn cwa, while the European model (ecmwf) has backed off somewhat bringing -30c
h8 temps. Either solution suggests the potential for historic
(record) cold as the polar vortex drops into the Great Lakes region.
The grids indicate lows well below zero during much of this period,
with Thursday morning as low as 23 below in our north. Appears there
will be enough wind to keep temperatures from really bottoming out,
but the bad news is wind chills may go as low as 45 below zero!
would mean the potential for -40F surface temps.
Even at -30C your still looking at potentially -30F !
esp with a massive snowpack...interestingly -40C is -40F
but flip that around in the summer( +40C 850mb temps) and you have a heatwave.....aprox = 105F
-40C (850mb temps) is insane! Never personally seen that here...this in (F)
-40C upper air temps can translate to similar surface temps