12Z 12DEC2019 GFS The emergence of small scales in vortex ring collisions
We all see the latest modeling, we are 7 days out from the assembled megablock, not only in the central Arctic, but constructed about the North Pole itself.
It's happening.
https://www.tropicaltidbits.com/analysis/models/?model=ecmwf®ion=nhem&pkg=z500a&runtime=2019121212&fh=192Remember in early November when the GFS blacked out on the North Pole and we had heat domes of 360 meters anomaly over 3/4 of a million square kilometers out at hour 360 in the op dets... for like two days? Nothing too surpising came of it? Well, I quit my job and got to work.
Over the past 2 days modeling has derived a vortex split in the higher confidence range, but NOT in the stratosphere. The strat PV is currently strengthening violently and is centered and shrugging off the climbing Rossby wave. But down at the level of clouds, boys and girls, we got a split coming
We're 7 or 8 days out from seeing a vortex core split.
Long story short, our polar cell vortex has reached upstream in flow to the point where the merged vortex unwinds, and we instead have two co-rotating polar lows. Put another way, imagine traveling up a wake vortex from an airplane wing on landing. Where the wingtip vortex and flap vortex meet & merge together is where we are right now.
We're seeing chevrons in vorticity and rays in the jet stream in modeling. Look at vorticity directly at the North Pole Dec 18-22 and you will see an hourglass created in many recent runs of GFS. Looking at the end of the run and you get the impression the hourglass thing continues, and we have a shear zone directly at the North Pole
I still think it will close up in the depth of winter, maybe for 6 weeks or something, but 2019 ain't over yet :x
So, co-rotating vortices are not the most stable pair, as they will try to helix around eachother and also start shedding badly downstream. We will find out how that works on a hemispheric scale.
Actual potential temperatures at 1000mb over the Arctic are drawing a guide. In the atmosphere what seems to happen is the Siberian High, Beringian Block, and Siberian Block, all assemble at the North Pole and allow two axes of rotation for the polar vortex.
Strat PV disruption following this is very likely, but it will unzip from the surface up and not the top down. Coupling between trop/strat PV is being seen in the models but not all of them. However, every single major weather model is locked on to what's coming in the troposphere.
I didn't plan on going today but I guess it's on. Lots of graphics here:
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