Stratospheric Warming Event Underway

Normally we see stratospheric warming events in late December or early January, so this one is a little late to the party.  Any image in this post can be enlarged by clicking on it. 

For those that are just learning, every winter we see a stratospheric vortex form over the pole. Don't confuse the stratospheric polar vortex with the tropospheric polar vortex, even though somewhat related, they work at different levels in the atmosphere, but changes in the stratospheric vortex are usually reflected to some extent in the the tropospheric vortex.  For more views of the stratosphere, I have multiple pages with tons of information:

• ​Stratospheric Time Series
• GFS Temperatures
• GFS Heights
• Euro Temps and Heights
• Stratospheric Details

What happens is that waves, called Rossby waves, move poleward through the troposphere taking heat along with them. When this heat flux and wave are strong enough, these waves travel upward to the stratosphere and are dissipated there, decelerating the winds and warming the Arctic.  If the heating is rapid and strong enough, it can cause the high level winds to slow or even reverse direction, which in turn causes disruption in stratospheric vortex, which in turn propagates down and interferes with the tropospheric jet stream which induces large amplitude blocking. In other words, a stratospheric warming event is beneficial for us as is helps to push the cold air off the pole and move it south though various blocking regimes. The blocking can also cause a buckling of the jet stream which can cause a very potent blast of arctic air as well as big storms on the periphery of the cold.

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In this image, we see a depiction of the temperatures in the stratosphere, notice the red colors at the top of the graph that started building just before the first of the year.

These are the pressure anomalies

This image depicts the amplitude or strength of Wave 1

The next 7 images are slices of the stratospheric atmosphere, beginning with 1hPa and going down to 70hPa. What we see in these images are a top-down warming that's underway. Notice how much stronger the temps are at 1hPa and how it diminishes as you go down in levels. Also take note of how steep the ramp up is. 

1 hPa

2 hPA

5 hPA

10 hPa

30 hPa

50 hPa

70 hPa

And here are a few Tweets regarding the strat warming that is underway. 

@chionomaniac @scotlandwx @antmasiello @webberweather indeed. Check out the O3 mix ratios, showing the surf zone. pic.twitter.com/YZRVxjlQGu

— Andrew - Andrej (@Recretos) January 11, 2016

Latest GEFS hinting of a Sudden Stratospheric Warming event about the North Pole during late January. pic.twitter.com/S9b5Lcnusb

— Michael Ventrice (@MJVentrice) January 11, 2016

@chionomaniac @scotlandwx @antmasiello @MattHugo81 @webberweather Also we have the first forecasted SSW. :D pic.twitter.com/OQcL5aGX0t

— Andrew - Andrej (@Recretos) January 11, 2016

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"Something always didn't sit right with me about the upcoming 10 days. I clearly see the -NAO (North Atlantic Oscillation), the -AO (Arctic Oscillation), the split flow etc. but yet my mind was sort of cautious when it came to the epic cold/snow calls. There are things in the back of my mind that are keeping me from hyping this period more than usual. Obviously the progressive, active Pacific Jet aided by a very strong El Niño would be one concern.

Strong GWO (Global Wind Oscillation) orbits in higher AAM (Atmospheric Angular Momentum) states happen a lot in El Niño. However, the current orbit is 1 of the strongest I've ever seen. It reflects a gradually increasing AAM state in an already exceptionally high AAM state. El Niño has now perfectly coupled with the atmosphere leading to classic STJ (Sub-tropical jet) and N PAC circulation. The combination of factors ahead: -AO, -NAO, very strong El Niño and strong GWO orbit has only happened twice in January...1958 and 1983. If you become more loose with NAO/AO, then suddenly 1998 jumps in there. The composite yields a polar to west based NAO ridge. Go figure.

Regardless of how the active train of waves transpire over the next 10 days, the pattern will develop into a classic precursor SSW (Sudden Stratospheric Warming) one:

1. Strong NE PAC low
2. Strong anticyclone over Siberia/NAO
3. Shift in mass over East Asia leading to a +MT (Positive Mountain Torque)

The third point is likely the direct catalyst for warming in the upper stratosphere at the end of ensembles. The wave 1 configuration in stratospheric heights, on the other hand, is from the first 2 points. Although, it should be noted that the Siberian High is what descends down the eastern slopes, causing the +MT.
Initially, this may all favor an increasing AO/NAO and then a likely jet extension in final week of Jan. We could temporarily go back to a more classic Niño pattern across America. However, I think this will all lead to a legit SSW and secondary AO tank next month. A period of exceptional snow potential would be possible as the SSW down wells and MJO possibly comes around again mid Feb.
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I don't mean to belittle the next 2 weeks; they certainly have potential and I think we'll see snow. I'm just not confident enough in a pattern like this, one where many things are opposing each other, to get cute and say "Kocin Storm coming."

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