02/20/18 - Off The Chart Teleconnections

Looking at the teleconnections this morning and what I see would be pretty historic if it actually comes to fruition. Instead of showing you all of the teleconnection charts, let's look at the numbers and try to put those into perspective.

I've captured the data from the 00Z model runs from the Euro, Euro ensembles, GFS, GFS ensembles, and the Canadian, and ballparked the values from the charts. I then compared the average of those runs to the historial March records as well as all time records to see how the current forecast stacks up.  It appears from the charts, the AO and NAO start taking a dive on or around the 23rd, so I would expect changes in our weather shortly after that. A few of the long term analogs are from ​​http://madusweather.com

Arctic Oscillation - AO

As we've talked about before, a negative AO is the result of higher pressures over the polar region, and in this case, it is caused by the stratospheric warming which is still underway. 

The model average is well below the historical average and would be a new March record if it holds true. The record minimum was set in February of 2010 and that record is also in danger of being broken.

Thes records go back to 1950, and there are only three years that had a negative AO in March, 1969, 1978, and 2013, so a very small sample size, but the image on the left below shows how the temperatures responded.

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1962, 1978, and 2013

20 years of March -NAO

North Atlantic Oscillation - NAO

The models are going wild with the NAO, and this is exactly what would be expected during an Easterly QBO with Stratospheric Warming. Strong pressures over Greenland and parts of the North Atlantic are responsible for this. 

As you can see, we've never had a March with a -NAO less than -2.470, so the implications are pointing toward extreme amplification of the Greenland block. These numbers would set the all time (since 1950) record for NAO values.  Not much I can show except the one year that set the March record, no other year in March has gone below -2.00. I would think values of -4 would change things considerably toward colder.
​I've include two images below, 1962 on the left and 20 years of -NAO years on the right. 

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Negative NAO

Eastern Pacific Oscillation - EPO

​The models are thinking the same way about the EPO, but the GFS is taking it off the charts. The Euro is headed down but not as negative at the same point in time.  Because EPO daily data is in a different format, I can't show any comparison to past data.

You can see the difference between a positive and negative EPO for March in the two images below. Historically, it doesn't seen to have much influence on the southeast during the month of March.

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March - EPO Positive

March - EPO Negative

All of the values in the charts I've posted are up to March 1. The models have the PNA pretty negative at this point, and that is NOT good for cold here. Keep in mind, as we approach March the PNA is on its way up to neutral or even positive while the EPO is trending negative. 

You can see examples of the PNA in its different phases. It would make sense that if the PNA goes positive, the EPO would go more negative, as the trough over the western US retrogrades west and is replaced by higher pressures. According to some meteorologist, the cold for the eastern US will be due to the retrograde of the cold over Europe, and would build in from the east to west over time.  Right now the current phase of the PNA is the one teleconnection not in our camp yet. 

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Here's a look at years with a positive PNA, neutral PNA, and negative PNA.

Positive

Neutral

Negative

MJO

MJO All Model Mean

​While technically the MJO is not a teleconnection, it's an important driver for our weather here. We have been stuck in a warm phase 7 for a record amount of time, but it now looks like the MJO is going to continue its progression through the phases that are more favorable for cold, phases 8, 1, and 2. 

The current pattern is always a combination of all the various patterns and teleconnections. The state of the La Nina/El Nino, teleconnections, stratospheric conditions... it's all a big interactive puzzle that is constantly changing and morphing.

I'm very much looking forward to the first couple of weeks of March, I just get the impression that there will be some wild weather across the US, and it will be interesting to see where it all ends up.

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