Sryanbruen, you fill us with so hope : )
If you look back to 2018 can you see any correlation between now and then, as in was it showing something similar a month or so pre split? Or is each lead time to an event different?
In late January 2018, we were seeing signs of a SSW event in deep Fantasy Island of the GFS operational run. At first closer to mid-January, this was looking like a minor wave-1 warming with the PV displaced from the pole which was a start as January had been an active month for the stratospheric polar vortex (SPV). I had fairly good confidence that something more notable would come from this closer to the timeframe as MJO phasing was looking good, heat flux was good etc. I made quite a bold statement on 25 January 2018 below:
The question on our minds at the moment is that will the beast be unleashed in February 2018? When it comes to the bigger picture - i.e. my methodology I use to make my forecasts - it does look pretty compelling.
The significant stratosphere warming (again not a SSW though) is still up for grabs in early February on the GFS runs, see the latest 12z for example below. Even the ECM is showing some warming going on in the stratosphere (though only at 10hPa and not at 30hPa at all).
I will not put any bets (you should never do gambling on weather anyway) on the Beast From the East coming but what I can say is that something is certainly up in the air here.
That bold statement verifying was all luck to be honest. The trop and strat could easily have not linked with one another or as in the case of Jan 2019, not project onto the NAO.
Split events tend to have quicker tropospheric responses than displacement events.
And has been posted above kindly by Gonzo, the latest GFS is indeed on the cusp of a split towards the end of its run. It does not quite have a reversal at 60N 10hPa (perhaps down to around 8hPa in the upper strat) but is on the verge of one. That is a fairly significant sudden stratospheric warming. It follows on from the 0z and to some extent the 06z too that looked prone to a SPV split. The 12z confirms my thoughts. If we were to get a major SSW event (zonal mean zonal winds at 60N 10hPa reversed to easterly), could be a big spanner for any seasonal forecasts which have already been poor for December.
As for Glosea5 nacho libre, it does not show a major SSW event but is in line with the ECM of showing a weaker than average vortex.
We shall see how it evolves but as I said in a prior post, before the longer range models backdated on the possibility of a major SSW event, this is the most excited I have been since 2017-18.