chionomaniac

What a beautiful synoptic mess bet you won’t find many charts in the archives like this

Unless you have come back from the future then you can’t say that yet. At this point it is better to wait and see what happens. There are always fine lines in this country to be able to achieve a significant snow event and the modelling is again demonstrating that.

I wouldn’t worry. You are doing great for your age and it took me ages with scores of papers, and many years of monitoring- and I still have so much to learn still.

Whereas any SSW is determined by trop wave breaks, the ‘internal upper cut’ is very unlikely to lead to a u wind reversal at 10hPa. I’ve never seen it. The way to achieve this is through the ‘riding external wave’ which leads to a tilt and baroclinic collapse from top to bottom.

Strat is getting better and better. Not a SSW but I reckon on latest run u winds close to reversal at 1hPa. And this will take time to filter down to 10hPa. My guesstimate for SSW was late December. Now, that may be a bit too early for it. But not ruling it out. charts courtesy of NW extra. New addition of 1hPa by @Paul so great job

There’s the difficulty - forecasting the MJO wave propagation and intensity

It needs a good kick to get it restarted, cos that will help. A lot

It’s the baroclinic tilt throughout the Strat that will be all important in bringing the Strat down. Lovely view there

I have every faith in the UK snatching defeat from the jaws of victory, as most here will have too. Still, theres a long way to go before we are into a reformed vortex over Greenland

Still a cracking hemispheric profile - Oh and a Scandi high - though poorly orientated

And there she goes.. .

Better negative tilt on our tropical feature by T+126 and it is getting ready to split and undercut. On we go - should be a good run this

18Z gfs day 10 at 10hPa Wave 1 stress with hint of wave 2. Never say never…

Just caught up and viewed the 18z gfs run. End of high res and low res 18z GFS is crazy in development. What it is seeing is signals, but can’t make head nor tail of them! I consider it like it has certain jigsaw pieces (the signals) but has placed them in the wrong position or wrong way around. It is trying to work it out but can’t at the moment. So, it is difficult to see the picture even if you squint. But eventually those jigsaw pieces will be put the correct way up and in the right position. How long it takes is anyone’s guess. To edit. I consider the signals good and the long term picture will be too.

I have also updated the Strat situation in The Strat thread. Still promising.

Looks like there are 2 main clusters. One keeping the cold, and another with the AL heading north with Milder temps. But check out where a lot of these milder members head after the mild blip. Yep, back to cold.

Still keeping an eye on the later reaches of modelling the Strat and we find the Strat still in distress from top to bottom. Significant distortion from wave one influencing things from 1-30hPa and wave 2 upwelling and splitting from the trop upwards. Not quite SSW territory…….. yet if we get enough tilt of the vortex with altitude - a baroclinic vortex -then it will collapse easier. We need a bit more than shown here.

Definitely getting closer to that Scandi High scenario with the Azores low being sucked underneath like some sideways lava lamp

Stalling Atlantic low, heading slightly north and not sliding with weak Scandi ridge. I like this run, but another variation on a theme

Good to see the signal is still present for the strong wave 1 upper Strat event. I will keep monitoring this to see if we can get a full blown SSW down the line

Days 10-15 over next few runs…jet stream positioning should open thermodynamic positioning to allow height rises. Obviously, I stick my neck out here, but it does look like a natural progression rather than retrogression at this point. If it doesn’t occur then I will be happy to say I am wrong. If it does then vice versa. oh. And I am not one to sit on a fence either! I’d rather fall on my sword than not make a call!

These are the ensembles that need watching. Helsinki surface pressure will be interesting to see where they head

The Azores low looks overblown to me, but in any case will have blown itself out before it reaches the UK. The modelling of the energy in jet stream dynamics here is all important. So let’s get back to basics… a surface low pressure forms at the left exit point of a strong jet stream where temperature differentials are at the maximum. Because of the Greenland high this is occurring far further south than usual as shown below because of this we have a player in the placement of a battle zone. But this will be a dissipating event should it reach the UK and we need to be concentrating on the background long wave patterns to determine what the future holds post this. And imo these are embedded and will be tough to shift. Scandi high will follow. Mark my words.

10 minutes so that those posting will not lose their posts…..

I have created a new thread here this one will be locked shortly so get posting over there!