Cheshire Freeze

The block wants to have another go at gaining latitude into FI Seen enough- cold, frosty (if not particularly snowy) from the 0z GFS That'll do me, sir!

0z GFS doesn't produce a robust GH like the 18z. I suppose that's moot at this point though as even from this point we could see Scandi heights take hold Would certainly be very cold with hard frosts and ice days likely in some locations I would imagine, given the time of year

Well either way, by 7am we'll either be left with a GFS vs UKMO and ECM or GFS and ECM vs UKMO situation. Neither are ideal as so many times the UKMO has proven correct when calling against a possible cold spell.

Time for the GFS to step up and show us it can get one of these scenarios called correctly...

UKMO computer says no Here's the GFS... Take your pick

Hold your horses... Critical point now at day 5 Need that very small low west of Iceland to do one...sharpish!

Get in from work and see that 18z GFS run. Lord almighty. Compared to the ECM it's night and day. We all need to pray with every bit of energy we have, for the GFS 18z.

Yes but the strong Nina is the reason the HLB signal became overwhelmed and winter pretty much ended on the 27th!

Spot on. I too have heard of this to be the reason for increased HP influence to the S. It really isn't good news as far as our winters go. It can't be surprising the modelling often fails to pick up on this too as naturally beyond a certain point they are more exposed to climatology bias. With this expansion of the Hadley cell being a rather recent occurrence, they won't have enough to go on RE most recent climatology trends. This is perhaps why we see them inflate the influence of these Euro heights closer to T0.

What is of most concern (to me) is the omnipresent limpet heights either to our SW, S or SE. It's almost as if they're consistently being displaced N towards our shores. We saw last winter just how stubborn these heights are.

If you could sum up the UK's luck with one synoptic chart, it would be this one

Seem to have bottomed out at -1.1 here for the time being.

Ahhh ok Just dipped below freezing here at -0.2C

Don't know your locale too well or whether the station is accurate but Chadderton is showing 2.2C Up at Saddleworth, it's just below freezing Taking the mean between the two locations I'd say you're probably at about 1C

0.7C and falling here with a -1 DP I'd estimate we'll be at or around -2 by dawn

Looking at the ECM tonight and I get a sense of de ja vu. All looks very very similar to how mid-late November panned out last year

This is where many in here let themselves down. It's nothing to do with being a 'glass half empty' or 'glass half full' person as hopes, wishes and subjectivity shouldn't even come into the picture when analysing the NWP etc. All the cheeriness in the world will not promote the outcome you desire and this thread is no place for misguided hope based optimism. My thoughts remain unchanged from last night. After all why should one set of model runs change my view?? That would be a bit 'knee jerk' wouldn't you say.

18z GFS ensembles for Cheshire... After previous runs grouping around the -5 at the 850hpa level, the 18z loses this signal.

Working all day, finished at half 10 this evening and have no data left on my phone. I have only had time today to take a couple of minutes on my breaks to view the output.

Where have you been all week... Pretty sure you can check my post history and see I have, in fact, been urging caution for a number of days... Regards

LOL I just don't think the model thread is a place for hopecasts and unfounded optimism...the banter thread can be used for that purpose. I promise you though that as soon as things genuinely look interesting (from a more holistic rather than just NWP perspective), I will be the first person making my optimistic thoughts known For interest, here is the latest CFS 850s anomaly for December...it has hardly budged on this for a long time now, if we look at the averages 3 month pressure anomaly D-J-F

Not really. If you step back and look at the bigger picture, you will see even the more learned on here have preached caution with the upcoming spell due to lack of supporting background signals, along with the longer range seasonal models which have almost unanimously and consistently pointed towards a +NAO tendency for the upcoming months. Of course you may say 'just one run' but it's pertinent to note that the flatter runs are closer to what we can expect given the stratospheric state at the moment, amongst a plethora of other factors to consider. With that in mind, you have to prepare for something many of us do not want to see i.e a more Atlantic driven outlook rather than one affected by an abundance of N blocking.

The speed of it was always inevitable, as we saw last year. It's what happens when you have an strat profile non conducive to blocking. Relying on the perfect trop pattern for wave breaking to occur successfully is risky and can quickly go wrong. It's the reason I have been ultra cautious all week. The signs were there yesterday and perhaps the day before that the AO may not go as negative as first thought. This was owing, in the short term, to a decrease in vertcial advection Pacific side. After that, it's a domino effect.

I've heard this one wheeled out before. In reality the models (whichever you decide to look at) generally have a very good handle on situations which mirror long term climatology. With this in mind, when a model forecasts zonal, it's usually proven correct. It's when it's the other way round the modelling tends to struggle. Seen many a time something 'juicy' has been shown, only to evaporate as the time nears.

Nick, I don't think it should come as any surprise that the extended ensembles are sniffing a move away from a -AO. The long range seasonals have mostly been suggesting a +AO/NAO winter for a significant period of time...including December.