The models once again go into full Scrooge mode this morning, no signs of of anything wintry right out into la la land. I’d imagine it will be over the Xmas period before we start to see positive changes, if at all that is. Until then all rather mundane after the next few days of dross.

Some odd comments this morning.  The models are firming up on high pressure being close to the UK for the Christmas period.  Exactly how that is positioned and aligned is still unclear but over or just to our south seems favoured.  Close to the high it certainly won’t be mild at the surface 

Out to Day 10 the ECM mean puts a strong high pressure cell just to our south west.

The SSW doesn’t occur for another week and it’s effects on the troposphere are unpredictable and subject to a lag of typically 2 weeks which puts us beyond the range even of the low res GFS.

---

Some odd comments this morning.  The models are firming up on high pressure being close to the UK for the Christmas period.  Exactly how that is positioned and aligned is still unclear but over or just to our south seems favoured.  Close to the high it certainly won’t be mild at the surface 

Out to Day 10 the ECM mean puts a strong high pressure cell just to our south west.

The SSW doesn’t occur for another week and it’s effects on the troposphere are unpredictable and subject to a lag of typically 2 weeks which puts us beyond the range even of the low res GFS.

It's starting from tomorrow onwards or do you mean from over the top of the N Pole?

---

Some odd comments this morning.  The models are firming up on high pressure being close to the UK for the Christmas period.  Exactly how that is positioned and aligned is still unclear but over or just to our south seems favoured.  Close to the high it certainly won’t be mild at the surface 

Out to Day 10 the ECM mean puts a strong high pressure cell just to our south west.

The SSW doesn’t occur for another week and it’s effects on the troposphere are unpredictable and subject to a lag of typically 2 weeks which puts us beyond the range even of the low res GFS.

Mid January being touted as the holy grail. I’d still urge extreme caution though we’re still not sure if we’ll see a split or just a displacement, the former really does increase our chances whislt the latter is a hit and miss affair.

Is there a second warming forecast then? Because based on the GFS strat charts there is no sign of a split vortex, in fact by the end of the run the strat is cooling again with the vortex still looking very healthy indeed. Surely a second warming would be needed to cause a split.

Hi Rob. The warming has begun and the rapid phase starts 22nd with the SSW and technical wind reversal due around 28th (current blend of solutions). Most modelled Strat profiles now show displacement only up to D15 but a full split has come and gone so might reappear.

Now let’s drop down to where all this matters. Downwelling to a tropospheric response (blocking, etc) would be from about 10days beyond the reversal so around Jan 8th so outside GFS although inside EC46 for instance hence why UKM might be quite confident of an Easterly January. The other crucial uncertainty is where any HLB forms and the data I’ve seen suggests a poor correlation between the position of Strat warming and trop HLB so don’t focus too much on where the remnant PV at 10HPa ends up.

My advice to anyone searching for cold stuff is to be patient and remember trying to forecast the weather is about more than just looking at a computer’s headline solution.

---

I

I wouldn’t call maxes of 5-8C ‘mild’ - I believe these are around or just below normal? 

I accept your predilection to inject balance but sometimes you come across as a bit too keen to show the milder options. I still believe there are issues effecting the longer range results and we’re going to see wild swings in output appearing in the next day or so. 

Thanks Neil.  Each to their own, and I am confident in my deciphering of the models.  Vive la difference.

---

UKMO extended keeps the UK in a mild flow of air with rain in the west

The models once again go into full Scrooge mode this morning, no signs of of anything wintry right out into la la land. I’d imagine it will be over the Xmas period before we start to see positive changes, if at all that is. Until then all rather mundane after the next few days of dross.

This morning's ECM has at least a nice, frosty and seasonal Christmas morning for much of the UK. Here I'll be lucky to see Christmas minima falling below 10c. Looks increasingly probable that I'll have observed more morning frosts in September than December this year. 

---

The very fact that Steve Murr is absent tells me there's not much hope. I always felt December would be a complete write off, and so it's proved.
January will be completely different IMO. It's a case of much patience required.

---

Mid January being touted as the holy grail. I’d still urge extreme caution though we’re still not sure if we’ll see a split or just a displacement, the former really does increase our chances whislt the latter is a hit and miss affair.

I did say the effects of a SSW we’re unpredictable.

An SSW doesn’t guarantee cold weather any more than an absence of an SSW guarantees mild weather.

---

https://www.theweatheroutlook.com/twodata/gefs.aspx?modelrun=na&lg=850&lglocation=london 

The GFS spaghetti is starting to pick up one or two much colder solutions into the New Year. Straws in the wind, perhaps?

---

The very fact that Steve Murr is absent tells me there's not much hope. I always felt December would be a complete write off, and so it's proved.
January will be completely different IMO. It's a case of much patience required.

A third of the winter is nearly over now and we’ve had one frost and zero flakes of snow. If the projected SSW fails to deliver the right Synoptics for Blighty then we can write another winter off, bar the odd cold snap perhaps. I much prefer surface cold over Greenland promoting height rises there ( like December 2010 ) than having to rely on a SSW to save our winter. 

The very fact that Steve Murr is absent tells me there's not much hope. I always felt December would be a complete write off, and so it's proved.
January will be completely different IMO. It's a case of much patience required.

But there’s never been any suggestion in the models that we’d see a cold spell this side of 2019.  

There’s nothing to justify any greater confidence in a cold spell in January either until we see how the SSW plays out.

---

 

I did say the effects of a SSW we’re unpredictable.

An SSW doesn’t guarantee cold weather any more than an absence of an SSW guarantees mild weather.

A split would really enhance our chances but a displacement rarely ends well for us going of past form.

Hopefully today’s runs will begin to pick up on a pattern change, gone downhill a bit too quick

It’s looking more and more likely that we’ll see a split rather than a displacement now, I think surface cold under a U.K. high being the holding pattern until we see the trickle effects of the above. I wonder if we can get a sustained well below average January under our belts?

Hi SC

It was only exactly 8 years ago this month when we had a sustained well-below average winter month and one which turned out to the the coldest winter month overall since 1986 and the coldest December since 1890. Therefore one doesn't have to go back 30 years or more to find such an occurance. That was also only a year after what I believe was our coldest winter overall since that of 78-79.

The last couple of SSW that I know of (the one in Feb this year and the one of early 2013) have both led to notable outbreaks of cold in the UK, so who knows?

---

 

But there’s never been any suggestion in the models that we’d see a cold spell this side of 2019.  

There’s nothing to justify any greater confidence in a cold spell in January either until we see how the SSW plays out.

That's simply not the case. The Met Office were talking about a cold December although the BBC long ranger didn't buy into it.

---

 

It's starting from tomorrow onwards or do you mean from over the top of the N Pole?

A gentle warming is not a SSW. The significant surge of warming is modelled on GFS for next week.

---

 

That's simply not the case. The Met Office were talking about a cold December although the BBC long ranger didn't buy into it.

I wasn't thinking about the long-range forecast, I was talking about the model output (as this is the discussion thread for that).

---

T

 

A gentle warming is not a SSW. The significant surge of warming is modelled on GFS for next week.

but is the surge of warming modelled for next week any more reliable than anything else modelled for next week I wonder ...

---