In the near term it is indeed looking like a continuation of unsettled weather with any wintriness reserved for the mountains of Scotland as we see a trough-ridge-trough pattern. As always in such a setup, the north and west cop the worst of the rainfall totals.



There seems to be a semi-permanent low pressure somewhere in between Iceland and Scotland and that theme continues into the medium term with polar maritime air perhaps more prominent as the lows potentially take a more NW-SE track. This is how we may introduce a greater wintry risk for favoured hills rather than just the ski resorts.



Now, there is a lot of cold air bottled up to the NE and it is encouraging to see less extreme cold heading into the States. However hard I want to cling to the hope of a Scandinavian high to eventualy unlock that deep cold to the east, I am struggling to see anything meaningful in what remains charts deep in FI. Previous GFS operationals for instance have not been well supported in the ensemble suites. I note the 06z which was a high pressure outlier for Oslo in its latter stages for instance.



So my main thoughts, if you're still clinging to something colder and more widespread happening, the most likely period for that remains mid-January but perhaps not from anything to the east/northeast. It is more likely, given (admittedly low amplitude) the MJO forecast that we see heights over SW Europe decline westwards and aid some modest amplification in the Atlantic which would help the jet buckle SE and steer the ever-present Icelandic low(s) deeper into Europe and drag colder PM (but not deep cold) air to our shores.

Before any of that tenuousness I suppose the succinct line from Shepherd above sums up the reliable. Wet and windy with cold rain ☺


 

Originally Posted by: Jacee 

What an absolute stunner. Great to have you posting. Welcome. 👍😊

Originally Posted by: Joe Bloggs 

Steady Joe, steady! .....😉🤪

Originally Posted by: Jive Buddy 

What an absolute stunner of a post. Great to have you posting. Welcome. 👍😊

Originally Posted by: Joe Bloggs 

Chart at 162 screams potential with looks like a massive col which could indicate a potential pressure build over Scandi, but charts progress in a different way at the moment

Originally Posted by: ballamar 

Agree 100% with this. Very interesting model watching now...with a growing sign of some significant wintry weather on the horizon.​​​​​​​
​​​​​​​​​​​​​​Reckon we need to get the next week of mild gunk out of the way, and then mid-January onwards looks poised for something much more akin to winter.    

Originally Posted by: moomin75 

Not sure it's that interesting for the southern third of the UK. Floods, floods and more floods would sum it up.

Originally Posted by: Ally Pally Snowman 

In the short term yes, I agree.

But its more mid-January onwards that looks interesting to say the least.​​​​​​​

On top of that, there now appears a strong signal for a proper and large SSW in about 10 days' time.​​​​​​​

We will still need a lot of luck and an SSW doesn't guarantee anything, but it stacks some of the cards in our favour at the very least.  

Originally Posted by: moomin75 

Actually, I'm afraid I don't agree. What we're seeing across Arctic Russia is what we see every winter: modest increases in temperature which ebb and flow, often moving west to east.

The subject of the behaviour of the stratosphere is way above my pay grade but I don't think there's any correlation between what we are seeing and possible SSW events.

Of course, even a notable SSW doesn't guarantee propogation down into the troposphere, let alone guaranteeing blocking in the right place.

Originally Posted by: Gandalf The White 

In the short term yes, I agree.

But its more mid-January onwards that looks interesting to say the least.

On top of that, there now appears a strong signal for a proper and large SSW in about 10 days' time.​​​​​​​

We will still need a lot of luck and an SSW doesn't guarantee anything, but it stacks some of the cards in our favour at the very least.  

Originally Posted by: moomin75 

It'll be interesting to see if the cooler zonal GFS has been showing for a while in its FI section materialises or not - there's been a few Januarys lately where it has done but generally a progged cool zonal for the far south ends up average or mild zonal nearer the time.

The charts aren't without interest though - in the near term cold enough in Scotland on and off for snowfall even down to lower levels at times (I know, not exactly unusual but against recent standards it's good to see) and an FI risk of colder air making it far enough South to bring interest to more folks in an unstable west or north westerly flow. Not generally any good IMBY but can deliver to parts of Wales, the North West and some in the Midlands. 

I assume this is all helping to add a decent amount of snow to the Scottish ski resorts albeit it's presumably a tad too breezy up there a lot of the time to enjoy it!

Whilst it's FI and will look different in a few hours for general amusement the T231 to T240 charts for Kent have 40- 60 mph gusts and rain or sleet/snow, heavy at times. Would be fun if it verified (unlikely though that is).

On the SSW front I think the latest GFS is showing the first warming event followed by a fairly major warming event, no idea if it shows a reversal though to meet the SSW definition? I don't really know much about SSWs but did read a few bits the other day that general warmings can lead to SSWs later so the GFS solution isn't implausible I guess. Whether it happens and whether it impacts the weather at our level (and how) are all unknowable at this stage - given SSWs happen fairly frequently on average and we don't get fairly frequent cold spells I think that's probably enough to show they're not the holy grail for cold but more a throw of the dice. 


 

Originally Posted by: Hippydave 

In the short term yes, I agree.

But its more mid-January onwards that looks interesting to say the least.

On top of that, there now appears a strong signal for a proper and large SSW in about 10 days' time.​​​​​​​

We will still need a lot of luck and an SSW doesn't guarantee anything, but it stacks some of the cards in our favour at the very least.  

Originally Posted by: moomin75 

at the moment it looks like cold zonality is favoured in the GEFS mid-January onwards. I'm not a big fan of SSWs if anything they are just as likely to cause extremely mild weather as very cold in my experience. Might be better off taking a spell of cold zonality.

Originally Posted by: Taylor1740 

Small adjustment at 174 for the low to become a ‘slider’

Originally Posted by: ballamar 

Significant SSW Temperature increase of some 60 or 70c at 1hpa?

A message for Brian or anyone who can help advise?

I see that there is also a significant increase in temperature at 1hpa which I assume is at the very top of the atmosphere especially over N Scandinavia, Svalbard and into the N Pole at the end of the run which has also been a trend and I was wondering if this can infiltrated lower down into the stratosphere at 10hpa and 30hpa and cause a SSW and build a blocking? Or are significant major SSW's at 1hpa irrelevant as it's too high up?

Thanks for thoughts in advance:

Originally Posted by: tallyho_83