[Model Output Discussion - Into 2024]

15 minutes ago, BLAST FROM THE PAST said:

Nothing imo has changed.  Very good chances going forward for very cold conditions.  There’ll be subtle changes to model runs.

So here’s something to think about.  If the way forward is the retrogression of the HP to Greenland, careful what one wishes for re the first HP.  If it moves too far north when it retrogresses all the real cold plunges to our east and the Atlantic rolls in under the block.  The ECM retrogression is perfect, that’s a direct hit.  We want the trough to plunge over the north sea.

 

point in case.  No further north that this.  Works out great….but only just

 

BFTP

I think that’s quite a good point. We need to be careful of heights escaping too far to the West of Greenland. However, a nice strong UK high should mean that cold is directed towards the Uk

[Storm Arwen]

I think this could be quite the storm tonight, particularly so for those in the NE. 

There have been very few gales in the last year with blocked weather patterns dominating on the whole

Combined with the fact that the wind is coming from an unusually Northerly direction, it may catch quite a few people off guard.

Thankfully, the strongest winds take place overnight when less people will be out and about. That could be the saving grace.

[Model output discussion - 7th January onwards]

The slightly slower evolution on the ECM may actually be preferable to the GFS as it allows more of an initial bridge in heights between the Arctic and Scandinavia. 

This could open the door to much deeper cold if we were to get some sort of Easterly flow towards the end of January 

[Far north and northeast of England - regional chat]

Here in Newcastle it’s been clear for a long period now. I’ve never seen so many lines of showers miss an area over the past 24hrs no matter what the wind direction it appears

[Far north and northeast of England - regional chat]

Incredibly heavy shower again here in Newcastle. Whiteout conditions. This last hour has started to make up for showers we missed out on earlier 

[Model output discussion - Post SSW - Will it turn cold?]

We may have to wait a bit longer on the ECM than the GFS for the real cold to set in but in reality it is actually much better synoptically speaking for a longer cold spell

[Model output discussion - mid January]

Also worth noting the possibility of some really low night time maxima in this upcoming spell as winds fall light at times under sub -10 uppers

[Model output discussion - mid January]

Wow what a 18z GFS. These upgrades really have progressed fast in the last day or two. 

These really are remarkable charts. Yes we may have seen slightly colder uppers than this reaching our shores from the East before but to have an extensive mass of -10 uppers approaching from the West also is truly amazing.

 

[Model Output Discussion - cold spell to end Autumn]

5 minutes ago, CreweCold said:

Indeed. 

We're looking out at day 9/10+ now for another go at getting some snow potential to our shores in any widespread fashion. That's FI in anyone's book. 

That's very true, but i always feel its nicer to be looking for potential out at days 9/10 whilst already in cool/cold flow, which we will be up until Thursday/Friday. Always have slightly more patience when you don't have to walk outside and it be 15 degrees and raining!

[Model Output Discussion - cold spell to end Autumn]

22 minutes ago, Building Blocks said:

Having a had a look at the latest trends being picked up by the ECM 12z and now the GFS 18z, it looks as though a complex pattern is evolving at around the 7 day timeframe.

This is based around two areas of high pressure, a blocking high to the NW centred near Greenland and an area of high pressure to the SE over Europe and two areas of low pressure, one out to the SW in the azores and one to the NE up over Northern Scandinavia

How these interact is crucial, obviously affected by the much maligned Shortwaves! The most favoured outcome for coldies is for more of the Southern high pressure to link up with the Greenie high, maintaining an Atlantic block, and allowing Northerly winds to flow down through the country. Conversely, the worst case scenario is for more of the heights to sink south, thus setting up a West based NAO- with winds coming up from the SW as the azores low is allowed to move towards the UK due to a lack of Atlantic blocking.

Obviously, with these kid of setups, the North and East of the country is in the best position as it is closest to any northerly outbreaks that may occur.

Now there is still lots of time for change with this set up and little alterations East or West will have a great impact on whether the UK see's the cold upper 850hpa's move down across the country or whether we are stuck in a somewhat milder set up.

What will probably happen? An evolution somewhere inbetween. 

However, the coldie in me wants the Northerly winds to win the battle!

Anyone mind me re-posting this? As it is one of my first posts so took a bit of time and it got lost in the free - for - all that seems to occur watching nearly every model run on here. Its crazy but we all love it!

[Model Output Discussion - cold spell to end Autumn]

Having a had a look at the latest trends being picked up by the ECM 12z and now the GFS 18z, it looks as though a complex pattern is evolving at around the 7 day timeframe.

This is based around two areas of high pressure, a blocking high to the NW centred near Greenland and an area of high pressure to the SE over Europe and two areas of low pressure, one out to the SW in the azores and one to the NE up over Northern Scandinavia

How these interact is crucial, obviously affected by the much maligned Shortwaves! The most favoured outcome for coldies is for more of the Southern high pressure to link up with the Greenie high, maintaining an Atlantic block, and allowing Northerly winds to flow down through the country. Conversely, the worst case scenario is for more of the heights to sink south, thus setting up a West based NAO- with winds coming up from the SW as the azores low is allowed to move towards the UK due to a lack of Atlantic blocking.

Obviously, with these kid of setups, the North and East of the country is in the best position as it is closest to any northerly outbreaks that may occur.

Now there is still lots of time for change with this set up and little alterations East or West will have a great impact on whether the UK see's the cold upper 850hpa's move down across the country or whether we are stuck in a somewhat milder set up.

What will probably happen? An evolution somewhere inbetween. 

However, the coldie in me wants the Northerly winds to win the battle!

[Model Output Discussion 01/09/17]

I think one major positive to take from the runs at the moment, in particular the GFS, GEM, and ECM but also the UKMO to some extent, is that these good looking charts for cold lovers are appearing at a relatively short timescale and not deep in FI (like is usually the case).