Model output discussion - here comes the beast!

[Summer Sun]

UKMO extended looks a bit more southeasterly bulk of the precipitation looks to be more focused Yorkshire northwards

[Staffordshire]

A wash streamer would effect parts of Central/Southern/Eastern midlands in this flow.

[frosty ground]

2 minutes ago, Summer Sun said:

UKMO extended looks a bit more southeasterly bulk of the precipitation looks to be more focused Yorkshire northwards

South Easterlies are pretty poor for the North West, but those lows are getting close to the SW of UK

[BLAST FROM THE PAST]

14 minutes ago, Steve Murr said:

Morning All -

ECM mean / GEFS Mean / ECM op & so all paint a picture of a 7 day plus 80's style evolution -

Infact the AO chart on the Operational EC @ 168 

Is probably in a 'top 5' Elite of Negative AOs - Think 1978 -

Infact it might even be the 'Top Gun' of AOs - The goose & maverick !

I can sense a bit of concern now from some people - & I its understandable that everything that we wish for will bring chaos & misery for others- Infact this popped up on TWO & is worth a share- The 2012 cold spell killed 824 people across Europe

https://en.m.wikipedia.org/wiki/Early_2012_European_cold_wave

I guess wwhether we like it or not we have no influence over whats happening - spare a thought for any people Uk / europe who may be homeless etc as this cold will be as bad if not worse -!

So- Snow, kicking off in the SE at about 10pm Sunday Night- then spreading west & also further up the coast throughout Monday - The high res models are beginning to come it range now but they will still be vague on streamers right up until T6!!

Still chances of that big snow event swinging up from the south - however at this stage it appears to be a slight outsider !

Have a great day

 

NYE 1978 ALERT on the GFS 00z.....now that would be feet of snow!!!

 

BFTP

 

 

 

I posted the above on Feb 14th......I believe it was in deep FI for next week.  A good call by GFS possibly..l

 

BFTP

[karyo]

19 minutes ago, Summer Sun said:

UKMO extended looks a bit more southeasterly bulk of the precipitation looks to be more focused Yorkshire northwards

The Azores high got bored of its usual location and migrated to Cabo Verde! It can stay there as far as I am concerned.

[Summer Sun]

Don't quite understand the worry over ICON tbh it still has very cold air through to the end and snow

850's

Snow predictions

 

[Timmytour]

In times of absolute despair at an outlook of depressingly mild Atlantic driven mush, I would often see a highly optimistic poster in denial put up a chart from a perb which showed there was still a possibility of Narnia

A measure of where we are now is that the polar opposite of such a punter would have a real job to find a chart promoting the opposite perspective!

Edited February 23, 2018 by Timmytour

[Mr Frost]

3 minutes ago, Summer Sun said:

Don't quite understand the worry over ICON tbh it still has very cold air through to the end and snow

850's

Snow predictions

 

Indeed! Not quite sure what Crewe Cold and The Eagle were on about earlier this morning - sleep deprivation? 

They are starting to remind me of these two...just a wee joke lads! 

 

[Yarmy]

Nice example of both a Wash and a Thames Streamer on the 5km WRF-NMM for Monday morning:

 

The UK-only chart only goes out to T72 on Meteociel, so this should come into range for 6z and 12z runs.

[Nick F]

2 hours ago, captaincroc said:

Can I ask the experts a question if possible about this chart. If you look you can see that even though - obviously - the east gets battered, there is a strip running from north Wales, across the north Midlands, NW England. I have seen this area in many a precipitation forecast the past week. Why is it there? As the Pennines seem to stop or lower precipitation further north? Is it a gap in the high ground? Just wondering as IMBY it would affect me but just wondering why that strip seems to always be there?

There is a trough developing in the easterly flow over the North Sea late on Monday, with an organised area of snow forming with it, that then tracks SW across N England and then on through Wales, so probably why there is enhanced snowfall accumulations in the areas you mention.

2 hours ago, Johnp said:

If that's remotely accurate won't there be a lot of disappointed people?

Eastern coastal counties of Scotland and England will be favoured most for largest accumulations, similar very cold NE / ENE flows can bring huge accumulations to SE Scotland and NE England (think Feb 1991), helped by higher ground here. Also other areas favoured in the east are downstream of the The Wash and areas bordering and inland of Thames Estuary where convergence zones set up + Kent and Sussex. Further inland for central and western parts less certain snowfall amounts and will depend on disturbances, such as the one I mentioned above this quote, to get organised snow inland, but there should be some diurnal snow showers triggered away from favoured eastern areas - as the increasing sun strength now begins to create some shallow warning above the ground causing convection inland.

We could see the high res runs of the models enhance snowfall predictions as we get into closer range, as they take in new data, certainly the case of them picking up snow streamers over last few runs that weren't there before.

Edited February 23, 2018 by Nick F

[Duane S.]

Friday morning. Fantastic model outputs again. Absolutely fantastic.

It really is getting very late in the day for a turnaround now. All along I've been of the mind +72 ought to be point where, if the charts are still be showing the same (which they are), we should be able to at least crack open a bottle of cheap cava and let a couple of party poppers go.

Maybe leave the bottle of Bolly on ice and 500 shot firework in the box for the following week, when the details firm up a bit.

I've been quietly confident because of the ultra rare near unwavering support. Not only from the model ops but also the ensembles and of course the background signals. But... we've all been burnt before, it's the UK and so on.

So with charts such as this..

STILL on display, it does look like it really is happening. Could it be a case of...

Patience is bitter, but its fruit is sweet (Jean-Jacques Rousseau)

[Timmytour]

2 minutes ago, s4lancia said:

Friday morning. Fantastic model outputs again. Absolutely fantastic.

It really is getting very late in the day for a turnaround now. All along I've been of the mind +72 ought to be point where, if the charts are still be showing the same (which they are), we should be able to at least crack open a bottle of cheap cava and let a couple of party poppers go.

Maybe leave the bottle of Bolly on ice and 500 shot firework in the box for the following week, when the details firm up a bit.

I've been quietly confident because of the ultra rare near unwavering support. Not only from the model ops but also the ensembles and of course the background signals. But... we've all been burnt before, it's the UK and so on.

So with charts such as this..

STILL on display, it does look like it really is happening. Could it be a case of...

Patience is bitter, but its fruit is sweet (Jean-Jacques Rousseau)

Some of the snowfall charts take me back to a time in the 70s in Herts when I was desperate for the flurries that we had for about a week to turn into something more significant, but they never did!

[Man With Beard]

ECM individual ensembles - ANOTHER UPGRADE for Wednesday/Thursday in terms of cold.

The majority of runs now have uppers of minus 17C / 18C crossing a part of the UK on one of those days. 

There's a definite increase in the amount of minus 19Cs too, and a couple of minus 20s sneak in on the runs where the northern push is more successful.

Very few runs are lower than this. The mean doesn't quite represent this because the "hot spot" is slightly different on each run.

Basically, take the GEFS ensemble diagram for Wednesday/Thursday's uppers and knock another 1C to 2C off.

Edited February 23, 2018 by Man With Beard

[tight isobar]

5 minutes ago, Man With Beard said:

ECM individual ensembles - ANOTHER UPGRADE for Wednesday/Thursday in terms of cold.

The majority of runs now have uppers of minus 17C / 18C crossing a part of the UK on one of those days. 

There's a definite increase in the amount of minus 19Cs too, and a couple of minus 20s sneak in on the runs where the northern push is more successful.

Very few runs are lower than this. The mean doesn't quite represent this because the "hot spot" is slightly different on each run.

Basically, take the GEFS ensemble diagram for Wednesday/Thursday's upper and knock another 1C to 2C off.

Thats preety much(cross) suites consensues..

Via upgrading/possible prolongment.

[tight isobar]

A notable southerly shunt in near term gfs 6z..

Although mid/longer term given synoptics..

More coming into play...countrywide.

[Nick F]

8 minutes ago, Man With Beard said:

ECM individual ensembles - ANOTHER UPGRADE for Wednesday/Thursday in terms of cold.

The majority of runs now have uppers of minus 17C / 18C crossing a part of the UK on one of those days. 

There's a definite increase in the amount of minus 19Cs too, and a couple of minus 20s sneak in on the runs where the northern push is more successful.

Very few runs are lower than this. The mean doesn't quite represent this because the "hot spot" is slightly different on each run.

Basically, take the GEFS ensemble diagram for Wednesday/Thursday's upper and knock another 1C to 2C off.

The EPS mean of -14C T850s into the SE UK is impressive enough, but this does leave the door open to those even colder ens verifying.

Lets hope we aren't heading for another Jan 1987 though, don't think the UK nowadays could cope.

 

[Buzz]

2 minutes ago, tight isobar said:

A notable southerly shunt in near term gfs 6z..

Although mid/longer term given synoptics..

More coming into play...countrywide.

Actually, if you compare it to the last run the main cold pool is a tad further north.

Edited February 23, 2018 by Buzz

[weirpig]

Showers really starting to pop up now on the GFS  Streamers etc  most of the country seems like seeing some of the white stuff

[ICE COLD]

GFS 6z T111 looking good ?

[TEITS]

Just now, weirpig said:

Showers really starting to pop up now on the GFS  Streamers etc  most of the country seems like seeing some of the white stuff

Yes its something I have noticed over the last few runs. This isn't surprising and I expect this to only increase as we get closer to next week.

[ICE COLD]

This is now only starts at T60 . Getting close everyone ?

[Midlands Ice Age]

24 minutes ago, BLAST FROM THE PAST said:

NYE 1978 ALERT on the GFS 00z.....now that would be feet of snow!!!

 

BFTP

 

 

 

I posted the above on Feb 14th......I believe it was in deep FI for next week.  A good call by GFS possibly.

 

 

• Report post
•  

Posted Tuesday at 09:54 (edited)

 

 

BFTP

I similarly tried to indicate the possible uniqueness of the current situation, in a posting which I posted on Monday of this week.

It is still looking possible that the long odds situation that I referred to could happen.

 

My QUOTE (to remind people what I actually stated - I was referring to one GFS run only).)

 

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•  

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Purga...

 Took this one run of yours from overnight, but it is one of many.

Whilst it is quiet in here I thought I would try and show how 'amazing' that last nights GFS 18z pub run rally was really was.

 

It started with the Beasterly (now pretty much nailed on)...

then went on to an attack from the  SW  giving a channel low   very rare in these conditions..

then went on (and quite naturally) into a section of the PV coming down over us (the so-called polar low), and all in 7 days.

 

Now I will try and put some figures on how rare this sequence might be.

 

Assume a beasterly occurs once in every 5 to 10 years.

Assume that a channel low might occur in a 1 in 10 chance (in bitterly cold air)..

Assume that a switch to a polar vortex low occurs as a 1 in 30 years occurrence ....

Note the above is roughly the figures for the UK.

 

Now normally the 'odds' are calculated by multiplying the numbers together.

That gives a 1 in 2250 chance of the events occurring one after another.

Now because the synoptics just seem to 'flow' naturally from one to the other you must assume that it is fairly well a  pre-set synoptic process and that once the situation sets up, one will automatically follow from the next.

So if I assume that this reduces the chances of it 'not' happening by a factor of 2 to 5. (A complete guess but must happen frequently!)

You still would only expect this sort of situation only once in from 400 to 1000 years.

Note  I am looking at the complete rapid sequence  in a few days here,  not just the chance of it happening in a total winter.

It did happen in 1962 for example but was separated by about 6 weeks.

 

So  the odds are against it happening!"!!!!

 

I hope that for the younger viewers it puts last nights GFS down as one to remember. It was a simply sensational run from a synoptic point of view.

I see that already the models seem to be upgrading the 'early' cold.

 

So I  went on to think about  how it could be bettered.......

Possibly by means of dropping the main PV over us is the only way I can see. This would have to be via Siberia I suspect..

Now I think that would be a once in a millennia event and could not possibly happen.

 

We could develop a 'low' in the beasterly ... Oh hang on the ECM does just that!

It is  once in a lifetime chance to view something special in the charts.

Can it deliver!!!!!!!!!!

MIA.

 

 

ENQUOTE

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Now I feel an update is required...

It is now certain we are getting the Beasterly this coming week.    - tick

The Channel low situation at the end of the week is still a possibility (give it a 25% chance of happening).   ?????

The following dropdown of the PV after the retrogression is now appearing more and more possible (50%?).

 

Still it is still long odds on us getting the 'full Monty'., and the 1 in 400 years event occurring.

But    - if we miss out on the Channel low occurring we are stiil at a roughly 1 in 40 years event occurring. It will still  be very notable.

The full impact scenario is just about possible.

What will enable it  to happen?

Well my money is the unique occurrence of 2 SSW's occurring in quick succession, both looking to hit the UK in a favourable way. It must also be pointed out that a third is still seen a s possible later on in March. 

Now I believe that this situation is probably extremely rare.

If it happens in the way it seems to be we could well be seeing  a 1 in 40 year event, but it would not take much to convert this in to the 1 in 400 years event, I mentioned above as being portrayed at that time.

It would take only small changes involving the Channel low to make it a 1 in 100 years experience. Rivalling  1947, 1881 and 1895 for snow amounts and disruption. In todays 'power' environment it could be argued that it will be worse.

Do not mis-understand me. It will not be the coldest ever, since  most of it will be happening in March. It  will however likely break some of the longer March recorded figures if it occurs as portrayed.

It is worth, the newer members at least, remembering these events if they happen as shown.

I still say again  - can/ will it happen?

MIA 

  

[ICE COLD]

GFS T120 

[weirpig]

Better from the GFS   Snow piling into the region via a streamer from the North Sea   infact showers get as far as Wales.  Seems to be upgrading the closer we get 

[ICE COLD]

T132 and it just gets colder 

And snowy

Edited February 23, 2018 by ICE COLD