Model output discussion - into the start of Winter

[Eagle Eye]

The chart lol

 

 

[kold weather]

18 minutes ago, XanderP007 said:

The chart lol

If somewhat cold rain gets you excited, then this is the chart for you!

If only those were surface temperatures!

Edited November 25, 2020 by kold weather

[Eagle Eye]

12 minutes ago, kold weather said:

If somewhat cold rain gets you excited, then this is the chart for you!

If only those were surface temperatures!

Not great runs best i could do

[Jeremy Shockey]

ECM 0z anomalie 500 hPa ( 4th Dec )

We need to see more of this IMO later on in the 12 z output.

Really quite a strong signal for high pressure in advantageous areas for UK cold weather . The PV away for as long as possible at the other side of the North Pole please !

[Allseasons-Si]

Just a quick one before i dash off for work

This mornings eps at day ten...

i've seen worse...a lot worse

[Anthony Burden]

All to play for regarding western Russia high pressure.Met office stating short term high

pressure likely win,into December any bodies guess in other words they haven’t got a clue.

As mentioned before stick to fax 120hrs until FOG CLEARS.

[bluearmy]

4 hours ago, LRD said:

I can see the troughs and high pressure systems. I just can not for the life of me see the difference in the green contour lines. I'm obviously being a bit dim. Perhaps I best leave trying to read those charts

The green lines are the 500mb lines - see current day 11 eps mean chart I have scribbled on below 

1 is the shallow euro trough

2 is the sharp e USA trough 

1 ? no idea why I marked 1 ! Anyway, it’s the W USA ridge.

these are all upper features at 500mb, not surface which is 1000mb. 

The lines on this chart should be roughly mirrored on the noaa cpc chart green lines.  There will be a flattening off on the cpc chart as it will usually be a mean of ecm, gefs and geps output on that day 

from the chart I have attached, you can see the flat flow across the Atlantic. The chart you put up from 2010 had an upper ridge mid Atlantic and a sharper trough in W Europe.  That illustrated that the ens means were in good agreement that we would get those two features !  Current ens mean chart is fairly flat mid Atlantic days 8/10.  course, it could mean that there is good agreement that we will get a flat flow across the Atlantic but the anomolys (dotted lines on the cpc charts) will help you to see where any variation to the mean is likely to be. On your chart, you see the USA ridge is backed up by a high anomoly in the same place and the e USA trough a low anomoly. Given the upper features are strong that’s not a surprise - the Atlantic anomolys are also reflective of a fairly flat upper flow which lends support to the chart being a decent representation of the mean through the 6/10 day period .....

will be interesting to see if today’s cpc begins to sharpen a euro upper trough and any Atlantic ridging. the former perhaps, the latter less so imo. 

[johnholmes]

2 minutes ago, bluearmy said:

The green lines are the 500mb lines - see current day 11 eps mean chart I have scribbled on below 

1 is the shallow euro trough

2 is the sharp e USA trough 

1 ? no idea why I marked 1 ! Anyway, it’s the W USA ridge.

these are all upper features at 500mb, not surface which is 1000mb. 

The lines on this chart should be roughly mirrored on the noaa cpc chart green lines.  There will be a flattening off on the cpc chart as it will usually be a mean of ecm, gefs and geps output on that day 

from the chart I have attached, you can see the flat flow across the Atlantic. The chart you put up from 2010 had an upper ridge mid Atlantic and a sharper trough in W Europe.  That illustrated that the ens means were in good agreement that we would get those two features !  Current ens mean chart is fairly flat mid Atlantic days 8/10.  course, it could mean that there is good agreement that we will get a flat flow across the Atlantic but the anomolys (dotted lines on the cpc charts) will help you to see where any variation to the mean is likely to be. On your chart, you see the USA ridge is backed up by a high anomoly in the same place and the e USA trough a low anomoly. Given the upper features are strong that’s not a surprise - the Atlantic anomolys are also reflective of a fairly flat upper flow which lends support to the chart being a decent representation of the mean through the 6/10 day period .....

will be interesting to see if today’s cpc begins to sharpen a euro upper trough and any Atlantic ridging. the former perhaps, the latter less so imo. 

I'll try and send a pm to LRD but got stuck with other things, the explanation by ba looks okay to me

[Duane S.]

There is a bit of an unusual look to the chart output, and the movement of pressure systems in general, at the moment.

I don't give two hoots about 10 days showing a stalled pressure system on one chart run, then the cold 850s slipping down towards Greece on the next. Personally I'm just loving this fairly non-standard chart output at the moment and taking all output permutations with an oversized pinch of salt.

With the main trop vortex looking likely to be drifting further NE away from GL, there will always possibilities down the line that will inevitably crop up. I'd say a decent 2 or 3 wave pattern looks like setting up over the coming period, it will be very interesting indeed to see what happens as we head through December.  Sort of reminds me a bit of the start of Winter 2012/13.

So in the words of the legendary Mr. Eastwood... Feeling lucky punks?

[Catacol]

21 minutes ago, s4lancia said:

There is a bit of an unusual look to the chart output, and the movement of pressure systems in general, at the moment.

I don't give two hoots about 10 days showing a stalled pressure system on one chart run, then the cold 850s slipping down towards Greece on the next. Personally I'm just loving this fairly non-standard chart output at the moment and taking all output permutations with an oversized pinch of salt.

With the main trop vortex looking likely to be drifting further NE away from GL, there will always possibilities down the line that will inevitably crop up. I'd say a decent 2 or 3 wave pattern looks like setting up over the coming period, it will be very interesting indeed to see what happens as we head through December.  Sort of reminds me a bit of the start of Winter 2012/13.

So in the words of the legendary Mr. Eastwood... Feeling lucky punks?

So long as the Dec 2012 failed easterly doesn't repeat. I'm still scarred.........!

 

Edited November 25, 2020 by Catacol

[SteveB]

12 minutes ago, Catacol said:

So long as the Dec 2012 failed easterly doesn't repeat. I'm still scarred.........!

 

We are all scarred from that failed Easterly..... nothings safe until it's within the 48-60hr mark.

[bluearmy]

7 minutes ago, SteveB said:

We are all scarred from that failed Easterly..... nothings safe until it's within the 48-60hr mark.

Surely the upgrades to the modelling wouldn't delver such a period of nwp like that again ??  was that the sunspot event ?? something happened 

[blizzard81]

8 minutes ago, bluearmy said:

Surely the upgrades to the modelling wouldn't delver such a period of nwp like that again ??  was that the sunspot event ?? something happened 

Something also tells me that there was a large uptick in solar activity at the time. Talking of which....... No, I won't go there. 

[Scandinavian High.]

This looks more interesting heading in to winter.  But is there any cold air around to start turning cold rain in to snow we’ll see.

[TSNWK]

11 minutes ago, abbie123 said:

This looks more interesting heading in to winter.  But is there any cold air around to start turning cold rain in to snow we’ll see.

Be nice to have that low shift to the right by about 700 miles... in the broader scheme not a great distance and plenty if time..

[Ali1977]

13 minutes ago, abbie123 said:

This looks more interesting heading in to winter.  But is there any cold air around to start turning cold rain in to snow we’ll see.

The ICON at T180 looks very similar. 

[blizzard81]

A good start to the 12z runs. Icon has made a major shift towards the ecm op at day 7 over the eastern US seaboard compared to it's 00z run of this morning. It is now going for that major amplification. Look at that warm air advection heading up towards the west of Greenland. 

[Met4Cast]

I think anyone looking for sustained blocking & proper cold might be disappointed, though there are many reasons to be positive. 

The MJO moving into phase 5 composites with high pressure to the east. I suspect the blocking we're seeing on the models at the moment & Atlantic wave break events is them trying to work out how we transition from the current pattern > something closely resembling the composite above, there is some evidence within the EPS/GEFS of the above pattern.

This week is cold, seasonal & blocked thanks to an Atlantic wave break throwing heights across the UK towards Scandinavia, things get a little bit messy thereafter but a clear direction seems to be back towards something more unsettled with a trough digging southwards, though perhaps ending up too far west. 

However.. I would take that. If the above pattern transpired, it'd be fairly poor in the short term for the UK, however it's a huge pre-cursor to a potential SSW/SPV weakening which could perhaps be better in the longer-term.

Models do seem to be settling down now the route forward with the MJO is becoming resolved, though expect a few more swings to come.

[That ECM]

T144 ukmo.  Pv shifted. Low barrelling from nw, then “room” for the high to go

[Eskimo]

Oh Dear Lord! 


 

Edited November 25, 2020 by PerfectStorm

[Met4Cast]

Just now, PerfectStorm said:

 

NH view is better - Vortex is actually clearing Greenland earlier on this run allowing for quicker upstream amplification. 

[Premiere Neige]

3 hours ago, Jeremy Shockey said:

ECM 0z anomalie 500 hPa ( 4th Dec )

We need to see more of this IMO later on in the 12 z output.

Really quite a strong signal for high pressure in advantageous areas for UK cold weather . The PV away for as long as possible at the other side of the North Pole please !

That low to the south west needs a little nudge over towards Italy....

[bluearmy]

7 minutes ago, Met4Cast said:

I think anyone looking for sustained blocking & proper cold might be disappointed, though there are many reasons to be positive. 

The MJO moving into phase 5 composites with high pressure to the east. I suspect the blocking we're seeing on the models at the moment & Atlantic wave break events is them trying to work out how we transition from the current pattern > something closely resembling the composite above, there is some evidence within the EPS/GEFS of the above pattern.

This week is cold, seasonal & blocked thanks to an Atlantic wave break throwing heights across the UK towards Scandinavia, things get a little bit messy thereafter but a clear direction seems to be back towards something more unsettled with a trough digging southwards, though perhaps ending up too far west. 

However.. I would take that. If the above pattern transpired, it'd be fairly poor in the short term for the UK, however it's a huge pre-cursor to a potential SSW/SPV weakening which could perhaps be better in the longer-term.

Models do seem to be settling down now the route forward with the MJO is becoming resolved, though expect a few more swings to come.

the bias corrected from today also headed into phase 5- not sure that we can necessarily trust the MJO forecasts just at the moment 

[bluearmy]

excellent continuity from the gfs op as we head into week 2…...…........ that's sarcasm btw

a good illustration how binary the scenarios may well be here, especially to our east - at the surface here, there may not be a huge difference with us sitting under an anticyclone.  

[nick sussex]

The GFS in a complete u turn with the block blown away and onto an attempt to bring in a northerly .

The UKMO only goes to day 6 but that looks a bit more like earlier outputs with the shortwave cutting back sw so might end up looking markedly different and more inline with the blocking scenario .

What we don’t want is a middle ground solution. So either full on block or full on northerly .