Model Output Discussion - Into November 2019

[feb1991blizzard]

1 minute ago, Bristle boy said:

Who is "she"? Any chance of an explanation for us divvies?

The purple lady - still a long way off as its 384 and then even if it verified, it will still need to propagate right into the pole and shred the votex, it is wave 1 as well so displacement rather than split at first but building blocks and all that......

plus needs to affect other layers of the atmosphere as well.

[Bristawl Si]

3 minutes ago, feb1991blizzard said:

The purple lady - still a long way off as its 384 and then even if it verified, it will still need to propagate right into the pole and shred the votex, it is wave 1 as well so displacement rather than split at first but building blocks and all that......

plus needs to affect other layers of the atmosphere as well.

Are these forecasts more or less reliable than the other model outputs? 

[feb1991blizzard]

Just now, Bristle boy said:

Are these forecasts more or less reliable than the other model outputs? 

More but i wouldn't get too excited yet - a lot would still have to go our way to get what we are after - after all the only index that really matters is a positive white fluffy anomaly and we are a long long way away from that still.

[Kirkcaldy Weather]

3 minutes ago, Bristle boy said:

Are these forecasts more or less reliable than the other model outputs? 

Worth keeping an eye on the strat thread, an interesting spell coming up as we head into December

[Gael_Force]

1 hour ago, feb1991blizzard said:

Vortex intensification - so what i am basically saying is the charts with a mangled spannered vortex that sometimes people get excited about are the equivalent of an October chart 50 years ago so are not necessarily as good as they seem as October is more likely to produce those charts in the normal course of events without way the climate has evolved over the last few decades as the polar vortex isn't usually as well formed by then.

I made this point a few weeks back; nothing unusual in the NH 500 polar set up for mid November

You may be right in the ice loss having a delaying effect on vortex formation but I would also add that the intense scrutiny of charts gets earlier every year. There's also the school of thought that a strong SSW or final warming at the end of previous winter manifests in a delay to the new winter season vortex formation.

[feb1991blizzard]

1 minute ago, Gael_Force said:

I made this point a few weeks back; nothing unusual in the NH 500 polar set up for mid November

You may be right in the ice loss having a delaying effect on vortex formation but I would also add that the intense scrutiny of charts gets earlier every year. There's also the school of thought that a strong SSW or final warming at the end of previous winter manifests in a delay to the new winter season vortex formation.

Does this delay help achieve blocking or does my theory that mid-late Dec coupling just scuppers the whole winter?

[Snowy L]

Looking at the mid range forecasts I'm guessing the troposphere and stratosphere are starting to become more connected? If so, perfect timing for a stratospheric warming to begin.

[Gael_Force]

1 minute ago, feb1991blizzard said:

Does this delay help achieve blocking or does my theory that mid-late Dec coupling just scuppers the whole winter?

I don't think there's any evidence it scuppers the following winter. The vortex will eventually form and then be subject to a new series of events/ teleconnections to impact it in the new season. 

[Don]

3 minutes ago, Snowy L said:

Looking at the mid range forecasts I'm guessing the troposphere and stratosphere are starting to become more connected? If so, perfect timing for a stratospheric warming to begin.

Hmm, crunch time perhaps for the long range seasonal models?

[Jordan S]

Slow moving light showers for particularly northern and western parts of England and Wales tonight and tomorrow other places drier apart from some showery rain into Western parts of Northern Ireland and northwest Scotland. Through tomorrow showery rain becomes focused more for central and Eastern areas tomorrow afternoon turning drier elsewhere. 

Arome.. 

Edited November 16, 2019 by jordan smith

[knocker]

The North Atlantic 500mb and surface analysis and sat image

A cold rather nondescript day today with some trailing fronts bringing cloud and patchy rain to some areas, mainly north Wales and England with showers continuing down western coasts of Wales and Cornwall. Elsewhere dry with sunny intervals. But in the North West Atlantic rapid cylogenisis is again taking place with the formation of another intense extratropical cyclone

Tonight many areas will be clear with frost by morning with the movement of the fronts confining the cloud to east and south east regions

A cold start to Monday, particularity in Scotland with quite a severe frost, but then a fine. if cold day, is on the cards. The exception being the east coast where it will be quite windy courtesy of a wave that has formed in the east and drifted into the North Sea. The old front will continue to bring some rain the far south east. Meanwhile the deep low is making it's way across the Atlantic

Some rain in eastern regions at first on Tuesday courtesy of the fronts associated with the north Sea low but this should clear during the day. But out in the central Atlantic the low is slowly filling and continuing to drift east and the associated occlusion will bring rain the western regions during the afternoon. Ergo most areas quite sunny

Over Wednesday and Thursday the east bound energy hits the buffers of the block in the east bringing the longitudinal movement of the low to a halt albeit the fronts do manage to cross the country and thus periods of rain interspersed with sunny intervals

Edited November 17, 2019 by knocker

[knocker]

According to the gfs major troughs continue to track across the Atlantic during the next five days until they hit the buffers but the process does, as usual, promote down stream ridging which results in a build up of pressure in southern Greenland;and that links to the strong European ridge Thus continuing unsettled and quite windy at times but not as cold as of late

Edited November 17, 2019 by knocker

[feb1991blizzard]

How about this to wake up to. Best warming in the strat yet,

[ItNeverSnowsInWindsor]

Better from the Gefs 0z run 

 

[Ali1977]

P11s FI would do!! Not too many positives other than that though and a few other decent ENS - apart from the FI strat warming, which should it come to a mini SSW may time well with you know what

Edited November 17, 2019 by Ali1977

[carinthian]

Morning all, quite a change in the latest UKMO run. Gone is the full Atlantic flow as the low hits the buffers and looks to slide. Maybe the next attempt will break the deadlock but the trend seems to be putting back in the medium term time scale. GFS run looks to progressive post 144t and GEM goes for Greenland height rises with an eventual Northerly . 

Edited November 17, 2019 by carinthian

[knocker]

The ext GEFS this morning has the vortex over northern Russia ridging in NW america into the Arctic adjacent to the extension of the vortex which is aligned northern Canada to the mid Atlantic trough.So still a very strong westerly upper flow running south of this which, although abating a tad in the east, is now unimpeded as the ridge to the east declines. This portends changeable weather but not as cold with temps creeping above average.

[Ali1977]

ECM with heights into Greenland from the Scandy area, much like the UKMO. The GFS not quite as strong in that area 

Edited November 17, 2019 by Ali1977

[carinthian]

17 minutes ago, carinthian said:

Morning all, quite a change in the latest UKMO run. Gone is the full Atlantic flow as the low hits the buffers and looks to slide. Maybe the next attempt will break the deadlock but the trend seems to be putting back in the medium term time scale. GFS run looks to progressive post 144t and GEM goes for Greenland height rises with an eventual Northerly . 

Also ,ECM slides the low at 144t. So the Atlantic put back again. That trend continues. No good really looking past 144t at the moment.

[Ali1977]

7 minutes ago, carinthian said:

Also ,ECM slides the low at 144t. So the Atlantic put back again. That trend continues. No good really looking past 144t at the moment.

168 is very different from the huge big low over us on the last run 

[knocker]

A quick glance at the ecm for the weekend

[knocker]

The ext EPS has the vortex over Franz Joseph Island, suppressing the declining European ridge, with an extension aligned to northern Canada wiith the energy running south of this, and the Greenland ridge, to a mid Atlantic trough, both of which have evolved during the evolution. Thus a more unsettled zonal flow over the UK to a toasty Europe

 

[bluearmy]

Will the ‘ridge’ hold from Russia to e Canada or will the Russian vortex extend its influence south to meet the Atlantic troughing ?

if the ridge holds then expect more of the same but the core of the wet further north as the jets gets further north with the slight easing of the block to our east (and more importantly the troughing to our south)  ....if the vortex punches through then we could get a mean northerly flow or sou’wester ...... yeah , not so clear cut then! 

[IDO]

1 hour ago, carinthian said:

Also ,ECM slides the low at 144t. So the Atlantic put back again. That trend continues. No good really looking past 144t at the moment.

Not sure in the current setup, wedges to our north, are going to deliver cold to the UK. The Atlantic and Euro ridge/waves/highs are winter killer scenarios, and they are the current drivers. GFS in FI conjoining these two which may lead to a pattern change as we enter December, with the Azores High in FI the main feature. That should at least allow E. Europe to cool down.

I think the promise of a cold NH mid-lat in November was indeed seen, though the UK missed the main thrusts, although still cooler than average, but will probably be remembered for rain and floods unfortunately.

So the rest of November will be absent of a sustained cold flow, though again fingers of cold pools passing through, after D8 less cool, before the pattern tweak (usual caveats):

D1-D8 D9-D16

 

[knocker]

5 minutes ago, bluearmy said:

Will the ‘ridge’ hold from Russia to e Canada or will the Russian vortex extend its influence south to meet the Atlantic troughing ?

if the ridge holds then expect more of the same but the core of the wet further north as the jets gets further north with the slight easing of the block to our east (and more importantly the troughing to our south)  ....if the vortex punches through then we could get a mean northerly flow or sou’wester ...... yeah , not so clear cut then! 

If that last comment is aimed at me I never suggested the evolving pattern was clear cut. There are always alternatives