Model Output Discussion - Into Autumn 2020.

[Catacol]

20 minutes ago, MP-R said:

Which is funny because in a normal winter, a chart like that is more likely in Feb than the other two months. Alas La Niña can turn winter back to front. The CFS January charts have really got my attention over the last few weeks. A bitterly cold heart of winter would be classic!

Yes - unless we get a shattered vortex style event ala 2018 I'm not seeing February as a cold month this time around. Nina works against it, and my interpretation of vortex development these days sees a generally more vigorous funnel that seems to have made cold in February particularly hard to get. 

As Crewe has hinted at quite openly, the door may be open this year to a cold first half. But I'm going to keep quiet on specifics for a good while longer yet - it is just too far out to be sure of much. We need to see how the temperature profile in the pacific develops over the next 2 months with associated MJO impacts, keep an eye on the atlantic profile, work out what the hell is going to happen with the QBO shape, watch for snow cover to the east etc etc. None of these on their own is worth much, but put together they give us half a chance of working out where we are going.

Always enjoy the long distance run in though - in some respects less stressful than the Dec-Feb period itself when tempers flare!

[Frosty.]

Although the ECM 0z op / ens mean trend cooler, autumnal / unsettled from the NW longer term, the GEFS 0z doesn’t really agree, the mean indicates more of a N/S or NW/SE split at worst next week with the south not bad at all and indeed, the situation improves further towards the end of Sept / start of Oct...so, there’s plenty of uncertainty and I wouldn’t rule out further warm spells...in the meantime, although temperatures are on the slide, it still looks pleasantly warm in the plentiful sunny spells as high pressure continues to dominate until early / mid next week..at least..please forgive me, the charts are not in the correct sequence..but I have an excuse..I’m autistic!!

 

Edited September 16, 2020 by Jon Snow

[MP-R]

1 hour ago, Catacol said:

Yes - unless we get a shattered vortex style event ala 2018 I'm not seeing February as a cold month this time around. Nina works against it, and my interpretation of vortex development these days sees a generally more vigorous funnel that seems to have made cold in February particularly hard to get. 

As Crewe has hinted at quite openly, the door may be open this year to a cold first half. But I'm going to keep quiet on specifics for a good while longer yet - it is just too far out to be sure of much. We need to see how the temperature profile in the pacific develops over the next 2 months with associated MJO impacts, keep an eye on the atlantic profile, work out what the hell is going to happen with the QBO shape, watch for snow cover to the east etc etc. None of these on their own is worth much, but put together they give us half a chance of working out where we are going.

Always enjoy the long distance run in though - in some respects less stressful than the Dec-Feb period itself when tempers flare!

Indeed. I don’t envy anyone trying to make a forecast when even just the difference between a weak and moderate La Niña is so great. Even a toned down December 2010 and more wintry January 2011 would make a decent winter even if Feb turns out useless. 

Fascinating if sometimes frustrating watching ahead.

[mb018538]

GFS again treads a more settled path - keeping the ex-hurricane to the north.

ECM 00z day 10 clusters below paints a much bleaker picture - all clusters showing a deep low near to or over the UK at day 10, as ex-Teddy makes it's presence felt:



Until this is nailed down, forecasts beyond this point are difficult to predict. 

[summer blizzard]

Euro this morning has the Atlantic moving in around day 6 and taking charge for the duration.

[Man With Beard]

Does seem Wednesday/Thursday is marked out as "changeover day" on ECM mean charts

But the GFS continues to call a near complete fail on the breakdown

And then a reload of heat

  

Brings back memories of Oct 2011 this one

Someone forgot to tell the ECM clusters - no clusters with such a strong upper ridge over Germany - only the smallest cluster is anything like the GFS.

[LRD]

Could the operational 6z run from the GFS today, 16 Sept 2020, be officially the most boring, uneventful run ever in the history of model runs?

Good grief model watching is tedious in Sept at the best of times but this year has taken the biscuit and the barrel. No wonder it's so quiet in here

Hopefully October can produce some actual weather

[LRD]

3 hours ago, mb018538 said:

GFS again treads a more settled path - keeping the ex-hurricane to the north.

ECM 00z day 10 clusters below paints a much bleaker picture - all clusters showing a deep low near to or over the UK at day 10, as ex-Teddy makes it's presence felt:



Until this is nailed down, forecasts beyond this point are difficult to predict. 

The ECM clusters will, at least, give us something to talk about

So, differences between GFS and ECM for later next week. Would be nice to relax and listen to some wind and rain battering my windows what with it being autumn. 

Edited September 16, 2020 by LRD

[Scorcher]

1 hour ago, LRD said:

Could the operational 6z run from the GFS today, 16 Sept 2020, be officially the most boring, uneventful run ever in the history of model runs?

Good grief model watching is tedious in Sept at the best of times but this year has taken the biscuit and the barrel. No wonder it's so quiet in here

Hopefully October can produce some actual weather

Far better than constant rain which we have had a few times this year. Give me warm, unbroken sunshine now while we can still get it.

[LRD]

20 minutes ago, Scorcher said:

Far better than constant rain which we have had a few times this year. Give me warm, unbroken sunshine now while we can still get it.

Don't want to derail the thread but GFS (he says keeping it on topic!) is basically showing what us in the SE have had since early April with some blips (late Aug being the most significant). I appreciate that you chaps in the NW have not had it as dry for so often and respect your view/preference

Edited September 16, 2020 by LRD

[LRD]

UKMO shows a likely end to the dominance of high pressure at 144

GFS, while showing similarities to UKMO, will result in similar to what we've already got. There are, however, differences between the two to our SW

Edited September 16, 2020 by LRD

[Zak M]

Now that's a beauutifullllllll end to the 12z GFS - in FI. 

[Allseasons-Si]

CFSv2 keeps on screaming these January charts out

 

Edited September 16, 2020 by Allseasons-si

[LRD]

Well someone's going to be wrong. GFS:

ECM:

Probably both wrong at that range. But which will prove to be the most inaccurate? Time will tell

[Tim Bland]

44 minutes ago, LRD said:

Well someone's going to be wrong. GFS:

ECM:

Probably both wrong at that range. But which will prove to be the most inaccurate? Time will tell

Smart money would be on the middle ground, unsettled North drier South

[Daniel*]

49 minutes ago, LRD said:

Well someone's going to be wrong. GFS:

ECM:

Probably both wrong at that range. But which will prove to be the most inaccurate? Time will tell

Evidently GFS has lost the plot more unsettled weather seems to appear more likely after Wednesday and what will become ex hurricane Teddy looks to assist that.

 

[damianslaw]

Major differences longer term between ECM and GFS as pointed out, all due to how they develop ex tropical storm systems, ECM wants to engage such systems with the jet and we end up with an unsettled trough dominated picture and a cool one, GFS on the other hand, keeps such systems away from the UK, and we end up with a prolongation of the dry ridge theme. GFS has a tendency to play around with scenarios, so don't be at all surprised to see next one or two runs in sync with ECM, only for ECM to flip and eventually as often happens they come to settle on a theme, quite often somewhere in the middle of both extremes.

In the short term, a very pleasant spell of weather for many, lots of dry weather at least, perhaps more cloud at times in eastern parts thanks to the easterly breeze, and the chance of some drizzly outbreaks but nothing substantive. The west looks best for sunshine. Temperatures a little above average maximum wise, but in the sunnier spots cancelled out by some chilly nights. 

 

Edited September 16, 2020 by damianslaw

[Dancerwithwings]

ECM all down hill, completely the opposite to the GFS 

But these tropical storms systems will have a big part to play, certainly interesting I must say.

 

Edited September 16, 2020 by Dancerwithwings

[Allseasons-Si]

Go on CFSv2,keep em coming.

predominantly pressure to our north and has been keen on this over the last few days. 

Edited September 16, 2020 by Allseasons-si

[cyclonic happiness]

There are some very wintry looking charts in FI for the north, with a good northerly and uppers of -6'c followed by something like northern blocking, forcing lows down southwards.   Evan looks like there could be an easterly setting up very far in fI on the GFS.

 

I know it'll change, but it's lovely to see

[bluearmy]

Nwp chucking out some interesting NH patterns this morning with a view towards winter ..... anyway, the 8/15 day picture doesn’t look great for those wanting a continuation of the late summer conditions......

Edited September 17, 2020 by bluearmy

[mushymanrob]

11 hours ago, LRD said:

Well someone's going to be wrong. GFS:

ECM:

Probably both wrong at that range. But which will prove to be the most inaccurate? Time will tell

Which is why some of us rely on the NOAA 500mb mean charts because theyll be closer to the eventual solution and iron our those differences. They help spot the rogue runs.

[ICE COLD]

GFS 00z brings in the -7 850s in September . We struggle for that in winter lol 

[mb018538]

Certainly seems to be a big shift today in blowing up a big block over eastern Europe/Russia, and perhaps out to our west somewhere.

GEM has gone all in on a mega Greenland block!



On today's evidence, the last few days of the month could be very unsettled, and even quite cold. Day 9 and 10 on today's ECM sees some parts of the north not even making double figures, and mid teens at best elsewhere. A very big shock to the system incoming!

[northwestsnow]

1 hour ago, bluearmy said:

Nwp chucking out some interesting NH patterns this morning with a view towards winter ..... anyway, the 8/15 day picture doesn’t look great for those wanting a continuation of the late summer conditions......

Yes it is beginning to look like the Atlantic will paying a visit mid term ..

In the meantime the pleasant conditions persevere ..

Glosea throwing some very +NAO projections for Winter, connected to its idea of a strong La Nina,all eyes on the Eastern Pacific over the coming weeks.(Coldies would want weak to moderate i guess).

Edited September 17, 2020 by northwestsnow