Model Output Discussion - Into Autumn 2020.

[sebastiaan1973]

21 minutes ago, jules216 said:

Thats what I was refering to.Window for -NAO between 5-20.11 and then back to +NAO at the end of the month. But even that period of potenialy -NAO is lacking low height anomalies to pull down anything reasonably cold which is reflected well with mean 850phPa temperatures never dropping below 0C and that is for a location at 650m.asl in central Europe.That may of course change but I have seen these -NAO EC46d at week 2 and beyond vanish more often then not or transforming to a west based -NAO because heigher heights in Sceuro/western Russia are quasi permanent past 5 winters.What you get is slowly filling trough stuck around UK with no cold to tap feom. I will be happy to be proven wrong of course but no way proper east based -NAO chart will excite me before hour 48h of forecast period. What will come will come,though if we get the snow somehow it will be hard to enjoy it because of basically all round lockdown

It's quite easy to check this. Just one picture.

[Daniel*]

I think we’re getting a bit ahead of ourselves here, the last bout of -AO and -NAO more former proved to be more resilient. I’d certainly bank EC46 quite a consistent signal end of week 1 of November a change in regime.

[Zak M]

Well the 12z GEM is following the ECM and is showing a very settled and warm end to October and start to November.

It even has the 16c isotherm in the SE for day 7.

[I remember Atlantic 252]

Aye, another EC too, with potential Indian Summer, could it break 20 degrees? maybe between Oct 30th and 2 Nov

Edited October 23, 2020 by I remember Atlantic 252

[Frosty.]

Looking at the GEFS 12z mean longer term into early November, I think most would agree there are a few flies in the ointment in terms of a potential settling down process..BUT I like P20, although not built to last too long..this particular chart would suit me sir!...for what it’s worth, I do believe we will see heights encroaching from the south early next month but it’s the northward extent of the fine weather which is more uncertain (rule of thumb being better the further s / se you are) but the earlier 12z op looked pretty good across most of the u k..for a time at least.

 

 

[Captain Shortwave]

Week one looks like a pretty standard mixed westerly regime with rain and strong winds at times.

Week 2...

 

UKMO at least hinting that high pressure to the south may gain more of a presence along with the GEM this morning.

Three potential outcomes depending on how mobile the pattern remains.

1) Low pressure remains more influential, mild and cloud with long fetch south westerlies.

2) High pressure gains more of a foothold, the potential for a very mild or even warm southerly with more in the way of sunshine.

3) High pressure builds closer to the U.K, temperatures very dependent on where the high sets up and the direction and strength of the wind (risk of fog and frost developing).

The long range forecasts probably suggesting that options 2 and 3 are more likely and perhaps transitioning from one to the other. At the moment it is only really the GFS promoting the Atlantic express train, true to form I guess.

[mb018538]

Looks like we’re going to settle at a midway point as usual - not as amplified as the ecm a few days back, but not as flat as the gfs was showing either. Looks pretty mild though.

[mushymanrob]

The NOAA charts never really allowed for the ECM's more progressive pressure build, so it comes as no suprise those "summery looking " charts have gone.

Theres too much mobility, although as the mean flow backs south of west it should be on the mild side and unsettled, transient ridges may bring a very mild few hours but nothing like what the ECM had previously suggested.

 

[bluearmy]

17 hours ago, snowking said:

Thanks for clarifying Nick, appreciate the ECM website data only runs out to week 4 in the main, but seemed too be too much of a sudden switch from what was being shown at week 4 to then be a raging +NAO - sounds like back to standard autumnal fare (which is what is probably to be expected at week 5 with a move back towards climatology)

 

17 hours ago, Allseasons-si said:

Now that is a long way off Blue

Don’t get me wrong - I wouldn’t be surprised to see it change again for the back end ......the AO/NAO charts weren’t quite a complete write off with a small decently negative grouping. 

just commenting on what the run showed ..

[Frosty.]

I gotta say, this looks absolutely stunning from the GEFS 0z mean for the time of year (early nov for gawd sake)..whether it verifies or not!!!!!

Edited October 24, 2020 by Jon Snow

[Methuselah]

Toasty, toasty; very, very toasty! 

    

[mushymanrob]

Just now, General Cluster said:

Toasty, toasty; very, very toasty! 

    

thats a bran flakes advert from 1984!

[E17boy]

32 minutes ago, General Cluster said:

Toasty, toasty; very, very toasty! 

    

Morning peeps

Hope everyone is keeping well. I have not posted here for a while but being a coldie my season is about to start.

looking at that chart I was saying dear oh dear there is no sign of anything cold developing just yet. But I am glad this pattern is showing up now rather than when we enter winter proper. I rather get all the mild weather out of the way now rather than seeing this in December or January . Like a lot of you I have waited this whole year for winter to start and now time is getting closer. I do hope that we at least get a few snowey days, as I have promised my nephew and neice I will definately take them out and we have been saying this since last winter.

With our little island it's so hard to even predict what will happen in a weeks time. I know as we go through November the minds of us coldies will be focused on how the building blocks are getting together, as it is this jigsaw if just right can deliver the cold and snow. I will be looking at how temperatures are doing in the east and north of us and also if any high pressure starts building. That said the weather will do what it has to unfortunately it's not in our control but we always live in that hope that maybe this winter.

Apart from the weather there are a lot more other things that has worried us this year and with Covid still on the scene does not look as if things will get better any soon. I hope you and all your families stay safe and sound and we all get through this storm.

take care all for now

stay safe 

kind regards

[Frosty.]

Yeah, stay safe guys..pfft..lol..anyway, the Gfs 6z op does eventually settle down..,I have a feeling in my water (approx 60 percent) that early nov will see a more settled spell?!

Edited October 24, 2020 by Jon Snow

[Frosty.]

Hmm maybe I’m too drunk...who really knows ?..but I’m seeing positive signs from the GEFS 6z.. omg.,1035 mb..bank,,bank..

Edited October 24, 2020 by Jon Snow

[Frosty.]

Jeez Louise, all I can say is early nov looks more settled than the next week or so according to the GEFS 0z/ 6z mean..fingers crossed gang!,..hiccup

Edited October 24, 2020 by Jon Snow

[Allseasons-Si]

Well there isn't much to discuss about the models this afternoon/evening as they look to be a standard affair with a NW>SE split with the best of the dryer sunniest weather in the SE and unsettled further NW as per the latest Met musings too

typical autumn weather really but i hope this pattern becomes unstuck as we trickle into the winter months 

stay safe all and try to enjoy the rest of your evening

laters. 

[I remember Atlantic 252]

still chance of Decent temps though, away from NW

[stodge]

Fairly predictable early autumn fare as others have said but broad signals for a rise in pressure into November with the HP ridging through the British Isles so a period of settled conditions lasting 7-10 days looks likely in the early part of next month. 

[Frosty.]

Wow so quiet in here, anyone would think winter was over or something????...lol,anyway, there seems to have been a few spanner’s thrown in the works regarding a settled extended outlook but there is still some support for an anticyclonic early November according to the GEFS 12z mean / perturbations!

Edited October 24, 2020 by Jon Snow

[Mike Poole]

Start of November by ECM, GEM and JMA:

ECM most favourable for the scandi Russian block.  But all models low heights on the other side of the NH and some semblance of higher heights over Russia. It’s just one to watch now, and how it impacts on the strat vortex, which at the moment is gathering momentum:

Hope the trop patterns evolve further to put more pressure on the vortex during the next month.  

Edited October 24, 2020 by Mike Poole

[Allseasons-Si]

1 hour ago, Don said:

No such thing as winter anymore.....

Course there is but which year ???

come on we are barely into autumn 

anyway,long post coming up:-

back to model viewing,i have an inkling that if we get a hp cell parked near or over the UK there is every possibility of it shifting west in time to allow for more of a polar maritime influence,i say this because the mjo is heading into the favorable phases of 7-8-1

gefs and ecm to a lesser extent as always because it's legs only go out to day ten

the only problem here is that they are not amplified enough(away from the cod)(circle of death) to diminish a full on zonality to become more amplified and meridional if you know what i mean,IE:- more amplified,the more meridional(red arrows)

here is an illustration of the jet in zonal and amplified modes-

to get the amplification you will need wave breaking,wave breaking is the break up of low pressures at an extent where high pressure forms in between lows sufficient enough to break the chain of the lows,this in turn causes amplification between low's and then a buckle effect is then created in the jet stream

the NAO/AO(North Atlantic/Arctic Oscillation)  are pretty much in the same family as to what drives our weather in the NH(NORTHERN HEMISPHERE),sos for the caps lol

at the moment the NAO/AO are at a neutral phase and are forecast to become slightly positive,this in turn enhances the zonality of the weather patterns

CPC - Climate Weather Linkage: Teleconnections

WWW.CPC.NCEP.NOAA.GOV

as you can see the AO is going into a positive territory,this in turn ramps up the pv from it's wake and sets the turn for a more zonal westerly regime forcing the NAO to aslo drive west

what we want is a -NAO/AO(dream scenario) but a -NAO can work as long as there is sufficient amplification in the Atlantic to slow the jet stream and become negative and buckled(meridional)

as you can see below,here are the 10/30 hpa temps over the north pole

Climate System Monitoring / TCC

DS.DATA.JMA.GO.JP

---

Climate System Monitoring / TCC

at the top of the strat the temps are colder the the average mean(grey line),this is quite normal,this is what i will always monitor going into the winter months

if you get an uptick like this going into the winter months then this signals a SSW(sudden stratospheric warming)

not all SSW's will result in a cold winter in the UK as we have found out recently(cannot remember the year)but favor more blocking and colder weather to push further south out of the pole into the mid latitudes 

sorry for the long post,i just got a bit bored,i wish that i didn't book/waste this week off work but my OH was in hospital until thursday this week with a stomach hernia so it has been hard going,she was tested three times over the ten days in staying in hospital for COVID-19 and all came back neg which is great news,i don't want to derail the thread but this year has been a testing time to say the least

i feel this winter has a more traditional feel to it,maybe just me but we do have some puzzles of the jigsaw in our favour:-

La nina(not to strong) -1.5 will do

solar minimum(time lag)-1-2 years

-IOD(a lot better than last year)-what a crap year that was

and lastly-QBO,GET A GRIP

and that is it,let the cat face the flap(Paddy Mcguinness)

night all and stay away from covidiots

 

 

 

 

 

[Weather Enthusiast91]

7 hours ago, Jon Snow said:

Wow so quiet in here, anyone would think winter was over or something????...lol,anyway, there seems to have been a few spanner’s thrown in the works regarding a settled extended outlook but there is still some support for an anticyclonic early November according to the GEFS 12z mean / perturbations!

Roll on the cold and crisp sunny days, which hopefully aren't too far away.
 

Edited October 25, 2020 by Weather Enthusiast91

[Weather vane]

Below are the 144hr for Gem, gfs, ecm, icon, ukmo. Cant see how we can get from these to a settled spell for beginning Nov. Atlantic too active and no blocking that could help.

 

[Weather vane]

Here"s the 192hr charts (apart ftom Icon which is 180hr). There is effort to build in hp in some, but form horse would be less settled than more settled IMO. (at least in Ireland where I'm based).