Model output discussion - Winter approaches

[Benny123]

 

[Methuselah]

Looks like the bog-end of the GFS 00Z won't verify... surprisingly enough, the cold pool over near Scandi has completely disappeared... Poof!

    

[Tim Bland]

it’s not great but I’ve seen worse. Look how far west the Azores high is pushed, a clearance of the PV over the north west and the angle of the jet stream...

[Methuselah]

So, I thought I'd have a peep at the T850 ens... and, wow, they look bad... But, always  remember -- the trend is your friend!

[blizzard81]

Anybody got any predictions for the 12z's? More of the same? Upgrades? Or worse than what they are already showing?

[KTtom]

32 minutes ago, General Cluster said:

So, I thought I'd have a peep at the T850 ens... and, wow, they look bad... But, always  remember -- the trend is your friend!

I'm afraid it does look like the chances of a settled spell most are craving and was being heavily backed by the Met are now slim to say the least. The models pretty much backing off any pause in the Atlantic onslaught, and now the Met also have totally re-written their forecast up to mid December. Hopefully, due to the strength of the jet the rain will move through quicker than it  has done for the last few weeks! 

[StretfordEnd1996]

It may not be much but the GEM at least is acknowledging here that December 1st marks the first day of the metrological Winter..

 

[Anthony Burden]

Met office did not wait long to change their 6 to 30 day U.K. forecast.

changeable to at least mid December.Reboot Glosea required.

[TSNWK]

33 minutes ago, Anthony Burden said:

Met office did not wait long to change their 6 to 30 day U.K. forecast.

changeable to at least mid December.Reboot Glosea required.

Oh! With one strike of the met office pen   it's all cleared up for the next month.. if only it was that simple.. so much to learn still and it's the lack of certainty that makes this enjoyable as well.. let's not write of the next 4 weeks. 

A mantra I use is reasonable detail up to around day 6 with a pretty fair but fading  indication of trend and broadscale out to day 14.. beyond that is guesswork and what fish wife Aunt Nelly thinks... 

Edited November 20, 2020 by TSNWK
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[Frosty.]

Hmmm, been away for a wee while ( dads very ill again!)... but I’m still seeing high pressure in the ascendancy during early December ( exact position / orientation unclear at the time of writing ) ?...no guarantee of course?... but that’s what the GEFS 6z mean indicates at the very least..as for the brief wild northerly blast..cough cough!, preety pathetic wasn’t it!?.!!

Edited November 20, 2020 by Jon Snow

[swfc]

1 hour ago, blizzard81 said:

Anybody got any predictions for the 12z's? More of the same? Upgrades? Or worse than what they are already showing?

I'm going for a stronger pressure rise threw to Iceland and a major slide sse of low pressure. Mabye a epic fi

[TSNWK]

Just now, swfc said:

I'm going for a stronger pressure rise threw to Iceland and a major slide sse of low pressure. Mabye a epic fi

I'll have the same please landlord!

[KeegansPerm]

3 hours ago, jules216 said:

It probably applies more to America then us first = Pacific jet behavior. EC has very weak MJO but there are discussions on twitter that models are not seeing propagation trough maritime continent which may happen. For us any effect would be felt if MJO is to continue through western Pacific in to phase 7 at least to induce enough of a Rossby wave train to help promoting blocking to the north = raising AAM momentum. But the interference of La Nina easterlies may not help. That is why there was a debate about EP La Nina being better then CP La Nina. With CP La Nina it is unlikely that MJO would be favored to enter phases 7 and 8. With this configuration at the moment we have a hybrid Nina with ENSO region of 4 seen a slight moderation in recent weeks, but note sure weather overall easterly tropical element will permit MJO to effect European weather regimes. 

But perhaps if EC long range has initialized MJO parametres wrong then their zonal 46d would be probably wrong, that is the hope. Any MJO infuence may only be seen after Dec 10 in weather models. 

There is a known difficulties with NWP in the Austral Summer / Boreal Winter regarding the MJO propagating from the Indian Ocean across the Maritime Continent into the the West Pacific. Which is based around zonal and meridional moisture gradients, some events are blocked and do not cross the Maritime Continent, while others are able to cross in the Western Pacific.  Generally strong MJO event are able to achieve better premoistening across the Maritime Continent (promoting an E'ward movement of convection), and have a greater chance progressing into the Western Pacific. 

I've popped a few model graphics below to show the MJO across the Indian Ocean on the 16th Nov where you can see the amounts of moistening ahead of the  convection max which we can roughly infer from the zone of enhanced 850hPa westerly winds, and as this enters the Maritime Continent on the 22nd in GFS there is significant areas showing negative precipitable water anomalies and not showing a great environment of pre-moistening (on both GFS and GEFS) and hence unlikely propagation of a marked MJO into the Western Pacific.  

As a result in this case from the GFS and GEFS data I can see, I would suggest the MJO will likely get blocked and not make it to West Pacific, much as shown by EC and GFS Wheeler and Hendon plots.

[mountain shadow]

1 hour ago, Anthony Burden said:

Met office did not wait long to change their 6 to 30 day U.K. forecast.

changeable to at least mid December.Reboot Glosea required.

Yes, it was obvious it had to change.

There goes the first couple of weeks of Winter.

[swfc]

1 hour ago, TSNWK said:

I'll have the same please landlord!

Looking at the icon my initial thoughts may have been a tad optimistic but steady as she goes

[Scandinavian High.]

Don’t worry guys jma as got this new signal for colder start to December what’s the betting as soon as meto drop the colder outlook and models pick it back up again..

[Ols500]

8 minutes ago, abbie123 said:

Don’t worry guys jma as got this new signal for colder start to December what’s the betting as soon as meto drop the colder outlook and models pick it back up again..

would be nice lol

[Froze were the Days]

1 hour ago, mountain shadow said:

Yes, it was obvious it had to change.

There goes the first couple of weeks of Winter.

We were never going to experience anything too cold going into December...they've been generally poor since the epic 2010 and also BFTP (Fred) forecast it to be fairly cold...so 

[swfc]

Altho the 12z gfs would appear slightly rancid for the UK there are still Heighths towards svalbard . Also decent ridge existing the esb. Bit of a straw clutch but beggers can't be chooses I guess hmm il get my coat

Edited November 20, 2020 by swfc

[blizzard81]

21 minutes ago, abbie123 said:

Don’t worry guys jma as got this new signal for colder start to December what’s the betting as soon as meto drop the colder outlook and models pick it back up again..

Isn't that the cfs?

[swfc]

17 minutes ago, Froze were the Days said:

We were never going to experience anything too cold going into December...they've been generally poor since the epic 2010 and also BFTP (Fred) forecast it to be fairly cold...so 

Yes looking at all output the dry cyclonic November touted has all but gone and a front loaded winter isn't looking on the cards. My optimism seems pointless

[Frosty.]

Here comes the high..yay...oh wait a minute, Thu..that’s yesterday’s Gfs 12z op isn’t it..?..oops, my bad..I’m still new to all this you know!

Edited November 20, 2020 by Jon Snow

[ICE COLD]

The models are very poor for a cold and snowy outlook or even frosty . The meto update has changed for the worse . I see N America goes fully into the freezer in FI . Seems to happen every winter now while we just stay mild , wet , windy and a few cool days now and then yawn . Same year in year out now . 

[georgiedre]

2 minutes ago, ICE COLD said:

The models are very poor for a cold and snowy outlook or even frosty . The meto update has changed for the worse . I see N America goes fully into the freezer in FI . Seems to happen every winter now while we just stay mild , wet , windy and a few cool days now and then yawn . Same year in year out now . 

It looks like a plume pushing up the west coast of greenland.. would this not result in higher pressure in the greenland-iceland area???

[Ols500]

7 minutes ago, ICE COLD said:

The models are very poor for a cold and snowy outlook or even frosty . The meto update has changed for the worse . I see N America goes fully into the freezer in FI . Seems to happen every winter now while we just stay mild , wet , windy and a few cool days now and then yawn . Same year in year out now . 

Can anyne explain how this happens? I get canada is close and all but thats not the reason... Why does the jetstream dip southwards there, I can only think of HP around alaska and a big trough consequently following southwards? Im a noob so thats probably wrong!