Jump to content
Sign in to follow this  
Paul

Model output discussion - late November

Recommended Posts

The ec mean for days 9/14 with the same sig as the gefs re the vortex centres .... I’m tempted to restart my weatherbell membership to try and get a handle on where we may be headed 

Share this post


Link to post
Share on other sites
1 minute ago, Mattwolves said:

Nothing quite like some deep FI cold to warm the cockles of the heart! Plenty of colder options from the GFS 12z moving forward... I certainly don't see a bang on very mild zonal set up at this stage... That could all change of course, but it's not the worst case scenario so far... Expect upgrades before much longer folks... Inside Info... 😂

gens-0-0-372.png

gens-0-1-372.png

gens-3-0-384.png

gens-7-0-336.png

gens-7-1-336.png

gens-10-0-324.png

gens-10-1-324.png

gens-11-0-384.png

gens-12-0-348.png

Some great charts in there - most of which as I alluded to before are perhaps more 'temporary cold' situations with the winds in from the N/NW all as toppler scenario's - now my opinion on those types of setups is 'thank goodness we're not experiencing mild SW'lies' rather than 'Hating these rubbish PM incursions - where on earth is the freezer from the East' !

Share this post


Link to post
Share on other sites

For me there's a trend the last few years of height rises in and around Greenland during late Autumn. Quite likely to be caused by the Summer melt etc. Of course quite like last year this has very little bearing on Winter proper. Indeed I think November last year was colder than any of the Winter months (over here anyway) The same happening again is possible I guess.

Time will tell but for now a zonal reset of sorts looks the favoured option. (Zonal as in the pv setting up over Greenland) How long it will last is anyone's guess.

Edited by January Snowstorm

Share this post


Link to post
Share on other sites
18 minutes ago, feb1991blizzard said:

No, they are 850's Its an Easterly packed December (admittedly quite dry at times but no doubt there would be enough snow to make it a stonker in places)

Here is the link for the whole run.

WWW.METEOCIEL.FR

Meteociel propose le modèle deterministe GEM

 

Noted - thought it was a pressure map. Apologies

Still don't like anomaly charts though!

Share this post


Link to post
Share on other sites

Whilst the ec mean at day 10 looks scary, there are plenty of options in our area, especially to our ene 

CF3156E3-B309-406B-B9D4-32115D63E5FA.thumb.jpeg.0cfa80e577d76c7f523c158093b8be3d.jpeg

Edited by bluearmy

Share this post


Link to post
Share on other sites

Looking at models, in particular the gfs ensembles, I'm seeing plenty of opportunities for cold weather through the first half of December, even with a zonal setup. 

The models could genuinely be a lot worse with raging southwesterlies for the next two weeks

Share this post


Link to post
Share on other sites
10 minutes ago, Catacol said:

 

There is very little value in a 240h ensemble mean like that on its own. It tells you nothing as to what is happening in the tropical Pacific, nothing regarding forcing in the stratosphere and therefore is about as much use as judging the speed of a car by the colour and shape of the bonnet.

There seems to be a lot of gloom in here this evening. I’m not sure why. The Atlantic pattern at our latitude is impacted by upstream forcing from the Pacific and the potential impact of wave flux into the stratosphere which can work its way through the layers. Early December sees the vortex intensify towards its seasonal highpoint every year, and the Pacific convection cycle has just returned to the Indian Ocean meaning less obvious support for high lat.blocking. In short we are approaching the time of year when we are least likely to achieve a reverse flow or an increase of blocking even in a year of greater ENSO activity and in 2019 the Pacific has aligned It’s cycle in such a way as to reduce those chances still further. There is a lot of debate out there as to whether we are really locked into a weak ENSO winter or whether in fact the MJO will remain active. Jury is out - slightly above my experience/knowledge base....but the fact that there is a debate about it shows uncertainty.

So ride out this early December mobile signal (which was always likely) and wait for the current phase of wave 1 warming to impact/stress the vortex while the Pacific fires up again later in December. Then we will see what we will see. We are going to need to be mostly patient for 2 more weeks, though we already know that next week is not without cold interest and the fact that Greenland appears to be less keen than usual to give up its high pressure signal still means that an absolutely flat Atlantic profile out to mid month is far from certain.

All good. I’ll post some charts and data later...

Agree with that @Catacol, the post of mine you quoted was tongue in cheek, I think a lot of people in here expected a return to a more zonal pattern in December, but were interested also in reasons why that might not happen.  It now looks the form horse, but what happens a couple of weeks later is still anyone's guess.  We will see...

Share this post


Link to post
Share on other sites

ICON toppling less fast on 18z T120, than 12z T126, 18z first:

image.thumb.jpg.eacf254181885bf116c2365338b92c06.jpgimage.thumb.jpg.82cbb6eb928422121a539efc62683b98.jpg

Actually, sorry about that, my posts have been infused with negativity tonight...and breathe...will be back to my usual self in a little while!

 

Edited by Mike Poole

Share this post


Link to post
Share on other sites

Mike its not just about the toppling 

look at the 18z again its the ridge extension to Iceland as well.

Share this post


Link to post
Share on other sites

Uppers hovering around -4 to -6 for many this weekend according to the ICON 18z

image.thumb.png.0105440f98a80acb8ec723bf59c0f34d.png

Share this post


Link to post
Share on other sites
1 minute ago, Steve Murr said:

Mike its not just about the toppling 

look at the 18z again its the ridge extension to Iceland as well.

I agree. If we can get enough negative tilt on that low SW of Greenland it could be game on for some WAA going up Eastern Greenland. One can hope I guess lol! 

Share this post


Link to post
Share on other sites
31 minutes ago, Steve Murr said:

Mike its not just about the toppling 

look at the 18z again its the ridge extension to Iceland as well.

I see that now Steve, thanks. 

But here is the thing, takes long swig of cider!  (Indication of possible nonsense to follow).

I strongly believe that the models beyond the usual reliable, and certainly the long range ones have been all at sea for months, and I think, and there is at least one research paper to back this up, that the models don't get all the impacts of solar minimum, and this one is more minimal than the last one.   

At least this months CP forecast did cite two reasons for a colder outlook, yes, solar minimum and tropical rainfall in Atlantic? Again, new one on me, I've only just got accustomed to the Indian Ocean Dipole as an actual thing.  But the probability favoured mild, but it is mostly model based...

I think there is a fairly small chance of developing a decent cold start to December that has legs, but the models all but snuff it out, but I don't trust the models.  Longer term there is potential.  So we will have to wait and see... 

 

Edited by Mike Poole

Share this post


Link to post
Share on other sites

The far southwest of England could see some rain for a short time on Saturday from that low to the southwest of the UK and there is likely to be a strong southeasterly wind for southwestern areas which with increasingly cold air pushing down from the north will make for a rather cold feeling day as this low slips to the south of the uk. 

Saturday 6pm..👇

1000155533_EUROPE_PRMSL_102(1).thumb.jpg.c230cb9f63815f62a749bd813574e697.jpg

Sunday 6am..👇

858512254_EUROPE_PRMSL_114(2).thumb.jpg.8aa2050b90919fcc61d3da9b367eeca3.jpg

EUROPE_PRMSL_144 (2).jpg

Edited by jordan smith

Share this post


Link to post
Share on other sites
1 minute ago, I remember Atlantic 252 said:

hopefully going like EC, great but very unusual start to Dec, could it really be dry?

gfs-0-150.png?18

Can happen more often than you might think. Some recent examples... even 2013 had a dry start! In fact, that chart you've posted doesn't look too different from 2014, whose cold predominantly came from chilly high pressure, especially towards the end.

archives-2016-12-1-12-0.png archives-2014-12-3-12-0.png archives-2013-12-2-12-0.png 

Share this post


Link to post
Share on other sites

I think this is point that the trop polar vortex, becomes the enemy, GFS 18z T186, although of course...it hasn't happened yet:

image.thumb.jpg.9b5edf09008eb2ca92edf6b0b8945bcd.jpg

Yes, we're looking to the strat now!

But really good wolf in a trilby in the above chart.  Dandy.

Actually, I've no idea what sort of hat that looks like! I'm not a hat expert. 

Edited by Mike Poole

Share this post


Link to post
Share on other sites
6 hours ago, lassie23 said:

 

Pretty consistent GFS from the 12z and 18z this evening.pv saying hello again

Share this post


Link to post
Share on other sites

The more the HP pulls away SW the better imo, floodgates for pM then aM air to bathe the whole country with anticipated displaced PV to our NE.  I think Carinthian’s local team suggested this as a route they were looking at too

 

BFTP

Edited by BLAST FROM THE PAST

Share this post


Link to post
Share on other sites

A few dry days and the deluge starts again

image.thumb.png.c39a4db3a87113e65b151ff8500bf57a.png

The azores high is trying to move its backside towards the far north of Canada though. Polar NW'ly to follow perhaps, as per the Met Office outlook

Share this post


Link to post
Share on other sites

Mehh .. not nice looking charts out towards D7-10.. 

image.thumb.png.6d21fd41fbc61d8201ebcd3514c76e1c.png

But hey every chance for twists and turns

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×
×
  • Create New...