Model Output Discussions 12z 01/09/2016

[Daniel*]

Stunning UKMO I'll have what it's drinking. Something definitely feels different in the air, to see a chart like at day 5 is a miracle in itself, irrespective of the outcome. Polar vortex 6 foot under, let's hope it stays in long somber. 

[SMU]

22 minutes ago, Mucka said:

JMA didn't go for it either Steve, even less so than GEM.

This afternoons runs seem to want to undercut the low I highlighted as a key player in the mid term earlier - UKMO is an extreme example but it has probably been most accurate out around 120 for our neck of the woods over the last few days.

Plenty of model wobbles, would of been an exciting (excruciating) watch in mid winter. 

 

Edit.

For noobies, just to compare Northern Hemisphere GFS 12z with undercut to 06z with little/no undercut to illustrate what I meant about increased prospects for sustaining MLB/HLB blocking through early Nov. 

How many times in the Undercut scenario has the UKMO 120 - 144 trumped the ECM / GFS

loads recently - !!

I expect that the tilt on the low is to negative at 120 but even vertical is fine - so lots of breathing space...

GFS to positive as usual on forward momentum!

[feb1991blizzard]

A stonking end to GEM in prospect.

[northwestsnow]

Well im not snow chasing just yet

But im looking at all that cold building to our east/north east on the 12z GFS.(day 10)

An early season easterly might produce for the UK if the blocking transfers to the North east (scandy) down the line ...:)

[Mucka]

1 minute ago, Steve Murr said:

How many times in the Undercut scenario has the UKMO 120 - 144 trumped the ECM / GFS

loads recently - !!

I expect that the tilt on the low is to negative at 120 but even vertical is fine - so lots of breathing space...

GFS to positive as usual on forward momentum!

 and UKMO was the first to go with a flatter jet against the other output when the Greenland high was being programmed so it has beaten the other models both ways so far this Autumn. 

I think you are probably right about UKMO overdoing things here and GFS being over progressive (though perhaps correcting?) - either way they are back trending in the right direction. 

[bluearmy]

Probaly won't be of any consequence but noticing a TS development in the Pacific nw at the back end of a few GFS op runs.  The aleutian low seems powerful enough  but some extra tropical air would be nice to see if we could get it into the system. 

[Severe Siberian icy blast]

Quite a startling set of models so far this evening,  the vortex is in absolute tattors litterely none existent it could be the middle of July looking at the northern hemispheric set up, I'm certain their will be ramifications as head into winter, November is a critical month for the vortex and to have such an assault on it this early can only be good for those looking for cold into mid lats, the knock on effect and trop feed back can really have a habit of reoccurring over one season, a bit like our second half of summer and into sept , we consistently saw the Azores high throw ridge after ridge into the south of uk giving plumes as it moved into Europe, this winter is getting more exciting by the minute. Can't wait. . . 

Edited October 25, 2016 by Severe Siberian icy blast

[Mark Neal.]

ECM at 7pm will be interesting i feel! The 12z suite (UKMO,GFS,GEM) shifting once again towards greater heights towards Greenland and especially Scandinavia. 

[Frosty.]

More cold Gefs 12z perturbations..

[knocker]

No huge change in the GEFS upper pattern this evening with Aleutian low, trough eastern Europe ridging mid Atlamtic and into the Arctic as WAA continues So we are still looking at an NW/W upper flow and the key question remains precisely where the ducking and diving takes place when systems swing around the HP and then SE. In the later period with an increase of amplification and flow more N we could be looking at a cooling down with temps below average and more chance of some wintry weather.

Edited October 25, 2016 by knocker

[Frosty.]

Further ahead, the GEFS 12z mean / perturbations show more arctic incursions..some stonking charts popping up which is so unlike this stage last autumn which was absolutely dire looking towards winter, but much more positive vibes this time..especially regarding the MO outlook for November which indicates winds predominantly from a NWly / Nly point. 

[MR EXTREMES]

well ecm is identical to the ukmo at 72hrs 

got feeling the ecm going to be a club banger tonight

Edited October 25, 2016 by MR EXTREMES

[I remember Atlantic 252]

14 minutes ago, MR EXTREMES said:

well ecm is identical to the ukmo at 72hrs 

got feeling the ecm going to be a club banger tonight

yes, 96 hrs though could be good? but feel cloudy, lucky spots with any sun (south) may see 20°? certainly not here though

[Frosty.]

The Ecm 12z goes for an Indian summer..BBQ time this weekend with summer like charts!

And the warm benign conditions last through the first half of next week too..exceptional!

Edited October 25, 2016 by Frosty.

[feb1991blizzard]

Wait for the 240 ECM, could be exceptional.

[January Snowstorm]

We've seen this before where the models initially go with blocking......back down.....and then suddenly switch back again!!

Awesome ECM aswell, synoptic wise

[MR EXTREMES]

getting close tho nice to see ridge up in the atlantic

[Matthew.]

Yes Frosty. Fog potentially on Sunday under light winds and the SW have some impressive uppers:

[Summer Sun]

Colder air moving south at t216 question is where will the low to our south west end up

[weirpig]

1 minute ago, Summer Sun said:

Colder air moving south at t216 question is where will the low to our south west end up

Surely south east. Then the flood gates open 

[pip22]

3 minutes ago, Summer Sun said:

Colder air moving south at t216 question is where will the low to our south west end up

That low has to go east because there is High pressure to the south, north and west.

[Summer Sun]

The low opens up a north easterly flow at D10

[Mark wheeler]

The first running commentary of a run this winter oh hang on its still Autumn.

[feb1991blizzard]

I will take that, lovely run, in fact a lovely afternoon suite of runs all round, make no mistake we are right in the game this year for a good run of cold before xmas.

[Frosty.]

So..the Ecm 12z goes for summer like weather this weekend and first half of next week and ends with wintry weather on the way and completely skips autumn..and the clocks fall back this weekend. who said the British climate is boring