Model output discussion - heading into 2018

[Summer Sun]

UKMO extended wet and windy UK wide

[feb1991blizzard]

EPS extended just about as bad as it gets.

[N/A]

6 hours ago, Draig Goch said:

Swansea GEFS 6Z: turning colder again next week, wet and windy at times (nothing stormy showing atm) but the main difference is we should see more in the way of sunshine after this drab cloudy even foggy weather we've had and continuing to have. Rain could hold off until late afternoon on Christmas Day, rain clearing to showers Boxing Day and the chance of a dry day on Wednesday so not too bad. 

GFS 12z keeps that temporary cooling down theme too, max 9C Boxing Day, 7C Wednesday and Thursday before turning milder again on Friday 11-12C 

[Ice Man 85]

I posted on the page before that maybe the proverbial fat lady had come down with laryngitis...

Now I see she's reaching for the strepsils...

[Borei]

4 minutes ago, feb1991blizzard said:

EPS extended just about as bad as it gets.

A descriptive narrative really would be helpful please. 

[mulzy]

10 minutes ago, feb1991blizzard said:

EPS extended just about as bad as it gets.

To be honest, they seem to a little troughy again (cf this morning) through the UK in the day 13-15 period. The clusters will reveal more but I would not call the ext eps “as bad as it gets”.

Edited December 22, 2017 by mulzy

[ACCOUNT DELETED]

7 minutes ago, Dafydd Tomos said:

GFS 12z keeps that temporary cooling down theme too, max 9C Boxing Day, 7C Wednesday and Thursday before turning milder again on Friday 11-12C 

Yes it does look to be temporary, GEM has early indications of widespread 13C across southern UK for New Year's Day with a plume of 10C @ 850mb across NW France! 

[feb1991blizzard]

11 minutes ago, mulzy said:

To be honest, they seem to a little troughy again (cf this morning) through the UK in the day 13-15 period. The clusters will reveal more but I would not call the ext eps “as bad as it gets”.

Low anomaly to the NW - high anomaly right across from the SW to the SE, not even much hint of cold zonality on their - probably not exceptionally mild but very snowless for most of the country if I were to be issuing a forecast based on that chart.

[Ice Man 85]

1 minute ago, feb1991blizzard said:

Low anomaly to the NW - high anomaly right across from the SW to the SE, not even much hint of cold zonality on their - probably not exceptionally mild but very snowless for most of the country if I were to be issuing a forecast based on that chart.

At this point, I'd settle for average. Need to see if the gfs 18z run follows the 12, but I'm not holding out much hope.

[ACCOUNT DELETED]

2 minutes ago, Dafydd Tomos said:

Wow, who knows it might be the start of Spring before Winter briefly returns in April   

Could be but at the same time, GFS 12z has a max of 5C on NYD so a big difference!

[bluearmy]

1 hour ago, Ali1977 said:

The latest ECMF weeklies showing heights around Southern Greenland and poss accross to Iceland week 2, not sure how good accurate these can be!!

Difference from previous run - it just shows a slightly less deep low anomoly in that position than the last run ! 

[Frosty.]

In a nutshell, looking at tonight's Ecm 12z ensemble mean...I can't see any proper mild weather after monday (christmas day)..next week becomes progressively colder from the n / nw with an increasing risk of wintry ppn, especially further north and on higher ground with significant snow in favoured upland spots and overnight frosts / icy patches..thereafter, it stays unsettled and although less cold than next midweek, not mild as such.

[Day 10]

1 hour ago, northwestsnow said:

Well i would love to discuss the 12Z EC tonight but unfortunately the wife is getting a bit miffed with the amount of time i spend looking at the models.

Hope the GFS/EC are going to arouse some interest!!

As long as it's weather models she should be fine. 

[bluearmy]

Finally the eps manage to find more than 10% scandi high mslp by day 15. Judging by the position at day 14 it would be nearer 10 than 20 % !!

with the anomolys less marked on the latest eps, I'd say the uncertainty as week two progresses is growing 

[knocker]

20 minutes ago, Borei said:

A descriptive narrative really would be helpful please. 

The 10-15 mean anomaly has a negatively tilted vortex back over N. Canada with a trough down the east seaboard and another south east over southern Greenland. Thus a strong westerly upper flow leaving the eastern seaboard south of the trough across the Atlantic portending a continuation of unsettled weather over the UK with temps around average. The usual caveats apply. Not a million miles away fom NOAA and the GEFS

[Paul_1978]

42 minutes ago, feb1991blizzard said:

EPS extended just about as bad as it gets.

Any charts then?

[feb1991blizzard]

7 minutes ago, Paul_1978 said:

Any charts then?

I wont post those charts because I'm not sure they are supposed to be for the general public but see knocker's post for an accurate description.

[ANYWEATHER]

Evening ! If I was to sum up the models tonight headlines would be " Cold Zonal " weather from Christmas onwards . No detail in the forecast , but expect some stormy weather at times but also cold enough for snow ,well at least for some even down south , be glad for you coldies that the synoptics look great for just about everything Winter has to offer ...Watch This Space....

[Daniel*]

The mighty GEM takes the sliding low much further S tracks it through channel / northern France. Can there be a Christmas miracle albeit a late one for us down south? 

[Allseasons-Si]

So some oppertunities for snow the further north you go looking at the latest from ECM and GFS as we go into the festive period with cool/cold pm shots, lows tracking further south,possible sliders in the mix,ok not a full on cold spell but plenty to talk about this week and hopefully beyond

ECM  preasure and 850's from t96 looks quiet cool apart from day nine with a brief milder day then a return to cooler/colder weather by day ten

the gfs from early Wednesday morning could be of interest as a low tracks across the country through the midlands and on it's northern edge could produce some good snow accumulations,i know this is IMBY'ism but this is not a done deal yet and could track further north or south so one to watch

pressure,850 temps,2m temps,dew points,total snow depth,dam,snow and ice and ppn type

from weather2 rain and snowfall charts latest gfs

http://www.myweather2.com/synop/player.aspx?synop=2

Mean pressure and height anomoly's from ecm and gfs at 240 hrs shows a cool/cold westerly flow and hints of a siberian ridge developing(one to watch)

latest from the 8-14 day 500mb outlook from the NOAA shows a block developing too over siberia/Russia

latest NAO/AO

so over to you 18z gfs

 

 

 

 

 

 

Edited December 22, 2017 by Allseasons-si

[Allseasons-Si]

The 18z icon has the low further south than the gfs 12z so more southern areas might have a chance of snow

[Catacol]

11 hours ago, Interitus said:

Three words - "Extratropical MJO initiation".

The simple assumption that the tropics drives everything is false, in particular the role of the extratropics in firing up or dampening down MJO phases seems to be totally ignored.

It might pay for you to read a post a little more carefully Interitus. I was making no comment on causes of tropical signature decline so to assume I know nothing of potential extra tropical origins of such is to overstep the bounds of your considerable intellectual bravado.

You might wish to go and read up further on the concepts behind the GWO -it might prevent any further posts suggesting a lack of understanding.

[bluearmy]

5 minutes ago, Allseasons-si said:

The 18z icon has the low further south than the gfs 12z so more southern areas might have a chance of snow

Pretty much the same as its previous run - possibly a tad further north actually! 

[Allseasons-Si]

3 minutes ago, bluearmy said:

Pretty much the same as its previous run - possibly a tad further north actually! 

I didn't look at it's earlier run BA,so sorry for that but i was comparing it to the latest gfs with it being further south.

Edited December 22, 2017 by Allseasons-si

[Allseasons-Si]

Not much difference at 144,the trough to the NW of the BI is a little bit more negatively tilted from 120 to 144,but we need that little wedge of heights to the north of it to grow a bit more but doesn't on this run.

Edited December 22, 2017 by Allseasons-si