Model Output Discussion 1200 hrs 15/11/14

[carinthian]

Latest ECM and UKMO models almost the same at 144hrs. Thereafter,the ECM becomes very progressive and note the total collapse of the Russian Block from 1045 mb to almost non existance in the time frame 144hrs -240 hrs. Here lies the doubt in the model forecast. The block will not disintegrate at that rate. So I think the forecast past 144hours remains in doubt with a high percentage.

C

Edited November 18, 2014 by carinthian

[Jason M]

Just to highlight the uncertainty re surface conditions for this weekend.

Similar to if we were in the depths of winter and there was a cold front heading east and hitting the block. The bigger picture has more confidence than the weekend's detail:

http://www.bbc.co.uk/weather/feeds/30105755

 

 

That's a really good video link!

 

Everyone's different in here, but looking out beyond day 7 I tend to just look at the ensembles and see if there is a trend. I treat the main runs beyond this point as just another ensemble run. The last set were again inconclusive  . I'm not a big fan of the 'means', so I tend to just pick two points in time and look across all the runs (at present 192 hours and 240 hours).

[swfc]

Better push here from the south west pressure wise at 120 hours on the 18z.Looking across the board possibly just delaying the push  from the atlantic but it is a diff approach on this run.haha pv moves into northern france!!!!next stop for the jet north africa in fi lol

Edited November 18, 2014 by swfc

[on the coast]

Yesterday's output exhibited sufficient deep lows within EC and MOGREPS postage stamps for UKMO to caution (in their briefing issued last night) about some stormy conditions possible by circa D12. Similar situation evident from current suites - thus I think 'average' might not be guaranteed as terminology, but we shall see. Either way however, fair continuity now in the broader expectation for the return - one way or another - to mobility, perhaps characterised later by some vigorous depressions. 

 

 

It looks like you could be spot on with the stormy outlook. GFS in the latter stages is showing a very stormy pattern and a very powerful jet stream. 

[Ali1977]

Interesting FI, Scandy high doesn't quite make it though.

Diving jet on the GFS and Parallel, maybe this is where the next change will come from.

Edited November 18, 2014 by Ali1977

[nick sussex]

GFS is pretty horrible in terms of cold in the higher resolution with the PV reforming and Siberia transporting reinforcements. The GFS P is still a damp squib but the PV remains split , both really are very underwhelming.

 

The GFS at T240hrs was obviously sponsored by the Daily Express as it delivers something to back their ridiculous headlines, after that the GFS throws a few crumbs with the troughing digging se'wards.

 

Overall it looks like more pain for coldies, the phrase no pain no gain may well be cremated in the next few weeks.

 

Both the GFS and GFS P look similar to the CPC charts with troughing running se'wards through much of the lower resolution  and some higher pressure to the ne. Unfortunately whilst you've got the PV chunk and low heights stuck in ne Canada this will just feed constant low pressure into the UK.

 

You really need a strong block to be able to disrupt that  energy and get the UK on the polar side of the jet, overall not a great outlook unless you like wind and rain.

 

That's still into the future, lets hope that the models are overplaying this.

Edited November 18, 2014 by nick sussex

[Cloud 10]

Just a snapshot of the GFS  P  at 240 hrs,but shows well what Ian F  mentioned earlier about possible stormy conditions with the jet being fuelled by cold air in the Atlantic.

 

[Man With Beard]

The ecm ens certainly more progressive east than GEFs or NOAA

I'm afraid you posted yesterday's NOAA - here's today's, followed by yesterdays, quite a big shift east on everything:

 

My sense is that our block to the east is going to start to slip even further east - letting the Atlantic in, at least for a little while. Cold unlikely within 14 days. Rain and wind could return after D8 - though, as I've said before, "it hasn't happened yet" ... and many a forecast of progression and zonality has already been ditched since October 1st. But wintery conditions will have to wait until at least ... winter

[Banbury]

It looks like you could be spot on with the stormy outlook. GFS in the latter stages is showing a very stormy pattern and a very powerful jet stream. 

http://modeles.meteociel.fr/modeles/gfs/runs/2014111818/gfsnh-0-312.png?18

 

Doesn't exactly blast the HP out of the way though

[bluearmy]

The parallel is an interesting if evolution - possibly the biggest 'trigger low' in history with the Siberian vortex pulled towards svaalbardi. not much upstream with a slack arctic set up. oh my, I'm dissecting a day 14 chart! (That's not the p/v Chris. Check the ISO charts to see thicknesses in instances like this)

Edited November 18, 2014 by bluearmy

[snowmadchrisuk]

PV Visits the UK on the Para , 

[nick sussex]

 These situations with troughing running se are ones that you often find fast developing shortwaves at the base of the main trough, these often bomb and can be a big problem.

 

I know I shouldn't say this in here especially as I'm a coldie but given the choice I'd rather have a strong Euro high, if its not going to be cold I'd rather it was drier and warmer.

[Derp Patrol]

Some really great runs tonight  

 

Looks like mild air will stay with us for the foreseeable future, this weekend will become mild with temperatures of 16C in the SE. Deep drawn southerlies are just what is needed at this time of the year.

 

 

 

A quick summary - no cold in the reliable time frame, just mild weather which is great really! 

Edited November 19, 2014 by Captain shortwave
Just trimmed the emoticons to make the post less provocative

[kumquat]

 

One thing that frustrates me about the ECM suite is the way that the ens mean often follows the theme of the op.

Surely this promotes more confidence in the model? Or are you saying there is not enough divergence in the starting data of the ensembles?

[knocker]

I'm afraid you posted yesterday's NOAA - here's today's, followed by yesterdays, quite a big shift east on everything:

 

My sense is that our block to the east is going to start to slip even further east - letting the Atlantic in, at least for a little while. Cold unlikely within 14 days. Rain and wind could return after D8 - though, as I've said before, "it hasn't happened yet" ... and many a forecast of progression and zonality has already been ditched since October 1st. But wintery conditions will have to wait until at least ... winter

 

Ooops. Cheers. Those senior moments...............clearing head.

[Captain Shortwave]

Some posts have been removed this morning. Can we please stick to the model discussion and not go off on tangents or post one liners.           

 

Cheers

Edited November 19, 2014 by Captain shortwave

[Nick F]

Looking at the 00z offerings so far from GFS, UKMO and GEM, the blocking certainly ain't giving up to the Atlantic without a fight. I've been a bit skeptical about any full on return of Atlantic mobility beyond early next week anyway but the 00z output so far underlines that.

The ridge of high pressure building from the SW early next week the first stumbling block for any Atlantic return and theres more emphasis from GFS + GEM to force the strengthening jet underneath this ridging as it spreads NE, with an increasingly negative tilt to the Atlantic trough trying to push in. There's enough blocking aloft by Day 10 to our N and NE, as a result of WAA early next week, to keep the jet diving SE across Iberia and into the Med, which sets up troughing over southern Europe. Still no deep cold advecting our way, but good to see any Atlantic energy being forced south of the UK.

Edited November 19, 2014 by Nick F

[Captain Shortwave]

Much better ECM this morning

higher heights to our east again fighting back the Atlantic train

temperatures look a little below par as we head into next week.

The GEM also does not usher in a more zonal pattern this morning with low heights draining towards the UK and Iberia.

ECM day 9 chart - looks like the ECM day 9 chart from 2 days ago. Looking at the current day 6/7 charts will this happen or will we see a weaker and more disrupted feature.

Edited November 19, 2014 by Captain shortwave

[knocker]

I obviously accept what Nick says above so the upgrades take on the next two weekends is posted purely out of interest. (note to self. make sure you have the right day and month) The jet is from the ops and just to add has the upper low over the UK at T216.

 

Charts courtesy weathebell.com

Edited November 19, 2014 by knocker

[Polar Maritime]

Just to echo CS above, I have deleted a few posts as they add nothing to discussion. Please keep on topic.

 

Thanks, PM

[Polar Maritime]

The GFSP & ECMWF this morning continues to send the Low way South over the UK, Taking the Jet with it in turn pulling in cooler air from the N/W. A very unsettled/wet outlook for Months end. 

 

Edited November 19, 2014 by Polar Maritime

[Nick F]

Quite a fine balancing act for the models to peform beyond t+168, on one side of the boxing ring there's the blocking close to and east of the UK, on the other side a very strong jet is modelled to blast across the Atlantic towards western Europe.

The models maybe overdoing the strength of the jet at that timescale, but even so, looking at yesterday's 12z ECM vs today's 00z, the Atlantic upper trough trying to advance east into NW Europe definitely has more negative tilt indicating the jet being forced SE towards Iberia rather than heading NE across the UK.

This battleground we seem to have ended up in still leaves the UK a long way from any deep cold. So the long wait looks to continue until the Atlantic jet shows signs of weakening and/or blocking positions more favourably.

Edited November 19, 2014 by Nick F

[IDO]

As I said yesterday, lots of flip flopping likely again with another Act of this repeating pattern (saga). GEM is what I think will happen:

 

 

The trough from the NW will release less energy due to upstream variables and the low will hit the UK, sit in situ and warm out unless replenished by another bout of lower heights. ECM is not dissimilar, but it looks like most of the flow will move North with some diving SE, though I don't see an undercut, maybe just an upper level low. There also remains a bias on the ECM op after D7 for low heights towards Iberia:

 

 

The GFS control is a take on the ECM and if you fast forward to D16 we end up with that cut off upper low after a period under a UK trough; seasonal but no route to cold due to the block holding steady and denying the undercut:

 

  

 

So more runs needed to handle the trough at D8+ but in all likelihood, as with the recent drama this is likely to be a miss, and looking at the GEFS I can see the whole pattern lining up again for another tilt late in FI. That type of pattern through December would be a waste but obviously better than last year. CFS has had consistent runs suggesting this type of flow continuing:

 

CFS December mean:

 

So December looks a holding pattern whilst we watch as wave 1 warming continues and await the STRAT to trop response in the last third of December. It seems unlikely the trop will find its own way to cold as things stand.

Edited November 19, 2014 by i'm dreaming of...

[BLAST FROM THE PAST]

As mentioned in previous posts by Nick et al, signs in todays models of negative tilt to Atlantic and jet going south sending LPs on NW/SE trajectory towards months end [which is FI].  Lets see if this continues into a trend.  I'm pleased as GFS, GEM and ECM show this...ok they then veer away beyond or deeper in FI.  Model watching is interesting now, and I feel even more to come.

GEM seems to hold the pattern longer and that trough on the end of the run would imo slip further south/SE as it progressed.

It seems that posts for Atlantic to win out and west to east movement has been posted by some for weeks now...

 

  

BFTP

Edited November 19, 2014 by BLAST FROM THE PAST

[mushymanrob]

Some really great runs tonight  

 

Looks like mild air will stay with us for the foreseeable future, this weekend will become mild with temperatures of 16C in the SE. Deep drawn southerlies are just what is needed at this time of the year.

 

 

 

A quick summary - no cold in the reliable time frame, just mild weather which is great really! 

 

somehow its unlikely to happen, the mild temps that is. not sure why as theres some decent looking uppers but the current temp predictions are around average, 12c is the highest ive seen but most of the country its around 9-11c which isnt cold but imho lower then the uppers would suggest.

a frontal system looks like robbing us of the driest, warmest, day (saturday) as the eastern high receeds allowing this system to cross the uk earlier then expected recently.