Model Output Discussion 31/07/14 onwards.

[h2005__uk__]

Next week looks distinctly unsettled and cool for the time of year with a definite early hint of Autumn..

 

Is this due to the aftermath of Bertha or is it unrelated?

[damianslaw]

Is this due to the aftermath of Bertha or is it unrelated?

 

 

Yes, it is, as it looks like phasing with the atlantic trough deepening this feature markedly helping to create a strong build of heights North-South over mid atlantic locking the UK on the cold side of the trough anchored by the southerly tracking jet.

[knocker]

One of those situations of nowcasting - however, its noteworthy how ECM and UKMO have continuously moved to the GFS scenario. Yes GFS does tend to perform better when it comes to forecasting position of atlantic lows.

.

 

Surely remains to be seen. The GFS has been putting the low across Ireland which is still a fair way from the ECM, METO position. It may well be the correct solution but still a bit early to assume it's correct. The 12z ECM may well have moved it's position but it's a country mile (literally) from the GFS)

 

As I've said before the GFS interpretation may well be correct but I'm not sure why people are assuming it is.

Edited August 8, 2014 by knocker

[Panayiotis]

Sticking with my prediction that the low will take the Track Alternative 2 (which the Met gave 10% probability) especially now EURO4 has jumped on board:

[Yarmy]

Sticking with my prediction that the low will take the Track Alternative 2 (which the Met gave 10% probability) especially now EURO4 has jumped on board:

Looks more like the 60% option to me?

http://f1.nwstatic.co.uk/forum/uploads/monthly_08_2014/post-12275-0-73581300-1407512909.jpg

[knocker]

The GFS this morning re. Bertha

 

0010 SW of Cork 994mb. heavy rain at centre.

 

0610 SW Wales coast 990mb

 

1210 Over Manchester 986mb

 

1810  Just east of Aberdeen 983mb

 

0011 Just east of n. Scotland 981mb

 

Summary

 

Needless to say as Bertha travels it's accompanied by a wodge of moderate rain and quite strong winds that obviously vary according to location and time

Edited August 9, 2014 by knocker

[knocker]

The METO fax has the track just slightly east of the GFS

 

Edited August 9, 2014 by knocker

[knocker]

It's quite puzzling that even at this late stage the ECM is going for quite different interpretation of the track.

 

[mushymanrob]

Yes, it is, as it looks like phasing with the atlantic trough deepening this feature markedly helping to create a strong build of heights North-South over mid atlantic locking the UK on the cold side of the trough anchored by the southerly tracking jet.

 

... and it looks like that pattern could last some time , theres no ridging azores high coming to return us to something more typically seasonal.

 

Edited August 9, 2014 by Polar Maritime
To remove off topic comment.

[Captain Shortwave]

21 days left of August left, I'd say there is still time for something decent to crop up.

What is that low in the Atlantic going to do? It does look like the Azores high could ridge in to bring better weather next weekend. That low needs watching as its movement could swing where we head in week 2. UKMO looks the most positive about a pressure build next weekend with the high in place even by Friday. The others are slower and less effective.

Edited August 9, 2014 by Captain shortwave

[Polar Maritime]

The GFS this morning shows some cooler air pushing South over the North of the UK for around the 20th. Iceland could get it's first Snowfall.

 

[IDO]

After the GEM op was going against its control and majority ensemble consensus the op has now come in line: 

 

JMA is similar with track and intensity as it travels NE: 

 

Navgem who has followed ECM blindly now has the GFS route: 

 

The hi res models show the potential for strong gusts tracking just south of Bertha centre:  

 

Still differences though: 

 

And where GFS has the worse rain in the Midlands, ECM has it as the driest: 

 

GFS for the next 5-7 days looks like cooler temps with the uppers 3-4c below average for London: 

 

The op and control are unsettled with no sustained higher pressure; tentative signs of next weekend settling down for the far south. But the end are in good agreement and the D10 mean reflects this:

 

 

ECM at D8 looks more promising but bearing in mind they are the only model going for a different track on Bertha anything that follows is debatable:

 

 

 

Unless of course they are right. Though ECM did not spot typhoon Rammasun till the morning it hit the Philippines whereas GFS had tracked it for over a week. In fact GFS spotted Bertha on 28th July and its timing was only about a day out even at that range:

 

[Polar Maritime]

Yes Im Dreaming.. The GFS has handled Bertha very well. And was first to pick up on the signals.

[WhiteFox]

It's nice to see the models flipping around as much in summer as they do in winter. Makes one look forward to the winter!

Anyway, IMHO, the ECM is not the right model for looking at forecasts as we come into the 36 hour period. The ECM is strongest from about four days out; glancing at the charts in summer with rather less regularity than in winter, it occurs to me that the ECM did pick up a rapidly deepening low about a week or so ago which was largely written off by most (understandably as such deep systems are fairly rare at this time of year). IIRC, the system was shown to be about 996mb off the coast of Cornwall, whereas the GFS at the same distance showed nothing of the sort.

Since then the GFS has gone for the deeper system whereas the ECM operational shows a shallower feature tracking further south. At this range I don't really trust either and pay much more attention to the FAX, being a blend of several models plus hi-res output, and the other available hi-res models. Having said that, the NMM was off target for yesterday, showing heaving rain mainly affecting Kent, Sussex and parts of East Anglia whereas in reality we had something of a deluge in Reading.

So, I'm sticking pretty much with met office guidance on this one which is not to say that the models aren't interesting in terms of spot the difference, but the detail is lacking, particularly in the ECM where only 24 hour time periods are shown.

[knocker]

It's nice to see the models flipping around as much in summer as they do in winter. Makes one look forward to the winter!Anyway, IMHO, the ECM is not the right model for looking at forecasts as we come into the 36 hour period. The ECM is strongest from about four days out; glancing at the charts in summer with rather less regularity than in winter, it occurs to me that the ECM did pick up a rapidly deepening low about a week or so ago which was largely written off by most (understandably as such deep systems are fairly rare at this time of year). IIRC, the system was shown to be about 996mb off the coast of Cornwall, whereas the GFS at the same distance showed nothing of the sort.Since then the GFS has gone for the deeper system whereas the ECM operational shows a shallower feature tracking further south. At this range I don't really trust either and pay much more attention to the FAX, being a blend of several models plus hi-res output, and the other available hi-res models. Having said that, the NMM was off target for yesterday, showing heaving rain mainly affecting Kent, Sussex and parts of East Anglia whereas in reality we had something of a deluge in Reading.So, I'm sticking pretty much with met office guidance on this one which is not to say that the models aren't interesting in terms of spot the difference, but the detail is lacking, particularly in the ECM where only 24 hour time periods are shown.

 

Don't follow that as my earlier post was 6 hour time periods.

[IDO]

Looking at the ECM ens at T48 hours, around 75% of members oppose the op and go with a deeper low tracking SW to NE across the UK (a la GFS). Looking at D5 to see how the op fares within the clusters it is is in the 5th of 6 clusters with only 10% support. It is now clear that ECM is struggling with this scenario and also the post Bertha prospects: http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2014080900!!/

 

 

[mushymanrob]

21 days left of August left, I'd say there is still time for something decent to crop up.

 

 

id suggest that times running out, and the current outputs do not offer any hope of anything 'decent', they have trended away for it. of course things might change, we might get something decent, but i for one wont be putting any money on it happening!

[WhiteFox]

Don't follow that as my earlier post was 6 hour time periods.

Indeed it is and that's the first time I've seen it! Regardless of this, I still find it better to look at blended solutions such as the fax within 48 hours rather than poring over each model. ECM Synoptics for further out along with GFS ensembles for an idea of patterns. Other than that the synoptic charts are useful for getting an idea of the possibilities as has been well highlighted by both ECM and GFS over the past week to ten days, but useless for detail outside of five to six days especially in setups such as this.

[knocker]

Yup Looking about right for the 60 per cent option.

Edited August 9, 2014 by knocker

[Summer Sun]

After an unsettled spell things slowly calm down from Thursday looking at the ecm ens though it will still be cooler than we've become use to with a northwesterly flow

 

 

Friday is a similar picture though pressure continues to rise from the south west

 

 

During next weekend and into the following week the move to higher pressure continues with winds slowly moving round to a westerly allowing warmer air to move back  in

 

 

[Polar Maritime]

Just had to delete a post, Can we please only discuss Model Output in here. There are other threads for "I told you so's" and Weather gambling..

 

Many Thanks. PM

Edited August 9, 2014 by Polar Maritime

[Milhouse]

... and it looks like that pattern could last some time , theres no ridging azores high coming to return us to something more typically seasonal.

 

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gif814day.03b.gif

 

This looks a bit like the Azores high to me?

 

[stainesbloke]

After an unsettled spell things slowly calm down from Thursday looking at the ecm ens though it will still be cooler than we've become use to with a northwesterly flow

 

 

Friday is a similar picture though pressure continues to rise from the south west

 

 

During next weekend and into the following week the move to higher pressure continues with winds slowly moving round to a westerly allowing warmer air to move back  in

 

Looks like a feasible run to me. The working week will be much cooler and windier than what we've been used to, conditions best in the S. By Fri it will start to settle down and slowly warm up, next weekend doesn't look too bad, especially for the S, surface temps look to be average. Hopefully not too much infill to ruin things. Think the major difference next week will be nighttime temps...a chill in the air! Should be better for sleeping anyway.

[Bobby]

Indeed it is and that's the first time I've seen it! Regardless of this, I still find it better to look at blended solutions such as the fax within 48 hours rather than poring over each model. ECM Synoptics for further out along with GFS ensembles for an idea of patterns. Other than that the synoptic charts are useful for getting an idea of the possibilities as has been well highlighted by both ECM and GFS over the past week to ten days, but useless for detail outside of five to six days especially in setups such as this.

 

You can get the ECM in 3 hour periods here

 

http://www.yr.no/kart/#lat=54.95086&lon=-2.21135&zoom=6&laga=trykk&proj=900913

[johnholmes]

You can get the ECM in 3 hour periods here

 

http://www.yr.no/kart/#lat=54.95086&lon=-2.21135&zoom=6&laga=trykk&proj=900913

 

thanks for that, very handy for a view to compare with UK Met-bookmarked