Jump to content

Archived

This topic is now archived and is closed to further replies.

Polar Maritime

Model Output Discussion - 1st July Onwards 18z--->

Recommended Posts

A new thread for a new Month. What will July have in store after a record breaking 'HOT' end to June?


 


 


As ever, Please keep it to friendly model related discussion in this thread, And head over to the banter Spring/Summer thread for moans, groans, ramps and more general chat:


 


https://forum.netwea...5/#entry3178481


 


We also have the Summer thread open for wider discussion:


https://forum.netwea...26-summer-2015/


 


If you're wondering where you can view the models, Many of them are available here on Netweather, Including the GFS,ECM, Ensembles, our own NetWx models, and others - All available from the Charts and Data page here:


http://www.netweathe...-and-data;sess=


 


Please be polite and respectful to other members on following the Forum Rules here;


 


https://forum.netwea...tion=boardrules


 


Old thread is here.. 


 


https://forum.netweather.tv/topic/83255-model-output-discussion-1st-june-2015-12z/page-85


 


Many Thanks, Please continue,  PM.


 

Share this post


Link to post
Share on other sites

If we hadnt reached the dizzy heights of 36c today im sure many people would be salivating over the GFS 12z showing 30c in the SE at 240h. And while it is a cooler trend into next week, there is enough to encourage those wanting a return to the summery conditions of present. Both ECM and GEFS means bring a rise in pressure from the south at the end of next week. Plenty to get through once we get there though.

Share this post


Link to post
Share on other sites

If we hadnt reached the dizzy heights of 36c today im sure many people would be salivating over the GFS 12z showing 30c in the SE at 240h. And while it is a cooler trend into next week, there is enough to encourage those wanting a return to the summery conditions of present. Both ECM and GEFS means bring a rise in pressure from the south at the end of next week. Plenty to get through once we get there though.

 

GFS 18z is showing 29 - 31C in the SE on Saturday!

Share this post


Link to post
Share on other sites

No escaping the continued ECM extended output bringing the lw trough into the the UK by the end of week 2.

Share this post


Link to post
Share on other sites

An overview of this morning's GFS can be summed up in one word.....mobile. The whole of the run is a continual dance between ridging of the Azores HP and systems running along on the general westerly flow. This leads to a fair bit of fluctuation of weather and temperature although the usual rule of thumb in these situations  can be applied and say the south fairs better than the north. Not much point in showing individual charts except as an example so just one 500mb isohypse chart will give the general isea keeping in mind this just part of the mobile pattern.

Chart weatherbell

 

post-12275-0-29778300-1435818324_thumb.p

Share this post


Link to post
Share on other sites

GFS is still showing the chance of some hotter temperatures pushing back up from mainland Europe later next week after a couple of fresher days around mid week

 

Monday sees temperatures widely in England and Wales around the low 20's but in the SE highs around 26c are possible - remember the models underestimated the temps by 3 or 4c over the past few days

 

ukmaxtemp.pngukprec.png

 

Tuesday sees another pulse of very warm to hot temperatures pushing up towards Lincolnshire with the high 20's in the SE corner maybe 30c for one or two spots, some rain around as well which could be thundery

 

ukmaxtemp.pngukprec.png

 

Wednesday is a fresher day as it showed last night with high teens / low 20's and some rain

 

ukmaxtemp.pngukprec.png

 

Similar temps on Thursday but less in the way of rain

 

ukmaxtemp.pngukprec.png

 

Friday sees another pulse of very warm to hot air moving up with temps widely in the mid to high 20's for England, some heavy rain over Northern Ireland and Scotland

 

ukmaxtemp.pngukprec.png

 

Saturday is another very warm to hot day Lincolnshire south with the SE corner in the low 30's, some rain in the north and much cooler in northern Scotland with highs for some of just 8 to 11c

 

ukmaxtemp.pngukprec.png

Share this post


Link to post
Share on other sites
HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON THURSDAY JULY 2ND 2015.

 

THE CURRENT GENERAL SITUATION A thundery trough will move North across the UK today followed by a slightly fresher SW flow for a time before humid East winds return later tomorrow in the South along with a further thundery trough.

 


 

MODELS-2 WEEK HEADLINE Becoming cooler and more changeable with some rain especially in the North. Drier and warmer at times in the South.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the Jet Stream flowing North over the UK currently. Over the coming couple of weeks it remains close to the UK but veering more towards a SW to NE axis or even West to East axis late in the period.

 


 

GFS OPERATIONAL The GFS Operational today shows the recent hot weather pulled back towards the extreme SE and South over the coming days before being largely eliminated altogether later in the period. The Jet Stream is responsible flowing more and more towards a less favourable for warmth SW to NE or West to East flow across the UK in association with Low pressure to the North and West. Rain at times seems likely though with High pressure never far away to the South of the UK next week the South could still find some warmth at times between very occasional showers. Later on though all areas look like turning showery in Westerly winds with nearer to average temperarures.

 


 


 

THE GFS CONTROL The GFS Control run follows the operational in theme this morning with just day to day variations in the distribution of rain bearing troughs and showery spells later. It also shows that temperatures will return to average levels for all once the last embers of the European warmth leave the SE next week.

 

THE GFS CLUSTERS(14 Days) The GFS Clusters continue to show mixed messages with nearly all members suggesting High pressure down to the SW with some or little influence across the UK so a mixture of dry and bright weather or cloudy with outbreaks of rain or showers in temperatures close to average given winds from most members are shown to be between West and NW.

 


 

UKMO UKMO today shows the heat leaving the SE at the weekend with a much more changeable look about the charts for the start of next week with Low pressure over or near the North with Westerly winds for all delivering occasional rain and showers through on temperatures close to the seasonal average.

 


 

THE FAX CHARTS The Fax Charts support fresher air eventually winning the battle against the humid and very warm conditions across the SE in the coming days as Atlantic fronts push NE then East across the UK towards the beginning of next week.

 


 

GEM GEM today shows cooler air encroaching to all areas through the weekend and the start of next week with some showery rain likely for all. High pressure is then shown to nudge back towards Southern Britain later next week offering a return to something warmer and more settled again at least for a time.

 


 

NAVGEM NAVGEM too shows a slow transition to more of an Atlantic influence with some rain at times for all in a Westerly breeze. It should be noted though that Southern Britain never lies very far away from more Summery High pressure based weather held just to the South of the UK for now.

 


 

ECM ECM today follows the other models in gradually turning things cooler for all and not just the North and West through the weekend and next week. There will no doubt be some rain at times but probably not much in the South as Higfh pressure looks like building to the SW which would mean a return to cool NW'lies and large amounts of cloud while any rain is restricted more towards the North.

 


 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night continues to show slack pressure gradients across the UK with a Low pressure up to the Northwest and High pressure to the SW with the light West wind gradually receding the warmth slowly away to the SE with time.

 


 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trends continue to suggest cooler weather for all with time as the Atlantic takes control with generally Westerly winds, average temperatures and a little rain at times.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 96.1 pts followed by UKMO at 95.2 pts and GFS at 94.8. At 5 days ECM  leads GFS at 84.3 pts with GFS at 82.0 pts and UKMO at 81.3 pts. At 8 days ECM clocks in ahead of GFS at 47.9 over 44.7. Then at Day 10 ECM remains ahead of GFS at 31.1 pts to 26.8 pts.

 


 


 


 


 

 

MY THOUGHTS It seems likely now that we are slowly losing the influence of the continental heat that has affected parts of the UK in recent days. The change is a slow one with still some high temperatures to come in the SE tomorrow before a slow trend to push the high temperatures away to Europe gains momentum from the weekend. The culprit is Low pressure in the Atlantic which gradually moves towards Scotland sending cooler Atlantic borne winds across the UK. Troughs in the flow will bring rain at times next week and while fine, summery weather never looks like being too far away to the South at any point on this morning's output there is little sign of it making any big push back within the confines of this morning's runs. ECM is not so good this morning either as it shows a worrying sign of parking High pressure to the SW late in it's run and feeding relatively cooler NW'lies down across the UK in a similar way that afflicted June so much. If this morning's cooler evolutions are correct it's a good call from GFS today as it's clusters have been suggesting High pressure to migrate to the SW again in it's outer reaches for some time and with the support of ECM this morning it must be taken as a possibility of evolving. So what do we need to see the heat return. Firstly I would like to see the Jet stream move further to the North and NW of the UK rather than over us as is currently progged. In that way the Azores High to the SW or a European version to the SE could push Summer heat back our way but for the moment that's not looking likely. Secondly and alternatively I wouldn't mind seeing Low pressure slip further South in the Atlantic so that pressure could rise to the NE over the UK to set up a Scandinavian High and feed warm but not humid weather from Europe across the UK. This is the pattern which is best assured of a longer warm period that what we have recently encountered although I appreciate that eastern coastal counties folk would not like this pattern as much. Still we have what we have and while it's looking a lot cooler and fresher over the coming few weeks for many it is unlikely to be a washout and no doubt there will be some reasonable dry and warmish periods between the occasional showers.

 

Next update from 08:00 Friday July 3rd 2015

Share this post


Link to post
Share on other sites

This mornings ECM ens shows the high having more of an influence from later next week

 

Reem1681.gifReem1921.gifReem2161.gifReem2401.gif

 

Temperatures would be responding if it came off probably looking at the mid to high 20's for a fair few

Share this post


Link to post
Share on other sites

Yes SS. It looks like the op is too willing to bring back the cool breezy northwesterlies, whereas the ECM mean maintains the idea of things hotting up again out at days 8 to 10.

 

But theres still lots of warmth closer to the present day and temperatures will be at or slightly above the seasonal average on Sunday-Tuesday even after the heat has passed. More like average on Wednesday and Thursday.

Share this post


Link to post
Share on other sites

This mornings anomalies are not showing complete agreement at day ten. They agree ridge Greenland but have some differences vis the orientation of the east European and east Atlantic troughs and the HP to the south east. Having said that there is no indication that the general W/SW flow won't persist and that the current interpretation by the ops runs of a mobile pattern of alternating weather scenarios is not far off the money.

http://www.tropicaltidbits.com/

 

post-12275-0-44718700-1435830453_thumb.p

post-12275-0-58754900-1435830460_thumb.p

Share this post


Link to post
Share on other sites

 

Saturday [11th July] is another very warm to hot day Lincolnshire south with the SE corner in the low 30's, some rain in the north and much cooler in northern Scotland with highs for some of just 8 to 11c

 

This has been downgraded to the mid-high 20s for much of England on the 6z GFS. It's been chopping and changing between mid-high 20s and low 30s over the last few days though so there's probably more to come before anything can be nailed down.

Share this post


Link to post
Share on other sites

This has been downgraded to the mid-high 20s for much of England on the 6z GFS. It's been chopping and changing between mid-high 20s and low 30s over the last few days though so there's probably more to come before anything can be nailed down.

 

Has it? GFS 06z is only updated to the 6th

 

This Saturday looks very warm to hot for many eastern parts

 

ukmaxtemp.png

Share this post


Link to post
Share on other sites

Ohh, I didn't realise weatheronline was first out of the block. Is that usually the case?

Share this post


Link to post
Share on other sites

Ohh, I didn't realise weatheronline was first out of the block. Is that usually the case?

 

Its news to me as well I always thought meteociel was the quickest, you learn something new every day

Share this post


Link to post
Share on other sites

Its news to me as well I always thought meteociel was the quickest, you learn something new every day

 

You need to look at the charts, most of the time scales are for older runs at the moment.

Share this post


Link to post
Share on other sites

Lincolnshire south still looking very warm to hot next Saturday that weatheronline chart wasn't correct

 

ukmaxtemp.png

Share this post


Link to post
Share on other sites

That's weird. I wonder what chart weatheronline is showing then as it's definitely the 6z it's showing (so it says).


EDIT: Just realised the bottom right hand corner of the chart says "Wed 18 + 240" so it's yesterday's 18z run even though it says today's 6z at the top! That's rather misleading and something to watch out for on that site.

Share this post


Link to post
Share on other sites

This post linked below from mid June is quite pertinent again in some ways at this time.

 

https://forum.netweather.tv/topic/83255-model-output-discussion-1st-june-2015-12z/?view=findpost&p=3216175

 

At that time, the model output suggested nothing at all, at face value, as to the quite dramatic changes that were set to occur towards months end and obviously most especially where we are right at the very start of this month. Its true of course that the post above didn't, and couldn't, have anticipated the arrival of the intense heat that we are seeing.

 

However, with the Pacific events as described unfolding as they were, it was very clear back then that a sea change in weather patterns was underway to a much more summer like pattern - the only question then was when this would start?. The type of pattern that has evolved this week, was anticipated as a possibility - but more towards the middle of the month  (albeit the sort of noteworthy heat we have seen could not have been predicted, and more particularly so soon as it has come)

 

The Global Wind Oscillation, having reacted to a major El Nino MJO convective induced spike in the Pacific, looks set to return through Phase 7 towards Phase 0 once again, as this convective wave dies - and, synoptically, provide a similar passage of rather flatter and more mobile Atlantic sourced weather as was seen in the period leading up to the current major plume of heat.

 

That is of course unless the heat has obliterated memories of what things were like two weeks back!

 

http://www.atmos.albany.edu/student/nschiral/research/gwo/gfsgwo_1.png

 

At the middle of mid June, Atmospheric and Angular Momentum was just beginning its decisive uptick to end long term intra phases of low tendency, as reasoned at the time it was poised to do. Convective activity was muted at this time - just prior to the large Nino spike in activity in the Pacific, and in response this has rocketed the MJO from a weak signal in the Western hemisphere, to a very high amplitude Phase 7 in the Pacific

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_51m_small.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCPE_phase_21m_small.gif

 

Its no surprise at all that such a kick to the atmosphere has triggered such a heave-ho downstream to the NH pattern - with low tendency AAM synoptic profile Atlantic High and downstream Sceuro trough, reversed quite spectacularly with Atlantic trough and downstream amplified Sceuro ridge.

 

This massive kick to the weather patterns (augmented by tropical storm Bill) has greatly magnified and intensified a regular, not uncommon summer type plume, into something that has broken a July temperature record.

 

It goes to emphatically prove and illustrate that significant changes in atmospheric AAM state, which suddenly break a long term stranglehold on weather patterns, and such as we have witnessed over the last 10 to 15 days, often give rise to high impact weather events - often some considerable distance away from where they originated.

 

So, what is the significance of that post from mid June in terms of the further outlook?

 

The de-amplitude phase of the tropical MJO, and ex-tropical GWO signals, initiates a lower tendency type AAM synoptic pattern again. Call it a 'faux -AAM' signal. No surprise therefore to see the flatter trough pattern advertised in the models attempting to extend troughing towards Scandinavia, with heights above the trough towards Greenland, and, as a consequence, suggestions of something of a tug of cooler air southwards.

 

However, much the same sentiments as typed in the linked post back on 17 June, I would not be duped by NWP and take too much as read.

 

The coming period beyond the weekend is going to be increasingly messy and uncertain to predict precisely as to where cooler boundaries to the north, and very much warmer boundaries to the south will lie - much like it was two weeks back.

 

Taking into account the background hemisphere detail, I am personally sceptical of any lasting cooler NW pattern with High pressure stuck to the west/south west and low pressure over the UK/Europe and Scandinavia.

 

The coming 10 day period will certainly see cooler conditions, most especially when compared with this week, but not cool in the real sense, and southern and eastern parts especially should see further warm conditions.

 

The ECM operational this morning looks to be overdoing the NW-erly incursion in the 8 to 10 day period as backed up by the Dutch ensembles which are naturally a good guide further east of here and where any cool northerly incursion would be most felt by lower heights towards Scandinavia

 

http://www.weerplaza.nl/gdata/eps/eps_pluim_tt_06260.png

 

Its also a low end solution against the mean on the London ECM ensembles

 

http://www.weathercast.co.uk/meteo/eps/ensemble-tt6-london.gif

 

This supports better emphasis, than suggested at face value on todays operational, of ridging to the south with a North/South split in the upcoming flatter pattern phase of weather as supported by the declining amplitude GWO Phase 7 towards 0

 

Much as stated in mid June, and from a similar position - its where the Global Wind Oscillation heads from low amplitude Phase 7/0 that will determine the extended period.

 

The post on Monday suggested that this brand new long term atmospheric pattern might re-boot itself in the extended period. Extended period, as written then, was not intended to mean the 10 to 15 day period - but beyond that.

 

This still remains a distinct possibility - and in this respect much like the middle of June there will be little or no clue at all from current NWP, ensemble data, or, more reliably, in the 8 to 14 day 500mb height anomalies.

 

Making suggestions for such long time scales has its very obvious caveats and disclaimers - and some I know will inevitably find the process of doing so very dubious.

 

However, this is where the GWO as a long term forecasting tool is very helpful in spotting and anticipating future possible evolutions which then transfer themselves into extended synoptic ensemble and other model data.

 

It will take some time for the MJO cycle to circumnavigate and renew and for further westerly winds to be added to the tropics and initiating fresh positive frictional and mountain torques. However, beyond a relatively cooler Atlantic phase, it is perfectly credible to anticipate and watch out for this - especially taking into account the long term step change that has happened to global patterns during June.

 

First though, before there is any possibility of that happening, or emerging in the bread and butter everyday model data, we have to allow the upstream pattern to complete its first cycle

 

With this in mind, things are proceeding exactly as should be expected :)

 

Edit later: Yes Knocker, the WWB relates to the MJO Pacific spike which has imprinted El Nino properly on the atmosphere, triggering poleward AAM momentum transport as the easterly trade winds are reversed :)

Share this post


Link to post
Share on other sites

Thanks Tamara and for linking not repeating, but do read the link folks.

Ax T comments on 17 June there was not much to suggest what has happened in the last week or so, certainly not from what I call the synoptic models. The anomaly charts I use for suggesting the overall weather type 6-15 days down the line were still toying with the idea of +ve height anomalies in the Greenland/Iceland region. By the 20th this had given way to what actually developed, a marked Atlantic trough reasonably close to the west of the country coupled with +ve height rises being increasingly suggested south and SE of the UK. I never got round to looking how the MJO was moving at that time but probably it would have signalled a few days earlier what the anomalies picked up as commented on above. Currently they suggest a flow from west rather than south in the main direction but with reasonable heights suggesting average to above temperatures. Probably on the changeable side and no emphasis (from the anomalies) of favouring south or north. Another interesting 6-15 day outlook starting to develop perhaps?

Share this post


Link to post
Share on other sites

In the  8-10 day range I notice Michael Ventrice is talking about a BIG interaction upcoming over the West Pacific between what could be a Super Typhoon and the North Pacific Jet. I don't know in what way but this could impact the pattern over N. America and thus downstream as well.

 

Is this what you are referring too in this quote Tamara or am I barking down the wrong wind tunnel?  "Likely the strongest Westerly Wind Burst on record during Summer o/the Western-Central Pacific this week" This would be Nino related. I'm developing a headache :)

 

https://twitter.com/hashtag/ElNino2015?src=hash

 

 

It will take some time for the MJO cycle to circumnavigate and renew and for further westerly winds to be added to the tropics and initiating fresh positive frictional and mountain torques. However, beyond a relatively cooler Atlantic phase, it is perfectly credible to anticipate and watch out for this - especially taking into account the long term step change that has happened to global patterns during June.

Share this post


Link to post
Share on other sites

Thanks Tamara and for linking not repeating, but do read the link folks.

Ax T comments on 17 June there was not much to suggest what has happened in the last week or so, certainly not from what I call the synoptic models. The anomaly charts I use for suggesting the overall weather type 6-15 days down the line were still toying with the idea of +ve height anomalies in the Greenland/Iceland region. By the 20th this had given way to what actually developed, a marked Atlantic trough reasonably close to the west of the country coupled with +ve height rises being increasingly suggested south and SE of the UK. I never got round to looking how the MJO was moving at that time but probably it would have signalled a few days earlier what the anomalies picked up as commented on above. Currently they suggest a flow from west rather than south in the main direction but with reasonable heights suggesting average to above temperatures. Probably on the changeable side and no emphasis (from the anomalies) of favouring south or north. Another interesting 6-15 day outlook starting to develop perhaps?

 

I wrote this on the 18th, following the 06Z GFS run - I'll just put in the link as you don't like us quoting ourselves.

 

https://forum.netweather.tv/topic/83255-model-output-discussion-1st-june-2015-12z/page-37#entry3216484

 

I was asking about the cyclical nature of the plume events but nobody suggested anything. This one has also been a record breaker, extending its range to the UK on this occasion.

 

Will there be another one to see out the month of July?

Share this post


Link to post
Share on other sites

I wrote this on the 18th, following the 06Z GFS run - I'll just put in the link as you don't like us quoting ourselves.

 

https://forum.netweather.tv/topic/83255-model-output-discussion-1st-june-2015-12z/page-37#entry3216484

 

I was asking about the cyclical nature of the plume events but nobody suggested anything. This one has also been a record breaker, extending its range to the UK on this occasion.

 

Will there be another one to see out the month of July?

 

Yes I remember your post Nouska but couldn't think of any useful suggestions to make at the time. I agree that doesn't normally stop me. But you did indeed call it correctly and I still can't think of a useful contribution. More thought required. :)

Share this post


Link to post
Share on other sites

Yes I remember your post Nouska but couldn't think of any useful suggestions to make at the time. I agree that doesn't normally stop me. But you did indeed call it correctly and I still can't think of a useful contribution. More thought required. :)

 

I don't see anything obvious either....other than the last time the PDO was so record breakingly warm in winter was 2003.

Share this post


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

×
×
  • Create New...