Model Output Discussion - 3rd May Onwards 00z--->

[Biggin]

The models are hardly shouting certainty this morning, even at 4 days out.

GFS

Digs the trough further south and slower, the GFS now shows temperatures reaching the mid to high twenties in the south with thunderstorms breaking out during the evening and overnight.

 

UKMO

The model is still sending the low quickly over the top of the high with a front straddling the country with its progress southwards being rather slow.

 

GEM

This model sits between the two, it suggests a very warm day in the south eastern third of the UK on Friday. The low develops much later than the other models.

 

Beyond this the UKMO/GFS develop a ridge west of the UK, whilst the GEM keeps the battle between the hot air to the south vs the cool air from the west going with frequent pulses of hot air and thundery weather as Atlantic systems clash with the hot continental air fighting northwards, an interesting run.

 

In typical fashion, the ECM has gone AWOL this morning

Simon Cardy â€@weather_king  6m6 minutes ago

00Z ECMWF run delayed due to processing issues at ECMW

[mushymanrob]

very nice, but has no support from the anomaly charts



which suggest a mean upper trough to our west/southwest pumping up southwesterlies across the uk. so, for me, until these charts change, ill not believe the ops penchant for building mid latitude pressure after next weekend.

 

 

Edited June 1, 2015 by mushymanrob

[Frosty.]

The Gfs 00z shows the south of the UK in particular becoming fine by midweek with pleasantly warm sunny spells, warmer by Thursday with 21 celsius in the southeast. Friday becomes very warm and humid in the south as we briefly import continental air but heavy, thundery rain pushes north up the western side of the uk, the weekend is cooler and fresher, mainly dry and bright in the south & east, more unsettled to the northwest but then next week becomes anticyclonic and pleasantly warm again.

[Frosty.]

I like the Gem 00z, it's not settled but it does deliver occasional pulses of continental heat and humidity from Friday and into next week with temperatures sometimes into the 80's F with thundery outbreaks and sunny periods.

[Light Without Heat]

I like the Gem 00z, it's not settled but it does deliver occasional pulses of continental heat and humidity from Friday and into next week with temperatures sometimes into the 80's F with thundery outbreaks and sunny periods.

Be like living in Florida 

[stodge]

Morning all

 

So where are we now and where are we going ?

 

http://www.cpc.noaa.gov/products/precip/CWlink/pna/nao_index.html

 

NAO continues to run nicely positive suggesting LP where it should be and HP where it should be confirming the current run of W or NW winds.

 

http://www.cpc.noaa.gov/products/precip/CWlink/pna/new.nao_index_ensm.html

 

The future shows a significant dip toward neutrality or even a negative value before recovery and then scatter approaching mid month so the very long term picture remains unclear.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060100/gfs-0-102.png?0

 

This shows why the NAO is falling - pressure rising to the south of Greenland and falling to the SW so a more complex synoptic situation and a cut off of the flow of cooler air and its replacement by something warmer.

 

The return to neutrality or just above suggests however this won't last:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060100/gfs-0-174.png?0

 

The HP is for now in place but a new LP coming off North America threatens to restore the more normal set up. 

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060100/gfs-0-264.png?0

 

Yet here we are in FI and that hasn't happened at all - the HP albeit with a more northerly focussed ridging still controls the UK weather and with an absence of heights over the mid-Atlantic, the NAO is held up

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060100/gfs-0-336.png?0

 

And this is the chart fans of heat don't want to be seeing in mid-June - with strong blocking over Greenland and the Azores HP displaced well to the SW, the door is opened for the trough to come back west and set up over the British Isles.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060100/gfs-5-384.png?0

 

The Jet also coming back south during the week which again would be poor for this stage of summer though not unusual.

 

None of this is certain and nor does it rule out hot weather in July and August.

 

Temperature wise, the 16c isotherm brushes the south east on Saturday but this is a familiar set up as the pulse of heat from Iberia glances SE England before cooler air returns.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060100/gfs-1-120.png?0

 

After that the synoptic set up keeps the heat trapped to the south.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060100/gfs-1-348.png?0

 

Some quite cold air for the time of year if (and it's an enormous IF) this verifies.

[Gibby]

I'm in Fuengirola Spain for the time being while my family look after things at home but I'll continue to supply reports to you each day with just the times being a bit later than usual for the most part.

 

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 MONDAY JUNE 1ST 2015.

 

THE CURRENT GENERAL SITUATION A unseasonably deep depression crossing close to NW Scotland will drive active troughs of Low pressure across the UK in very strong SW winds.

 

http://www.wetterzentrale.de/pics/Rtavn001.gif 

 

MODELS-2 WEEK HEADLINE Changeable, windy and cool at first then drier, warmer and sunnier for all later.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows a strong Jet flow moving NE across the UK over the coming days. Eventually it shows signs of buckling and weakening as it tries to migrate to latitudes further north of the Uk for a time next week.

 

http://www.netweather.tv/index.cgi?action=jetstream 

 

GFS OPERATIONAL The GFS Operational today shows deep low pressure slowly giving way to a day or two of warm and humid weather before a breakdown from the SW returns more changeable conditions before and over next weekend. High pressure then forms to the West of the UK for a time bringing cooler, fresher and drier air before the pattern breaks down again to Atlantic Low pressure close to Northern Britain late in the run.

 

http://www.wetterzentrale.de/pics/Rtavn1441.gif

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif 

 

THE GFS CONTROL The GFS Control in many respects follows the course of the operational as cool weather returns after a couple of warm and humid days late this week. The pattern then shows High to the West and relatively cool North or NW breezes down over the UK before Low pressure gradually reasserts authority towards the end of the run from Scandinavia.

 

THE GFS CLUSTERS The GFS Clusters today show a real mixed bag of options, so much so than no real clear definition of where synoptics will lie at the two week time point can be determined

 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

 

UKMO UKMO this morning shows things gently improving from midweek as the strong and unstable Westerly airflow prior to this is replaced by light winds and warm temperatures across the South although unsettled conditions look like remaining over the North and West with the warmest conditions restricted more towards the SE where thundery showers could occur on Friday.

 

http://www.wetterzentrale.de/pics/Rukm1441.gif 

 

THE FAX CHARTS The Fax Charts show the tentative improvements later in the week as High pressure sucks warm and humid air into the South and East for a time before Atlantic fronts erode it again from the West by the weekend.

 

http://www.weathercharts.org/ukmomslp.htm#t120.

 

GEM GEM today looks very changeable in stature this morning as it indicates spells of unsettled weather under low pressure alternating with short spells of High pressure based conditions when some fine and warm conditions could be enjoyed for all between rain and showers..

 

http://www.wetterzentrale.de/pics/Rgem2401.gif 

 

NAVGEM NAVGEM never look very dynamic with it's weather patterns over the next week with the SE at risk of both thundery showers and some of the best conditions too under bith Hiugh and lower pressure periods. The NW is shown to be more commonly changeable and rather cooler through the period.

 

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

 

ECM ECM doesn't look too bad this morning with a lot of very warm air flirting with the South at times over the coming week. There could be some thundery rain at times as various trough interact with the flow and give rise to some cooler conditions more prevalent late in the period as winds swing more Northerly

 

http://www.wetterzentrale.de/pics/Recm2401.gif

 

ECM 10 DAY MEAN N/A.

 

http://www.wetterzentrale.de/pics/Reem2401.gif 

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend for better weather looks to be somewhat more diluted from some of the output currently.

 

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 96.6 pts followed by UKM at 95.4 pts and GFS at 95.0. At 5 days ECM  leads UKMO with 85.9 over UKMO's 82.0 pts with GFS at 81.7. At 8 days ECM clocks in ahead of GFS at 50.5 over 44.5. Then at Day 10 ECM remains slightly ahead of GFS at 28.7 pts to 22.0 pts.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png 

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig

 

 

MY THOUGHTS There has been some watering down of the overall shift towards warm and sunny weather since my last report with more interventions from either cooler air from the North or NW or unsettled conditions moving in from the West. The main concern to me looks the desire to eventually have High pressure shifted out to the west of the Uk with further cool Northerly winds likely as a result across the UK later in the period. While this all might seem doom and gloom talk on the face of all there is still a shift towards at least a period of warm and humid conditions especially the further SE you live within the UK which by the same token could give rise to the greatest risk of thundery rain here too. The further North and West you travel though would likely see morespells of cloud and rain from depressions moving NE across the North and the resultant rise of pressure behind one of these at the weekend could give rise to the cooler Northerly winds I mentioned earlier. Still the ensembles still point to a very mixed picture with no clear trend shown to where we might be synoptically two weeks from now so hold on to your horses would be my advice as I expect to see more shifts of emphasis between warm and settled and cooler and unsettled to be shown in the upcoming days between all models.

 

Next update from 08:00 Tuesday June 2nd 2015

Edited June 1, 2015 by Gibby

[NO LONGER POSTING]

if we're cherrypicking .....image.jpg

 

This post made my day.. LOL!   

 

My turn.. 

 

 

 

 

   

 

 

Edited June 1, 2015 by Surrey

[Tim Bland]

Pleanty to be possitive about IMO.  General theme from ensembles is for pressure to be high and precipitation low with temps reaching 20C or higher on most days.  Below is for Central England. North western areas will be coller and more unsettled but I suspect if you live in this part of the worlk you are used to it!

 

 

 

[Captain Shortwave]

The ECM operational is now out, Friday's chart is pretty much identical to the middle ground GEM version

 

This low could be pretty nasty with the risk of thundery downpours pushing north with also the potential for strong winds as the low winds up Friday night.

 

Beyond this you end up with a very frustrating set up with the continental heat struggling to push north as the main ridge ends up west of the UK. So the three main models all want the ridge west of the UK this morning and cut-off the upstream low in the process. I can only assume that the 12z suite will probably throw another different scenario for next week

[William of Walworth]

Interesting links from stodge, but as he himself suggests, definitely not written in stone yet. Anything beyond this coming weekend is FI and there's plenty of time for positional shifting as we head further into June..

 

stodge said

 

None of this is certain and nor does it rule out hot weather in July and August.

 

Nor more settled/warmer conditions later in June either, I'd say. Too early to be in any way sure etc. There's always the chance of the traditional NW/SE split as well

Edited June 1, 2015 by William of Walworth

[shaky]

at least the plume has backed west a bit for friday which means temps of 25/26 degrees for central and southern england compared to the 16 and 17 degrees that was showing on yesterday's runs!!wouldnt be surprised if the 12z backs the plume even further west!!could be some nasty storms Thursday or friday night coming up from france aswell so plenty to be excited about!!

[summer blizzard]

Euro ends on a settled but cooler note.

 

[mountain shadow]

Awful runs this morning for the North West with Saturday now looking miserable where as a couple of days ago, it was BBQ stuff showing. The anomalies and models really overplayed any continental heat and underplayed the continued strength of the jet stream. The +5 isotherm does not make into Northern Ireland at all this week on the ECM and then only briefly towards the end of the run.

 

Any dry stuff now back in FI land.

[chionomaniac]

Rtavn2401.gif

very nice, but has no support from the anomaly charts

610day.03.gif 814day.03.gif

which suggest a mean upper trough to our west/southwest pumping up southwesterlies across the uk. so, for me, until these charts change, ill not believe the ops penchant for building mid latitude pressure after next weekend.

Hi mushy, I have looked 2 or 3 times at this post and tend to disagree. The GFS op chart that you have posted does have broad agreement from your attached anomaly charts. I can't see where you see that there is a mean upper trough to our west/southwest from these. If I imagine hard then I can envisage a slight weakening of the ridging that stretches from Europe out into the Atlantic, but no more than that. 

[Tamara]

GWO forecasts continue to emphasise an orbit drift through to Phase 3/4 with possible rebound thereafter to Phase 2.  

 

Should the GWO rebound (very briefly probably if it does happen) to Phase 2, as currently suggested, then this would encourage renewed ridge amplification to our west across the NE Atlantic, and further high pressure re-enforcement to follow immediately from the initial plume

 

I think that extended GEFS members are showing support with this possible immediate reload theme - with the next ridging arriving and holding across northern UK into week 2. Therefore there is no requirement for any intra output hiatus over differences in GFS output pressure, CAPE and precipitation parameters - the model (like all the global synoptic models) is dealing with complex and real Atmospheric processes which are underpinned by Science, and not to try to give emotionally induced palpitations to heat seekers or those who want storms over their house each afternoon and evening after the BBQ has been lit 

 

Away from chasing such fine details, which is futile several days away, in broad UK synoptic terms the larger scale pattern translates to, maybe, one peak in convective thundery activity for especially the south and/or south west of the UK, and then the new ridging re-setting the pattern back to a further heating up from the continent thereafter as pressure across the north of the UK continues to consolidate itself.

 

A couple of days later, and despite some GFS histrionics wrt the white noise over the problematic engagement of the plume late this week ( which in itself still has to be resolved completely in detail) the above suggested evolution is still well on course - with the models clearly growing in agreement for the next ridge to extend itself across  us, albeit with the main centre rather to the west of the UK, -  and the cut-off low sat immediately to the south below it underpinning the ridging, but too far west, taken at current face value, for further plume destabilisation from the continent

 

http://www.meteociel.fr/ukmo/runs/2015060100/UN144-21.GIF?01-06

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015060100/ECH1-168.GIF?01-12

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015060106/gfsnh-0-168.png?6

 

Much as the above highlighted post, and the post yesterday stated, the GWO is firming up now to  backtrack its orbit to Phase 2, and is the reason why we do not see the more widespread and longer lasting plume that the models were advertising early in the weekend. It also explains the slight retrogression adjustment of the renewed High with its centre shifted to the west of the UK - a characteristic placement in view of a small fresh injection of downward Atmospheric Angular Momentum tendency

 

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

 

With orbit into Phase 4 not being sustained (which would have supported the original modelling of the plume being longer sustained) and rubber banding so fast back to Phase 2, it should not be a surprise that there has been some volatility in modelling in the last day or two - and that the Iberian low and Euro Heights looking to remain in place through the weekend has been replaced with an emphasis on upstream momentum instead.

 

Those who are viewing the further possibilities for storms and humid heat will be a little frustrated with such an indicated synoptic set-up from the weekend onwards - for these people, the new High clearly needs to be further east to allow the cut-off low to trigger a second round of destabilisation, for the UK, from the south-west. 

 

On the other hand, after tonight and daylight tomorrow, we are about to lose the legacy of the troublesome cold upper trough over Northern Canada which has been providing the cool and sometimes unseasonally inclement conditions for some time - and which is currently right at, and from, t0 coming to something of a climax with the very wet and windy autumnal conditions imminent.

 

So, with the strong jet stream about to blow itself out from tomorrow, any slightly retrogressed pattern does not mean a return that type of cold upper troughing sliding down across the UK and to those same unpalatable conditions - even if the track of weaker and shallower 'warmer' lows over the top of the ridging may have to be watched for NW'rn most parts, depending on the strength of the ridge on its northern flank.

 

Perhaps more important still than just losing the unseasonal cool and autumnal type pattern, is that I would think that those who simply enjoy some pleasantly warm quiet summer weather without cloying humidity will be very happy with prospects, at least post the end of week plume event.

 

The High may be placed to the west, but it is modelled to be orientated in such a way as to extend a ridge quite some way eastwards into Europe. This, at present, looks set to prevent anything much of a cool down occurring from the north, even if for storm and heat fans it is also suggesting, at least for the time being, preventing the higher temperatures and humidity returning and encroaching as far north towards the UK as they would like

 

Its not yet worth dwelling too much about any fuller retrogression at this time to allow significantly cooler and less settled conditions down from the north. This will depend much on where the GWO heads from Phase 2 - and a laddering up to higher momentum phases 3 to 5 is at least just as likely as any further backtrack into Phase 1 which would be the trigger for fuller retrogression. 

 

I would actually argue, and have argued already more than once - that a more permanent shift of Atmospheric pattern, to replace Nina-esque GWO phasing, and to instead more closely imprint the growing El Nino oceanic signal is overdue already

 

Higher GWO/AAM phasing would mean consolidation of summer ridging, with a shift eastwards in contrast to further retrogression - and consequently perhaps a further re-cycling of heat and storms (at least for those who want this) might not be too far away

 

Today though (putting aside the end of week brief plume and its ?? details tbc)  is one of those glass half full or empty days not just according to your weather preference - but also your overall philosophy based on the poor fare that is being served up to date.

 

Its definitely half full for me at least

[mushymanrob]

Hi mushy, I have looked 2 or 3 times at this post and tend to disagree. The GFS op chart that you have posted does have broad agreement from your attached anomaly charts. I can't see where you see that there is a mean upper trough to our west/southwest from these. If I imagine hard then I can envisage a slight weakening of the ridging that stretches from Europe out into the Atlantic, but no more than that. 

 

Hi

dont those anomaly charts show a trough to our west?.. the green lines dip there then rise to our east, the upper airflow is southwest is it not? i cant see a high to our west like the one i posted from the gfs on those charts, but a high to our east/ southeast in southern europe?

id have thought this cherry picked chart from the gem was closer to what the noaa charts show is it not?

anyway, im happy to be wrong , its part of the learning curve !

Edited June 1, 2015 by mushymanrob

[chionomaniac]

Hi

dont those anomaly charts show a trough to our west?.. the green lines dip there then rise to our east, the upper airflow is southwest is it not? i cant see a high to our west like the one i posted from the gfs on those charts, but a high to our east/ southeast in southern europe?

id have thought this cherry picked chart from the gem was closer to what the noaa charts show is it not?

Rgem2282.gif

anyway, im happy to be wrong , its part of the learning curve !

This operational GEM chart does show a trough to the west, but I would rather see the GEM ensembles for that timeframe.

Check here: http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/model_guidance.php

 

and we see the ensembles giving a more positive anomaly across the UK from east to west more in line with the GFS

 

 

 

Look at the anomalies rather than the 500hPa green height lines for a better overall impression - this chart here shows the upper trough to the west of Greenland day 8

 

[coldcomfort]

These could of course be wrong, but still nothing in the way of warmth showing up across the next 10 days, let alone any heat. In fact temps are shown to be at or below normal for 90% or more of the UK ... http://wxmaps.org/pix/temp4.html

[Frank Trough]

These could of course be wrong, but still nothing in the way of warmth showing up across the next 10 days, let alone any heat. In fact temps are shown to be at or below normal for 90% or more of the UK ... http://wxmaps.org/pix/temp4.html

 

"normal" temps for june would be warm, would it not? "nothing in the way of warmth" would more accurately describe the last few days I think. the "hot" conditions that were being modelled a few days ago have been substantially downplayed though, I definitely agree with you there coldcomfort.

Edited June 1, 2015 by Polar Maritime

[Biggin]

"normal" temps for june would be warm, would it not? "nothing in the way of warmth" would more accurately describe the last few days I think. the "hot" conditions that were being modelled a few days ago have been substantially downplayed though, I definitely agree with you there Coldcomfort.

Of course the last few days "nothing in the way of warmth" were in May.

Edited June 1, 2015 by Polar Maritime

[gottolovethisweather]

It may have been requested way back on the 3rd May but it still applies, chaps and chapesses.

 

• 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

As ever, PM is a good alternative for any pertinent questions revolving around non-model related discussion inside netweather towers. Us moderators are here to help.

 

Please continue in the manner expected by us moderators and most forum users. 

Edited June 1, 2015 by gottolovethisweather

[mushymanrob]

This operational GEM chart does show a trough to the west, but I would rather see the GEM ensembles for that timeframe.

Check here: http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/model_guidance.php

 

and we see the ensembles giving a more positive anomaly across the UK from east to west more in line with the GFS

 

canm500_maps.d08.2.gif

 

alens500_maps.d08.2.gif

 

Look at the anomalies rather than the 500hPa green height lines for a better overall impression - this chart here shows the upper trough to the west of Greenland day 8

 

alens500_maps.d08.1.gif

 

cheers.... ill try to get my head around these... please feel free to correct me anytime , otherwise i (we) will never learn

[Polar Maritime]

A new thread coming up, Please hold off posting for a moment.

 

New Thread here; https://forum.netweather.tv/topic/83255-model-output-discussion-1st-june-2015-12z/

 

Thanks, PM.

Edited June 1, 2015 by Polar Maritime