Model Output Discussion - 1st June 2015 12z--------->

[Gibby]

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 SUNDAY JUNE 7TH 2015.

 

THE CURRENT GENERAL SITUATION A ridge of High pressure is developing across the SW half of the UK with the cool NW flow across the North decreasing and veering north tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE Quite settled for a time with sunny spells and warm conditions by day locally before more unstable conditions develop late in the week and next weekend.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast continues to show the same pattern as previous with the flow relocating to the NW of the UK over the coming days before a trough developing across or near the Uk soon after midweek dips it back South again albeit in much weaker and ill defined form by next weekend and beyond.

 

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

 

GFS OPERATIONAL The GFS Operational today shows a ridge of High pressure lying across the UK over the next 3-4 days before it is squeezed back to the West both from the South and North by falling pressure which then develops a Low pressure complex around or eventually over the UK for the rest of the run with cool and at least showery conditions for all areas from later next week on for the remainder of the period.

 

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

 

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

 

THE GFS CONTROL The GFS Control run differs greatly in the second half of it's run with High pressure ridging back across the UK after an unsettled period and establishing a fine and warm spell for all areas through Week 2.

 

THE GFS CLUSTERS The GFS Clusters today show a strong bias towards the likelihood that High pressure will lie out to the SW of the UK two weeks from now with a ridge towards Britain ensuring a good deal of dry and bright weather. A minority do still show more influence from the Atlantic with some rain at times especially for the North.

 

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 High pressure taking a back seat later next week as showery Low pressure moves up from the South soon after midweek and encompasses much of the UK by next weekend.

 

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

 

THE FAX CHARTS The Fax Charts indicate falling pressure later in the coming week after several days of High pressure across the UK in the first half of the week.

 

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

 

GEM GEM today shows an unusually cool and showery period following the High pressure of the first few days of this coming week. Then towards the end of the run a ridge of High pressure topples East over Britain cutting off the flow and bringing warmer weather to all and more settled weather too in the SE while the North and West continue to see occasional rain from Atlantic fronts.

 

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

 

NAVGEM NAVGEM too shows showery and rather cool conditions developing across the UK well before next weekend as Low pressure in a light Northerly flow becomes established across the UK.

 

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

 

ECM ECM shows showery conditions too developing especially across the South later in the week though on this run at least an attempt to hold a weak High pressure area close to the North is shown which gradually develops a link to the Azores High and restricts showers to the South later and possibly eliminating them altogether by Day 10 as High pressure re-establishes NE across the UK.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night shows slightly better hopes than recent versions as the emphasis appears to be for a greater influence across the UK from the ridge of High pressure from the Azores High towards the South

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend continues to ebb and flow  towards a more unsettled and showery interlude at least to develop across the UK late next week.

 

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 96.7 pts followed by UKM at 95.5 pts and GFS at 95.1. At 5 days ECM  leads GFS with 85.5 over GFS's's 81.5 pts with UKMO at 81.3. At 8 days ECM clocks in ahead of GFS at 49.4 over 43.2. Then at Day 10 ECM remains slightly ahead of GFS at 31.1 pts to 23.2 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 Things seem no clearer this morning between the output as all models show various outcomes between each other and also differences in what they were showing last evening indicating unusually low confidence should be given credibility to any one slution at this time. The ensembles too give very little indication of longer term prospects as the members all show some influence from High pressure out to the SW but how much is very speculative and disagreed upon. So as a result we are left to the part of the period where things are more certain and that is that the next 3-4 days which will see a lot of fine and dry weather though never overly warm and with some unseasonably cold nights for this stage of the year. A few showers in the East tomorrow could enhance the cool feel and then a more coherent deterioration in conditions look like arriving from the South or SE from Thursday as thundery showers begin to affect the SE before likely spreading to other areas in the days thereafter. From then on no clear signal is given with a lot of output showing cool and showery weather persisting under Low pressure while other output recovers pressure later to return dry weather to many. This theory does currently hold the balance of power but a good few more runs are needed yet through the early days of this week before the final outcome for the second week is likely to become resolved. So while some pleasant weather is likely over the coming few weeks some interruptions from cool showers, heavy at times are likely and while the weather could be described as 'could be a lot worse' I feel it could be a good deal better too from some output at times given the time of year.

 

Next update from 08:00 Monday June 8th 2015

Edited June 7, 2015 by Gibby

[knocker]

The GEFS anomaly this morning still plugging a quick transition from trough to HP

http://www.tropicaltidbits.com/

 

[Polar Maritime]

A cool/unsettled outlook from the GFS this morning, With Low Pressure sitting over the UK as Heights get pumped up over Greenland giving a N/W flow over the UK after a slack Northerly around the 12/13th..

 

ECMWF is very much different, With High Pressure setting up over the UK towards the end of the run for the 16th/17th. So some very mixed signals this morning from the Models suits out into week 2, Giving great uncertainty.

 

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

the gfs  is suggesting a possible wet spell  from June  11  at the  moment

[mushymanrob]

And how's that looking now?

GFS has been on the money for the return of the unseasosonal weather, the Euros playing catch up.

 

nothings changed in what i posted.

we will get 5 days of pleasant mainly sunny and dry weather...

something hot might emerge as long as we are dallying with high pressure, and this morning it seems we might well lose the high pressure influence after this week. so 'something hot' is looking less likely. its looking like we will stay on the cool side of average, and might become more unsettled after this week.

so no early heatwave, but no monsoon either and until a southerly tracking jet establishes (which its not expected to do) with a strong greenland high, im happy enough to get a 'normal' summer.

[Summer Sun]

The GFS ens still wants to build pressure again after next weekends unsettled spell

 

 

The position of the high as ever will be depend on what conditions are like the 850's gradually rise as the week progresses, but the high also starts to back west as the week progresses, so more of a northwesterly flow and the warmest temperatures in the southwest where you'd have some shelter

 

So the ENS is following on from yesterday settled till Thursday though a noticeable breeze at times and temps on the low side for the time of year turning unsettled Friday to Sunday with a risk of rain / showers anywhere and temperatures still low for the time of year then into the following week hints of another rise in pressure with temperatures slowly recovering

[Nouska]

I see what you mean, barby time in the south west on Sunday. One things for sure Nouska wouldn't want that chart to verify.

 

Uh oh.....

 

  

 

 Meteo France app showing the double lightning bolt symbol - I expect an early heads-up from Keraunos.

 

A violent night in prospect but probably a visual mess in terms of sky and ground.

[ANYWEATHER]

Good morning campers!  Looks as though we can all enjoy some settled weather albeit with some cloudier conditions with some light showers in places, although rather cold at night with some frost in one or two prone locations. Ive not really been here since Friday, but gfs and ecm still broadly show the same synoptics , so by Thursday , pressure falling from both north and south with some rain pushing into both top and bottom of the country......

Edited June 7, 2015 by ANYWEATHER

[bluearmy]

The gfs op seems to be slowly positioning the cut off upper low a bit further south (trending towards ECM in that regard). However, it's a long way from the ECM 00z op so perhaps we are heading to a place where the upper trough gets into central France and then ejects ne, clipping the se corner of the UK on Thursday. Whether that's followed by the system from the north sending the cold front associated with the Scandi trough through the country or one from the Atlantic drifting in the settle the upper trough across nw Europe or even the Azores ringing towards us is unclear.

[Polar Maritime]

The GFS is ramping up the Northerly around the 14th, With Snowfall risks for parts of the Highlands and parts of the far North of England over high ground. It's looking likely that the Snow patches over Scotland's Mountains in 2015 are in for a good/lasting year. High Pressure does try and push in from the S/E towards the end of run, But the 6z continues to show a rather cool/unsettled picture into week 2.

 

Edited June 7, 2015 by Polar Maritime

[knocker]

What a difference six hours makes

Charts weatherbell

 

[Summer Sun]

The met office is suggesting it may be hot in the southeast on Friday clearly they are not following GFS then

 

Edited June 7, 2015 by Summer Sun

[knocker]

Although not in complete agreement the GEFS and ECM both looking to shift the upper trough by the 16th

 

[Milhouse]

Still the general picture around the middle of the month seems to be high pressure attempting to settle things down from the SW.

 

[Frosty.]

The Gfs 6z shows a largely fine and pleasant spell continuing until later next week with lots of strong sunshine and light winds but with chilly nights where skies clear. The weather then turns very unsettled in time for next weekend but then a big recovery during the following week with the Azores high building in bringing gradually warmer and settled conditions

[coldcomfort]

For the 7th day in a row the 10 day anom chart shows temps several degrees below normal across the whole UK.

 

http://wxmaps.org/pix/temp4.html

 

The main difference from past runs however is these cooler conditions are now forecast to push ever farther southwards, with even parts of S France and Iberia losing their hitherto above or even well above average status. IF and I accept it is an IF the latest GFS run verifies then the early part of next week looks truly grim, with single digit maxima not remotely out of the question under any rain......and yep, snow does look possible on ground above about 1000m.

Edited June 7, 2015 by coldcomfort

[Milhouse]

I wouldnt place any significance on any single run for next weekend. Just take a look at the individual GEFS ensembles and there is considerable variation in conditions from warm and sunny to cool and wet. The means are still the best place to look to gauge the overall trend.

[Frosty.]

The GEFS 6z mean shows there is very strong support from the perturbations for the Azores high to build in across the UK after next weekend's cooler unsettled blip, mid to late June could become largely fine and warm/very warm.

[Tamara]

It is not a subject I know anything about (other than GP's writings) - when I read Tamara's post with the GEFS extreme forecast, I looked to see if Nicolas Schiraldi had an archive to look for similar events. I was hoping someone might be able to shed more light.

From the tone of Dr Ventrice it must be notable and unusual?

Those GEFS forecasts need a little reading between the lines interpreted to them.

 

A little further clarification maybe as to what the chart is showing, (and what it might mean to us on the ground in simple English!)  might help - as it can be confusing!

 

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

 

Todays forecast in the link continues to show angular momentum falling as the Global Wind Oscillation heads back from Phase 4 (transitional toppling AAM stage) to Phase 1 (low AAM phase) as predicted and detailed in many recent posts.

 

Phase 2 is a transitional state to higher AAM (Phase 3) 

 

Convection in the Indian Ocean (MJO passage to MJO Phase 3) can always be taken as a signal for the GWO to head to low AAM state Phase 1/2. Orbit stuck in Phases 1/2 signifies a persisting low AAM state, but orbit which takes the GWO towards (and into) Phase 3 signifies a rebound of momentum towards higher AAM momentum (Stage 3 itself)

 

The high amplitude Phase 2 orbit towards 3 predicted in the model forecast representation is indicative of the relative strength of upswing in momentum that is predicted from the low state in Phases 1/2. However, future forecasts will determine the longevity of the upcoming low AAM phase, and ascertain if the amplitude re-bound to higher momentum is too progressive. Based on the Indian ocean MJO forecasts, its as well to be cautious for the moment.

 

Interpreted and translated into simpler synoptic language the forecast is representative of the initial retrogression of the High pressure in the Atlantic later this week (Phase 4 heading back to 1). Amplified Atlantic state in Phases 1/2 is indicative of UK/Europe lower pressure anomaly and more marked Scandinavian trough. Then, in the further outlook, any increase in amplitude in Phase 2 towards Phase 3 signifies a breaking down of the amplified state in the central/western Atlantic as the Pacific jet stream gathers strength upstream.

 

This implies that any cooler northerly regime in the amplified GWO Phase 1/2 state should break down during GWO Phase 2/3 passage as the upstream jet pattern changes, pushing the Azores/Atlantic High east. On that basis both GFS and ECM fantasy island modelling today has some credence, and also supports the posts that Knocker has made a few times wrt the anomaly charts.

 

However, the *cautious* caveat is added here. Suggestions of re-bound of the pattern upstream are some way ahead and subject to change as reasoned above

 

Yesterdays observations about the stand-off between air-masses to the north and south of the UK are maintained in ever closer focus as we draw towards the period in question of the retrogression of the High pressure over and just to the west of the UK later this week

 

As suspected the influence of the Scandi trough looked a little overstated yesterday in its southward extent to cover the whole of the UK. I continue to be sceptical that the GFS suggestions of recent modelling look a little too extensive in this respect.

 

Nevertheless, with pressure leaking away, the cool air will make some inroads southwards at the same time as the warm humid air over the continent brushes with SE parts. 

 

I think the jaundiced perception of the late Spring/early Summer has quite some justification and sympathy attached in some of these northern parts.

 

Its a dogs breakfast of an outlook from the weekend. It may well evolve eventually to a different kind of NW/SE split. I think that if forecast suggestions of the GWO orbit phase 2 towards and especially into 3 verified at face value, that will be the signal for the pattern to become more mobile generally, for a short time, as the amplified state of the retrogressed high in the western Atlantic flattens out from upstream.

 

However, as already hinted, this might well be the cue for the Azores High to ridge eastwards again and promote a downstream ridge over Europe, whilst at the same time weather fronts pass to the NW .

 

This scenario might attempt to pull humid air to the south northwards again in another attempted plume - but *caveat disclaimer*  this evolution is a long way off and very uncertain at this time

[chapmanslade]

For the 7th day in a row the 10 day anom chart shows temps several degrees below normal across the whole UK.

 

http://wxmaps.org/pix/temp4.html

 

The main difference from past runs however is these cooler conditions are now forecast to push ever farther southwards, with even parts of S France and Iberia losing their hitherto above or even well above average status. IF and I accept it is an IF the latest GFS run verifies then the early part of next week looks truly grim, with single digit maxima not remotely out of the question under any rain......and yep, snow does look possible on ground above about 1000m.

I don't think you are interpreting those charts correctly. They are showing mean surface temperature (not maximum) or temperature anomaly where -2C/-4C is over much of the UK - this could simply be reflecting cold night temperatures in dry air dragging the mean down rather than cold maxima. Whilst it clearly isn't showing a heatwave it isn't exactly ice axe weather either. In fact it isn't far from average, which for a lot of people on here seems to be frustrating, but by its definition by far the most likely.

 

Incidentally the figures themselves are open to interpretation - we have just reached 20.4C here when predicted 17C today so at this time of year with very strong sun they can be a little under estimated

[Roadrunner]

As currently modelled, will any rain that falls next weekend be in the form of showers or persistent rain? Or is it too early to say if anything substantial will occur? Reading all the posts it would seem no one model is to be trusted or followed?

[Backtrack]

As currently modelled, will any rain that falls next weekend be in the form of showers or persistent rain? Or is it too early to say if anything substantial will occur? Reading all the posts it would seem no one model is to be trusted or followed?

Pinning precipitation 6-7 days out is near impossible

[Summer Sun]

As currently modelled, will any rain that falls next weekend be in the form of showers or persistent rain? Or is it too early to say if anything substantial will occur? Reading all the posts it would seem no one model is to be trusted or followed?

 

Difficult to say at this range, but what I would say is current suggestions from the met office are for some thunderstorms in the south and a lot of uncertainty how far north any rain will get I doubt we'll have any decent confidence for the weekend till Wednesday or Thursday

[Backtrack]

The high already looking a little further north and east on this run, as well as looking a little stronger. Thursday's temperatures just got a nice little boost, this could be a good run.

[shaky]

ukmo looks very warm and potentialy thundery from Thursday onwards!!gfs is slowly delaying any northerly on each and every run over the last few days!!