Model Output Discussion 31/03/14 onwards.

[shaky]

Very good ecm this morning warmth continues well into next week!!and both gfs and ecm agree on a pressure rise after the hopefully thundery sort of break down midweek!!this is looking good folks!!proper summery weather at last!!ukmo has gone further east though beware!!

[tinybill]

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

 

morning all  hope to get the shorts on soon once  the sun comes out!!  but looking deep into fantasy world  the bank holiday looking a  washout at the  moment!

[Gibby]

HERE IS THE LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM TODAY SATURDAY 17TH MAY 2014.

 

THE CURRENT GENERAL SITUATION. High pressure will decline slowly across Southern Britain while a cold front continues to move very slowly East across Northern and far Western areas tomorrow.

 

GFS The GFS Ensembles pack indicate slack Low pressure sets up towards the SW of England towards the middle of the week with outbreaks of rain carried across the UK on a warm Southerly wind. Later in the week and through week 2 changes look quite slow with slack and showery Low pressure never far away from the UK maintaining the risk of heavy Springtime showers mixed in with some warm sunshine.

 

UKMO UKMO ends it's run with Low pressure elongated from a position NE of Scotland SW to a slack and broad trough to the SW of the UK. With light winds across the UK next weekend further showery rain will be scattered about with average temperatures but with some bright, warm and humid weather at times too.

 

GEM The GEM operational maintains the trend towards Low pressure across the UK later this week with rain and showers in places before it trends towards a pressure rise from the SW later with drier and brighter weather extending NE across Britain in Week 2 with average temperatures.

 

NAVGEM NAVGEM keeps slack low pressure areas to the South next weekend with the South at risk from further showers while the North becomes drier and brighter under a weak ridge of High pressure.

 

ECM today maintains a showery week to come under Low pressure to the SW culminating next weekend in a strong build of pressure over Europe which in turn maintains Low pressure to the West of the UK. This would mean quite warm conditions persisting but with further outbreaks of rain and showers, these chiefly in the West and SW, heavy at times. Later in the output Low pressure remains well in control crossing the UK with cooler and still unsettled weather likely to continue for many with perhaps some cooler air in tow as winds turn more SW.

 

MY THOUGHTS  Today's charts continue to interpret showery weather as the main theme across the UK as slack Low pressure to the SW remains a dominant player in the weather for the next week or so. With the Low being to the SW the weather should remain reasonably warm and humid feeling in SE winds between the showers and thunder is a strong possibility for almost anywhere through the next week as a result. Longer term there seems little general consensus to bring an end to this pattern anytime quick with Low pressure remaining close by with High pressure locked over Eastern Europe although there is a minority of output that shows at least a chance of pressure building somewhat from the SW late in Week 2.

[knocker]

Yes the ECM is going for a not bad next weekend but I can't see it being excessively warm. The upper anomaly is edging towards its long term theme of pushing the warm air to the east further west.

 

[IDO]

The two European models are the most varied by D6 this morning:

 

ECM:   UKMO: 

 

GFS and GEM are in between. NAVGEM with UKMO: 

 

The GEFS mean is close to UKMO: 

 

At the moment it looks like some confidence in a stormy few days at the end of the next week for France:

 

 

Would not take much to put the SE in the frame. However the op run is further west than the mean for the plume of high uppers so we need the hi-res to drag the mean that way.

 

Each run changes the dynamics of the surface conditions so just guess work at the moment, though a period of unsettled weather for the UK as a whole centered more to the NW/W for intensity and cooler the further NW you are.

 

Preston GEFS:   Average to below average temps with plenty of rain.

 

London GEFS:  Above average with smaller rainfall events and totals.

 

I suspect the ECM for the end of next week show 3-5c higher temps than the GFS op as again the ECM op is at the top of the best case scenario with the cut off upper low and the jet running well to our north:

 

  Translating to higher 8-10 Day 2m temps: 

Two GEFS members (up from one last night) now go with this scenario; trend maybe?

Edited May 17, 2014 by i'm dreaming of...

[shaky]

We have been following the mean all week and it has always been slightly cooler than the op but am pretty certain so far the ops have been the closest to getting this weekend right at least!!

[Man With Beard]

The two European models are the most varied by D6 this morning:

 

ECM: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifECM1-144 (5).gif  UKMO: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifUW144-21 (5).gif

 

GFS and GEM are in between. NAVGEM with UKMO: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifnavgem-0-144 (2).png

 

The GEFS mean is close to UKMO: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifgens-21-1-144 (4).png

 

 

These charts show the knife-edge nature of the situation all week - eastern areas with higher chance of staying dry and warm, western areas highest chance of being wet, but a trip of 100 miles could transport you from hot summer to cool washout - and there won't be agreement on where that line is until much nearer the time.

 

In the long term, I think the more unsettled scenario is generally favoured, just because I can't remember too many times in the past, if ever, when a cut-off low to the SW has not eventually made progress towards the NE. The latter stages of ECM get better and better for summery conditions, but in accordance with my thoughts above, I would be really surprised to see the low pressure fade away to the west in this way:

 

[SMU]

Well this week sees a large heat plume building over central & most of Western Europe,the UK however sitting on the western periphery with the trough anchored to the SW of us & southerly flow just strong enough to push the hot air sliding to our East-

 

However as the trough eases & high pressure over Europe gets a firmer grip theres always a chance we could attract a more easterly flow allowing the hot air to filter into the South east- the chances are though there could well be some instability associated with that air, so it may well trigger some thunderstorms.

 

The heights over Europe look very similar to the heat that built over the summer of 2003-

 

The other added bonus is the angle & tilt of the azores high all the way up towards Iceland steering the atlantic well away from the UK-

 

All in all a good picture with the chance of some locally hot weather in the SE next weekend again.

 

CIAO

[A.J]

Well this week sees a large heat plume building over central & most of Western Europe,the UK however sitting on the western periphery with the trough anchored to the SW of us & southerly flow just strong enough to push the hot air sliding to our East-

 

However as the trough eases & high pressure over Europe gets a firmer grip theres always a chance we could attract a more easterly flow allowing the hot air to filter into the South east- the chances are though there could well be some instability associated with that air, so it may well trigger some thunderstorms.

 

The heights over Europe look very similar to the heat that built over the summer of 2003-

 

The other added bonus is the angle & tilt of the azores high all the way up towards Iceland steering the atlantic well away from the UK-

 

All in all a good picture with the chance of some locally hot weather in the SE next weekend again.

 

CIAO

morning Steve, nice summary....must admit though, saw you post and had to frantically check the latest model output to make sure an artic northerly blast wasn't on the cards!  .......just kidding, nice to see you post during the summer months

[IDO]

The ECM mean for uppers at D9:   Op: 

 

The op again looks in outlier territory at the moment:

 

op:  mean:

 

 

[bluearmy]

Outlier ID? Really?

It wasnt so many days ago that the x model ens guidance took the temps back down below 15c by tomorrow. As each day has passed, that cooler spell has been put back and back and it now shows only thursday as being likely to touch the mid teens in london. The point being that the progressive ecm ops have proved to be closer to the mark than the ens means. anecdotally, the ecm spreads have proved very informative.

[A.J]

Gordon, for your reference, as you haven't yet read pm's sent to you by the site team..

 

"The Team have had cause to remove one of your posts from the model thread today due to one of the following reasons:

 

• [*]

off topic [*]a short one-line post adding nothing to the discussion [*]social commentary/banter [*]inappropriate attachments [*]bickering

Please remember that the model thread is used by thousands of members each day who tell us they want to see it packed with information, informed posts and good analysis - with a good community spirit.  Please self-moderate your posts in future bearing these priorities and the more general forum guidelines in mind.  Any future removal of one your posts may be followed by a short suspension in your ability to post in the model thread.

 

Thanks

Forum Team"

[summer blizzard]

An incredible end to the 0z Euro, that looks to be an extremely stable pattern with no threat from anywhere.

Not to mention hot and dry.

[IDO]

Outlier ID? Really?It wasnt so many days ago that the x model ens guidance took the temps back down below 15c by tomorrow. As each day has passed, that cooler spell has been put back and back and it now shows only thursday as being likely to touch the mid teens in london. The point being that the progressive ecm ops have proved to be closer to the mark than the ens means. anecdotally, the ecm spreads have proved very informative.

 

 

Hi. Sorry referring to the synoptic of the cut off upper low at T216, as the outlier. This allows a ridge to slide in between the low and the jet:

 

 

Promoting the  warmer upper flow to be dragged towards the UK.

 

Other models showing the Atlantic Ridge being toppled as the flow deamplifies from our west and the trough is pushed east/SE. ECM has a pattern that has little support in the GEFS ens, that is, an upper ridge over Europe:

 

 GFS mean says no big time to that synoptic: 

 

The ECM ENS not really going for this amplification or locale, though more support than the GEFS: 

 

Knowing how of late ECM have been over progressive with heights I would like to see more support amongst other models.

 

As for the temps variability in the models from a few days ago, surface conditions were always going to be dependent on where the low meandered and how slack the trough was going to be. The mean has always been split into two clusters (cooler or warmer), so the mean temps were either going to be too low or too high. 

 

Lets hope for once the ECM has spotted a new pattern change correctly.

[bluearmy]

Thanks for the clarification. I did post last evening that the cut off upper low should be looked for as a possible direction of travel. I wouldn't label it an outlier solution based on the past 48 hours of output.

[Summer Sun]

After a warm start to the week UKMO still showing it turning fresher slowly from the north by Thursday though the SE is likely to hold onto the warmer air the longest

 

 

[ANYWEATHER]

Both ecm and gfs show unsettled weather next week, but the pressure charts are so different from both with ecm showing low pressure close to the west of the uk and gfs showing low pressure to the south of the uk, which is quite odd that the gfs is doing this in light of its previous output...  and as regarding precipitation next week forget any detail progged now , and wait to a more reliable timeframe...

Edited May 17, 2014 by ANYWEATHER

[Man With Beard]

ECM tonight fits in with what normally happens in these situations - after a few days hanging around to the south west, the cut-off low gets caught up in the westerly flow and moves NE, allowing a cooler HP to move in on its tail. I think this is the best bet - warm/thundery until midweek, a complete breakdown Thurs/Fri and something cool/showery next weekend, maybe not BBQ weather but not a washout by any means.

[ANYWEATHER]

ECM tonight fits in with what normally happens in these situations - after a few days hanging around to the south west, the cut-off low gets caught up in the westerly flow and moves NE, allowing a cooler HP to move in on its tail. I think this is the best bet - warm/thundery until midweek, a complete breakdown Thurs/Fri and something cool/showery next weekend, maybe not BBQ weather but not a washout by any means.

I think some members with all respect to them get carried away, but the warmth gets pushed East just as the cold continental weather in Winter. I think we should say we will be on the cold side of the heat on the continent, but it does not stop the uk getting some thunderstorms. but I think thundery torrential rain is more likely.....   :closedeyes:

[phil nw.]

Yes the Atlantic looks like winning through in the end after a couple more days of warmth in the SE.

The modeling for Tuesday shows the unsettled picture as rain/showers,maybe some thundery outbreaks become more widespread.

 

It looks like bands of showers or rain will move north and east across the country at times through the week with sunny breaks in between.

The 500hPa pattern modeled by the 12z op runs for Thursday next

 

keeps the continental heat to the east with the UK remaining under the influence of the upper trough during the coming week.

[Frosty.]

Although it will become cooler in the west / sw with showery rain, the eastern side of the uk, especially the southeast, will stay very warm and become more sultry with a continuation of long sunny spells but with an increasing risk of thundery showers breaking out...so it's a west / east split during the next five days or so with the lovely warmth holding on in the east / se for much of the week ahead.. A few more BBQ's then... Cheers :-)

[Captain Shortwave]

In the end the cold air dropping into the Atlantic was just too strong and prevented the low being cut off to our south west. This pretty much allows the low to eventually lift out in due course and makes the euro/scandi ridge less favourable to back westwards. Though at the moment I think looking beyond the end of the week still looks dodgy in terms of confidence.

There is still a plume event on Thursday which still clips the eastern side of the uk (models all quite close on this). So definitely a chance of some interesting weather that day in terms of possible thundery rain. It does look like turning fresher on Friday.

Edited May 18, 2014 by Captain shortwave

[knocker]

Greenland Block  animated in the 500mb parameter

 

http://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-51.94,62.32,497

[mushymanrob]

hmmmm ..... theres a huge difference this morning between the operationals and the anomaly charts. i always use the anomaly charts now for the best indication of what might lie ahead beyond 6 days time, they are very accurate when they agree, and even when they dont they are still pretty close.my feeling is that this weeks complex area of low pressure close to us throws up too many solutions and throws the evolution out of sync.... i like the anomaly charts which suggest the mean upper trough will drift further away from us and with high pressure to our northeast and far northwest lock in the trough. so whilst itll be unsettled at first, it should dry up especially in the northwest as the uk picks up a southeasterly draft. if the anomaly charts are correct, the last week in may should be a very pleasant one, especially in northwestern areas which could become hot.however, the anomaly charts, whilst most accurate 6 days ahead +, can change dramatically overnight, being such a long range prediction. so which set of runs will be right? the operationals that suggest a messy unsettled, warm but showery/thundery/muggy regime until the end of the month, or the anomaly charts which suggest it becoming drier and warmer especially away from the southwest. (after an unsettled week).

[Gibby]

HERE IS THE LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM TODAY SUNDAY 18TH MAY 2014.

 

THE CURRENT GENERAL SITUATION. A trough of Low pressure to the West and NW of the UK will pivot East on it's Southern flank to lie North to South close to Western Britain by tomorrow with a new Low forming towards the SW approaches later. Pressure will continue to fall steadily across the British Isles.

 

GFS The GFS Ensembles show an unsettled week to come with the current very warm conditions tempered by outbreaks of showery rain driven by slack Low pressure areas close to SW Britain through the week. next weekend and week 2 shows a continuation of the showery theme with various areas of quite shallow Low pressure close to the UK continuing to generate showers while the trend towards the end of the run is for pressure to build from the SW and the weather to become drier and more settled.

 

UKMO UKMO also shows slack and showery Low pressure maintained across the UK through the coming week and into the Bank Holiday weekend. Some heavy showers with thunder look likely and with little wind a lot of rain could fall from slow moving storms at times. After a very warm start temperatures look like slowly returning to average by day though humidity could remain quite high.

 

GEM The GEM operational shows a good week's worth of shallow Low pressure close to or over the UK with heavy, showery outbreaks of rain at times before a temporary rise in pressure across the North and East promotes a drier phase perhaps over the Bank Holiday weekend.

 

NAVGEM NAVGEM shows n such rise of pressure next weekend and with shallow Low pressure through the coming week too heavy showers are likely for all areas at times and this could be accompanied by longer spells of rain too next weekend, especially in the South where it may feel rather cool by then.

 

ECM looks broadly similar to last night's offering with Low pressure through this week maintaining very showery conditions, heaviest and most widespread towards the South and west with the very warm weather slowly ebbing away over the next few days. Later in the run as Low pressure moves North cooler Atlantic SW winds look likely to develop through next weekend and Week 2 with some cloud and rain at times with the emphasis for this shifting more towards the North and West with the driest and brightest weather then most likely towards the South and East.

 

MY THOUGHTS  The very warm conditions still present for some at the beginning of this week will continue to ebb away and by midweek shallow Low pressure zones to the SW of the UK will bring all areas a mix of bright spells and heavy, thundery outbreaks of rain for the remainder of the week and well into the Bank Holiday weekend. The humidity will be high and though days will be cooler night's will continue fairly warm for most. With time the longer term trend remains for most of the output to try and shift the axis of Low pressure further North and East and as a result showery rain will affect more Northern areas while the South and SE may become drier and warmer again through next week although there are some exceptions to this trend which maintain a showery picture under further shallow Low pressure. Any return to the current High pressure early Summer type weather type does look unlikely from the output shown this morning.