Model Output Discussion 01/06/2012

[A Winter's Tale]

Thankfully, no rain has arrived yet in London with the Queen's Jubilee. Currently the front is over SW and W Wales, SW England and SE Northern Ireland.

The above chart is last nights future rain chart. It seems that it has got the positioning of the heaviest and main areas of the ppn correct aswell as the showers over Moray and Aberdeen. But generally, a slightly better day than I would have first thought after viewing the models last night.

The Highland frost predicted by the GFS 18z UK minima charts was also correct with lows including -2.5C.

Last night I mentioned how the theme of the next 4-5 days is for low pressure systems to sweep through the country from the SW as a result of the presence of high pressure over Greenland. The chart below shows 1024mb over Greenland than illustrates the fact of our weather being dominated by this.

Some sunshine is likely at times in clear spells between systems and like today, some drier periods are also likely and generally, temperatures should be around the mid teens so it shouldn't feel as cold as recent days.

A brief look at what the next few days have in Store:

WEDNESDAY

A milder scenario at 6am with SWly winds and upper air of 5C for the majority of England.

It looks likely the majority of the precipitation should be over Scotland with the heaviest to the east. Again some rain is likely down the east coast, North of England, NI and showers in the SW.

Possibility for early morning sunshine around London and the Midlands.

Midday, again the weather system is present over Scotland although it could end up affecting more far north eastern areas. Showers are likely elsewhere and some sunny periods are likely when the cloud cover breaks up - particulary in the south.

Temperatures are projected to be cold at 7C in the Central Scottish Highlands with the warmest in the S and E with 18C possible in London. Not a bad day for making the most of the weather.

At 6pm, we may still have the remnants of the rain over the NE of Scotland and with another system approching the SW. Inbetween, showers are likely but sunny spells are also likely anywhere from Lochaber to Southampton. The above chart shows the trail of low pressure systems out in Atlantic, ready to move NE over the UK towards a Scandinavia where pressure is considerably lower than in Greenland.

THURSDAY

6AM, another system in the west ready to drench Ireland and western parts of England, Wales and Scotland. Should be less showery elsewhere.

12pm, the heaviest of the rain is likely to be over Ireland but more persistent - and in some areas heavy - rain is moving northwards to give the S and SW some rain. Parts of Scotland and NE England should remain dry and some sunshine is likely on eastern coasts.

That is the outlook for Wednesday and Thursday but I'll return later to have a look at what the following days have in store and whether this endless theme of low pressure from the SW will continue.

[PubliusEnigma]

Yes synoptically there has been no change from the last few summers, so you would expect this pattern to hold fast for next month and least, but we know suggesting that is illegal. I'm not sure I can see a changee occurring anytime soon either, I do think we are going to have to be either very very patient, or resigned. Either way the evidence on the table right now, doesn't suggest a huge amount of optimism for what people might see as a fairy tale summer.

Regarding the models, look where the cold green spot is located in 10 days time.. Yes you've guessed it..

I do wonder if we suffer some kind of climatic boundary outflow, similar to one that occurs in situ after a major storm. So that we kind of attract the toughing to this

region of the northern Hemisphere. Again this set up sees ALL of Europe basking in summery weather even Scandinavia, the one exception being the UK which is

grey and rainy, like today. On a positive note, we've lost the cold cloudy easterlies of this weekend to be replaced by mobile westerlies for the foreseeable future.

At least with these there are some sunny intervals between the rain bands and clear skies especially at night..

[Andy Bown]

Thankfully, no rain has arrived yet in London with the Queen's Jubilee. Currently the front is over SW and W Wales, SW England and SE Northern Ireland.

Looking at the latest radar rain is an hour or so away from Central London meaning another cancelled fly past is probable.

The rain band is approximately 3 hours wide which means rain from about 15.00-18.00 in Central London.

[PubliusEnigma]

Hmmm.... The MJO suggests a rapid transit from phase 5, through to phase 8 and 1 by the end of the prediction. Phase 8 and 1 for june suggest high pressure over/close to us, so some hope possible after a spell of low pressure domination. Id be happier though IF the 500mb anomoly charts supported a phase 8, 1, synoptic. They dont.

The thing is Rob, High Pressure may well be close by, but if its in the wrong place, ie. NW or south or North etc.. we'll end up with cloud and rain.. Remember this is Britain.

It needs to be slap bang over us without an inversion, or positioned over Benelux for anything approaching seasonal weather.

Looking at the latest radar rain is an hour or so away from Central London meaning another cancelled fly past is probable.

The rain band is approximately 3 hours wide which means rain from about 15.00-18.00 in Central London.

Its pouring with Rain in Surrey now, apparently the fly past has been cancelled. I have no idea why they would try to organise something

like a fly past and all these outdoor precession style events at this time of year, when its likely to be wet or cold ??

[PubliusEnigma]

Now that is more like a summery chart..

Although I would prefer that Northen Scandy High wasn't there, as that could well scupper the likelihood of this coming

off..going by past events.

[Cheese Rice]

My comments are based within the day 10 timeframe, all i see is low after low, a northerly and then a warmer low.

Anybody that thinks this is a good outlook probably thinks England will win Euro 2012, i have viewed the models long enough to know what good and bad synoptic outlooks are and this is bad.

We have lost the colder 850s though which prompted maxes of just 6/7.c on Sunday under the rain. With this in mind we can still see some relatively nice days in between percipitation. Illustrated Yesterday where most of the UK saw plenty of sunshine, maxes in the 15-17.c range. Although disappointing for June it still feels warm in the sunshine. Tomorrow is another example where temperatures could reach 20.c over a wide area providing there are any lengthy spells of sunshine in between the showers.

NAE for example going for the highest temperature in the UK of 18.c over Leeds. Could well see 19/20.c.

So while yes the outlook is disappointing -and I firmly believe this pattern will last into mid June- there will be spells of sunshine in-between lows, making this outlook not as dire as the first half of May which saw endless cloud, rain, and suppressed temperatures.

[Lewis]

Please do explain your reasoning.

If it's that FI is showing high pressure then your point is invalid as it isn't coming into reliable time frame (sub T192).

Anyway a nice warm day showing up on the NAE.

A showery one yes but in sunshine temperatures should rise to 20.c in the South.

I'm sorry but was it not only 2 days ago you yourself was making claims that the weather would be a period of continuous cold and unsettled days and you was falling back on and posting charts in FI highlighting that HP is a long shot, and it's going to stay unsettled with low pressure.

[Cheese Rice]

Its pouring with Rain in Surrey now, apparently the fly past has been cancelled. I have no idea why they would try to organise something like a fly past and all these outdoor precession style events at this time of year, when its likely to be wet or cold ??

Don't be ridiculous. The UK's default pattern is one that is changeable, illustrated by the hot spell at the end of May.

Please push your agenda on the climate change thread, not the model output. You've made it quite clear what your views on the summer will be, please just leave it at that. Otherwise your posts will cause more arguments and conflict.

Post in the the effects of the jet-stream thread.

http://forum.netweat...the-jet-stream/

[Cheese Rice]

And here we have an extract from my post..

We could see some warmer 850s dragged north associated with the lows which if all timed perfectly could bring the odd hot day.

Which is what we are seeing tomorrow.

[shedhead]

Really can't see any point in the constant digging/point scoring. I think it's pretty obvious to all with eyes that the next week or so looks pretty dire, but to suggest the start of a slow improvement into week 3 is neither inaccurate or misleading at this stage, in fact it does look more likely than not. No one to my knowledge is forecasting a rapid transistion to heatwave conditions, simply a slow but steady improvement, which to be fair should not be difficult.

[Lewis]

And here we have an extract from my post..

We could see some warmer 850s dragged north associated with the lows which if all timed perfectly could bring the odd hot day.

Which is what we are seeing tomorrow.

Was just saying you was linking to charts in FI based on your long range prediction, but as soon as someone else does this they are promptly asked to explain themselves "yet they have only done the same as you the other day using charts in FI".

I don't see a problem at all posting charts in FI, at the end of the day the models go to that time frame so the output has to be considered, although FI is at the lowest resolution part of the run and is less likely to verify it still warrants anyone to make claims based on the output. Nothing wrong with that at all, if it confuses me with regards to the bickering of the long range outputs, what is it going to do for new members, guests, and those that are trying to learn or get a sense of what's happening?. It will bring nothing to the table for them.

[Cheese Rice]

Was just saying you was linking to charts in FI based on your long range prediction, but as soon as someone else does this they are promptly asked to explain themselves "yet they have only done the same as you the other day using charts in FI".

Please read my post where I addressed the issues with looking at FI and where it is plausible.

[A.J]

I've come across this amazing new concept for forum posting here on NetWeather....It revolves around actually heeding the site-members requests with regard to posting on-topic, non argumentative, non-biased, non sniping/baiting posts et al....you know, the sort of posts that members agree not to post when they join the forum.....perhaps a few members who frequent the Model Output Discussion should embrace this concept...Go on, give it a try, what have you got to lose?....

[Scorcher]

The thing is, I think people are getting to hung up on the unsettled/settled thing, it's either all or nothing for some people. If the models are not showing high pressure in control with warm temperatures some think that means the outlook is 'poor' or 'dire'. For instance, even this week the models are suggesting there will be some dry spells, as there are today.

Today is cooler than average in most areas and cloudy, but is it dire? Certainly not in my opinion. Sunday may well have come into the 'dire' category, it certainly did for me due to the constant rain coupled with unseasonably cold temperatures. I agree with Cheese Rice's point that we have lost the cold uppers that we had on Sunday and the models illustrate this. For me this takes this week firmly out of the 'dire' or 'atrocious' category which for me would mean constant rain and wind with cold temperatures.

[PubliusEnigma]

Don't be ridiculous. The UK's default pattern is one that is changeable, illustrated by the hot spell at the end of May.

Please push your agenda on the climate change thread, not the model output. You've made it quite clear what your views on the summer will be, please just leave it at that. Otherwise your posts will cause more arguments and conflict.

Post in the the effects of the jet-stream thread.

http://forum.netweat...the-jet-stream/

Since the 5th April, we have had one, dry warm and sunny weekend. We are now into June. thats roughly one in ten weekends that have been suitable for

outdoor events. With such odds against fine weather at this time of year, I wouldn't personally want to risk an outdoor event.

[PubliusEnigma]

this week the models are suggesting there will be some dry spells, as there are today.

??

It's 13oC and steady moderate rain under leaden grey skies and has been since around 1pm

[bluearmy]

And here we have an extract from my post..

We could see some warmer 850s dragged north associated with the lows which if all timed perfectly could bring the odd hot day.

Which is what we are seeing tomorrow.

Are you off to the med then tomorrow CR !!If tomorrow is classed as 'hot' then PE really is right!Good NAEFS 00zrun for better conditions post mid month but aside from a general rise in heights to our se which slowly encompasses the Uk, no obvious route from the model of how we arrive there. Until we see a broad solution on a consistent basis from the fi ens, I'll remain cautious.

[gottolovethisweather]

I've come across this amazing new concept for forum posting here on NetWeather....It revolves around actually heeding the site-members requests with regard to posting on-topic, non argumentative, non-biased, non sniping/baiting posts et al....you know, the sort of posts that members agree not to post when they join the forum.....perhaps a few members who frequent the Model Output Discussion should embrace this concept...Go on, give it a try, what have you got to lose?....

How about this aj, can we have some Model Output Discussion, from now on please!

Let's face it, a few in here are simply not abiding past requests to post on topic and will ultimately be facing a longer holiday period than they might have envisioned.

Happy holidays and what of the forecast?

gottolovethisweather

[A Winter's Tale]

Wednesday and Thursday looks like a story of showers, some sunny spells and low pressure systems - a very changeable theme with no one weather type around for too long.

We've seen many times on the various runs and charts for the weather this week shows a consistent trend for low pressure systems moving in a SW-NE direction, it looks like this theme may continue in the reliable time-frames but as Model watchers it is our job to spot any slight change in the movement and positioning of systems and the influential high pressure over Greenland within a reasonable time-frame. But first and foremost it's essential to talk about what the models are showing and what it means for us.

FRIDAY

The chart above is an interesting one. A clear-cut low pressure system is situated over the UK with 992mb over Wales. In a low pressure system the wind moves in anti-clockwise direction so for example the wind direction in SE England is a SWly, SEly in NE England, Ely in N Scotland and NWly in Ireland. The isobars are close together over Ireland and the SW so I would imagine the wind will be relatively strong here whereas between Edinburgh and Aberdeen there is a larger distance between isobars so wind direction should be lower. Still over Greenland, the highest pressure is 1024mb and that high pressure has an influence on Iceland aswell a small triangular area to the south of Greenland. That tip of the high pressure south of Greenland is forcing the low pressure systems to the west of it - for example the depression leaving Newfoundland - further South and East whereas on the UK side of the block sees the depressions take advantage of the lack of blocking to the east so we end up with low pressure moving NE, over the UK to Scandinavia where pressure is lower. Over in Ukraine and Poland where the UEFA Euro 2012 Championships will be played, it seems that it will be warm and settled.

The complex nature of this system means that there will be various areas of rainfall and some areas that will remain dry, but the wild nature of this means that nothing is for certain and what element of weather you get won't be around for long. A definite swirling nature in the rainfall in this depression with a strip of rain bending from the Netherlands, NWrds to Scotland, S to Ireland and E all the way to the English South East. Parts of Eastern England may remain dry at this time with some sunshine also likely, but as I say nothing is for long so some areas that have the sunshine may have the rain and vice-versa.

And this chart here shows that some areas may hang onto the rain though those drier areas in the east may also get the rain too. Heaviest in NE Scotland, NI, SW and the S.

6pm doesn't look too inspiring as generally wet conditions across the UK prevail with the heaviest now over SW Scotland. And out to the west there is another strip of rain which suggests more rain to come for some.

SATURDAY

Saturday could be an improvement for quite a few areas, but typically, some areas will get some rain in some shape or form. Still we've got more depressions out in the Atlantic and poised for the UK thanks to the Block over Greenland forcing the jet south.

It should be a considerably drier day for most although remnants of the previous weather systems and showers is likely. Little sunshine with skies poised to be overcast.

Temperatures typically around 15C in the South and as low as 10C in the north and west.

On this chart, rain is likely to be most common and persistent over Scotland and yet again there is that all too familiar blue blob to the SW.

SUNDAY

Confidence isn't all too high at this stage so further observation of the models will explain all the subtle variations and differences. So the timing, positioning and firmer details will change. But this chart shows two different low pressure systems at different ends of the country. You can see that the warm front of the depression is over the south-west with the previous depression leaving the NE of Scotland.

In between it's likely to be clear but through experience it's a short restbite with this pattern of low pressure firmly locked. The heaviest of the rain again to the SW on this chart with some patchy rain in parts of N Scotland.

The difference this time is that for once, the rainfall doesn't move NE, instead it moves eastwards across much of the south of England. North of Manchester will be driest but still, some showers and patchy rain is likely here too.

9pm, smaller areas of rainfall dotted around the western and southern areas with the East enjoying some dry weather.

MONDAY

Still, importantly, High pressure remains over Greenland and more low pressure systems lurking out in the Atlantic.

TUESDAY

Far out, so things should change but here we see some differences. Not exactly what some may hope for as we have a cold northerly air stream over the north. Low pressure in the Atlantic looks like moving a bit further south and away from the UK. The isobars are very far apart in the area of the Atlantic including the seas around Iceland and Greenland. Perhaps this is forcing the low pressure systems further south and allowing a northerly air flow for some parts of the UK.

WEDNESDAY

Confidence and accuracy is low by default here but the continued theme of high pressure over Greenland and Iceland continues. Some variations with high pressure close to the north of Scotland at times - similar to a few days ago.

EXTENDED OUTLOOK - FI

Here, we see low pressure over the UK. This suggests that some warm air may not be far from the SE but because of the poor quality of detail here, it's unlikely to turn out exactly like this here. High pressure is still to the north of the UK. But 1024mb is over to the NE of Iceland for a change.

Although there seems to be more yellows and oranges near the UK, to my eye, this chart doesn't look much different from the ones this week as essentially we've still got the continous trend of northern blocking and low pressure to the SW.

At the very end, the high pressure to the north loses its grip with low pressure moving northwards, subsequently warmer air over the UK. But most importantly, we know that for this week and probably the next 10 days we'll see high pressure over Greenland and low pressure moving SW-NE with some short clear periods. But we have to bear in mind there will be subtle changes in the models so finer details will change and we have to accept that things can come out the blue and even in this current set-up, localised - unexpected changes at short-notice can occur with some period of sunshine. But it's a constantly changing scenario, not ideal for warm, sunny weather for the outdoors but hey, it's the weather anyway so it can't be all that bad - even with a set-up like this.

Keep watching the models for short-term changes and potential changes in the current set-up, I feel that eventually we'll get rid of this post 2007 summer set-up eventually with the doors opening for much appreciated warmer and sunnier conditions but like ths current set-up, with the classic and wonderful changeable conditions that we have in Britain.

[johnholmes]

I find it very sad that there is this constant arguing, no other word for it, why the devil can you not ALL post your views and illustrate those views with a chart or two. So long as you state quite clearly that you are showing the GFS/ECMWF/Met chart for T+xyz you cannot then be accused of cherry picking.

Thankfully I'm on holiday for a few days after tomorrow so may sadly have to miss what will almost certainly be further bickering.

I'm not posting charts but will refer you to the NOAA 8-14 day outlook issued last night and the ECMWF-GFS output for 10 days issued this morning. Not too hard to find!

Both in my view, well not ECMWF, but the other two do PERHAPS show the first glimmerings in that time scale of some height rises east and NE of the UK. That is pretty similar to what they showed some 12-15 days before the last high pressure settled spell. Whether it will give similar heat and sunshine is far too early to say.

[phil nw.]

Ok some of you have had your posts removed,Stuff that`s of no use here and just amounting to petty point scoring.

This clutters up the thread and spoils it for other members and visitors who want to learn about the latest outputs.

.

If you disagree with someone then simply post your views linking some data to show your reason-simples.

If you can`t do this and want an argument then go to a chatroom or send each other hate mail.

[PubliusEnigma]

A look ahead to the weekend, and the focus on the rain moves to Northern Britain with a wrap around of a Low Pressure centered

over Scotland. The south should be drier first thing, but some beefy showers could get going from late morning onwards. What I

continue to find remarkable is the extent how far south the jet is, with a train of attendant Low pressures positioning along the

40n Latitiude, and the Azores HP non existent. High Pressure, east of Greenland is ridging SW into the Atlantic diverting zonal

weather a lot further south, more in keeping with what one would expect in winter. We could really do with the complex

Low over Scotland drifting westwards which would allow some warmer air to be dragged in from the SW. Still a few days away

and small changes can make a big difference in temp profiles under this type of set up.

[Lewis]

They may be uncertainty with regards to our longer term pattern, but there's no uncertainty that during the short term we are going to experience a more fresher, low pressure dominated pattern of weather, with some possible convective weather for central & eastern parts tomorrow.

Another change is occurring now as a LP system off the Atlantic becomes established and moves North Eastwards towards the United Kingdom.

There is currently an area of precipitation giving moderate to heavy rainfall for central southern regions and the South East, this area of precipitation will continue to edge North Eastwards during the course of this evening exiting East Anglia during the early hours.

As we head further North, they may be a period of precipitation overnight tonight for Central and more Eastern parts of England, pushing through to Northern England.

The heaviest of the precipitation is more likely to be across central areas, mainly pennine areas.

Overnight tonight temperatures will be much more respectable than of late, with temperatures expected to be 10-11c quite widely, with the highest of the temperatures across the South East where they could reach 12-13c, although locations experiencing prolonged rainfall may have lower temperatures, of around 8-9c.

As we head in to tomorrow morning it will be a cloudy, dreary start for many, with extensive cloud cover, very little in the way of breaks to start off with.

Throughout tomorrow temperatures will be a little up on today with highs of around 15-16c quite widely, with some areas possibly hitting 17-18c.

Throughout the course of tomorrow showers will develop fairly quickly, heavy in places with localised thunderstorms. I'm keeping an eye on a trough tomorrow drawn on the fax charts for the South East and East Anglia, they could be some very sharp showers with thunder and lightning developing tomorrow, then as we head in to the afternoon and early evening the risk extends Northwards across the East Midlands, Lincolnshire and then through to East Yorkshire/Humber area.

As you can see on the below image, some energy is available from the word go in the form of moderate levels of CAPE and a negative Lifted Index, covering a bulk of Eastern and central England, and also parts of Wales.

As we head in to the early evening tomorrow CAPE and LI values become more prominent across N Yorkshire, East Yorkshire, Lincolnshire, East Anglia and the East Midlands;

These showers may become more organised and slow moving giving torrential downpours for many of these parts, and also the risk of some moderate to severe thunderstorms with frequent lightning.

Although cloud cover will be rather extensive, and it's a feature that many members may think will play a big part tomorrow of conditions not being favorable for thunderstorms, as always this is always a possibility, a risk we run with, but with an approaching trough, I think this will aid the activity and be the trigger in terms of convection.

Dew Points are favorable, in the low to mid teens, although it would be good if we could hit maybe 14-15c, something we need to keep an eye on tomorrow morning and as the afternoon develops.

As we head on through the week the unsettled theme will continue with weather fronts making their way in off the Atlantic, South Western and Western areas look to bear the brunt, with Ireland possibly taking a battering from a deepening area of low pressure, something to keep an eye on no doubt.

But it's certainly an unsettled spell of weather to come for many of us

Regards,

Lewis

[Supacell]

Lewis, you should copy part of your post into the convective thread as its very informative regarding storm potential tomorrow

[Cloud 10]

This evening's ECM still showing that low pressure affecting the UK on friday,although the wind has

been toned down a touch,but still some heavy rain associated with it.

Later in the run,something to warm the cockles of Gavin D's heart.