Model Output Discussion 18Z 18/6/13 onwards

[Gibby]

Hi Gibby, and thanks for another excellent update.

 

However, I disagree with your line: "if only we could get the ridge across to the East and feed Continental air over the UK I would be more optimistic for a sustained spell of settled weather. "

 

 

 Many members (including me) would probably like to see the High drift east of the UK, but that's not conducive to a sustained spell of settled weather, because it leaves the door open to the Atlantic and/or a hotter breakdown from the south, neither of which fits your desc

 

In situations like this, the orientation of the high is of crucial importance.  I think it's unrealistic to expect the models to have a handle on that kind of detail at this point, especially later on next week and therefore it is very hard to predict what the surface weather is going to be like.

 

For my money, I'd say that (especially in the south) we are looking at a 'quiet' spell of weather.  If the HP is close to, but not over the SW of the UK, that would produce a flow from the W/NW which would be slack in the south, a little more brisk in the north meaning that showers and longer spells of rain can be expected up there, over the top of the high, whereas rainfall in the south is likely to be significantly below average, with the SW possibly experiencing little or no rain.  However, sunshine could be locally very variable and temperatures are likely to be subdued with that kind of flow, probably no more than 20 at best. 

 

However, that may alter as the week goes on an inevitably the High's position changes, although it could be a change for the worse if the High pulls back into the Atlantic, allowing the development of a UK trough, rather than progress towards Denmark leaving us in the more continental flow that you are alluding to.....but that is all miles ahead.

 

I think all we can say for now is that we have a short and unfortunately time spell of cool and wet weather over the weekend, followed by relatively settled weather next week which is unlikely to give us any real heat in the short term. 

I take your point entirely and what you say is right but in my 50 years of studying weather the most sustained period of Nationwide Summer weather occurs when there is a blocking High up to the NE with a dry and very warm Continental feed of air from SE Europe over the UK. This has been known to hold off the Atlantic for days and sometimes weeks especially if the Azores High is present too with only limited influence from thunder from the South, an extreme example was Summer 1976. As it is no model that I have seen supports this synoptic setup so I remain to be convinced that improvements next week will be limited to 2-3 days and most likely for the South.

Edited June 19, 2013 by Gibby

[Summer Sun]

It looks like some parts are going to return to a fairly dry period again

 

[stainesbloke]

It's not a brief ridge, it's a proper anticyclone which lasts for most of next week, most of the model output shows a settled and pleasantly warm spell next week apart from the Navgem 00z which is very much on it's own, currently there is a lot to be encouraged about for next week, nearly every single post you put on here is a moan.

Actually I was commenting on the GFS run. That doesn't show any strong anticyclonic conditions in between this weekends low and next weekends awfulness. Just shows 2 days of quieter conditions. However, winds from the NW won't be warm and they are usually cloudy. I'm not moaning, I'm just stating things as I see them, trying not to be rude to other people.

[Scorcher]

The pattern next week looks like perfect "forum weather" to me. Not horrible enough (yet) to be greeted by billions of toys being thrown out of tiny cyber prams and not good enough for all the kitten-drowners to suddenly appear and start scrabbling frantically through the charts trying to find the breakdown and then posting all the charts that show it.

 

Remember last year when every weekend was greeted with a massive, spiralling, dartboard low? I do, beacuse it wrote off about 80% of my fishing season. This hasn't been the case so far this year so it's almost comforting to see this weekend being written off, next week looking ok (while i'm at work) and then potentially (if the GFS operational at t+240 whatever with limited support from the ensembles is to be believed) a repeat the weekend after.

 

Fantastic post, thank you. There really hasn't been enough mention of the fact that the patterns this year are VERY different from last June. It seems like many are hyping up the lows when they move in and playing down any signs high pressure moving in, despite the signals being strong from the ECM 00Z this morning. We are certainly going to get a lot more reasonable dry days over the next week than washout days. Funny that many are complaining about a lack of heat when last June they'd have bitten your hand off for a dry day at 19C.

[johnholmes]

It really is funny if you understand weather models and the charts they produce to read two differing views on what the models are showing for next week.

For those not too sure of how to interpret the models a brief summary.

After the weather over the weekend and perhaps into Monday being dominated by low pressure then surface high pressure begins to extend its influence from the SW lasting towards Friday before another Atlantic system is predicted to return the country to mostly unsettled or changeable whichever phrase suits you. Tuesday to Thursday GFS, IF it is correct, and it has support from ECMW and Met to a large extent, is suggesting afternoon temperatures around 21C for the bulk of England, not everywhere but the bulk, so a pleasant enough spell IF the model is correct.

[Frosty.]

Actually I was commenting on the GFS run. That doesn't show any strong anticyclonic conditions in between this weekends low and next weekends awfulness. Just shows 2 days of quieter conditions. However, winds from the NW won't be warm and they are usually cloudy.I'm not moaning, I'm just stating things as I see them, trying not to be rude to other people.

Try to stop moaning then, not sure how you get away with it to be honest.

[nick sussex]

Wow the Wimbledon curse looks to have been broken! For those tennis lovers out there the start of the Championships look nice.

Indeed theres a decent chance at the moment of the first week being largely dry, the ECM ensemble mean solidly behind a ridge holding out at least for southern areas, in terms of the ensemble spread theres no real shocks there with the largest spread to the nw and this would be in relation to how deep any low pressure might be as it tracks eastwards and how far south it gets. Alot depends on whether theres any forcing from building pressure to the ne, the operational does begin to develop that later, personally I hope that doesn't verify.

No heatwave on the way but pleasant conditions with generally light winds, best of the temps and sunshine in the se, perfect conditions for the players.

Edited June 19, 2013 by nick sussex

[Bristawl Si]

Doesn't look too bad for remainder of June (bar this w/e).

OK, not great but like others have said better than last year!

First 10 days of June were decent, the last week has been changeable, the last week of June looks reasonable.

Would we call that "Average" for June, as a whole? Possibly.

Certainly no disaster or unsettled, as some on here have been quoting in the last couple of weeks. Anomaly charts may say it's one type of pattern, but Joe and Joanne public only see what the weather brings each day.

Changeable at worst IMO.

[Scorcher]

Fair enough, but last June was truly extraordinarily bad. Not really something to compare to, is it? I always thought comparisons were made with the average? 

 

This June has compared pretty favourably to the average. In fact it's been much drier and sunnier than average so far with the temperature running below average mainly due to the cool nights. Then again you do live in the South East where it has been rather cloudier than areas further north. I imagine people further north and west (such as myself) would have a rather different opinion of June so far.

[Buzzit]

At the risk of a perma ban I am sticking up for myself and saying that I am sick and tired of all the moaning from Stainesbloke. There is a moaning thread go and moan there !!!!!!! Its model output discussion not psychotherapy discussion for your feelings about what the weather might be like.

[Methuselah]

Right peeps. Cut out all this silly bickering please. Use the moaning thread for moaning?

[johnholmes]

Fair enough, but last June was truly extraordinarily bad. Not really something to compare to, is it? I always thought comparisons were made with the average?So far this 'summer', my location (usually one of the warmest) has achieved the average maximum temperature TWICE. Note not exceeded, just achieved. Since then cloud cover has been consistent, temperatures suppressed and very windy conditions frequent. So forgive me for 'moaning', but that is the reality. I am biased towards hot and sunny weather, but at the moment average would be fine. Not screaming gales, cold and constant grey skies.

rather than clutter this thread up I am posting the actual data in the moaning thread which is where most of your posts should be, for Heathrow, pretty close to Staines unless my memory is wrong, so everyone can see just how awful your weather has been Edited June 19, 2013 by johnholmes

[Frosty.]

The Gfs 06z operational is a better run than the 00z in FI, remember that vigorous depression around T+240 hours on the 00z, well, on the 6z it's a much more shallow feature and slides down to the southwest of the uk, it does show a brief unsettled spell with a relatively weak showery trough over the uk but then high pressure starts to build in again, as for next week, the 6z shows pressure rising across the uk with a lot of fine and sunny, pleasantly warm weather with temperatures into the low 70's F but for a while next week there is still a low to moderate risk of some afternoon/evening showers but many areas would miss them and stay fine and warm. I've added a gfs 00z chart to show the difference on this run.

 

So in summary, becoming unsettled from tomorrow, thundery rain across southern uk during tonight and tomorrow, patchy rain across scotland & n.ireland, turning cooler, some residual showers on friday clearing east followed by wet and windy conditions by friday night and into the weekend from the southwest followed by sunshine and heavy showers and then the trough filling and pushing away northeastwards early next week with the azores/atlantic anticyclone gradually building across the uk.

Edited June 19, 2013 by Frosty039

[Captain Shortwave]

Hmm, 06z showing some signs of some heights building to our North East. Doesn't turn out great this run but a few tweaks involving the trough to our east moving out of the way then you could quite easily get a scandi high from there. Something to watch as it could give a fine and very warm end to the month.

[Geordiesnow]

The only problem with the start of next week is that it might be one of those set ups where things will start to dry out but with cool uppers, this set up does tend to lead up to a sunny start with cloud bubbling up and flattening out into stratuscumulus and with the cool uppers, it will feel quite chilly but even though the weekend does not look too promising(perhaps slightly drier on Sunday but still to early to firm the details down yet), at least the low is showing signs its not going to hang around for say 5 days like low pressure systems did last year so all in all, a mixed output. How much high pressure influence we may have next week, still far too early to call but the signs look reasonable too me. 

Edited June 19, 2013 by Geordiesnow

[AWD]

Just a quick one from me. Admittedly I haven't got time to look at all the data I would like to look at. From what I can gather from the NWP output this morning is that after a wet and unsettled weekend, things look like turning less unsettled into next week. However, I would ugre caution in assuming it will last all week and also assuming it will affect the bulk of the country. If we take a look at the main 3 models at 144 hours;

They all agree on the broad pattern of the Azores High ridging further NE towards the UK. However, there are small differences with pressure values and the extent of ridging and extent of troughing to our east. It might be small differences but ultimately it could have a large affect on surface conditions we receive.

The EC Det is the most persistent with reference to the troughing to our east, as shown above and below at 240 hours;

With the troughing so close, this would bring a lot of cloudcover as well as some showery interludes to the eastern half of the country. The west, and more particularly South West fairing the best. A look at the EC Mean at 144 hours;

and at 192 hours;

shows the high slowly making inroads into the UK, slowly reducing the showery threat further east. By 192 hours we start to see sunshine becoming more widespread but as soon as decent ridging appears possible, the 240 hour mean flattens things out again;

This is also broadly supported by the GEFS SLP suite;

notice the MEAN spread quickly returning to more average values after a brief rise in pressure. It doesn't suggest a return to unsettled conditions as such, but does suggest a return to more benign, changeable, showery conditons inbetween less unsettled spells, much like this week without the heat or humidity.

The NAEFS also suggests a flatter pattern towards the end of next week;

Similiar to the EC, troughing very close to the east there. The anomalies suggest troughing also close to the UK longer term too, but in a shallow form, suggestive of frequent ridges of pressure inbetween any unsettled interludes;

This is helped not so much by the Jet Stream moving north, but by it weakening substantially;

The link I have to the 500mb anomaly charts isn't updating properly, so unfortunetly I can't include this useful tool. Perhaps John can help here?

Anyway, it is all suggestive of frequent ridging of pressure rather than a full on Anticyclone taking control. The ridge never going too far away from the Southern half of the UK, so plenty of dry, useable weather here with just brief periods of rainfall. The north, being a little further away from any pressure rise will always be subject to more of an Atlantic influence.

Temperatures, regardless of location, don't look like getting much above average though. This is to be expected with pressure close to the SW and troughing close to the east. The airflow often being from north of west or even north;

The Birmingham ens show this nicely;

As do the London ens;

Where sunshine does break through, and there will be some, it will feel warm enough as you would expect for late June. Where your stuck under cloudcover, and again there will be some, it may feel rather fresh at times.

Rainfall looks like dropping off too, in response to the more settled theme ahead;

However, you can see some small spikes remaining, suggestive that at times, showers or weak fronts make it around the eastern flank of the pressure cell;

So all in all, typical British summer weather really. No heat wave and no washout. The centre of the pressure cell looks to remain out to the SW of the UK so areas further east and north will always be subject to weak fronts going around the pressure cell as well as cloudcover and showers from troughing to our east. With a north of west airflow, temperatures won't get to any special values either. There should though be a lot of useable, benign weather around, perfect for such events like Glastonbury and Wimbledon. The South West probably fairing the best in this set up.

Edited June 19, 2013 by AWD

[Buzzit]

It may be 'continually' in FI but one thing I have noticed over the last week with respect to GFS output is that it has consistently shown the jetstream originating and running at higher latitude from around the start of July onwards. At the same time there are still some lower latitude streaks hanging around on most of the output over the same period which complicates matters. I am currently 'hopeful' that July and August will turn out more settled than currently expected as I see slow growing hints of a proper pattern change allowing the jetsream to generally sit above the UK.

 

By the way I am looking forward to the rain clearing on Sunday in time to see the biggest perigee full moon on the 23rd June. (biggest until August next year) Should be quite a sight to see once the rain disperses.

[legritter]

Good afternoon all ,certainly a very nice june day and looking at Modells and Data we must enjoy it while we can .so as modells have been saying an unsettled 3/4 days awaits ,the price to pay for a peck of june in all her glory .iv realy enjoyed the posts today plenty of information and constructive input .i would like to slip in whilst in a quieter time of day some pointers for new members and learners .a very good way in my opinion to perhaps understand Upper air charts at different levels in the atmosphere would be as iv pointed out before is to take a look at ,The science of Contrails there are several sites .although clouds also show you a very similar guide to whats happening up there i find these injections of moisture and particles etc very informative .anyhow back on track and early next week not looking too bad but past T168 it looks like atlantic will try and make inroads again .this time last year i was in canada for several weeks ,Bereavement and holiday ,and the good old UK made the weather channel most days with severe weather of some sort ,so things are atleast not too bad .catch up later .

[Frosty.]

Well, out of all the 00z output this morning, the Navgem 00z stuck out like a sore thumb with it's cool and unsettled trough dominated pattern next week and this appears to be what the met office are indicating for next week with an east-west split with eastern & northeastern areas being cool and cloudy with showery outbreaks of rain, locally heavy in places, drier further west but still with a lot of cloud but with some sunshine in sheltered spots, and then for unsettled weather to spread from the west to all areas later next week, so, no indication from the latest update that the azores/atlantic anticyclone will build northeastwards across the uk according to that outlook, more like our weekend trough persisting to the northeast of the uk for the first half of next week with some weak ridging only getting into the southwest and west of the BI before another atlantic low moves in.

[lorenzo]

Ryan maue put up an interesting stat showing a rare ECM wobble for correlation at the120 range. Dropping below the 0.8 baseline

MJO projection between it and GFS looking well different too. Can July deliver...

[Frosty.]

Ryan maue put up an interesting stat showing a rare ECM wobble for correlation at the120 range. Dropping below the 0.8 baselineMJO projection between it and GFS looking well different too. Can July deliver...

I hope July does deliver but it's a little concerning that the current extended met office outlook is for below average temperatures and above average rainfall, if there is going to be a radical pattern change in july, surely there would be at least a faint hint by now.

[bringmesunshine]

I hope July does deliver but it's a little concerning that the current extended met office outlook is for below average temperatures and above average rainfall, if there is going to be a radical pattern change in july, surely there would be at least a faint hint by now.

Now then Frosty lad, don't start getting negative please, there are enough people on here to do that for us and your positive interpretation of the models cheers me up every day. To be honest the metoffice outlook has been pretty dire for weeks now but many, if not all of us, are having a perfectly reasonable June so far. For any sign of  a pattern change I wouldn't look to the met but tend to keep an eye on John Holmes, Tamara, Gibby, TWS and others who in the last couple of summers have flagged up changes miles before the met, who seem to have become a reactive organisation, cautious to the point of paralysis.  

[Summer Sun]

I hope July does deliver but it's a little concerning that the current extended met office outlook is for below average temperatures and above average rainfall, if there is going to be a radical pattern change in july, surely there would be at least a faint hint by now.

 

I'm doing my best to just ignore the update at that range they always change as we know

 

UKMO shows high pressure moving west to east early next week Monday starts dry and possibly cloudy in the west but in the east some rain is possible with the low still hanging around here

 

 

Tuesday though sees the high moving over all the UK it could be cloudy in places but where it does clear it will feel very pleasant

 

 

GFS also shows the high extending east on Tuesday

 

 

Still in place on Wednesday

 

[Frosty.]

After the mostly very promising 00z output, the Gfs 12z keeps the high pressure trend going strong during next week with a significant pressure rise as the weekend trough slowly fills early next week and drifts away northeastwards with the azores/atlantic anticyclone ridging up and across the uk, however, despite the high pressure, the gfs still indicates a risk of afternoon showers developing but I would think the fine, warm and sunny spells would outweigh any showers risk, especially as the high continues to build, the showers risk would continue to fade as indeed it does, by midweek it looks more settled and pleasantly warm.

 

 

Now then Frosty lad, don't start getting negative please, there are enough people on here to do that for us and your positive interpretation of the models cheers me up every day. To be honest the metoffice outlook has been pretty dire for weeks now but many, if not all of us, are having a perfectly reasonable June so far. For any sign of  a pattern change I wouldn't look to the met but tend to keep an eye on John Holmes, Tamara, Gibby, TWS and others who in the last couple of summers have flagged up changes miles before the met, who seem to have become a reactive organisation, cautious to the point of paralysis.  

Thanks bringmesunshine, I will carry on being positive.

[Frosty.]

This is a good run from the Gfs 12z, the high pressure is far enough north in the atlantic to keep the unsettled weather generally to the north of the uk for most of the time, the southern half of the uk is safely in a settled pattern and pleasantly warm with strong ridging, trending warmer towards the end of the run too.

Edited June 19, 2013 by Frosty039