Model Output Discussion 12z 30/06/13

[Summer Sun]

A set of extremely dry and increasingly warm / hot ensembles

 

 

Precipitation forecast out to July 16th

 

 

Once again some coastal districts look a lot cooler than inland spots an example of this is below

 

 

Eastern coasts look to be the worst affected during this spell as the winds will be coming in from the east once again so given the cool north sea still it will certainly feel fresh along this part of the UK cloud could also affect the east coast at times as well

Edited July 1, 2013 by Summer Sun

[Geordiesnow]

The outlook still remain on this morning of a quick pressure rise for the end of the week and into the weekend at least, won't go as far in saying its going to last 2 weeks or anything daft like that but the high pressure projected look like a blocking high and if heat starts to build, then the Atlantic/jet stream will find it harder to break through, all in all quite a good output if it occurs. 

[johnholmes]

the look at the 500mb anomaly charts I promised with a forecast

looking at how the 500mb anomaly charts have moved in past week-1 july 2013.pdf

copied to other thread as well

[Milhouse]

I didnt think i'd see a chart like my avatar anytime soon but the GEFS mean places a strong high centred right over northern England at T+168

 

[Milhouse]

ECM as well

 

Wouldnt be suprised to see the high 20s right up into Scotland given the position of the high

[Milhouse]

Somewhere in Yorkshire e.g Leeming in the vale of York looking the hot spot on Sunday at present.

 

[Milhouse]

UKMO as expected builds high pressure strongly over the weekend and ends with a breakdown nowhere to be seen.

 

[Tamara]

More proof that certain members spending days on end patronising members who are looking in the models for warm shots may come back to bite them. Some good midrange forecasting by Frosty et al, assuming the warm spell verifies - which looks likely now.

This sort of thing is completely unecessary and doesn't bring anything to the discussion - it isn't a competition to win or a war.

 

Worth looking at these - you can't get better agreement from the EPS individual members out to at least a week away for Summer High pressure than this. The fine spell of course starts half way in that week long time period, but nonetheless, there is unlikely to be any immediate breakdown from that point illustrated.

 

 

I think the models may try to be progressive in the FI period in the coming days to retrogress the High into the atlantic and lower pressure to the NE. This is a valid eventual signal I think, but its worth considering that the models may over anticipate it and try to bring it in too quickly. On that basis, it is not unreasonable to expect the fine and very warm spell to last, at least, well into next week.

[Walkinglad2013]

Will it be Hot and Sunny on July 20th - 21st weekend?

There is no sign of summer today its raining here in leeds

[Milhouse]

Will it be Hot and Sunny on July 20th - 21st weekend?

There is no sign of summer today its raining here in leeds

 

Impossible to tell that far away.

 

Today doesnt feel very summery here either but the models have tended to upgrade high pressure for Wednesday and Thursday so before the main high arrives it should turn quite warm and humid again around the middle of the week.

[stainesbloke]

This sort of thing is completely unecessary and doesn't bring anything to the discussion - it isn't a competition to win or a war.

Worth looking at these - you can't get better agreement from the EPS individual members out to at least a week away for Summer High pressure than this. The fine spell of course starts half way in that week long time period, but nonetheless, there is unlikely to be any immediate breakdown from that point illustrated.

I think the models may try to be progressive in the FI period in the coming days to retrogress the High into the atlantic and lower pressure to the NE. This is a valid eventual signal I think, but its worth considering that the models may over anticipate it and try to bring it in too quickly. On that basis, it is not unreasonable to expect the fine and very warm spell to last, at least, well into next week.

Good post (as usual). There are signs that the high will attempt to retrogress. Personally, i think it's too far away to be concerned about but it's certainly worth noting. At the moment it looks like we will see 5 days of warm/hot settled weather after Thu. That could well extend further, with any luck

[Evening thunder]

30C in the south if this verifies?

 

The high may not get east of us much but they're excellent charts. In fact IMBY that chart could well give higher temps than a southerly with higher uppers, as a southerly would come off the sea. My hottest temps often come of easterly drifts e.g 33C at Exeter Airport on two days in the 1976 from the charts posted previously on this thread.

 

the ECM does seem to show slightly higher uppers than some models like the GFS and the ensemble means, but  high 20's in places at least look quite likely to me as long as there isn't now a shift in model outputs. 

 

Yes personally I'm also not going to worry yet about a retreat of the high pressure or whatever, considering the charts before that have only recently entered a more reliable timeframe. It may happen but is by no means certain of course although it will end somehow at some point. The Met Office outlooks say there are signals of the dry settled weather continuing with below average rain, above average sun and above average temps at least half way through their 16-30 day outlook. That would do very nicely if that was to occur, I think I'd be crying out for rain by then considering we've had no significant falls here since May here and the top of our lawn is already looking dry!

[Summer Sun]

This morning I've read in the papers high pressure will last till August heard it on the radio and thought to my self how long will it be till the models show low pressure and GFS 06z does have it this morning at times although there won't be much rain around cloud could become an issue suppressing temperatures

 

 

We then see a decent weekend but in Scotland trouble is brewing

 

 

I will take a look at the cloud amounts for this settled spell in a separate post

[Milhouse]

Predicted temperatures for Sunday

 

[Frosty.]

Here are the highlights of the Gfs 06z, it delivers a lot of warmth and sunshine for a time but by the middle of next week it's over bar the shouting, at least for the north & west of the uk, there is too much disruptive low pressure to the northwest of the uk which erodes the high at it's weakest point, the northwest of the uk, however, i'm expecting the upcoming heatwave to last much longer and be a nationwide event and not tail off to mediocrity as the 6z op run does.

[Summer Sun]

So now lets take a look at the cloud amounts and temperature for this spell all will be based at 18:00 BST the coolest spots in this spell are the coasts of the UK with temperatures here struggling to get above 20c the once exception to this is parts of the south coast (Brighton, Bournemouth ect)

 

On Sunday we have some thick cloud affecting parts of the north but Yorkshire south looks sunny will very little cloud

 

 

Temperatures are widely into the high 20's but there are exceptions these are mainly coastal areas and Scotland

 

 

Into Monday and ts only western Scotland which is stuck with thicker cloud else where its clear blue sky

 

 

Temperatures again are widely in the mid 20's but once again we do have exceptions the east Anglia coast looks one of the coolest spots along with the far south west where these 2 spots struggle to hit 20c an easterly to SE'ly wind is to blame for this is east Anglia

 

 

Into Tuesday and once more Scotland is stuck with thick cloud the rest of the UK has more cloud than Monday but the sun should still break through although it may be hazy

 

 

Temperatures in parts reach 31c but as with previous days the far south west and east Anglia really struggle with temperatures in the high teens rather than high 20's again the easterly to SE'ly wind is affecting east Anglia

 

 

Into Wednesday and thicker cloud is affecting more of the UK with sunshine becoming more hazy

 

 

Temperatures start to fall away as well with only the far south seeing high 20's east Anglia and the far south west coasts continue to struggle with temperatures this time its a north westerly

 

 

 

By Thursday thicker cloud is with most of us sunshine will be limited to just hazy spells

 

 

 

Temperatures are lower for all lower 20's inland instead of high 20's coastal areas are now down to the mid teens with winds coming down from the north to north west

 

 

The working week ends on a cloudy note

 

 

 

Temperatures are in the high teens to low 20's East Anglia, the far south west and the wales coast are the UK cool spots stuck in the mid teens at best NW Scotland is also struggling with the low teens at best

 

 

It warms up again for the weekend but once again the coast is the place to avoid if you want some warmth

 

 

And a line from the met office update today confirms we can't rule out what GFS is showing in its latter stages this morning

 

There are some signals that the high pressure could possibly ease away to introduce slightly less settled conditions by mid-month.

 

Edited July 1, 2013 by Summer Sun

[JK1]

How come low pressure easily pushes away high pressure? it's how it seems

Edited July 1, 2013 by JK1

[Alexis]

Informative, but I'd place zero faith in cloud forecasts that far out!

[Summer Sun]

How come low pressure easily pushes away high pressure? it's how it seems

 

Its because the high doesn't build strongly enough to flight low pressure

 

 

ECM however does build it strongly so low pressure can't get in

 

Edited July 1, 2013 by Summer Sun

[Pennine Ten Foot Drifts]

How come low pressure easily pushes away high pressure? it's how it seems

 

At which point in the current outputs are you seeing this ? GFS 06z has high pressure pretty much in control from T96 out to T192. ECM has it in control from T96 right out to the end of the run. If you're concerned about what GFS 06z is showing at T204 onwards I have a simple suggestion. Ignore it, it'll change.

 

This is arguably the best spell of settled weather we've seen modelled during UK summer output for 5-6 years, and much the same as when we get excellent cold charts modelled in winter, there is always some conjecture about the 'breakdown', even when it's in far distant FI.

 

To be honest I'd rather concentrate on the T48-T102 timeframe as this is where we need to see the current modelling maintained, because whilst current output looks favourable for an extended period of settled weather, the fact it's still 4 days away, and the other side of a more active Atlantic period, means there could yet be some significant changes to what happens after the rest of this week.

[Frosty.]

Informative, but I'd place zero faith in cloud forecasts that far out!

I wouldn't trust this 6z run as far as I could throw it, it looks out of synch in relation to the background signals, I'm sure the very warm settled spell will last much longer than the paltry few days of fine weather the north of the uk gets on this run.

[Buzzit]

Good time to remind new users that the GFS6z and 18z are slightly less reliable (stastically speaking) than the 12z and 0z due to slightly less initialisation data. In the current situation with a high confidence across all models of what I would call a strong adjusting pattern change by the end of this week. I would concentrate on the 0z and 12z output only - but that is just me

[snowking]

Good time to remind new users that the GFS6z and 18z are slightly less reliable (stastically speaking) than the 12z and 0z due to slightly less initialisation data. In the current situation with a high confidence across all models of what I would call a strong adjusting pattern change by the end of this week. I would concentrate on the 0z and 12z output only - but that is just me

 

Unfortunately not necessarily the case - its more of a bit of an urban myth. Certain posters on here agree with the sentiment after their own research, others do not, its very much a grey area

 

But in terms of cold hard facts well currently the 6z is one of the better verifying GFS run through days 5-8:

 

 

Its a case of taking each model run as it comes, and analysing it vs. what is shown elsewhere, as well as against verification stats, to decide how reliable a particular run might be. It would be far easier if we were to know exactly which runs to disregard, but where would the fun be in that eh?

 

Regards

SK

[pad199207]

I dont like the GFS 6z. This is similar to last Dec when ECM went off on one with a perfect blocking high with roaring easterlies! GFS was also onboard too, but then the GFS started hinting on a different scenario and then only to develop this further amongst everyones disgust and then the ECM happily went along with the GFS's take on things

[Evening thunder]

The 06z run does bring in a cooler flow a bit earlier than most other models and ensembles e.g the ECM, support though, Also relating to charts posted further up bear in mind that the lower resolution temp charts will not be able to correctly resolve temps in places like SW England, as there is only one point in Devon and Cornwall (in N. Devon) that the temp charts are plotted from that isn't over the sea (and none on the Netweather charts after T+192

 

The Met Office 16-30 day forecast still has this for the time being 'There are signals that the dry and settled weather from the first half of the month should continue across most parts of the UK during at least the first half of this period. This means rainfall should be below average, with mainly above-average temperatures and above-average sunshine amounts.' 

I wouldn't be surprised if it did turn a bit more unsettled/cooler before the 16-30 day outlook though, but I'm not gunna worry about that yet or look for the end of this spell before it has even began, or concentrate on the negatives.

 

Surely some aren't already despairing over one GFS 06z run after at least 5 days of very warm or hot weather in many places! the 06z is hardly a disaster either. The 06z ensembles show a few cooler members but even then mean 850hpa temps stay near 10C in the south right to the end of them.

Edited July 1, 2013 by Stormmad26