Model Output Discussion 18Z 18/6/13 onwards

[Frosty.]

 

this summers looks like going down as the biggest heat tease ever... always in fi, never in reality.

You need more patience mushy, it will change soon, the beginnings of the change could be as little as 6 days away, the met office update is improving, the model trends are heading in the right direction.

[Cheshire Freeze]

 

hope so karl, but 7 years of disappointment (7 years of the fi tease) , all im seeing is a delay in the expected heatwave. anything settled, warm, sunny is being pushed back or downgraded. the ever building azores ridge that inevitably collapses into nothing much, plus theres no tangible support from the mjo or anomaly charts for anything prolonged, settled and warm.

 

I didn't know a heatwave was expected. All I've seen is some low res charts showing 29-32C temps. Anyone who invests in low res modelling knows the risks! I.e it's not especially odds on to materialise.

 

The main issue I see (looking at those ECM mean charts above) is the one which we have faced since late May. The main core of the heights are further west than some people would like....the main feature around our shores is a ridge which is thrown our way as an offshoot of the main HP centre. As we get closer to the timeframe we're looking at, the ridge is often weaker or shunted further away, allowing weak trough offshoots to make their way across the country.

Edited June 28, 2013 by CreweCold

[phil nw.]

Once we could see the wavering jet heading for our latitude it was always going to be difficult for the models-even on a very short tinescale.

This Summer pattern of Icelandic troughing and sporadic Azores ridging with fronts strung out across the UK inbetween is historically quite common and which i often seen over the years.

Surface conditions can vary daily from north to south,depending on the timing and buckling of the fronts straddling the UK.

I am sure the professionals at the MO scratch their heads sometimes over the fine details,especially the temperatures.If the cloud unexpectadly breaks in a warm sector then they can end up much higher than forecasted.

Look at the varyance in the 500hPa pattern from run to run -the main features are similarly placed but what makes the difference in this setup is the subtle changes in the modeling of the amplitude of the jet and small changes in wavelengths.

As ever i would suggest following the trends in the means and height anomaly outputs day on day-these are less volatile and show the main trends in the 500hPa patterns and help to show if a particular operational run is out of kilter,especially beyond 4 or 5 days when they tend to throw out different solutions.

Edited June 28, 2013 by phil nw.

[Weather Boy]

Once we could see the wavering jet heading for our latitude it was always going to be difficult for the models-even on a very short tinescale.This Summer pattern of Icelandic troughing and sporadic Azores ridging with fronts strung out across the UK inbetween is historically quite common and which i often seen over the years.Surface conditions can vary daily from north to south,depending on the timing and buckling of the fronts straddling the UK.I am sure the professionals at the MO scratch their heads sometimes over the fine details,especially the temperatures.If the cloud unexpectadly breaks in a warm sector then they can end up much higher than forecasted.Look at the varyance in the 500hPa pattern from run to run -the main features are similarly placed but what makes the difference in this setup is the subtle changes in the modeling of the amplitude of the jet and small changes in wavelengths.As ever i would suggest following the trends in the means and height anomaly outputs day on day-these are less volatile and show the main trends in the 500hPa patterns and help to show if a particular operational run is out of kilter,especially beyond 4 or 5 days when they tend to throw out different solutions.

I'd like to thank you for the on topic post, seemingly rare in the last page. Why can't people go to model banter thread with their posts that add nothing to the analysis? I've reported one or two moaners whose posts just drone on negatively without anything to back up their whining as I am personally fed up with it. I appraised the position a few pages back and little has changed except that for me, the latest ECM nails the coffin into last night's errant run. Looks to me like we can expect summer to arrive properly in about a week (in the south) with potential heat later - unsure as to heat at this point.The models have been remarkably conistent as to the arrival of warmer and more settled weather. Only the flirting and dropping of serious heat has changed, but at that range that was virtually inevitable. Absent any early breakdown, though, it's more likely than not that thing will warm up as HP transfers east.

[phil nw.]

A number of posts have been shifted into the model moaning thread.

http://forum.netweather.tv/topic/76235-model-banter-moans-and-ramps/

 

Please think before posting in here as to whether it is more suited to the other model thread(above).

 

Thanks.

[phil nw.]

I'd like to thank you for the on topic post, seemingly rare in the last page. Why can't people go to model banter thread with their posts that add nothing to the analysis? I've reported one or two moaners whose posts just drone on negatively without anything to back up their whining as I am personally fed up with it.

I appraised the position a few pages back and little has changed except that for me, the latest ECM nails the coffin into last night's errant run. Looks to me like we can expect summer to arrive properly in about a week (in the south) with potential heat later - unsure as to heat at this point.

The models have been remarkably conistent as to the arrival of warmer and more settled weather. Only the flirting and dropping of serious heat has changed, but at that range that was virtually inevitable. Absent any early breakdown, though, it's more likely than not that thing will warm up as HP transfers east.

Thanks WB .

I really would like to see views exchanged wrt the charts without folks getting abrasive.

We can only comment on the outputs at the time and when they change it's no ones fault and pointless harking back over things.

The point of my post was to perhaps explain,especially to the newer members,how things can and do change and what we see today for say a week away often will change nearer the time.

All part of the ups and downs of model discussion.

[Tamara]

To be honest this run got very messy, the last few frames could be compared to a 5 year chucking paint at a map of Europe. Personally I feel dubious of that trough which sticks over Shetland for a full 72 hours. 

Actually it is quite feasible that troughs during the early to middle/late part of next week might get stuck and straddle the country. I tried to quietly make the point earlier that, especially at a transitional time of the jet stream, there can be a wavering of fronts as they straddle the country until the final secondary troughs have exited eastwards and the jet stream lifts further northwards afterwards., Which is very much what they are suggesting and supports the more settled spell by the end of next week.

 

However there is so much neandethral arguing about what might happen after this time that any other actual model related comment gets ignored...

Edited June 28, 2013 by Tamara Road

[DTHFCJ]

Actually it is quite feasible that troughs during the early to middle/late part of next week might get stuck and straddle the country. I tried to quietly make the point earlier that, especially at a transitional time of the jet stream, there can be a wavering of fronts as they straddle the country until the final secondary troughs have exited eastwards and the jet stream lifts further northwards afterwards., Which is very much what they are suggesting and supports the more settled spell by the end of next week.

 

However there is so much neandethral arguing about what might happen after this time that any other actual model related comment gets ignored...

Tamara..your posts and  posts by a few others are never ignored by me(and many)i admire your input,very similar to Bluearmy's input makes alot of sense lets hope that people get what they want and others well...get what they want,its a good site this

 

meanwhile..

http://www.cpc.ncep.noaa.gov/products/predictions/610day/610day.03.gif

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

@John Holmes....thats 3 days now ive been looking....looks pretty good Sir??

[Weather Boy]

Actually it is quite feasible that troughs during the early to middle/late part of next week might get stuck and straddle the country. I tried to quietly make the point earlier that, especially at a transitional time of the jet stream, there can be a wavering of fronts as they straddle the country until the final secondary troughs have exited eastwards and the jet stream lifts further northwards afterwards., Which is very much what they are suggesting and supports the more settled spell by the end of next week. However there is so much neandethral arguing about what might happen after this time that any other actual model related comment gets ignored...

Absolutely right Tamara, but there is currently little model support for this, so I'd say that that's an unlikely option at this stage. Last night's ECM did very much support this (although IIRC it was more a return of the trough rather than it getting stuck) but thankfully that seems to have little support and I would expect that to fade into model history no, but who knows I could be wrong. Gavin has been posting consistently very dry ensembles too.100% agree with your last comment, especially!Btw, still bewildered as to your location!!!! Goodness knows where you are referring to! What town do you live near?

[Geordiesnow]

Got to say, people who say the good charts in FI never coming off are just quite frankly talking nonsense, we had some decent settled weather this summer with very respectable temperatures, especially at the start of the month.

 

Maybe I was a little short sighted with the output earlier on, the positives are is that heights are projected to stay low, this means that any low pressure systems won't just sit and stall, winds should generally come from a mild direction but it does not mean its always going to be blue skies and sunshine and there will be some drier interludes at times.

 

Monday could be a decent day for most but with cool uppers, its not going to be overly warm, Tuesday looks like being wetter although timings could change this and after that looks more uncertain but a pressure rise can't be ruled out but I am reluctant to back this will be the case just yet. 

 

On a side note, look at the intense heat projected for Hudson Bay!! 20+C upper air temps, just wow! As impressive as the continuous Siberian heat, surely records are being broken quite widely so far this summer season and we are not even into July yet!

[Captain Shortwave]

Actually it is quite feasible that troughs during the early to middle/late part of next week might get stuck and straddle the country. I tried to quietly make the point earlier that, especially at a transitional time of the jet stream, there can be a wavering of fronts as they straddle the country until the final secondary troughs have exited eastwards and the jet stream lifts further northwards afterwards., Which is very much what they are suggesting and supports the more settled spell by the end of next week.

 

However there is so much neandethral arguing about what might happen after this time that any other actual model related comment gets ignored...

fair enough I was more or less commenting on the track of that low which literally moved a large distance in 24 hours and then limpets in the same place for 3 days. Just the movement of the low on the ECM looks un-natural to the untrained eye whilst other models simply move the system north east which looks fine. Add to that the frequent times the ECM this summer has managed to trap low pressure just to our north east only for it to be either be less intense or out of harms way (for example the ecm was predicting a cold northerly flow for this part of the country over the past few days which never happened). I just felt it looked dubious and the run as a whole looks like the start of a model backtrack like what we saw during the winter with the gfs.

Hope that makes sense (probably sounds like total codswallop )

adding to your last sentence (sigh), there is nothing wrong with being cautious especially when the explanation has substance and logic behind it, it's just feels like many have already written this summer off which is shocking considering the vast improvement on last year.

Edited June 28, 2013 by Captain shortwave

[Captain Shortwave]

I might as well add that the 18z GFS run was superb in the later stages of high resolution with high pressure building straight through the UK, a lot better than the 12z run.

 

Still backed by the ensembles

Edited June 28, 2013 by Captain shortwave

[Captain Shortwave]

Good runs this morning most notably this so far from the ECM

 

Edited June 29, 2013 by Captain shortwave

[Frosty.]

I've taken a snapshot at T+144 hours of the latest 00z output to show how much the weather pattern is in the process of transition to a much more settled and warmer outlook, the gem is still poorest but is improving and all the rest are looking very healthy, especially the gfs, ukmo and ecm, it looks like we are in for a very summery spell through a large part of July, in the meantime we have an increasingly good weekend for the south & east with long sunny spells, 20-22c today but even better tomorrow at 24-27c, perfect for the british grand prix, very high pollen count though so lots of sneezes.

[Frosty.]

A pretty good Ecm 00z with high pressure building northeast across the uk and becoming very warm, a big improvement on recent runs.

[Frosty.]

And the Gem 00z which looked pretty poor at T+144 hours turned into a gem of a run, better than the ecm with no spoiler low to the west at T+240.

[mushymanrob]

interesting charts this morning, both the gfs and ecm agree on some kind of pressure rise later this week (after a pretty poor week it must be said)

 

 

the anomaly charts too give support to this general synoptic possibility

these charts support the oporational runs, whilst

appears to support the gfs's version with the suggestion of a large, strong, area of high pressure over us.

 

so some sort of warm up later in the week does seem plausable going of current runs, whether its the strong area of high pressure the gfs is currently championing, or a weaker more temporary (?) version the ecm suggests only time will tell.

 

after a month of the promise of ridging azores high threatening to provide something nice, only to be downgraded or shortened, this time things just might go right for those of us looking for a decent spell of warm summery weather the like we havnt seen for 7 years now.

Edited June 29, 2013 by mushymanrob

[ANYWEATHER]

Unsettled up to the semi reliable timeframe T+96  and then afterwards pressure does rise, but for how long and strong is up for debate as per usual. Ecm looks  thundery at t+240 , and I personally would welcome that, But!!!!  

[Frosty.]

The Gfs 00z turns into an absolute peach of a run with a very warm and anticyclonic outlook which stretches well into July and appears to keep renewing itself with more high pressure, it would be a perfect summer outlook, a real tonic after all the cold and unsettled weather we had through spring. Tomorrow looks very warm across the southeast, locally hot.

[mincemeat]

Many thanks for warm welcome johnholmes, This current page seems to be a great example for one to save and look back on next Friday! With very optimistic Azores high FI charts and some more cautious forecasting possible troughs for next week.

I guess that's the ups and downs of weather forecasting.

It,s great to also read people's different opinions of the charts, and I guess any forum with people's opinions can get rather personal!

As a "newbie" I will sit back and watch the conclusion of the next 7 days with great interest!

[Summer Sun]

Only slight concern with ECM is the low coming in from the west hopefully it will be another outlier with the ensemble run is out shortly

 

[johnholmes]

Tamara..your posts and  posts by a few others are never ignored by me(and many)i admire your input,very similar to Bluearmy's input makes alot of sense lets hope that people get what they want and others well...get what they want,its a good site this

 

meanwhile..

http://www.cpc.ncep.noaa.gov/products/predictions/610day/610day.03.gif

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

@John Holmes....thats 3 days now ive been looking....looks pretty good Sir??

 

Indeed there is consistency for the development of a surface high beneath the +ve anomalies being shown edging into the SW of the UK.

I would not expect it to be necessarily long lasting though as there is still no sign on those charts of any actual 500mb ridging. Having said that I can remember instances where a similar upper air pattern allowed a surface high to remain close by/over the UK some years ago. Whether this actually then created more favourable conditions at 500mb I am unsure but the 500mb flow ending up ridging and a spell of warm to hot and dry weather affected a largish area of the UK for, I forget how long, but several days perhaps getting on for a week.

So in short it is looking more promising than for a while. Not yet had time to look at the ECMWF-GFS issue this morning but will do so now.

the link below

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

They do both show some sign of ridging over the UK and E/SE which is more than the NOAA 6-10 or 8-14 is showing so still some caution about how long the surface high may last always assuming it does form.

Remember this is for day 6 and beyond not prior to that.

The Met Fax chart for T+120=next Wednesday, see below, shows the probable weather pattern at the surface, a deepish low with the surface high still well WSW of the country

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

Edited June 29, 2013 by johnholmes

[Captain Shortwave]

Only slight concern with ECM is the low coming in from the west hopefully it will be another outlier with the ensemble run is out shortly

 

 

 

 

 

 

More the issue is that the latter frames build heights over Greenland which forces the jet southwards again. This has no support in the ECM ens with the Jet staying north of Scotland with low pressure over Greenland and high pressure ridging into the UK.

I would have to say I've been disappointed with the ECM op recently, it's been rather poor pulling runs with next to no support from other models and ens but also the fact that there is absolutely no consistency between each output. 

[Thundery wintry showers]

I'm aware that there will have been regional variation but the past week at my location, which many forecast to be fine, warm and sunny thanks to the proximity of high pressure, was cloudy on five days out of five, had near or slightly below-average daytime temperatures and had rain on two of the days, highlighting the issue of high pressure sometimes being in the "wrong" place.

 

This weekend is set to see sunnier and warmer weather extend further north with most of England and Wales affected, and temperatures of around 25-27C may happen in the south tomorrow, but Scotland is set to remain mostly grey.  Monday looks set to be a brighter day in Scotland with scattered showers, not much potential for intense convection though due to the ridging Azores High, while England and Wales should have another dry day with sunny intervals.

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130629/00/42/ukmaxtemp.png

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130629/00/42/ukprec.png

 

Between Tuesday and Thursday a low pressure system is set to track further south which will bring a rain belt south-eastwards although most of southern Britain probably won't see much rain from it, and then behind it, the ridging Azores High will most likely prevent any significant showery activity from developing in the polar maritime airstream with most places dry with sunny intervals.

 

After that there are strong hints that pressure will build substantially from the south sending warmer and sunnier weather further north.  Since this build of pressure is forecast for the 7-10 day timeframe I am feeling quite cautious about it, particularly for northern parts of the country, because while current model outputs are generally suggesting a warmer and sunnier spell than many of us have had during the past week, the positioning of the high is still potentially prone to revision.  However, the NOAA 8-14 day outlook does suggestt a fairly significant build of heights at the 500hPa level just off north-western Ireland which is a pretty strong indicator that the high may get further north and east this time:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

[Summer Sun]

More the issue is that the latter frames build heights over Greenland which forces the jet southwards again. This has no support in the ECM ens with the Jet staying north of Scotland with low pressure over Greenland and high pressure ridging into the UK.

I would have to say I've been disappointed with the ECM op recently, it's been rather poor pulling runs with next to no support from other models and ens but also the fact that there is absolutely no consistency between each output. 

 

And once again the Op and ensemble run are miles apart

 

 

Some of the driest ensembles we've seen in summer for years

 

Edited June 29, 2013 by Summer Sun