Model Output Discussion - 30/6/2014 Onwards - Covering July.

[Milhouse]

The ECM continues the good summer so far. High pressure innitially to the east of the UK is replaced by high pressure centred to the west of the UK. The air stream is generally from the north but where we get high pressure ridging across southern England we will still see some very warm days occur. Its a cooling off process, but still remaining very pleasant with temperatures in the range 20-25c. No sign in the reliable timeframe of the Atlantic stirring up either.

[Stormyking]

Still signs of things changing as we go into the start of August with some a more unsettled picture showing again, but not to unsettled

 

Rest of the week still looking nice and warm with some thundery showers thrown in over the next couple of days for Southern Counties of England by the looks of it.

[Captain Shortwave]

We will experience a load of mini battles which will determine what conditions we will experience come the start of August. The first battle was this weekend and after a lot of chopping and changing the outcome was not so good for hot and sunny fans.

A much greater area of cold air gets pulled south eastwards and connects to the instability over northern Europe. This will bring a temporary cool down on Sunday and Monday before warm air from the mid Atlantic filters back in. The next battle occurs early next week and will determine where the next trough will set up, will it be east or west of the UK.

Here we have two cut off lows, one near the Azores and one just south east of the UK. At this point there is no point debating beyond this point as we will see runs which will develop an Atlantic trough and others which will develop a Scandi trough. At the moment you would call an Scandi trough though how cool and unsettled things would get is debatable. Still time for things to change and put the Atlantic trough as the winner which of course would bring much warmer weather to the UK.

 

ECM ens in week 2 are pretty flat and average in terms of pressure and temperatures.

[phil nw.]

I have removed a number of recent posts which contained no useful model discussion.

Please only post in here if your views are explained properly with model related content not simply speculate to get a reaction.

 

A reminder there is the moan/ramping model thread that can be used to express preferences.

 

Thanks.

[mushymanrob]

well the gfs still wants to return the uk to an atlantic/low driven pattern from next week onwards, as illustrated by various posters.

 

however, the noaa 6-10 anomaly chart doesnt support that as a long term picture

 

 

and suggests a ridge off the azores will edge towards us, although its sited just to our west, it might continue its easterly track. the ecm 12z (yesterday) supports this.so the heat is going, to be replaced by more average conditions into next week with a hint that any unsettledness might be replaced by more settled , dry and sunny later next week. but atm, no return to the heat.

[Polar Maritime]

The GFS this morning is showing a much stronger signal for a cool down by Months end off the Atlantic, Bringing wet and unsettled weather to start August, With the Jet retreating South, The GFS has done very well at picking up this signal. 

 

Edited July 24, 2014 by Polar Maritime

[Sweatyman]

The GFS this morning is showing a much stronger signal for a cool down by Months end off the Atlantic, Bringing wet and unsettled weather to start August, With the Jet retreating South, The GFS has done very well at picking up this signal. 

 

how can it have done very well with it if it hasn't happened yet?

[Polar Maritime]

how can it have done very well with it if it hasn't happened yet?

 

The GFS has continued to show this for some time, And the signal is stronger this morning. Hence "it's done well at picking up this signal". We will always be looking into the future reg the Models.

 

Not what's happened/happening..

Edited July 24, 2014 by Polar Maritime

[Frosty.]

how can it have done very well with it if it hasn't happened yet?

He mentioned stronger signal which is correct, we know it hasn't happened yet but there is growing model support for it to happen..PM is spot on!

[Captain Shortwave]

A bit early to be popping open the bubbly and celebrating the demise of summer. Some of the charts posted are at timeframes which have already been proven to be horribly wrong going by how the output has changed over the past few days.

Interestingly the ECM keeps the southern half of the UK under the 8C isotherm for most of next week and into the following weekend, that's not cool or even average in terms of temperatures. This is mainly due to dropping the next trough further west.

You can see the low over the Azores being increasingly exposed to cooler air feeding into it from the north, this helps develop the week 2 trough further west. We also see the cut off low for this weekend become trapped over central Europe.

The other models (GFS/GEM) close this low off more which means the trough is further east and hence cooler for the UK. This is also not helped by this weekends trough being a magnet for further cool air to feed south eastwards into north west Europe.

 

Subtle differences between these two models, but the changes become much larger come next weekend.

Edited July 24, 2014 by Captain shortwave

[Sweatyman]

He mentioned stronger signal which is correct, we know it hasn't happened yet but there is growing model support for it to happen..PM is spot on!

fair enough frosty And PM i see what you mean

[terrier]

Apologise for not been able to post charts as on my phone. But looking at the gfs charts it does seem like the Azores high will retreat south. Allowing in more cooler showery weather. Which ties in with the met offices 16/30 outlook with the south hanging onto warmest temps longest. But we can't complain if August ends up been a wet month as June July have been excellent.

[Guest]

Apologise for not been able to post charts as on my phone. But looking at the gfs charts it does seem like the Azores high will retreat south. Allowing in more cooler showery weather. Which ties in with the met offices 16/30 outlook with the south hanging onto warmest temps longest. But we can't complain if August ends up been a wet month as June July have been excellent.

It could well end up being cooler than July given the output, but the charts to me don't look overly wet at this stage.

[carinthian]

I think it will certainly turn cooler Sunday into Monday over the bulk of The British Isles with the introduction of a more maritime air mass, however, the mixing of cooler air and its developing instability as it approaches the increasingly very hot air over Southern Europe ( notice the high thickness values over North Africa and Southern Europe ) is more likely to change medium term forecasts for next week rather than looking to the west, I think .

[Summer Sun]

UKMO shows next week starting with some rain / showers for parts of the east whilst the further west you are its shown to be drier temperatures low than of late ranging from high teens in the north to low 20's in the south

 

 

By Tuesday pressure is starting to build though with a northerly flow setting up it would be as warm as of late but pleasant enough in any sunshine, no 850's available for Tuesday

 

 

By Wednesday pressure remains high though we begin to see a north westerly flow setting up the 850's begin to rise again with +8's becoming more widespread again

 

[Man With Beard]

Maybe use of the word "cooler" is going to mislead some. This is my reading of the charts. Today until Saturday (maybe Sunday in the far south if the trough is delayed slightly) -  more of the same, generally hot and sunny with a few thunderstorms in central/western areas. Generally high 20s and I think 30C could continue to be reached, even exceeded on each of these days.

Next week: there are actually still some fairly warm charts. For example, next Wednesday:

Away from Scotland, I'd expect sunny conditions with several areas reaching 25C, maybe even 27C or 28C. Not really a "cool-down". I'd have thought Tuesday/Thursday would be similar.

Into the following weekend ... clearly we are going to lose heights, but the actual evolution is up for grabs. Here are three ensemble members, I wouldn't write off any of them yet given the overall ensemble profiles of ECM or GFS:

One unsettled and cool, one unsettled and warm, and the last chart could be very warm considering the time of year.

Edited July 24, 2014 by rjbw

[Stormyking]

Judging by this morning, GFS showing more a cooler and unsettled theme, and the ECM is showing a more unsettled theme but with some warmth and thundery shower potential. I personally think we still have one or two more warmer spells as August goes on, but only time will tell.

[SteveB]

Well all I see from the GFS this morning, is more of the same for most of next week bar a few degrees cooler, and a slight blip this weekend.

 

Once we get past next Thursday, thing do look like turning a little less settled, but temps look like holding up in the low 20's in the South still.

 

So yes, a little more unsettled maybe later next week, but still pleasant enough I think.

 

 

 

Edited July 24, 2014 by SteveB

[knocker]

Looking at the GFS abd ECM ens for 00 they are both plumping for cyclonic surface conditions for the following weekend, The GFS anomaly is slightly more bullish with the trough but both are on the same page,

Edited July 24, 2014 by knocker

[knocker]

Meanwhile in the US

 

 

[Summer Sun]

UKMO shows things turning fresher and more unsettled during the first half of next week though the south west looks best placed for the driest and brighter conditions

 

The eastern side looks most prone to rain / showers mid week with the driest weather the further west you are

 

 

Temperatures will be falling back to around average for just about all

 

 

What happens beyond this will depend on the low if it moves away east could the high move back in?

 

Edited July 24, 2014 by Summer Sun

[Man With Beard]

UKMO shows things turning fresher and more unsettled during the first half of next week though the south west looks best placed for the driest and brighter conditions

 

The eastern side looks most prone to rain / showers mid week with the driest weather the further west you are

 

 

Temperatures will be falling back to around average for just about all

 

 

What happens beyond this will depend on the low if it moves away east could the high move back in?

 

Yes indeed, a faster clearance of the low into Scandi could allow things to stay settled as the end of next week approaches. A contrast with the GFS, which stalls the low in the North Sea, drawing down cooler and cooler conditions.

My mind does goes back to many similar scenarios this year - the end result was always like UKMO, with the low being pushed NE with almost no effect felt south of the Scottish border.

[Summer Sun]

Looking at the 12z's to t144 we have GFS and ECM is pretty good agreement for the position of the low

 

 

UKMO and GEM both have different options to the above

 

[Captain Shortwave]

This isn't too bad a position to be in to be honest, all the cool air is going to be sucked towards the Azores. Watch heights rebuild over Europe during the latter frames, maybe the south eastern half of the UK might get in on this too.

 

....Or the ECM could flatten everything out. In the end the ECM doesn't end up too bad.

Edited July 24, 2014 by Captain shortwave

[Stormyking]

This isn't too bad a position to be in to be honest, all the cool air is going to be sucked towards the Azores. Watch heights rebuild over Europe during the latter frames, maybe the south eastern half of the UK might get in on this too.

 

....Or the ECM could flatten everything out. In the end the ECM doesn't end up too bad.

This is what I am reckoning will happen aswell, which in theory should give us another boost of warmth and thundery weather again . 

 

ECM showing high pressure trying to build behind this aswell