Model Output Discussion - 1st July Onwards 18z--->

[Summer Sun]

This mornings ECM ens is showing something much warmer later next week possibly getting into the low 30's in parts of the SE

 

 

Becoming fresher by D8 as winds shift to a westerly

 

Edited July 11, 2015 by Summer Sun

[seaside 60]

Just out of interest the Latest North Atlantic SST anomaly

http://www.tropicaltidbits.com/

Thats a very large % of the Atlantic below average.

Is there any reason for this and will it change quickly, also any effects on the coming autumn/winter.

[knocker]

Thats a very large % of the Atlantic below average.

Is there any reason for this and will it change quickly, also any effects on the coming autumn/winter.

 

Complicated question. This might help.

 

What’s going on in the North Atlantic?

 

http://www.realclimate.org/index.php/archives/2015/03/whats-going-on-in-the-north-atlantic/

Edited July 11, 2015 by knocker

[bluearmy]

Extended ECM eps maintain the scrussian trough edging west to take in nw Europe. (And importantly, to remove the solid euro heights to our South. )

Naefs not so gung ho on this and keeping the euro heights

[Captain Shortwave]

06z GFS coming out now,a slower and deeper Atlantic trough from midweek, more in line with the Euros.

 

Certainly more in line

Friday looking very warm widely to hot in the south east if the models are calling this right.

28-30C looking at the temperature chart, widely across Central/Southern England.

Edited July 11, 2015 by Captain shortwave

[knocker]

Extended ECM eps maintain the scrussian trough edging west to take in nw Europe. (And importantly, to remove the solid euro heights to our South. )

Naefs not so gung ho on this and keeping the euro heights

 

Yes the ECM seems to incorporating the complicated low pressure set up day ten with the connected trough to the NW with a trough over the UK at T360. The GEFS is having none of it also. and as has been noted there is still much uncertainty in the pipeline.

Charts weatherbell

Edited July 11, 2015 by knocker

[summer blizzard]

Euro mean above a good pattern for a pressure build if the Euro trough weakens. High pressure over Canada with a strong sub-tropical jet over the US could produce a cut-off low near the Azores.

The spoiler here is that heights are too far east (more towards Greenland) and there's a strong Screuro trough which may attract what would have been the cut off low.

Plus of course, that's a one day, day 10 mean.

[Summer Sun]

As CS says above Friday could be a hot day quite widely for England with temperatures in the high 20's and probably into the low 30's for London and the SE

 

[seaside 60]

 

Complicated question. This might help.

 

What’s going on in the North Atlantic?

 

http://www.realclimate.org/index.php/archives/2015/03/whats-going-on-in-the-north-atlantic/

 

Thank you, if I remember last year we had a big round cold area central Atlantic, this year the whole lot is colder with an extra warm bit to the west of Greenland.

Do the models ever factor in large anomalies of colder/warmer waters.

[Winter Cold]

Not sure I agree with this "average" summer idea, not if the GEM/ECM are onto something. There seems to be something in the atmosphere that is conducive to mid-Atlantic troughing - this week, its almost as if the models have defaulted to that position (at times) in the absence of other strong drivers. We know that the route to extreme heat over the UK is this very scenario as it creates a southerly pull from the regions like Spain. So whilst sustained heat is not as likely as if we had a July 2013 style UK high, extreme heat becomes not a certainty but more of a risk.

The current charts from ECM, both 12z and 00z, show scenarios not far off bringing those mid-30s to the UK again. Certainly the French will be wondering what on earth is up with the weather this summer.

So average? maybe it will be, but plenty of room in the models for something more exceptional, yet again.

 

I think the reason we are seeing some say average and some not is purely down to location. This summer so far has been very IMBY and so lets say we divided the country up into 3 parts then someone down south will probably say its been good with a lot of warmth and hot days, whereas someone like me from the middle part would say average for sure, and then our Scottish friends would say below average.

 

The models are showing some potential plumes yes but these are as fleeeting as the other one on the 1st, and also only really affecting the SE again. On the other hand some much cooler days are shown aswell so maybe it all averages out to truly become an average July.

 

GFS 0z ensembles for instance are actualy below average for my location. Average for July here is 21-22c and the whole run has the mean and op at around 15c so thats a good 5c below for the rest of the month if they are to be beleived. Even allowing for undercooking which it does then maybe 20c at best so average at best!

 

I just think its all very localised this year

 

[Nouska]

Comparing the GFS op with the 00Z ECM ensembles for London, we see that from the seventeenth, the GFS is very pessimistic in that it mostly tracks the lowest point in the ECM pack.

 

 

This may ultimately be the correct outcome but at this stage it would be difficult to envisage such an autumnal picture as GFS paints over the bulk of the UK.

[Nouska]

Thank you, if I remember last year we had a big round cold area central Atlantic, this year the whole lot is colder with an extra warm bit to the west of Greenland.

Do the models ever factor in large anomalies of colder/warmer waters.

 

SST anomalies are a very important part of the medium and long range weather model calculations. A wee schematic of all the parameters.

 

 

 

http://www.atmo.arizona.edu/students/courselinks/fall12/atmo336/lectures/sec6/weather_forecast.html

Edited July 11, 2015 by Nouska

[Frosty.]

It's both surprising and disappointing that the latest met office update doesn't mention any warmth / heat later next week considering how good some of the recent models have looked, the ecm 00z especially, even the gfs 6z shows a very warm day next Friday. I actually thought there was a chance of a mini plume for the south. We could be looking at short term pain for long term gain though because the outlook for later in july and into August sounds more summery.

[knocker]

They seem to be ignoring the background signals currently. Wonder if the met office computer has got a bug on it that needs fixing hence why their illustrating what they are.

 

I don't follow that in the slightest. The 06z GFS looks exactly like the METO forecast for next weekend

Chart weatherbell

[Summer Sun]

They seem to be ignoring the background signals currently. Wonder if the met office computer has got a bug on it that needs fixing hence why their illustrating what they are.

 

UKMO still a fair bit different different

 

[Frosty.]

The highlight of the Gfs 12z is next Friday which looks very warm and humid for most of England with a brief injection of continental conditions but after a sunny morning, thundery rain spreads from the west. The rest of the run is abysmal with charts I would like to see in winter but not in mid summer!

Edited July 11, 2015 by Frosty.

[Frosty.]

The Ecm 12z is better than the gfs/gem and holds the worst of the Atlantic at bay to the northwest. Later next week becomes very warm with temps into the 80's F, the best of the weather in terms of fine and sunny conditions across the s/e and a nice ridge of high pressure builds from the southwest next weekend followed by another pulse of very warm air and then a chance of high pressure building north and east beyond T+240.

Edited July 11, 2015 by Frosty.

[Milhouse]

Well although the outlook is best described as mixed, there doesnt look to be anything overly cool this coming week. Temperatures will remain around average for the most part, but there is still the sign for a mini plume to send temps into the mid, possibly high 20s for a time.

[knocker]

I wonder how the pattern change in the US after next Sunday turn out downstream  It's all a bit of a dog's biscuit. At T168 we have a very mobile pattern with ridge Alaska, trough western US and LP NE Canada shooting energy west south of the Greenland HP to the troughs UK and Russia, Not good, But this changes over the next five days or so and importantly we lose the low NE Canada and HP Greenland leaving a much less mobile zonal flow generally influenced by the Azores HP. Question is will this lead to the Azores at last becoming more dominant or will that sneaky little trough Iceland combine with the Russian trough and spoil the party?

Charts weatherbell

http://www.tropicaltidbits.com/

 

[Polar Maritime]

The GFS continues to show an Atlantic influence from the 14/15th, As Lows aided by a strong jet at times swing in from the N/W over the Northern half of the UK bringing cooler more unsettled weather.

 

A pretty unseasonal Northerly shot is showing around the 20th, As Heights one again try to push up into Greenland, Which seems to be the ever continuing theme so far this Summer..

Edited July 11, 2015 by Polar Maritime

[Methuselah]

The GFS continues to show an Atlantic influence from the 14/15th, As Lows aided by a strong jet at times swing in from the N/W over the Northern half of the UK bringing cooler more unsettled weather, A pretty unseasonal Northerly shot is showing around the 20th..

Ah. So it's all progressing 'as anticipated'?

[Polar Maritime]

Ah. So it's all progressing 'as anticipated'?

 

If only it was that easy eh! The models have certainly toyed with other ideas.

[Methuselah]

If only it was that easy eh! The models have certainly toyed with other ideas.

That's my point: it's never that easy!

[summer blizzard]

Worst output in some time. While not cold (bar perhaps the GFS), they are all very unsettled for the time of year. Even the GEM and Euro end with low pressure in control.

An attempted warm spell for the south late next week.

[knocker]

Will not bother even with a short overview of the GFS this morning. Nothing much has changed from previous days but as pictures paint a thousand words three charts which tell the story. Apart from the chart for next weekend the usual caveats apply

http://www.tropicaltidbits.com/

 

 

Edited July 12, 2015 by knocker