Model Output Discussion 31/05/14 onwards.

[Tamara]

The ECM operational as it stood this morning looks unlikely within 10 days - at least for the time being.

 

We are starting to see the suggested change as muted in Fridays post towards a shift of fortunes to bring the generally warmer conditions further south, whilst the north becomes cooler and, very gradually, less settled. The current advertising of the High pressure to the west of the UK to send a toppling ridge across the south of the UK, whilst the jetstream sends frontal incursions into more north western regions looks good value at the moment with support from most of the major model ensembles and also as indicated from GEM and GFS operational output

 

That NW/SE eventual split is gaining increased confidence as a destination arrival point. Timing still uncertain however - but most likely the following weekend/ into week 2 and towards the end of June.

 

We are seeing the beginning of the process of energy transport from the western Pacific across to the states as jet stream patterns change there.

 

Edit: The updated ECM operational is again very progressive with the renewed jet stream energy, as described above, and pushes this south very quickly. Another look required to see how it sits in the ensembles - but it remains, at least at this time, as going against 10 to 15 day guidance. The weather becoming more unsettled in the NW with time looks correct, but the speed and extent of the changes are questionable at this stage

Snippets from yesterday for continuity

 

The ECM as it stands this morning looks much more realistic and back in line with that guidance suggested yesterday. The upstream increase in the jet stream also as discussed and reasoned in terms of background NH changes yesterday with regard to the Pacific pattern looks to have downstream consequences that revert the UK to more typically average summer conditions synoptically with a more mobile atlantic profile than seen for a while.

 

Putting such mobility in context though, that does not mean any summer washout by any means - just a more familiar changeable outlook most especially for NW areas who have seen some lovely summer weather of late. Which has been good to see

 

Timing for these changes as previously indicated, still looks on course for completion by or soon after the weekend after next - and this clearly defines the over progressive nature of the deterministic ECM outputs yesterday for the outliers they were.The GEM, GFS and GEFS members have been much more consistent with the trend to this time

 

At 5/6 days away there is a good agreement from the EPS members for ridging holding until then - with many southern areas especially still seeing the prospect of a good deal of fine and warm weather.  The Scandinavian troughing as mentioned yesterday away from any influence over the UK

 

 

Its still worthwhile being cautious about any arrival of less settled conditions further south - this process could be erratic as the background signal will still support high pressure reasonably close to our south west in line with the anomalies posted yesterday and fronts could have quite a struggle initially to move south eastwards through the UK. This is unlikely to apply anyway until we get into week 2.

Edited June 19, 2014 by Tamara תָּמָר

[Summer Sun]

Monday and Tuesday staying fairly settled looking at UKMO by Wednesday we have hints of the high starting to decline which will probably introduce more in the way of cloud for the north and some rain for parts of Scotland

 

 

GFS has the high taking slightly longer to leave with it turning more unsettled for just about all at day 9

 

Edited June 19, 2014 by Summer Sun

[SteveB]

GFS 12z looks like keeping thing settled and warm for the bulk of the UK next week. The first full day of Glasto looks to be dry and warm.

 

It's again only in FI that it turns unsettled for all.

 

 

 

[summer blizzard]

When i came on tonight and noticed 2 comments on the 12z it was obvious that the models were not going hot, the consensus is still broken.

 

I was going to post the Euro chart to highlight the pattern but for 3 GFS runs in a row we've been drenched at day 9 so i thought i'd post that evolution since it's hard to imagine a worse summer chart..

 

[SteveB]

GFS 0z still showing a dry warm week for the bulk of the UK and again but always with the possibility of showers, it's only when GFS goes into FI it turns cooler and unsettled for all.

 

The start of Glasto is looking warm but with the possibility of some showers close by.

 

 

 

 

 

 

 

 

 

Edited June 20, 2014 by SteveB

[knocker]

The GFS anomaly has the colder air to the east slipping further east at 00z next weekend with the Atlantic taking over The ECM weeklies is not quite so bullish as this but moving in a similar direction. The jet is quite strong running around the upper low over southern Britain.

 

So a period of quiet rather nondescript weather for Thursday, Friday and Saturday with the rot setting in on Sundaywith a low west of Ireland and generally wet over the UK and by Monday the low is plonked over the UK and the weather foul. I can see this settling into a period of a typical unsettled westerly scenario.

Edited June 20, 2014 by knocker

[mushymanrob]

The GFS anomaly has the colder air to the east slipping further east at 00z next weekend with the Atlantic taking over The ECM weeklies is not quite so bullish as this but moving in a similar direction. The jet is quite strong running around the upper low over southern Britain.

 

So a period of quiet rather nondescript weather for Thursday, Friday and Saturday with the rot setting in on Sundaywith a low west of Ireland and generally wet over the UK and by Monday the low is plonked over the UK and the weather foul. I can see this settling into a period of a typical unsettled westerly scenario.

 

..... on the other hand thats all in deep fi and after a period of considerable disagreement and uncertainty this evolution (although depected on some current models) is far from nailed.

[SteveB]

It's inevitable it's going to turn unsettled eventually, but it does seem to my untrained eye this is slowly getting pushed back, with the next 7 day's looking similar to the last couple of weeks.

[knocker]

..... on the other hand thats all in deep fi and after a period of considerable disagreement and uncertainty this evolution (although depected on some current models) is far from nailed.

 

Oh I quite agree. The ECM ops is not buying it for a moment.

Edited June 20, 2014 by knocker

[ANYWEATHER]

Looks like a general concensus that pressure will be falling around about Wednesday time both ecm and gfs show this to some extent....

[Polar Maritime]

It's inevitable it's going to turn unsettled eventually, but it does seem to my untrained eye this is slowly getting pushed back, with the next 7 day's looking similar to the last couple of weeks.

 

Yes Steve, It certainly looks settled for most next week with pretty similar conditions as you say. Months end looks very unsettled and wet, Will it keep getting pushed back... We shall see, Mid-Summer has arrived.

 

Edited June 20, 2014 by Polar Maritime

[Summer Sun]

Tuesday and Wednesday looks relatively settled from UKMO, by Thursday pressure becomes more slack so an increasing risk of some showers developing of which some could be heavy and thundery

 

 

Now ECM is interesting as it shows the high never going far away, yes some showers are possible at times again some could be heavy and thundery but it may not be too long till high pressure returns

 

Edited June 20, 2014 by Summer Sun

[knocker]

The ECM ens is not supporting the ops

Edited June 20, 2014 by knocker

[summer blizzard]

Out to day 8 and still no consensus. Euro has a weird Euro low followed by rising pressure. GEM has a northerly. GFS has a messy and stagnant pattern.

 

[SteveB]

GFS 6z shows a mostly settled week with the warm spells, looks mostly dry with only the occasional chance of a shower.

 

FI looks less unsettled & not as cool as previous runs.

 

 

 

 

[mushymanrob]

i dont think i can remember such an 'unknown' outlook... well they are pretty uncommen anyway, usually we have some idea of what lies ahead out to 10 days albeit with no detail. (pressures likely to build here or there resulting in 'x' or 'y' type of scenario)but the anomaly charts appear to change randomly at will, the ops are clearly undecided, in all its looking a mess, but what will emerge? im not so sure we can have a week or more of messy synotics, something stronger is bound to emerge isnt it? we might be on the cusp of a memorable hot spell, or yet another let down as the atlantic might win out.but for mow ill be happy to enjoy the bright warm sunshine

[SteveB]

Me to Mushy, lovely start to Wimbledon & hopefully a full weeks play & not to hot for them either, just about perfect.

Weston Airday this weekend which should draw in the crowds with the lovely weather on offer.

Edited June 20, 2014 by Polar Maritime
Let's keep to Model Discussion please, Many Thanks.

[IDO]

Though not much support (again) from the mean for the return of higher pressure in the 7-10 day period.

 

OP at D10:   Mean: 

 

 

ECM ensembles show after D6 the members going more unsettled: 

 

With the op in the warmer clusters: 

 

None of the models fill me with confidence as to the upcoming evolution but it looks unlikely early July will be HP dominated. Looks more of flatter pattern with transient short wave ridges and troughs; so as a whole average. The JMA early July looking like that is viable:

 

week 2:  week 3-4: 

 

The Chinese model for week 2 into week 3 shows an upper low anomaly over the UK: 

 

While CFS for July has pressure dropping more towards the south: 

 

The GFS 06z member suite for D8-16 has the mean pressure falling and rainfall becoming more likely:

 

 

Though unlike the current 7 days where uppers are average at best, the flow is warmer ,so conversely though more unsettled, probably warmer:

 

 

So FI has been consistent for a while in lowering the pressure over the UK but seemingly as usual this signal has been modelled over progressively. It remains in FI but most long range models are in unison with agreement over the change from the current settled run.

Edited June 20, 2014 by i'm dreaming of...

[summer blizzard]

i dont think i can remember such an 'unknown' outlook... well they are pretty uncommen anyway, usually we have some idea of what lies ahead out to 10 days albeit with no detail. (pressures likely to build here or there resulting in 'x' or 'y' type of scenario)

but the anomaly charts appear to change randomly at will, the ops are clearly undecided, in all its looking a mess, but what will emerge? im not so sure we can have a week or more of messy synotics, something stronger is bound to emerge isnt it? we might be on the cusp of a memorable hot spell, or yet another let down as the atlantic might win out.

but for mow ill be happy to enjoy the bright warm sunshine

 

Aye. The ensembles suggest a westerly flow and judging from the thickness contours probably more cyclonic than not but N/S.

 

[johnholmes]

i dont think i can remember such an 'unknown' outlook... well they are pretty uncommen anyway, usually we have some idea of what lies ahead out to 10 days albeit with no detail. (pressures likely to build here or there resulting in 'x' or 'y' type of scenario)but the anomaly charts appear to change randomly at will, the ops are clearly undecided, in all its looking a mess, but what will emerge? im not so sure we can have a week or more of messy synotics, something stronger is bound to emerge isnt it? we might be on the cusp of a memorable hot spell, or yet another let down as the atlantic might win out.but for mow ill be happy to enjoy the bright warm sunshine

 

There are always some instances when the anomaly (500mb) will not give good guidance but not that often, they signified several changes over the past few weeks if watched carefully and the usual cautions I often quote are followed. Currently they are (well EC-GFS) are not consistent with one another or run to run, the NOAA set of charts, 6-10 and 8-14, have been more consistent and thus probably give the best guide as to the type of upper air pattern to expect 5-15 days from now.

see links below

 

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

and

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[Thundery wintry showers]

The models have certainly moved away from the UKMO/ECMWF outlook that we saw over the last couple of days, with its evolution towards a more changeable westerly type.  I thought the GFS was out on its own with the high pressure clinging on in the north of the country and only slowly being eroded, but this morning the UKMO and ECMWF have moved more in line with yesterday's GFS with any breakdown being messy and sluggish and probably not until the last few days of the month.

 

The weekend is certainly looking on the warm side for most parts of the country with some sunny spells and broken cloud, though the GFS indicates possible scattered showers in central and eastern areas:

https://max.nwstatic.co.uk/gfsimages/gfs.20140620/12/51/ukprec.png

I think the GFS will be overdoing these and that most places will stay dry, but there could be a few fairly isolated sharp showers about.

 

In terms of temperature and sunshine amounts, next week could still go either way, especially for eastern areas, even if the high takes hold- the GFS 06Z had shown a change to cool cloudy conditions for eastern Britain mid to late week with maxima of 14-17C, but the 12Z has completely backed off from that scenario, with the high ridging further east and the same areas projected to have maxima of 20-23C mid to late next week.  As usual, much depends on precisely where the anticyclone ends up.

Edited June 20, 2014 by Thundery wintry showers

[Captain Shortwave]

taking a look at some of the operationals being chucked out, I think the ensembles and anomaly charts could be next to useless here. We have heights south west, south east and north of the UK, all trying to nose in with low heights scattered around and trying to break through any connections between said ridges of high pressure. Confidence at even 5 days out is very very low at the moment.

GFS

Weak heights over the UK, variable flow and fairly warm.

 

UKMO

Ridge further east with a southerly flow. Low pressure set to take control at day 6, GFS is having none of this.

GFS this run is trying to desperately establish a Scandi high and an easterly flow across the UK. Completely different to its previous run. 

They don't really have a clue here. 

[Summer Sun]

Once again we are back to no agreement from for the UK at t144 GFS and UKMO couldn't be more different

 

 

Will be interesting to see how things pan out

[Captain Shortwave]

The ECM is a bit of a mess really, pressure stays fairly high throughout 

Probably only a few showers around. In the sun temperatures will be a little above normal, cooler in any cloudier spells.

[Milhouse]

ECM really sums up the outlook at the moment and thats an uncertain one. Pressure remaining fairly high but with no real warm air to tap into temperatures will remain rather average which will feel warm in the very strong June sun. Showers cant be ruled out on any day though.