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

[Swave Snow]

Well fancy that.

 

 

Whats it suggesting?  An Atlantic onslaught or more of the current hot weather

[Captain Shortwave]

Low pressure over the Azores at this time of year doesn't usually result in cool unsettled weather as the Azores high has to go somewhere else, usually closer to the UK.

No surprise to see the high near the UK on both the UKMO and GFS, the crucial part is getting the high to build on our side of the Atlantic which will prevent troughing developing in a location to bring cooler weather. This looks like a fine and warm set up for now rather than hot. Though it must be noted that the position of the low near the Azores could come in handy for heat later on as this could encourage an Atlantic trough to develop. GFS FI shows this nicely with very warm/hot conditions getting into the southeastern half of the UK.

Edited July 22, 2014 by Captain shortwave

[knocker]

One would suspect part and parcel of the reason for this change showing towards the end of model runs is this:

 

 

I wouldn't be hedging too many bets on this just yet with the ECMWF signal by far the strongest (and quite honestly, given it's record this side of the Atlantic over the last 2 years, it can no longer be considered as any better than any other output), but still not supported fully, though the GEFS seems fairly close to it too.

 

Whether the change is temporary or longer lasting is the question that follows, and one which we are some days yet from knowing.

 

SK

 

For the benefit of the ignorant like myself could you briefly explain why the MJO phase influences the dynamics of the middle troposphere in the eastern Atlantic in summer and thus the surface prognostication. I don't seem to have come across any reasonable explanation. A link will suffice. Ta.

 

I'm guessing

 

Edited July 22, 2014 by knocker

[knocker]

Whats it suggesting?  An Atlantic onslaught or more of the current hot weather

 

Well it's a long way down the line and only one model so wouldn't take much notice but if the Bermuda/Azores high did move south of west in the 500mb anomaly then it probably would be more unsettled.

[terrier]

Looking at the models so far it's looking to me like the beginning of August we will see a cool down with unsettled weather becoming the dominant player. Think August will be our wettest and coolest weather this summer. Not great for the summer breaks.

[Captain Shortwave]

Looking at the models so far it's looking to me like the beginning of August we will see a cool down with unsettled weather becoming the dominant player. Think August will be our wettest and coolest weather this summer. Not great for the summer breaks.

You can tell that the end of the month is approaching. Every month the following month gets written off as cool and unsettled. 

Well the GFS ens show next week to be a story of a transient Azores ridge moving slowly fro west to east bringing a mostly fine week before transferring towards the Euro/Scandinavia region.

August could again start on a very warm note. If this is close to the mark. 

The Metoffice don't seem keen on any widespread unsettled weather for the foreseeable future so I think calls like the one above are very premature to say the least.

[Djdazzle]

Looking at the models so far it's looking to me like the beginning of August we will see a cool down with unsettled weather becoming the dominant player. Think August will be our wettest and coolest weather this summer. Not great for the summer breaks.

I fail to see this in the model output. A couple of hints at a cool down is not a reason to write off a whole month!

[stodge]

Evening all

 

A rare chance to have a glance at the 12Z Operational output. GFS is very anticyclonic in high-res and by early next week it's still looking settled:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2014072212/gfs-0-144.png?12

 

HP firmly in charge but a much better orientation for those not keen on the heat with the air sourced from the Atlantic so pleasantly warm rather than hot.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2014072212/gfs-1-144.png?12

 

Really pleasant conditions if we get some sunshine.

 

http://modeles.meteociel.fr/modeles/gem/runs/2014072212/gem-0-144.png?12

 

GEM looking rather different at the same point with the HP further west and a more Atlantic influence.

 

http://modeles.meteociel.fr/modeles/gem/runs/2014072212/gem-1-144.png?12

 

850s looking reasonable but suspect if GEM verified it would be a cloudier scenario,

 

http://www.meteociel.fr/ukmo/runs/2014072212/UW144-21.GIF?22-18

 

UKMO more like GFS but ECM still to come.

[stodge]

I fail to see this in the model output. A couple of hints at a cool down is not a reason to write off a whole month!

 

http://modeles.meteociel.fr/modeles/cfs/runs/2014072206/run1m/cfs-0-408.png?06

 

Well, there's always CFS if you think it's correct - this wouldn't be an inspiring summer chart.

[Cloud 10]

ECM firing on all cylinders this evening after the gremlins of yesterday,and joins the other models in building high pressure in the mid-atlantic over the weekend with some weak heights over the UK and an increasing chance of showers.

 

 

 

Perhaps over doing it at 120 hrs though?  (jetstream over-amplified again)

 

 

 

[Djdazzle]

CFS flips more times than a pancake. It was showing August 2003 type runs the other day!

[Summer Sun]

Once again its UKMO and GFS v ECM for early next week with ECM still refusing to build high pressure within the t144 time-frame

 

[Guest]

Looking at the models so far it's looking to me like the beginning of August we will see a cool down with unsettled weather becoming the dominant player. Think August will be our wettest and coolest weather this summer. Not great for the summer breaks.

Thank you for providing balance to this topic, even if it's way off the mark 

Glorious outlook from the models as this summer goes from strength to strength

[harryc]

Looking at the models so far it's looking to me like the beginning of August we will see a cool down with unsettled weather becoming the dominant player. Think August will be our wettest and coolest weather this summer. Not great for the summer breaks.

Anything to back that up with?

[phil nw.]

Looking at the models so far it's looking to me like the beginning of August we will see a cool down with unsettled weather becoming the dominant player. Think August will be our wettest and coolest weather this summer. Not great for the summer breaks.

If you want your views to have some substance terrier then you should provide some data or charts.

Unsupported pronouncements like this are not useful in this thread.

Edited July 22, 2014 by phil nw.

[MP-R]

I think if August were to be a cool and unsettled month, there would have to be some sharpish signs of a pattern change, which I can't personally see on any of the models yet. As has been the case this summer, unsettled spells have lasted no longer than 3 days at a time and none of them since June 4th have been cool, rather average at worst. I may stand corrected nearer the time but I don't see why the warm and mostly dry theme won't continue into August - all Atlantic onslaughts have been majorly watered down so far this summer and I don't think the weather is ready to break fully just yet. I would say the difficulties are going to be positioning of high pressure, whether we are influenced by a Euro, Scandi, UK or Azores high.

[Bristawl Si]

Seems like we're in a repeat & rinse re the latest model output.

A more permanent breakdown to the predominately dry, sunny and warm conditions has been on the cards for a couple of weeks now it seems but has failed to materialise, in real terms, so far. Bar the odd few days of storms and showers it's been a pretty decent summer down here.

I do recall about 2 weeks ago one particular poster wrote off the last third of July. Hmmm.....

Edited July 22, 2014 by Bristle boy

[Captain Shortwave]

Seems to me that the mean HP that's been on so many charts according to the latest CPC 8-14 day data has been removed and instead it looks low pressure orientated. Then again the NOAA charts have teased us quite a bit lately, but anyway here's the height anomoly chart for tonight:http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

The NOAA chart shows a weak positive anomaly over the UK, again suggesting a transient ridge with a deeper trough developing in the Atlantic, this is more representative of this afternoons GFS in mid range developments. No real signs of the Scandi trough suggested by the ECM/GEM which is good news for now.

[draztik]

The models at day 6

 

ECM

GFS

 

the verification stats at day 6

 

[johnholmes]

I think great care is needed when making comments about the anomaly charts at either 6-10 or 8-14. Don't read too much into individual outputs. Look for consistency day to day with each model and for consistency between all 3 main models. I use the idea of at least 3 days of this before making any comments about what they may mean. I've been away for a week, although I was able to look at them each day but not the same detail as a copy and paste then comparing over 3 or more days allows me

 

For what it is worth from the anomaly outputs I would think the dry rather than wet, over the country as a whole is the most likely 6-10 day ahead and a bit less heat for southern areas. Possibly a trend to a slightly less settled pattern starting to show in 8-14 days. Maybe I am being a bit premature with memories only of the anomaly charts over the past week. Just looking at a week last Sunday compared to the issue this evening and the upper pattern being predicted is quite a bit different.

In turn looking at the actual 500mb flow today compared to the 6-10 day prediction and .

 

The predicted chart shows a marked trough for about 20 west and so does the actual with a hint of ridging over and east of the UK on both predicted and actual. So maybe the current prediction of a more westerly upper flow will be orrect-6-7 days from now we can check.

 

sorry I am showing no charts to illustrate my points.

Edited July 22, 2014 by johnholmes

[damianslaw]

Settled rather than unsettled best word to sum up the foreseeable future. All models firmly agree heights will back west by the weekend allowing more of a NW flow to develop with chance of showery outbreaks in the north and generally a less humid feel but with temperatures widely low-mid 20's still.

 

As others have stated GFS is keen to see a quick ridging of heights NE once again as we end the month these nosing towards Scandinavia again - carbon copy of events in the past 2 days. ECM keener on a stronger atlantic influence with heights staying to the SW. Hard to say how things will pan out, but we could see another very warm start to August just like last year..

 

August on average sees the atlantic crank up a gear, always a tall order to expect lengthy settled conditions prevail from second half of July and through a decent portion of August, last occasion was 2003. 2006 saw things break in August, likewise last year and we ended up with fairly average conditions often cloudy. 1995 and 1990 were exceptions like 2003. Will we see a 2006 or 2013, or a 1990, 1995 and 2003? who knows... What I can't see is a change to predominantly unsettled anytime soon, atlantic does appear very weak at the moment with little oomph in the jet, but as move through August watch for tropical storm developments, they can play havoc and change things rapidly, more so during the second half of the month mind.

[Man With Beard]

The models at day 6

 

ECM

GFS

 

the verification stats at day 6

 

That's what I'm thinking tbh Draztik, this should be ECM's bread and butter territory, D5, no northern heights issues, in the past I would have had no hesitation backing it on calling such a pattern change ... but it's not got all of these right recently, it really needs to get this right to be deserving of its reputation as the best mid-range model.

It is not in complete agreement even with its own mean chart, though, which is much more like GFS or UKMO.

With such uncertainty at T120, the outcome of which will make a huge difference from T144-T240 ... how on earth can we have much confidence about August. (Though I respect anyone who dares to make a forecast, terrier )

[Captain Shortwave]

That's what I'm thinking tbh Draztik, this should be ECM's bread and butter territory, D5, no northern heights issues, in the past I would have had no hesitation backing it on calling such a pattern change ... but it's not got all of these right recently, it really needs to get this right to be deserving of its reputation as the best mid-range model.

It is not in complete agreement even with its own mean chart, though, which is much more like GFS or UKMO.

With such uncertainty at T120, the outcome of which will make a huge difference from T144-T240 ... how on earth can we have much confidence about August. (Though I respect anyone who dares to make a forecast, terrier )

Both the GEM and ECM are much more progressive with this cooler incursion compared to their respective ensembles. Despite the timeframes involved, given it's a UK/Scandi trough formation then there are definitely warning signs over the reliability of the operationals here given their past history. More runs needed I think.

 

Whilst people are chucking claims and counter claims about August, just one little nugget, both the GFS and GEM ensembles want to build another Euro/Scandi ridge during the first week of August. The UK being on the western periphery. One to watch and see how that develops.

Edited July 22, 2014 by Captain shortwave

[damianslaw]

BBC in there longer range outlook (9.55pm forecast) yesterday suggested 2 scenarios as we end the month, higher heights to the SW and lower heights to NW, or higher heights over the country, whereas today they were more confident in the former scenario verifying i.e. low heights to NW and higher heights to SW, which chimes with ECM this evening, even though UKMO model would suggest the latter scenario.

[knocker]

The ECM ens 6-10 500mb anomaly has a swathe of cold air to the north, a ridge eastern Europe, warm air in the western Atlantic and the usual cutoff low, A general westerly flow with generally unsettled surface pattern with temps around average.

Edited July 22, 2014 by knocker