Model Output Discussion 22/07/12 Onwards.

[Scorcher]

well looking at the models can we call summer over its looking wet now even deep into fantasy world at the moment

http://www.meteociel...hp?mode=2&ech=6

I don't think I've ever seen you post without referring to rain or 'dire' conditions, have you not looked at ECM today?

[andy100]

Edited August 24, 2012 by hector

[phil nw.]

The 12z GFS and UKMO agree on a cooler and changeable outlook in the next few days.

A wet day for much of the UK tomorrow as the advancing Atlantic low moves across the country with extensive slow moving and sometimes heavy showers,

Sunday now looks the driest and brightest day nationwide over the long weekend as a brief ridge moves across.

As many regular model watchers know this doesn`t last with the next low and it`s attendant fronts moves quickly into the west during BH Monday.

The rain affecting most areas by the end of the day.

The unsettled and rather cool conditions looks likely to continue through most of next week before pressure is modelled to rise from the south west towards next week end.

There is still much uncertainty whether this will be any more than temporary though as the 12Z GFS and 00z ECM mean runs tend to keep the Azores High rather flat with only brief ridges into the south where conditions will likely be fair from time to time.

Certainly the 00z ECM operational run showed more of an AH build by day10 than it`s mean output so i would suggest there`s no strong agreement of a UK wide settled spell yet.

Edited August 24, 2012 by phil n.warks.

[ANYWEATHER]

I would urge everyone to be carefull of the Ecm output.....Why?. Ive been quite interested as of late as of which model takes the lead in suggesting synoptic pattern changes. Some favour Ecm some Gfs, but as of late the Gfs has out performed the Ecm on many times. I think personally that anyone thinking that we will see a repeat of last September need to pinch themselves. We have seen this scenario before loads of times this Summer. and what we are left with is unsettled conditions. Im sure there will be some fine spells coming up but the overall trend is for unsettled conditions...The met=office update is plain

[bluearmy]

if you read phil's post of noaa discussions yesterday and then look at today's, you will see that gefs have come into line with ecm ens re the east coast usa trough. thats why we now see naefs day 10 looking much closer to ecm mean when yesterday evening, they were way apart. i cant really remember a time when the longer range ens charts such as naefs and noaa cpc changed so much on a day to day basis. now we have agreement between gefs and ecm ens, i suspect we may see the output settle down. whilst noaa cpc charts look promising, especially the further south you are, they are mean representations on a six day period and it would be no surprise to see fronts making it right across the uk before the next ridge built in. however, the odds on a decent first week (and maybe even third) september have grown again today after a few days of uncertainty.

[The Northern Ramper]

Tonights ecm still on track for settled conditions from Thursday.

I note what people are saying about the GFS picking up on things lately that the ecm does not but on this occasion the Met Office are also backing the outcome.

[Milhouse]

well looking at the models can we call summer over its looking wet now even deep into fantasy world at the moment

http://www.meteociel...hp?mode=2&ech=6

That just isnt the case. Its obvious to me that tomorrow is looking wet, then we see a dry day on Sunday and for the eastern side of the UK on Monday. All the while rain will spill into the western side of the UK, but this should have cleared out into the north sea by the start of Tuesday which will leave a day of sunshine and scattered showers. Wednesday will see another low pressure affecting the UK bringing more rain, but by Thursday pressure will be rising from the southwest which will mean a drier end to the week. Thereafter, surely even a novice can spot the trend for high pressure to becomre more dominant to the south of the UK meaning quite a bit of dry weather for the southern half of the UK with low pressure closer by to Scotland. the ECM mean has high pressure developing more widely bring more widespread settled conditions.

[NUT]

I think as per most septembers recently we stand a good chance of getting 1 last hot blast for the year

[The Northern Ramper]

The pub run has just delivered, the below is after it has been settled and warm for a week.

[shedhead]

All 3 main players starting to latch onto to ridging plan this morning, even as early as T+144hrs. Summer is coming, regrettably in Autumn tho...

GFS

ECM

UKMO

Edited August 25, 2012 by shedhead

[Frosty.]

The latest models show a marked improvement in the weather by the end of next week with rising pressure across the uk, the gfs 00z is more generous for northern areas extending a ridge further north next weekend but the ecm is not good for northern britain with lower pressure but for the midlands, wales and south it all looks good for anticyclonic conditions to become dominant, especially further south but for northern and western parts of the uk it currently looks like low pressure is going to be in control for long periods. There is likely to be a lot of low pressure in the iceland region and extending further south and the ecm 00z shows northern britain exposed to the lower pressure with generally more changeable/unsettled weather but for the south it should become fine and warm by next saturday and well into the following week. Today looks very unsettled across southern uk with some torrential downpours but then pressure rising from the west by tomorrow should bring a fine day for most if not all of the uk tomorrow but with a cooler feel and overnight ground frost in parts of scotland, then monday becomes wet and windy from the west although the gfs 00z shows the southeast having a largely fine and dry day until late on, tuesday has some patchy rain or showers but some areas dry and bright, wed/thurs are more unsettled with heavier showers and more persistent rain but by friday it should improve from the southwest as pressure rises.

[johnholmes]

my shorthand notes on anomaly charts this morning

so a marked change from their previous 4-5 day upper air pattern prediction. Another day or two and the prob of this pattern being a 'real' one will be fairly certain in my view. That is for the end of August into early September.

Sat 25 au-gfs

Sat 25 august

Ec-gfs

Keep same idea as last issue=ridge/+ve over uk

East of uk then gfs shows much more of this than ec, both similar to west with it and even further west over states

So overall trend last 2 ec-gfs and 1 noaa is for ridge over uk

[johnholmes]

I did a comparison a few days ago of what GFS and the anomaly charts were predicting the 500mb flow would be todday.

The updated pdf shows how they both fared compared to the actual 500mb chart at 06z this morning.

Comparing the predicted charts from Tuesday-14-15 august.pdf

[Frosty.]

I did a comparison a few days ago of what GFS and the anomaly charts were predicting the 500mb flow would be todday.

The updated pdf shows how they both fared compared to the actual 500mb chart at 06z this morning.

Comparing the predicted charts from Tuesday-14-15 august.pdf

Cheers john.

Your input is superb as always.

[A Winter's Tale]

After the showery regime of late, it seems like there could be a trend of warmer weather for the start of September with high pressure moving in from the SW. However, currently, we have showers over the British Isles and in particular in England there could be some thundery downpours if you catch a shower. A cooler day too with northerly winds. These showers should vanish over night and skies - particulary in the west - should be clear.

A cool night too for us all but Ireland places could see lows of 5-7C and in Scotland lows in some areas could be 2-6C and possibly even colder in the Highland glens - A touch of frost perhaps?

The chart above does show upper air of 0C in the northern isles to around 7C in the south coast but the high pressure should mean a day of sunshine and dry conditions. Maximum temperatures not too bad either at 15-21C. It doesn't last though.

A depression moving in off the Atlantic is set to bring wind and heavy rain to us all on Monday, possibly some tricky conditions in the western highlands. The upper air may be warmer but maximum temperatures could be a degree or two cooler on Monday despite the southerly winds. Once this band of rain clears out into the north sea we should return to a sunny conditions on Tuesday with some showers near northern and western areas with south westerly wind. Temperatures quite pleasant too at 17-21C. On Tuesday night, another system is set to move in from the SW bringing some rain to most of us for a time.

Wednesday should also be a wet day for most us but perhaps a little brighter in Ireland.

And as you can see on the chart below, there are signs of high pressure moving a little closer to the SW of the British Isles.

And high pressure does move in from the SW according to the GFS 06z so conditions could be a lot drier in southern areas and possibly into the north aswell on Friday.

But as ever, Britain seems to be a battleground between high pressure in the south and the atlantic lows moving in from the west but some strong and warm SWly could be a result of this. It's always a hard scenario to call when high pressure does try to move northwards over Britain.

The theme of westerly winds and interludes of high pressure continues through the very unreliable realms of FI.

In my opinion, it's not too bad an outlook for this time of year at all. With sunshine and dry days likely, some pleasant temperatures and changeable conditions between showers and fronts, with winds coming from all sorts of directions aswell as hints of high pressure moving in from the SW aswell as the presence of low pressure systems and even a possible touch of frost in the glens - I'd say that this is fairly interesting and pleasant outlook for late summer into early September with something for just about everyone.

[Cheese Rice]

Something for the cold fans, signs that autumn could soon be upon us with a cold northerly showing in FI.

I'm not suggesting this is going to happen, just that theres alot of colder 850's north of the UK showing in that northerly which we wouldn't be able to achieve in July.

Edited August 25, 2012 by Cheese Rice

[damianslaw]

Models all showing preety typical fayre for the time of year, once again an unsettled end to August with low pressure firmly ruling the roost, I've lost count of the number of unsettled bank holiday august weekends... Monday looks a washout for western parts in particular. As we head into September, strong signals of a change to much more settled conditions thanks to the jetstream tracking on a more northerly path allowing the azores high to ridge NE into southern parts. Whether this suggested change will be the beginnings of a lengthy settled spell remains to be seen, however, I think the probabilities are preety good, the first 10 days of Sept tend to bring very settled weather on average.. its been a common theme of many recent Septembers.

In overview, once again it seems the start of autumn could be about to deliver conditions that should have been reserved for the summer..

[mushymanrob]

well looking at the models can we call summer over its looking wet now even deep into fantasy world at the moment

http://www.meteociel...hp?mode=2&ech=6

of course you are correct, as by the time the settling down occurs itll be autumn! :lol:

aint it just typical?... all summer long most of us have searched for signes of a settling down, now that summer is as good as over, here it apparently comes. the models do suggest a strong possibility of pressure rising by next weekend, and the 500mb anomoly charts also predict high pressure dominance after this week. ill be grateful for a break in these record breaking growing conditions (never known grass grow so long, for so long, due to the wet and warmth). its just a pity that its september yet again thatll deliver this faux summer. (see my sig).

[Scorcher]

of course you are correct, as by the time the settling down occurs itll be autumn!

aint it just typical?... all summer long most of us have searched for signes of a settling down, now that summer is as good as over, here it apparently comes. the models do suggest a strong possibility of pressure rising by next weekend, and the 500mb anomoly charts also predict high pressure dominance after this week. ill be grateful for a break in these record breaking growing conditions (never known grass grow so long, for so long, due to the wet and warmth). its just a pity that its september yet again thatll deliver this faux summer. (see my sig).

Thing is Rob, it's early September so will be better than getting it in late September as we did last year! I think we should look on the bright side. It would have been nicer to have it in mid July but beggars can't be choosers. GFS seems to be coming more into line with ECM all the time. Certainly pleasing to see when many predicted the opposite would happen!

[damianslaw]

Mods - perhaps time for a new thread, this has got to 53 pages long and is over a month old now...

[The Northern Ramper]

Yeah and maybe title it "Summer is over and warm settled conditions no longer count! Model thread"

[Thundery wintry showers]

It is now looking likely that tomorrow will be the best day for most outdoor activities during the Bank Holiday weekend as Monday will have the persistent rain spreading in from the west. A westerly incursion is then likely with sunshine and scattered showers on Tuesday and Thursday, perhaps some more organised rain for a time on Wednesday as a secondary depression tracks over the British Isles.

I am detecting a fair amount of ramping regarding the early-September outlook as the model outputs are pretty consistent in shifting that high pressure cell eastwards to the south of the British Isles. With a broad moist tropical maritime airflow over the British Isles a NW-SE split is more likely with cloud and breeze tending to restrict maximum temperatures, although this will change if the models revise the high pressure cell northwards. It may be that we'll eventually get a high sat over the British Isles after a couple of failed attempts, but nothing is showing that within the reliable timeframe.

[Frosty.]

The Gfs 12z looks a lot more like the Ecm 00z this morning with the anticyclone at the end of next week rather further south than the gfs 00z was showing, so it would mean the fine and warm weather would be restricted to the far south of the uk initially, with progressively more breeze, cloud and rain further north but the high does build strongly by the end of next weekend into the first half of the following week with more widespread fine, dry and warm weather before a breakdown to more unsettled weather spreads from the west later that week but coming back to the next 7 days, tomorrow is the best day with only one or two showers dotted around in england and most areas dry with pleasant spells of sunshine, a clear night to follow with a ground frost in parts of inland scotland but then things go rapidly downhill on monday with wet and windy weather pushing east across the uk, the worst of the rain and strongest winds in nw britain. The rest of next week will be briefly better in the south and east but a slow moving trough to the northwest/west will then push slowly east across all areas with the usual mix of heavy showers and longer periods of rain but by friday we will see pressure rising from the southwest.

[Summer Sun]

High pressure anyone?

Don't pack those BBQ's away summer aint finished yet

Edited August 25, 2012 by Summer Sun

[Milhouse]

The calendar will have only just ticked over into September so i very much imagine conditions will be not that different to if this spell has occurred in mid Summer. The ECM 12z has most of the country bathed in 10c upper temperatures so the mid 20s would be achievable. Only difference is that nights are longer than they are in mid summer which would allow temperatures to drop into single figures in places.