GFS, ECM, UKMO all pretty reasonable for many for the bank holiday this morning 👍

---

It would be a good year for all BH having a decent ones.  ECM show stronger HP over us by Monday.

Hi everyone. Here is the report on the weather output from the big 5 models for this morning Wednesday August 21st 2013.

All models are gradually firming up on ideas for the weekend as the projected very warm weather only looks like influencing Eastern and Southern areas from now until Friday. With weak pressure gradients over the UK for the rest of the week winds would be light with showers floating around in the equally light winds aloft. By the weekend a more organised area of showers and outbreaks of rain will edge East across the UK into the warm air over Eastern areas which could give rise to a spell of potentially thundery rain, especially in the SE. Over the weekend a trend towards slightly fresher conditions move in from the West with NW breezes and cooler air but still with some showers towards the East.

GFS then moves through next week and most of the rest of it's run with High pressure out to the SW and a ridge across the British Isles delivering fine and bright weather with sunny spells and light winds and temperatures close to average overall. The far North and South could see a little more cloud at times and the odd shower in an otherwise dry picture.

The GFS Ensembles though not spectacular suggest OK conditions for the South at least for much of the time as rainfall is suggested to be small with plenty of bright and dry weather around. There is somewhat more variability suggested for more Northern parts with rain here a more frequent commodity. Overall on average the uppers are shOwn to be close to or slightly above the long term mean, the latter in the South.

The Jet Stream shows the flow gradually moving towards being to the North of the UK next week as high pressure ridges slowly in from the SW. Later on the flow settles more directly across the Atlantic towards the UK on a strengthening trend.

UKMO today shows a 'col' area over the UK to start next week with a sunshine and shower mix across the UK with the SE probably seeing the most showers. Temperatures would fall to more average levels from the high's of early in the weekend here.

GEM today shows NW winds next week with High pressure never far away from the UK with a continued mix of sunshine, patchy cloud and the odd shower, these more especially towards the North.

NAVGEM too shows a ridge from the SW over the South towards the middle of next week with the North seeing a little rain from troughs crossing East in the Westerly flow up here.

ECM too shows a ridge across Southern areas as we move towards the latter stages of next week with a NW flow prior to that. The weather next week would be largely dry in the South once the weekend showers clear away East. With winds in the NW temperatures would be average. Later in the week winds back Westerly and a North/South split develops with some rain from Atlantic fronts affecting the North while the South under the Atlantic ridge looks dry, bright and reasonably warm.

In Summary the models are beginning to show some pattern developing this morning as it looks like we are going to slide back into a pattern we have seen so much of this summer with High pressure to the SW ridging across the British Isles giving light winds from the NW in what will most likely be benign and tranquil conditions for many with sunny spells and temperatures close to average. Rainfall will be low in amount for most with only the North seeing any notable rain with some dry spells here too at times.

---

UKMO walks on the edge for the weekend, but overall we do finally have reasonably good agreement on what will happen for the August bank holiday.

Martin's summed it up very well as usual - all I can add is that the fresher air might struggle to make inroads against a continental flow down towards the SE, which GFS shows in the form of very warm temperatures on Sunday. By Monday most models have the fresher air in place, although it's soon chased out by some warm tropical maritime air which leads to higher temps again from Tuesday for a day or so (many more according to GFS).

Monday is still open to some notable changes if either the continental air hangs on longer or the TM air arrives faster.

---

Thanks Martin.

Best in the west..For the report and the weather.

---

GFS 00Z brings in some 80F+ temps by the end of next week, briefly.

http://www.wetterzentrale.de/pics/Rtavn18617.png 

Starting to look like a pretty decent end to August all in all.

Funny how often the models' initial ideas out in FI are fairly close to the mark, but then they waver hugely in the mid term before returning to something pretty close to what they first suggested! I've noticed that happening in winter a lot, too. The pattern tends to be: A hot/cold spell is picked up at about 300 hours. The models run with it for a couple of days, then just as the media pick up on it, they flip dramatically around the 216-240hr mark, and it looks like the media forecasts are going to be way off the mark. Then at about 168-180hrs the models revert back to showing the originally modelled pattern, albeit usually in a rather watered-down form.

---

I find that a lot of model error comes down to overdoing things one way or the other. The extent increases with time to verification, with 168h+ being susceptable to considerably overblown synoptics. This works both ways with a given situation IMO; in other words if the models see a signal for snyoptics to trend in a certain direction such as a flatter jet, then they'll nearly always take it too far. This also occurs quite often if the signal is to amplify the pattern.

When it comes to individual events, it's the way they handle energy that's the problem. To me it seems that they in some way manage to transfer energy more efficiently than can actually occur. This results in overcooked storm systems and perhaps also over-modification of airmasses (the rate of temperature change could be too rapid) resulting, for example, in too much rainfall being progged from frontal systems.

With regards to next week, it looks like the models had the PV becoming too powerful and have now backed down on it's intensity, reducing the extent of it's influence and -  significantly for us - it's ability to drive LP systems right into Scandinavia.

---

http://www.wetterzentrale.de/pics/Rtavn1801.png 

---

As ever with convective precipitation, it probably won't be as uniform as the GFS charts suggest, and potentially not  as widespread either (it tends to overestimate the Convective Available Potential Energy), but some areas will see plenty of showers while others escape with nothing much at all.

That said, a weak frontal system edging west to east through the weekend will provide a focus for the showers that should make it hard for anywhere to stay completely dry.

I'm very much anticipating the usual electrification of showers on the coast around Bournemouth and from Salisbury Plain northward but with a strange lull in between

---

The models seem to be indicating that HP may become more influential as we go through next week. Much as I hope they are right on that one, after the downgrading of the settled weather for the coming weekend I'm not reading too much into anything beyond the weekend just now.

---

 

---

http://www.meteociel.fr/modeles/geme_cartes.php?ech=6&code=0&carte=0&mode=0&archive=0

Look just off the coast of Canada at +90 hours and you'll see the little LP that pushes the HP NE and turns this GEM run into a cracker

Unfortunately there is no support for that LP from UKMO, ECM or GFS. That said, GEM was among the first to spot the small trough sliding SE and then sinking away into the continent... something to watch out for, just in case

---

Good evening. Here is the report on the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Wednesday August 21st 2013.

All models show a Low pressure trough crossing the UK tonight and tomorrow with showers and outbreaks of rain affecting parts of England and Wales overnight and becoming showers, some thundery in the SE tomorrow. Elsewhere an area of slack pressure develops over the UK tomorrow with fine and bright weather for many as well as fairly warm conditions. On Friday a new front advances into the UK from the West at the same time as very warm air pumps North over parts of the UK from the South. As it moves in some of the rain with the associated trough will become thundery over Central and Eastern Britain in particular late in the day. On Saturday, Sunday and Bank Holiday Monday the emphasis looks to be for the best weather to be in the North with the SE in particular at risk from thundery showers as low pressure close to the SE early in the weekend shows reluctance to clear away. The North should lie under a ridge of high pressure with a fine and dry Bank Holiday Weekend for here.

GFS then pulls the ridge down over the UK early next week at the same time as the associated High cell advances East over and to the East of the UK by the weekend. From then on a slow progression towards somewhat more changeable conditions develop from the North though it takes a long time for any significant influence from this to reach the extreme South.

The GFS Ensembles show grouping around or just above the long term average with regard to temperature. Rainfall is unspectacular for the most part, mostly in the form of showers rather than sustained widespread rainfall events.

The Jet Stream shows the disorganized flow as at present eventually settling to a position West to East just to the North of Scotland next week and beyond.

UKMO shows a showery trough to the SE and an Atlantic trough moving in from the West over the North next Tuesday. Central areas would see the best of the dry and bright weather while the SE could still see a few showers left over from the weekend while the North and West of Scotland and Northern Ireland see rain at times too.

GEM tonight shows High pressure building strongly over the UK next week following the showery weekend. Temperatures would climb comfortably into the mid 20's for many areas in light winds and prolonged spells of late Summer sunshine.

NAVGEM shows the showery trough to the SE early next week quite slow to leave it's influence over the SE before further weak troughs slip SE in the NW flow that develops midweek. Eventually the South becomes largely dry with the rain such as it is more restricted towards the North late in the week.

ECM shows progressively more settled conditions returning in the second half of next week after a changeable start. The weather would turn dry for almost all parts by midweek with some very warm and sunny weather developing for the South as a High pressure cell migrates East to Germany by the start of the second weekend.

In Summary the models continue to jostle about with synoptics tonight. The one constant is there never looks to be much in the way of general rain with showers more likely than not. These will be most prevalent over this Holiday weekend and may be slow to clear the SE early next week. Thereafter, there looks a reasonable chance that High pressure will rebuild from the SW, perhaps substantially so as indicated by GFS, GEM and ECM with another associated warm and sunny period for many.

---

Thanks martin.better late than never Joke by the way.

Yes the wife's birthday today so had to take her out for a meal. She made a joke by saying we had better go back as your friends on your website and the forum will be waiting for you. I didn't think my anxiety showed.

---

Matty does a good line in therapy

Funny that. My wife's birthday as well. Just got in to read it 

http://www.wetterzentrale.de/pics/Recm2161.gif

Ecm trying to settle us down.

Been very dry around here , night rain would be welcome

---

Hope we dont see too many charts like that next winter

Andy

---

http://www.wetterzentrale.de/pics/Rtavn1141.png

http://www.wetterzentrale.de/pics/Rtavn11417.png

BH Monday warming up nicely

 

---

Ditto , that would be a disaster

---

For some  

---

http://www.wetterzentrale.de/pics/Rtavn1141.png

http://www.wetterzentrale.de/pics/Rtavn11417.png

BH Monday looking decent

---

Hi everyone. Here is the morning look through the outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Thursday August 22nd 2013.

All models show a cold front clearing East out of SE England this morning leaving a warm airflow over the Southern half of the UK with a slight Easterly or variable drift to the wind flow over the UK. After early rain, apart from a few afternoon showers the weather will be dry today. Tomorrow a new cold front is shown moving into the West and this crosses slowly East over the following 24 hrs developing a small but slow moving Low centre close to SE England over the weekend which is shown to recede only slowly away East by Bank Holiday Monday. In the North a ridge of High pressure develops behind the front on Saturday with a lot of dry and bright weather for the North and NW over the holiday weekend while showers, some heavy are likely elsewhere.

GFS then shows a ridge of high pressure across the UK next week with fine, bright and reasonably warm weather for most. However, there remains a weakness close to the SE where the occasional shower remains possible until the weekend. The ridge then extends to all areas and strengthens in week 2 with a large High centre locating to the West and extending across the UK late in the run it what would be a very dry and settled latter half to it's output this morning for all of the UK.

The GFS Ensembles show the operational as one of the warmer members with quite tight clustering in Southern locations through the run today, all hogging the long term average level for most of the run. There are few warm members shown but a few chilly ones showing up while northern locations see a lot more spread in a changeable weather pattern up here. Rainfall in the South remains programmed to be below average.

The Jet Stream today is shown to be well North of the UK at times in the next two weeks but probably too high to the North over the Atlantic with something of a returning arm South from Iceland close to the UK at times especially later meaning the warmest air in association with High pressure will be away from the UK.

UKMO today shows a slack NW flow over the UK by midweek next week in association with a broad ridge across the UK from High pressure just to the SW. The weather would be largely dry and benign with sunny spells and comfortably warm conditions for most away from cooler northern and Northeastern coasts.

GEM shows a strong ridge across Britain early next week which then develops into a closed cell of strong high pressure close to Western Britain late in it's run with a light northerly drift over the UK. Dry weather would be almost universal away from a few showers in the North early in the week. Thereafter a benign and quiet spell of anticyclonic type early Autumn weather would ensue with reasonably warm and bright days but cool and misty night could develop inland too.

NAVGEM has the scenario of losing the Low pressure away to the SE only slowly next week with some showers for a time down there while pressure will be High elsewhere with fine and dry weather which extends to all areas late in the run with fine and warm conditions with cool and misty nights as High pressure anchors over the UK.

ECM shows a slack Northerly flow over the UK for much of next week with some showers in the East for a time before it too brings High pressure across from the West over Northern Britain with a fine and settled spell developing for all with warm sunny spells by day and some cool and misty nights.

In Summary today it's a High pressure based pattern which looks set to rule the roost over what's left of our meteorological Summer and the beginning of Autumn. Nearly all models support an evolution which suggests High pressure sitting over or close to the UK later next week and beyond which would bring a period of fine and settled weather. All models seem to wish to keep the High just to the West of the UK which would bring a cooler injection of air into the mix at times holding temperatures towards the rather warm instead of very warm category but nevertheless the Farmers and Growers will welcome this news this morning for the continuing harvesting season. There is just one small caveat, this synoptic setup could deliver some quite chilly nights and now that the nights are approaching parity with daytime in length there is increased time for some cool nights to develop with a much increased risk of mist and fog in places, clearing readily in the mornings though.

---