Good morning. Here's a run down of the 00zs for today Tuesday September 11th.

All models show a cool NW flow for all today. Tomorrow this backs Westerly and strengthens somewhat as a series of troughs cross East over Britain. A ridge crosses over the south on Thursday followed by more fronts Friday (weak in the south) when a very strong Westerly gale develops for the far North. The weekend shows pressure having risen from the South with much less windy, brighter and eventually warmer weather for all away from the far North by Sunday. All this translates into changeable conditions with some rain at times between drier and brighter interludes away from the troughs with a better weekend to follow especially in the South by Sunday.

GFS then shows next week starting with High pressure migrating to the East with a warm Southerly drift over the UK. Pressure will be falling and a cold front crosses by midweek introducing fresher, cooler conditions behind a band of rain. The model then shows FI to be cooler and fresher with rain at times as High pressure sits in mid Atlantic steering Low pressures down from the NW to the British Isles.

The GFS Ensembles show the operational and control run colder options in the later stages of the run. The mean for the pack rise above average at the weekend before cooling to levels near the long term mean later. Rainfall is sparse in the South until after the 19th though in the North more evenly distributed. There is a huge spread in the Scottish ensembles from the 17th.

The Jet Stream is shown toppling South over the UK in the next 72hrs before reverting to a West to East low near Scotland over the weekend.

UKMO for midnight next Monday shows high pressure centred over Germany with a light SE flow over the South and a light SW flow in the North. A lot of dry, bright and very warm weather would be likely in the South for a few days with less bad conditions for the North where it too should stay dry with rather more cloud than further South.

ECM too looks very similar to UKMO at 144hrs moving forward with a few days of unsettled weather midweek before High pressure builds back strongly from the SW to affect much of Britain with drier and brighter weather as we move towards the weekend.

In Summary the weather can best be described as changeable as we go through the next few weeks. There is likely to be rain at times for all though longer dry spells in between for the South as High pressure always remains close by chasing the troughs away. Further North some very windy weather looks likely for a while before some dry days are possible here too at times early next week. It looks like becoming very warm again especially in the South early next week. The models diverge in the longer term with GFS sitting High pressure out in mid Atlantic with cool and unsettled weather for all in a NW to SE flow while ECM in 10 days shows a strong ridge of High pressure centred to the SW ridging strongly North.

Here's todays video musing looking at the weather for the second half of September;

http://gavsweathervids.com/

A mixed picture - Thinking the last week may turn cool and unsettled, but confidence is low.

Edited by user 11 September 2012 12:22:22(UTC)  | Reason: Not specified

Originally Posted by: Gusty

Yet again people tend to want to draw on the negatives and concentrate on potential unsettled conditions in 8-10 days time rather than concentrating on positives in the shorter term that indeed looks set fair for most.

It only gets worse as winter approaches, Steve.
On many occasions in 2010 we had heavy snow falling outside in -3C and people were complaining the outlook 8 days ahead was starting to look less cold

Originally Posted by: Gavin P

Originally Posted by: Gusty

The outlook looks warm and settled through the weekend and into the early part of next week, apart from perhaps the NW of the UK at times. Yet again people tend to want to draw on the negatives and concentrate on potential unsettled conditions in 8-10 days time rather than concentrating on positives in the shorter term that indeed looks set fair for most.

If the messages I'm getting on my website and on Twitter are anything to go by a change to unsettled, autumnal conditions is what they are waiting for and far from being a negative, they view it as good news.

I've noticed a lot of people seem to like the "correct" temperature for the "correct" season. So they think hot weather is fine in summer, but in autumn they are looking for something cooler and more "seasonal"

I've pointed out September is often a month that doesn't really belong to either summer or autumn, but from what I've seen a lot of people are getting fed up with these summary conditions keep coming back.

Coming back!?

When were they here last? May?

This mornings ECM was good for a majority of England right to the end of the run, while the 6z GFS seemed to go absurdly mobile very early on in the run. The 'default to zonality' happening early.

12z on it's way now

Well it seems as though for the south of the uk in particular, the current interlude of autumn heads back settled and precip out till the 18th is pretty well absent. so what of the then proposed shift to unsettled for the final third of the month ? although naefs builds a pretty strong greeny anomoly, i have little faith in week 2 offering at present. no reason why an incursion of less settled mid next week shouldnt be followed by another ridge moving in. i'd like to see what the telecons are saying as the theme of mid lat highs was signalled late august for september and thats proved pretty reasonable.

Hi Folks. Here's how I see the output of the big three forecasting models tonight.

All models show a Westerly flow over the UK veering NW at times. A succession of troughs will cross the UK in the flow followed by cooler NW winds. By the weekend High pressure develops near Southern Britain though westerly winds remain strong over the far North. The weather translates to changeable conditions overall with some rain at times mixed in with drier interludes. Temperatures will be slightly on the cool side before temperatures rise in the South at the weekend.

GFS then shows a very changeable pattern as we move through next week with the first half seeing High pressure more dominant in the South at least though with occasional wea troughs bringing the risk of rain on occasion. As we move into FI the weather turns colder as a sharp trough moves through turning winds Northerly and dropping temperatures abrubtly with rain followed by showers. Through the rest of the run the weather turns more Autumnally changeable with strong winds, rain, cool and fine weather all featuring at some point.

The GFS Ensembles show the warm up at the weekend before a gradual fall off to levels slightly below average later in the run. In scotland a similar pattern is shown though as usual rainfall is more prominent throughout the run than locations further South.

The Jet Stream is shown to dip SE over the UK in the coming days before settling West to East near scotland over the weekend and next week.

UKMO shows High pressure engulfing Southern Britain at midday on Monday with several days of fine and dry weather from that chart with high temperatures likely.

ECM couldn't be different to it's European cousin tonight bringing Low pressure quickly in at the start of the week with the rest of the run showing Low pressure domination for all with a chill NNW flow later in the week accentuating an Autumnal spell.

In Summary the models are all over the place from as early as the late weekend. ECM and UKMO are unusually at total odds at 144hrs with GFS somewhere in the middle. In essence with that degree of difference between the models all options shown thereafter must be taken with a pinch of salt as it's likely they will all have different evolutions by the morning. So in conclusion FI is at t100hrs tonight with no real idea of a trend from the output.

A bit of a fly in the ointment on sunday now as a couple of fronts courtesy of a stronger than originally progged low pressure system penetrate countrywide.

http://www.wetterzentrale.de/pics/brack4.gif