Marco has posted on SM stating that the UK as an average is circa 20% down on rainfall today’s date. At this point you’d have expected to have recorded circa 93% of the summer’s long term average,  and its circa 72% this year, currently. 

Not model-related, but related to above convo 

Well that's the theory but having read latest Brian's tea leaves in another post and the new idea that this autumn may not be as wet as some anticipate, we'll have to see what happens...

It’s true that the models show little rain for the area north of the Cairngorms this week but elsewhere looks like seeing some decent amounts and even that area gets some beyond next weekend.  

For the south the exact track, timing and amount is understandably not agreed yet but there could be up to 50mm in some areas in the southern third of the country on Saturday.  Given the ground is rock hard that will cause some issues.

Oh dear! 🙄 

If it happens at all then hopefully it will be at night or at least not in those critical couple of hours. That far out it could be nothing like that, timing wise 🤞 There seems to be something with weather enthusiasts that we never get what we hope for!

MetO rainfall chart showing a front approaching from the west today, intensifying over the NW but breaking u over the SE (and, as so often this summer, a breakaway area of heavy rain heading for N France and avoiding S England). More rain for the NW esp NI tomorrow (Thu) with yet another 'blob' heading for France. Only on Saturday does most of England get significant rain, a large area moving across the north in the afternoon and a narrower but active front for the south.

GFS Op; a general area of LP for Britain with localised centres developing from time to time; 990mb W Scotland Fri 29th, 980mb NI Sat 30th, 995mb SW Ireland Wed 3rd. Then a brief rise of HP for the weekend of Sat 6th before an elongated trough of LP N-S over Britain and a new centre 990mb E England Tue 9th, which unusually spreads W-wards to Fri 12th

ECM; somewhat like GFS but with regional variations in locations and dates of LP centres - Fri 29th the same, Sun 31st 975mb also W Scotland, Thu 4th 995 mb N England. The rise of pressure Sat 6th is less marked.

GEM; like GFS but lower pressures for the LP centres.

AIFS; London, maxima close to 20C until Tue 9th when cooler, rain in fairly small amounts to Fri 5th then dry. Edinburgh, maxima high teens until again a cool down Tue 9th, rain also in fairly small amounts but persisting. This model is expecting less rain than MetO.

GEFS; mean temps a little below norm to Fri 12th,some rain at any time, perhaps drier after Sat 6th in the SE; some runs show enormous totals in the SW from Wed 3rd

One of the great modelling mysteries of this year. Why?

Saturday's rain event continues to be downgraded in central and eastern areas of England. The models seems to have dropped the idea of developing a secondary disturbance which would have brought the higher rain totals further south.

If it comes to pass the story of the forecasting last few months. Light rinse and occasional repeat IMBY.

MetO rainfall; in the NW at any time; in the W today (Thu), in the S tonight, everywhere on Sat becoming heavier and more persistent s it moves N (but breaking up before it reaches the far NE), otherwise always the chance of a shower anywhere.

GFS Op 0z; LP near NW Scotland 990mb replaced by new  LP 975mb off N Ireland Sun 31st slowly moving NE-ward and filling but as it dies away, spitting out secondaries along the Channel 990mb Tue 2nd and Thu 4th. Then a slow rise of pressure over Britain (but winds in the N as LP stays over Scandinavia), eventually covering the country 1025mb Mon 8th. Then a broad Atlantic trough moving through before HP is back Sat 13th.

ECM; a bit like GFS - omits the secondary on Tue 2nd (but keeps that on Thu) and the rise of pressure starts on Sat 6th, well in place  over the N Sea by Sun 7th with a burst of warm S-lies.

AIFS; London maxima 19-20C, cooler after Wed 10th, some rain from time to time to Thu 4th, heaviest Sat 30th, then drier. Edinburgh, rather similar, maxima a couple of degrees lower and rainfall spread across the week.

GEFS; temps quite close to norm for the next two weeks, good agreement from ens members, rain in the S most likely Fri 29th and around Thu 4th but more evenly distributed in the N, everywhere fewer runs showing rain after Sat 6th but not entirely absent and one or two with very big totals in the NW

GFS looks very wet for the SE corner tomorrow morning though

I wouldn't be surprised if it becomes as a line of showers, some thundery, rather than persistent heavy rain.

The only consolation from this as far as the east of Scotland is concerned is that this is now been modelled as a mostly UK-wide event rather than just a south of England (and possibly Wales) event.

However, I still wouldn't be surprised if our rainfall amounts from that were small once again, especially as this system weakens yet again as it approaches the east of the UK.

Oh, it'll be persistent heavy rain here...

😡

Some very unsettled looking model output for the first half of September. Whether it delivers the much needed rain though remains to be seen. Not sure we will have had a September looking this unsettled for a while though.

MetO rainfall chart much like yesterday. There could also be widespread heavy rain next Tue (2nd) for England, working its way up to S Scotland on the 3rd.

GFS Op 0z; current LP over Scotland filling, new LP N Ireland 980mb Mon 1st, moving N-wards but producing a secondary 990mb Cornwall Wed 3rd (does this correspond to the Meto above but 12 hours or so later?) Atlantic LP then swings past N Scotland but is sufficiently far away for ridge of HP from the SE to form Mon 8th 1025mb England, briefly disturbed by LP running up the W coast Wed 10th before re-establishing over Scotland Sun 14th. Hurricane appears near US coast Sun 14th.

ECM; Like GFS at first but the 'Atlantic LP' is closer to Scotland and indeed affects most of Britain, no HP on Mon 8th.

GEM; LP N Ireland Mon 1st is deeper 970mb with gales, and the secondary on Wed 3rd only gets to S Ireland before moving N-wards. The HP following is in place by Sun 7th rather than Mon 8th and is further east, near Denmark, giving a strong warm S-ly for the start of that week

AIFS; London, maxima ca 20C to Fri 5th with a little rain, then warmer for a few days and drier before a dip Wed 10th, but recovering. Edinburgh, coling from present 18C to 15C Fri 5th, rain at times; dry and warmer for the weekend than back to square one.

GEFS; Generally mean temps near norm for the next fortnight, spread of ens members increases noticeably from Mon 8th (op warm, control cool) In the S plenty of rain for this week, now and around Thu 4th, mainly dry later, in the N also wet but rain more spread out esp in the NW

GFS 00Z and ECM 12Z rain aggregates for the next 10 days. 

Despite the above, there does seem to a signal for drier conditions, at least in the south, during the second week of September.

We seem to always get an Indian summer in September.  This  year will be no different I imagine

GEFS has been quite consistent in signalling drier conditions for the south around 07/09 for several days now. Comparable plots for the north west show it staying more unsettled.

I’m not seeing too much in the output at the moment that will help the areas affected by water scarcity currently. There looks like being some rain for virtually everyone in the next week to ten days and that will help the gardens at least.

MetO rainfall; showers in between bands of rain working their way N-wards across Britain today and on Tue 2nd, late Wed 3rd, all linked to a centre in or near Ireland so forming an arc which (excepting today) pulls back to the NW leaving E Scotland on the dry side.

GFS Op 00z; LP 970 mb off NW Ireland today, drifting slowly N-wards but troughs in its circulation crossing Britain Mon 1st/Tue 2nd, Wed3rd/Thu 4th, Sun 7th/Mon 8th, before a period of general W/SW-lies which is brought to an end by a general rise in pressure 1025mb  Mon 15th. The hurricane by the US coast noted yesterday is absent from today's chart.

ECM; similar to GFS but the troughs tend to be a day or so later, and a ridge of HP is squeezed in between them on Sat 6th/Sun 7th

GEFS; temps close to norm, perhaps a little warmer Sun 7th and (in the S) Sat 13th. In the SE, rain in most runs  Wed 3rd, Fri 5th and Wed 10th but a dry weekend 6th/7th; in the SW mainly Wed 3rd and Sun 7th; in the N, rain more spread out over time and the dry window is briefer; within that quite a lot of rain for the far NW and not very much for the far NE.

AIFS; London, maxima around 20C, a little warmer for the weekend 6th/7th, small amounts of rain this week and then some on Wed 10th. Edinburgh, maxima high teens this week, dropping to 15C Mon 8th onwards, rain at any time except for the dry weekend. 

Not last year though. Terrible September. 

This year looks more promising. I need about 180-250 growing degree days to ripen my grapes enough between now and harvest in mid October (250 would be enough to make good still Pinot, 180-200 good for sparkling). GDDs are degrees above 10C for the daily average, so with 48 days to picking I need between 3.75 and 5.2 per day ie average of 13.8 and 15.2C. 

Is it looking like a good season for English wines? 

MetO rainfall chart generally with widespread showers, persistent in W Scotland (esp Mon 1st, but never much in the NE) and than a batch of heavy rain moving from the SW across much of England on Wed 3rd.

GFS Op 0z; current LP off NW Scotland slowly filling, but generating LP 985 SW Ireland Wed 3rd which runs quickly NE-wards, then quieter W-lies. New LP from Atlantic 980mb S of Iceland Sun 7th, preceded by warmth from the S, part of which breaking away 985mb W Scotland Mon 8th. Then more W/NW lies with HP never far from S England, moving in to cover Britain 1025 mb Tue 16th. The previously mentioned hurricane is back.mid-Atlantic Tue 16th.

ECM; like GFS at first but begins to deviate Wed 3rd when the secondary LP is further SE, near Cornwall, but not as deep. Then a distinct departure from Sun 7th as the next LP ca 995mb is positioned off W Ireland moving N & S but persistently bringing warm, even hot air up from the S through to Wed 10th when there is a threat from thundery LP over France.

GEM; has elements of both GFS and ECM; on Wed 3rd the LP is near N Ireland; the warm S-lies are present for the weekend of 6t/7th but LP moves north from France by late Mon 8th 1005mb Dover and thence into the N Sea

AIFS; London, maxima 20C but with a couple of warmer days weekend 6th/7th, some rain likely Wed 3rd, and then just a little after the weekend. Edinburgh, maxima 15C or a little above, again with warmth  and dry for the weekend but often significant rain at other times. (Aberdeen, trivial amounts until Fri 12th)

GEFS; in the S, mean temps up and down but mostly close to norm (several warm outliers around Mon 8th), rain probable in moderate amounts Thu 4th, Wed 10th,  in some runs also in the SE Sun 14th. in the N, mean temp more consistently close to norm later even slightly below, and the hot outliers are absent; rain on similar dates, also small amounts at other times generally, quite a lot in the NW at any time