Usual rules- take it away folks!

http://www.wetterzentrale.de/pics/Rtavn5417.gif

As previously mentioned, Saturday looks a BBQ day

Nice weather for barbecued ducks? 

http://www.wetterzentrale.de/pics/Rtavn544.gif 

I don't get why GFS shows highs of 26C while simultaneously showing very heavy rain. Unless it's overestimating thunderstorm development, one of those things isn't going to happen.

I am assuming the maxima will occur prior to, after, or between any rain or downpours? (Except of course further north where it will no doubt just rain the whole time). It is already another wetter than average month here with over a third of the month to go. Roll of autumn - actually hang on, we are there already.

The WZ chart is I think shows rainfall accumulation for the 6 hours (rather than 3 hours used on TWO and most other sites). You can see the extent of the cloud cover here, so there is the prospect of sunshine too. 

Higher res models, such as this one from Hirlam, shows a combo of high temps and potential convective development. Not that unusual at all. (except for here of course, where vigorous convective showers have been shockingly absent this summer )

This looks pretty wet in places!

Oh dear Michael sucked in by the GFS ppn charts again lol

Fortunately the beeb are completely at odds with the timeline you have shown

Well the Met Office are forecasting showers followed by rain here on Saturday with heavier rain on Sunday and Monday so I would say they also have been sucked in? 

The UK Met Office forecast for Saturday to Monday States the following - for the UK as a whole.

"Generally unsettled with showers or spells of rain, often heavy. Sunny spells most likely in the east, but showers still possible. Warm, maybe very warm in the southeast at first." 

www.metoffice.gov.uk 

Seems to tie in rather well with the GFS precipitation charts?

Ah yes, you're probably right. It does appear that we will have some sunshine on Saturday, and any rainfall will be convective - with hopefully the general rain area staying further west.

Even Sunday looks good here with the rain staying at bay until later, and reaching 24C - which is a big upgrade.

And beyond then - not so great early next week but once again getting warmer.

So, locally, August could end up slightly above average after all - albeit cloudy and humid.

Latter part of BH looking good and once September arrive we get long awaited nationwide HP but will it come to fruition?  Not to be trusted as those are 3 world modelling and media forecasts we have had been very wrong all summer.  When the last time the stupid computer models bring the strong HP down to 12 hours range? It always disappeared and now next week more like October pattern without a reason why LP spinning around like a leper that won't go away and not moving away to Russia then China by few days time?  Last week it was showing a hot week with HP around.

http://www.wetterzentrale.de/pics/Rhgfs1864.gif

Is that really going to happen with UK miss out the warmth? Just yesterday it was in the high 20's.  We should have a right to slate at the stupid computers since it arrived and made a whole thing wrong constantly this summer.

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON FRIDAY AUG 21ST 2015

THE CURRENT GENERAL SITUATION. A large depression South of Iceland will dominate the Eastern Atlantic and the UK with a warm and moist SW flow across all areas. A weak cold front will become slow moving over Western areas reinvigorating later in situ.

http://www.wetterzentrale.de/pics/Rtavn001.gif

MODELS-2 WEEK HEADLINE Remaining somewhat mixed with a lot of dry weather for all but with occasional rain too at times.

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow moving SE towards Spain before turning sharply North across the UK over the coming days. The flow then slowly veers to a more SW to NE flow across the UK later next week and further North still in Week 2 as High pressure builds from the South for a time.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS Operational Run today shows Low pressure developing over and eventually just to the North of the UK. This will bring very unsettled weather to all areas for a week or so with showers and longer spells of rain. While warm and humid in the SE to begin cooler and windy Westerly winds will blow for much of next week. Then over the Bank Holiday Weekend it looks like pressure will be building from the SW, too late for the start of the weekend but OK for the day itself with a spell of warm and sunny weather for many for several days. Then the end of the run shows a cold front moving South and an early season Northerly delivering cold Autumnal winds and showers to end the period.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif

THE GFS CONTROL The GFS Control Run today is only different in the second week as one would expect. It delays further the onset of High pressure from the SW bu once it does bring it in some very warm and sunny conditions look possible in Week 2 aided by an ex tropical storm to the West of the UK pumping up very warm air from the South over the UK with any rain from this restricted to the far NW.

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning still look generally good in two weeks time with most members liking the idea of the close proximity to the UK of High pressure to the West and SW with any influence from the Atlantic restricted to more Northern areas.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

UKMO UKMO today looks very unsettled next week as the humid thundery airflow of the weekend gets swept away East by blustery and cooler West to SW winds with rain or showers at times for much of next week in association with Low pressure just to the North or NW.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts this morning show the week trough currently over Western Britain rejuvenating tomorrow as Low pressure forms along it to the South which then moves North across the UK and sweeps the trough East with a very unstable WSW flow across the UK to start next week.

http://www.weathercharts.org/ukmomslp.htm#t120.

GEM GEM today shows very unsettled conditions developing across the UK over the coming days as Low pressure develops and moves North over the UK setting up cooler westerly winds with rain and showers for all of next week. Improvements on this run are muted in regard to the Bank Holiday Weekend with lighter Westerly winds shown but still with enough instability across the UK for rain and showers to continue.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM also follows the theme of Low pressure in control in a big way over the next 7 days with cloud and rain at times for all and temperatures after a warm and humid start falling to average at best in a developing blustery west or SW wind. Some limited improvements are hinted at for Southern Britain next weekend.

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

ECM ECM this morning too looks unsettled and breezy with the same Low pressure complex over Western Britain late in the weekend only slowly moving North with West or SW winds affecting all areas with rain and showers, especially towards the West and North. Warm air is shown to flirt with the SE again later next week but conditions are shown to remain changeable up to the start of the long weekend when High pressure over the Atlantic ridges in to the UK. pressure is low over Iberia though and this threatens the South with thundery showers come Bank holiday Monday with the North seeing the best conditions then.

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last evening shows very slack conditions across the part of the Northern hemisphere around the UK with a slight bias towards lower pressure to the NW and higher pressure to the South. This is made up of members who show a variety of options where no one pressure pattern is established for that time.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models are all in agreement of a spell of unsettled and windy weather under Low pressure next week with some signs of slow improvements next weekend to rather better conditions to start September.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM. This morning's verification statistics show ECM leading the way at 3 days with 95.9 pts followed by UKMO at 95.6 pts and GFS at 94.7 pts. At 5 days ECM is stll king at 85.7 pts followed by UKMO at 85.5 and GFS at 82.9 pts. Then at 8 Days ECM still leads at 61.0 pts over GFS's 55.1 pts. Finally at Day 10 ECM leads GFS at 42.5 pts to 38.0 pts from GFS.
 
http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig
 

MY THOUGHTS It looks pretty nailed on now that the UK is going to see a spell of potentially very wet weather in a few days with just location yet to be nailed down on where the heaviest rainfall will be, all this as a cold front engages some very warm and humid air moving North over the East of the UK from Europe. Thundery rain looks inevitable from tomorrow becoming widespread and heavy currently expected to be most likely across Central and Western areas as a Low develops and moves North along the axis of the front over the West. Then next week sees all the humidity swept away East with Westerly winds on the Southern flank of Low pressure anchoring to the North and NW for much of next week delivering further spells of rain and showers in blustery and cooler winds than of late. We then have to look at whether the models are still focusing on improvements for the Bank Holiday Weekend and on into September. In general they are but whether it is in time for the Bank Holiday Weekend is open for debate as there is some delay in this on today's output making the weather for the UK an improving scenario as the weekend moves on rather than a dry one from the start. Nevertheless, signs are encouraging that not unusually for this time of year the Jet stream may move North at the start of September which could allow the Azores High to ridge into the UK more meaningfully and give us a pleasant period of weather at least. No report tomorrow morning but back as usual on Sunday.

Next update from 09:00 Sunday Aug 23rd 2015

People bang on about how bad the models have been this Summer but in actual fact they have been largely accurate for much of the time. As I say the verification stats I publish everyday prove that, it's the now-casting and local detail that has occasionally been short of par, borne out of slack synoptics when almost anything can happen hour to hour as well as mile to mile. On my travels around the South Of England this Summer I have witnessed first hand how you can go from 14C and rain in the West to 29C and hot sun in the SE, in just a distance of 100mls. There have been a few notable blunders which even the Met office have been embarrassed about on occasion with an apology from Mr Ian Ferguson on the heavy thundery washout day which never materialized only last week. The reason why we have such early Autumnal looking charts such as those shown for next week is down to the Jet stream being once again too far South. For reasons why that has been the case this Summer and in many Summers recently is more down to climatologists to study as I do believe the Arctic Ice melt is having an effect on our Gulf Stream and the temperatures of the waters in the NW Atlantic which has knock on effects on the weather and pressure patterns that occur over the UK and elsewhere as a result. However, that's a discussion that should be and has been addressed elsewhere in the forums.

I firmly believe that while NW Britain has had a horrific Summer many Southern and Eastern parts of the UK have faired reasonably well for much of the time and while there certainly hasn't been hardly any cloudless, hot and nationwide sunny spells the weather has certainly not been that wet across the South and East and for those that criticize the models I will just say that how many times in the reliable 6 day period has High pressure been shown across the UK, I think you'll find hardly at all and that is in fact is what has verified. All High pressure and deep Low pressure for that matter which has been shown in 6+ days has generally been modified as new evidence come to light which it obviously did. The problem is that people have short and selective memories on individual good and bad weather events from certain synoptics which can taint their overall longer term appraisal of the models.

Sorry if this post comes across as a bit of a rant but I thought it would be worth posting an opposing view of some people's opinions on how the models have performed this Summer from a view point of someone who study's them avidly everyday. I'll shut up now and go back to work.

Thank you Martin for the outlook.. Agree with your comment.

Having had a quick skim through the models and looking at Gibby's post, it does look like I'll be going from Summer heat to Autumnal gales in the space of 48 hours here at this end of Kent. However, I may appreciate the cooler fresher westerly-type airflow as we go into next week but still get to feel pleasantly warm in any sunny breaks we - or rather - I do get.

There is a August 1984 feel to all this from where I'm sitting.

I wouldn't rule out some intense thunderstorms later tomorrow either.

Central/Southern England and The Midlands look at risk from this at the moment.

I've not complained about the models, just the weather!

My opinion is that the boundary between 'good' & 'poor' weather has seemed to be narrower than normal this summer, so even any 'nowcast' slight deviation to the expected set-up means a whole lot of people being affected - and, Sod's Law in action, it's mostly been a case of the 'bad' weather boundary shifting the wrong way (so more people are impacted)

I'd just logged on to post this - the GFS 00z really piles in the rain events next week and has some slow moving or stalling frontal systems on a number of occasions.

That's the trouble with being sandwiched between an increasingly hot NW Europe and the Atlantic westerlies. I can see the potential for totals in the next 5 days to be on a par with some of the wettest weeks in winter 2013/14, which is really saying something.

Tallying up the rain events on the GFS run for the next 7 days:

1: Stalling, pivoting frontal boundary this weekend (20-30mm for Wales, central and western England, and SW Scotland).

2: Mass of heavy rain associated with LP moving up from the S or SW on Monday (another 20-30mm for much of England and Wales)

3: Another area of heavy rain passes close to or over SE England with showers elsewhere (close shave on this run - no more than 5mm for most)

4: Very slow moving frontal boundary from the NW later Wed and right through Thursday for much of England (20-40mm for E & W)

5: Stalled frontal boundary reinvigorates across the SE while there's showers for most other places (up to 20mm for the SE, nearer 5mm elsewhere).

Here's how the 7 day totals look:

Which really does bring back memories of Dec 2013 and Jan 2014! 

Factor in the fact that the showery spells could deliver a fair bit more than the 5mm suggested by GFS in some places, and it could be a rough week for a lot of us.

Obviously the details are likely to change, potentially by hundreds of miles regarding where the frontal boundaries set up shop. This run is one of the wettest so far from GFS, though this only seems to have brought it in line with recent ECM and UKMO runs so it's worth taking seriously on this occasion.

Very wet for most if the ECM 00z is to be believed and very muggy.