We can only hope that the suggested improvement over the Bank Holiday weekend from GFS and ECM plus the MetO's 6-15 day updates over the past few days materialises. We could sure do with a proper dry spell, especially if next week turns out as bad as currently predicted!

Isn't September often quite a dry month? Here's hoping anyhow.

And oh look, this small corner of Kent just happen to be the only place to catch what could the first proper severe gales of the  . . . er . . . late Summer season come Monday evening with sustained winds of 50 mph for a few hours. I would disregard it as it is still three days away in forecasting terms and the other models are showing a toned down version but this particular model had not only ran with the idea in the past few runs but also slowly upgraded it and I do find that the GFS is quite accurate with this kind of handling.



Hope I wake up tomorrow and find that this was just a bad dream, but otherwise that'll make for some rough Channel ferry crossings.

Euro4 offers a glimmer of hope for those attending events in Southern England on Sunday, as the frontal boundary pivots in the Channel and the eastern segment looses a lot of its punch before moving inland. However it's still not quite enough for the Super Car Showdown (needs dry road for the cars to be able to accelerate and decelerate properly), and would still bring issues with low cloud bases to Bournemouth Airshow.

In short, this trend south in the pivot point needs to continue, delaying the arrival of the rain until dusk or later. As a bonus, the very warm air ahead of it would allow temps to hit the mid-20's again, maybe higher. It's a long shot I know! 

Sign's of high pressure to start September if today's GFS and ECM are to be believed! 

Predicted by P*er's sunspots six months ago. We'll never hear the end his gloating now

His record stacks up that he's an extremely poor amateur forecaster. 

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 SUNDAY AUG 23RD 2015

THE CURRENT GENERAL SITUATION. Complex Low pressure will be centred around or over the UK for the next 24 hours or so followed by a cooler and fresher Westerly flow later tomorrow.

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

MODELS-2 WEEK HEADLINE Remaining very unsettled this week with rain at times. Perhaps rather drier as we move into September.

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast still shows the flow inappropriate for the UK to sustain dry weather for any length of time over the next few weeks. It lies across or to the South of the UK early this week with cyclonic conditions over the UK. With time it drifts North but never far enough to the North to sustain anything other than drier phases for the UK as a whole.

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

GFS OPERATIONAL The GFS Operational Run today shows well in control of the UK weather over the next week as the thundery complex of Low pressure currently near the South of the UK drifts North and deepens to allow fresh to strong West or SW winds and cooler weather with showers or spells of rain at times throughout this week. Through the Bank Holiday Weekend further Low pressure is shown developing near Southern Britain with further thundery rain which delays yet again the onset of higher pressure for the second week which is still shown to at least give the South a spell of better early September conditions to finish 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 little different for Week 1 but is better for next weekend with less made of Low pressure developing over the South. In fact with High pressure not that far off to the SW plenty of dry and benign conditions look possible over the weekend and this is shown to improve further through the second week as High pressure migrates East across the UK to lie to the East later setting up some more humid Southerly winds late in the period with some rain from troughs in the West but dry weather over the East and SE.

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show a 65% /35% split in members  this morning with the largest bias towards a lot of High pressure lying across the UK with some warm and settled weather in 14 days. The 35% that show less settled weather show a strong Low pressure area either over or to the NW of the UK with strong winds and rain at times for most of not all as a result.

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 shows a changeable and often windy week with temperatures falling back to average in a blustery West flow with showers or longer spells of rain especially across the South at first and the North later as pressure begins to build from the South towards next weekend.

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 a much improved outlook for the British Isles eventually but we will have to be patient and it may not be soon enough to rescue the bank Holiday Weekend. In the meantime much of this week is shown to be cool and windy with showers or spells of rain, heavy at times with a gusty west wind developing. Then from next weekend pressure steadily builds from the SW with High pressure developing across the UK when we all go back to work with increasingly fine, sunny and warm weather developing for all.

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

NAVGEM NAVGEM is less rewarding for next weekend as it maintains something of a trough down the Eastern Atlantic just to the West of the UK with weak SW airflows but occasional rain at times with the warmest conditions in the SE, all this following a week of turbulent late Summer weather under the influence of strong Low pressure to the North and NW.

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

ECM ECM this morning takes a much more arduous route to somewhat better conditions in the second week I'm afraid.. This week is broadly similar to what the rest of the output shows which maintains very unsettled cyclonic conditions all week and with a small Low moving NE across the South early next weekend this looks unlikely to change much for many over the bank Holiday. Winds then switch to a chilly Northerly in the second week as High pressure inches towards the UK from the West but the air may be still unstable enough to support showers in the North and East at least.

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

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last evening shows very inconclusive suggestions for the weather in 10 days. No doubt made up of members that support various scenarios for that time point the bias remains slightly in favour of a trough from the North down over the UK but with plenty of options pointing towards higher pressure and warmer conditions too.

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

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models maintain the theme of a very unsettled and windy spell this week but still show the jury is still out on the extent on improvements thereafter.

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 96.0 pts followed by UKMO at 95.7 pts and GFS at 94.7 pts. At 5 days ECM is stll king at 86.1 pts followed by UKMO at 86.0 and GFS at 83.0 pts. Then at 8 Days ECM still leads at 60.7 pts over GFS's 55.1 pts. Finally at Day 10 ECM leads GFS at 42.9 pts to 37.5 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 Here we are at the start of a new week and another set of output which in the short term at least is far from what one would hope to see towards the end of August. The current thundery Low affecting the South and SW of the UK will move North and be superseded by a less thundery but still potent Low pressure tonight and tomorrow feeding more heavy rain and strong winds into those areas that have already seen quite a lot over the last 24 hours or so. Elsewhere away from the SW will see more rain from this feature than has been so far from the current one as it trundles North toward Northern Britain early in the week setting up a windy and unsettled week with rain and showers in cool and sometimes strong Westerly winds. All eyes then are on the chances of a pressure build from the South or SW making it in time to bring a change to fine and dry weather but in all honesty from what I can make out this morning improvements are likely to be too slow to give the UK anything other than an average Bank Holiday Weekend with the threat of at least some rain or showers still evident. Thereafter there are plenty of charts which do show a full blown improvement in the shape of High pressure crossing the UK giving fine and warm weather in early September but as has been the case all Summer the desire not to release the persistent trough over the Eastern Atlantic from some output is a worry with some output still showing only muted and half-hearted improvements resulting still changeable conditions across the UK in early September too. So while this weeks guaranteed wet end of Summer period unfolds we must hope that the model runs that show High pressure moving into the UK as we get into September have got a handle on things correctly and we can put to bed this rather poor Summer for the North and West but an OK one elsewhere if not a little disappointing for much of the time given the near continent has has an almost continual Summer of impressive heat and dry weather.

Next update from 09:00 Monday Aug 24th 2015

Tomorrow, a small area of low pressure crosses England from SW to NE and entrains some cooler air aloft on its NW flank. The models are suggesting that this will result in a lot of heavy rainfall with embedded downpours - similar to this morning across the SW and CS England, except that precipitable water levels look a bit lower so not quite so dramatic.

I reckon Euro4 and NMM give decent snapshots as to the sort of rainfall pattern to be expected, while also highlighting some uncertainty regarding placement:

Some high-res models (e.g. France's high-res AROME) have the heavier stuff only clipping the SE. 

Run through the 00z here and to be honest the low resembles a tropical storm with hints of an eye: http://www.meteociel.fr/modeles/arome.php

...which is hopefully coincidental. I do wonder if the system could be warm-core though?

Anyway, worst case scenario for accumulations is probably Euro4:

Even bearing in mind 10-15 mm of that is from today's rain, there are some troubling totals in places. Will it be overblown? Today's rain certainly hasn't been here, in fact I'm already above what the 00z Euro4 has for me up to 12 noon.

Not that the past tends to have much bearing on the future with the British weather 

Following on from all this, an increasingly fragmented band of rain affects much of the UK on Tuesday (Scotland escaping driest), perhaps heavy at times across the S in particular. Then it's more or less a rinse and repeat for early Wednesday. Precipitable water amounts rise to almost as high as we have this morning so some downpours may be possible.

A trailing frontal boundary responsible may then develop a wave that brings quite a bit of rain to the SE during the afternoon, but this could well end up further NW or SE.

The same goes for another wave on Friday, currently looking to miss us to the SE but worth keeping an eye on for any adjustments NW.

Overall, it's not looking as bad over the coming 5 days as it once did, but there's still quite a lot of rain on the cards:

As for next weekend... GFS has added another moisture-laden low that again interacts with hot conditions over NW Europe. High pressure has also been dropped from the ECM output, but with the rainmaker passing to the SE.

August is clearly an autumn month this year! 

If today's ECM is to be believed, we could also be looking at the first autumn frosts too. Shouldn't be too much of a shock to the system though given that we've already had them during high summer. 

In a week's time ECM wants to give the SE a burst of late summer heat.  Will have to work hard to beat yesterday's 31c at Gravesend though!

The 12z is out as far as 7 days ahead and so far has proved particularly wet for a large part of England.

Firstly, it nudges up the rain rates for tomorrow's event (snapshot of peak below left). Then you have the two areas of rain on Tuesday and Wednesday (peak of latter shown below right).

Following this, it develops more than just a wave along the frontal boundary for Thursday - we get a small low pressure system instead, which drenches Southern England through the day. This feature existed on the ECM 00z but tracked SE of the UK:

Two drier days follow this, but by Sunday, low pressure of Iberian origin is on the cards again:

...which means the potential for another batch of weekend downpours, potentially slow moving if the low gets trapped under a ridge as this particular run showed. The rainfall charts actually have the heart of the low largely dry, with the rain strung out around the edges, but I find that hard to take seriously - but I do take seriously the idea of the low pressure existing in the first place, given that GFS did well spotting - some 7 days in advance - the low we've been dealing with this weekend.

ECM took a fair few days to latch on to the track of the system, will it be the same again this time around? Certainly the low was in the vicinity on the 00z op, but it was held to our SE.

The GFS takes its turn (as did the 0z ECM) at throwing heat into the southern UK at the end of the month.  Some hit and miss intense rain too!

Worth a weather eye to keep watch!

If that Iberian-origined low were to centre 3/4 hundred miles east, it'd be a fantastic set-up for the majority of the UK.

It could get a bit tricky along parts of the South Coast tomorrow afternoon... those are some of the highest rain rates I've seen HIRLAM project since it appeared among the options on TWO.

It seems to be a result of converging low level flow in the area, but driven by the LP rather than the wind meeting the coast (as the wind is from the N to NE across The Solent at the time of the chart shown).

Obviously this could well end up a bit further north, or south, and the intensity could be quite a bit lighter... or heavier - though the precipitable water charts from other models such as NMM suggest that 40 mm per hour should be the upper limit to the rain rates for the most part.

A glance at Euro4 reveals a similar focus of the intense rain rates toward the coast, and while HIRLAM transfers them to just S of London over the following three hours, Euro4 opts for a broader swathe of heavy rain with less suggestion of downpours.

The high-res models that focus on France (AROME, NMM 2km) suggest slightly more inland progression of the downpours even with the LP following a similar track. That's most likely down to differences in model physics/parametrisation.

I have to say, running through AROME is borderline hypnotic (http://www.meteociel.fr/modeles/arome.php).

It's a great example of where high-resolution modelling of convection is aiming to go. The development of those intense 'cores' of precipitation is key to assessing the risk zones for severe events. A key thing to bear in mind is that we can never expect a model to predict the exact location of individual cells - there's just too much chaotic motion for that to work. It's all about identifying the general regions in which development is most likely 

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 MONDAY AUG 24TH 2015

THE CURRENT GENERAL SITUATION. Low pressure will move NE close to SE England today followed by an active trough of Low pressure moving NE over England and Wales tomorrow.

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

MODELS-2 WEEK HEADLINE Remaining very unsettled this week with rain at times. Perhaps rather drier as we move into September.

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast pattern this week will see the flow blowing mostly from a SW to NE direction across England and Wales. It will be quite strong at times given the time of year. Through next weekend it may ridge North somewhat although very briefly before through the second week the flow remains locked in a trough like state over or around the South of the UK.

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

GFS OPERATIONAL The GFS Operational Run today shows Low pressure well in dominance across the UK for the whole of this week with rain or showers at times in rather cooler and blustery conditions than of late. Towards next weekend the South and East may enjoy a brief drier and warmer interlude with humid air spilling back briefly before Low pressure returns from the SW. The rest of the second week is then governed by various areas of Low pressure and attendant rainfall affecting the UK on various occasions with temperatures on the slide somewhat again.

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

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

THE GFS CONTROL The GFS Control Run today is almost a replica of it's operational partner in that a lot of unsettled and wet weather at times this week could give way to a dry and warmer interlude at least across the South and East to start the weekend. On this run unsettled weather is also shown to return under developing Low pressure over the North before a more substantial ridge could give a spell of fine and warmer weather across the South and East later in the second week, though it may not hold for long past the term of this morning's run.

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show a bias towards better weather in the South than the North in 14 days time. The majority of members suggest that Low pressure will reside to the North with High pressure to the South stretching various degrees of influence across at least the South of the UK in a predominantly Westerly airflow pattern by most members.

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 shows a changeable and often windy working week with showers in the North and some more prolonged rainfall in the South on occasion. Over the weekend the weather may turn set fair for many as a ridge of High pressure moves NE across the UK settling things down somewhat under light winds.

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

THE FAX CHARTS The Fax Charts this morning show this week as being unsettled and at times breezy with rain or showers at times. Slow moving troughs with waves along it will affect the South and SE at times with more prolonged rainfall while the North shows more showery conditions under a cool West or SW breeze.

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

GEM GEM today shows an unsettled week too with troughs delivering rain at times with brighter showery conditions in between. Pressure rises by the weekend and it could become warmer and more humid again in the South with the risk of further thundery rain as the troublesome trough to the South never really moves far away despite rising pressure. Then next week High pressure makes a more pronounced attack on the UK from the West with fine and dry if not overly warm conditions developing for many under chilly nights.

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

NAVGEM NAVGEM is less rewarding for next weekend as it maintains something of a trough down across the UK with showers at times and probably quite cool conditions. In the week leading up to that the weather is equally unsettled as the other models show with Low pressure in control with rain at times for all.

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

ECM ECM this morning still shows improvements as we move out of this week, through the weekend and next week but the pace of this is very slow. There is plenty of unsettled weather with increasingly windy weather this week as the pressure gradient steepens across the UK later in the week. Then a slow rise of pressure from the SE allows better weather to affect some parts over the weekend as the trough across the UK fills out. By early next week High pressure has a much better grip on the weather as it extends slowly NE with a lot of dry and fine weather for many with temperatures near average by day but cool by night.

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

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last evening shows a growing trend to build High pressure slowly NE across the UK next week with fine and dry weather developing then as a result.

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

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models maintain the theme of a very unsettled and windy spell this week but there remains suggestions that improvements in conditions could still be on the horizon for next week.

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 96.0 pts followed by UKMO at 95.8 pts and GFS at 94.7 pts. At 5 days UKMO is king at 86.5 pts followed by ECM at 86.3 and GFS at 83.2 pts. Then at 8 Days ECM still leads at 60.9 pts over GFS's 54.9 pts. Finally at Day 10 ECM leads GFS at 42.9 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 The models continue to paint a very mixed picture across the UK over the coming two weeks but it's not all bad news. This week shows all models illustrating a very unsettled pattern as Low pressure areas centred around the UK amalgamate into one large complex to the NW later this week with stronger SW winds for many as a result. Rain or showers at times is likely for all and while High pressure never becomes far away from the SE the polar front lying just to the SE of the UK late in the week and for that matter this weekend it could still threaten some thundery rain at times in the South and SE as ripples run NE along it while slow improvements develop elsewhere if not overly warm conditions. It's from the weekend on in fact where divergences within the output begin to take shape with some output such as GFS developing more Low pressure near the UK next week with rain at times and eventually rather cool and windy weather while some of the other output including GEM and the much respected ECM looking much more High pressure orientated next week. So obviously more runs are needed to pin down details on how the situation may evolve around the UK after the Bank Holiday Weekend. While current thoughts on the weekend are that it shouldn't be a write off with regards to rainfall it looks far from memorable from a temperature perspective and I would suggest that some showers are possible in places too but with a lot of dry and reasonable weather in between these. My own fears are that with High pressure in some form staying in the Med next week the stalled front expected to clear the SE at the weekend may be blocked by the Med High on it's movement SE and could return more NW at times than is progged currently which would feed potentially thundery rain across the South and East at times despite relataively high pressure. Then we have to hope that GEM and ECM have things correct in their projections of High pressure extending NE across England and Wales with fine and settled conditions developing for all bringing us a quiet start to Autumn 2015 though night times could remind us of the longer darkness hours now as temperatures drop quite low and valley fogs start to become an extra ingredient to the new seasons weather.

Next update from 09:00 Tuesday Aug 25th 2015

Thanks Martin.

With the 1st September appearing on the calendar next week you can guarantee that the ECM and GEM are on the money with their High pressure progged outlook.

We can only hope that ECM is proved to be nearer the mark for next week than GFS. Having said that, my understanding is that ECM has been verifying a bit better than GFS recently so there is some hope that it has a better handle on developments going into next week.

I remember how a week or so ago, GFS was in a number of runs showing HP trying to build in from Scandi during this week and holding the atlantic at bay for a few days at least. However, at the same time, ECM showed low pressure taking charge of proceedings for this week and never really bought into what GFS was going for. Hopefully ECM will be similarly accurate for developments as we head into September.

Hope so as August the Autumn month are coming to the end and September which renown for a summer month will deliver the goods. that usually last between 2-3 weeks of decent usable weather before last week of September when proper Autumn weather arrive, sometimes it doesn't and continue to October.

20C uppers on Sunday and I remember 2 weeks ago the GFS was hinting a hot BH weekend, will this being restored? I notice it a westward position which this morning run show 20C over south London. Surrey, Sussex and Kent area, then cooler but decent BH Monday.  Will this make the 4 BH car boot sales being on this year?  Last year stats was 2 on and 2 cancelled out of 4 BH.

Midday GEFS updates have trended notably to a more unsettled outlook in September.

Usually kids go back to school and the good weather returns. Could be different this year though!

I personally think summer is behind us now as we slowly slide into Autumn.

Still you can get some pleasant weather in September if conditions allow.

This August has not been exactly very good either.

I think autumn has arrived early this year. Birch & chestnut trees are turning already. Toadstools in the local parks.. All rather early for down here.