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Afternoon All- Having 45 mins to kill while im relaxing I thought I would just pitch up a post of what Im looking for in a model which indicates a probable move from say Mild to a colder outlook- ( especially in winter ) This isn't a definitive process however after watching every model / model run for the last 15 or so years you get to see whats happening in some models & where they are going to follow another. A text book one this week comes from UKMO V ICON. I place UKMO at the top of the pile at the moment & this current evolution of the 'lorenzo' track its had nailed from pretty much 144 onwards - However its the subsequent ridging & block formation west of Scandi thats been the difference for me again. You may have seen me comment that the ECM has been way to progressively lately & it was following the ICON for its 'slower' progression, well the ICON has been to progressive V the UKMO- Post Lorenzo UKMO always had decent residual heights to the North generating an 'undercutting theme' heres the 3 day ICON evolution leading to *07am Sunday* ( IE they are all the same timestamp ) You will note across 8 runs we see a ridge appear from nothing in the East to a full blown block. - If you watch the signs you can forecast model 'change'. On Monday 12z Ive highlighted the first attempt at energy undercutting identified by the model. We now over the last 36 hours in a model going from T174 > T120 been able to note a model trend & forecast a block to the North.... Hope this helps people why I post how I do & also why I posted the central European ENS swing to cold yesterday as the change was coming .... Best S

Assuming that the Fax chart for 12Z Friday turns out to be about right then Lorenzo, or rather its remains, is going to follow a pretty unusual track=NNE then ESE. I honestly cannot ever remember either in internet days or in my work period any major low doing that sort of track into the UK. Perhaps others can show something similar?

14 for me please - Genuine snow chances.

Apologies about keeping the full post but it seems appropriate. Interesting post Steve. The situation is not that different from an empirical rule used in UK Met LONG before computers arrived in trying, in winter, to predict when a Scandinavian high could develop. The charts you show are not too different from the ideas behind the empirical rule and the probability of the ridge then persisting for more than 48 hours. Remember in the 50's and 60's only human forecasts were done so trying to predict beyond 24-48 hours was pretty unusual.

I noticed quite a bit of Arctic potential lining up for just after mid october on the GEFS 12z...I wouldn't rule out some surprisingly early snow this month!❄

Current synoptics and those forecast for the rest of the week, in the depths of winter would bring a snow/freeze fest - classic synoptics for snow in winter.. alas its the 1 October, but an unusual pattern none the less, low heights coming unstuck against a block to the north, a front moving north then back south.. followed by a cold ridge and then an undercutting low pressure sliding through the UK with scandi heights.. Its good to see some more interesting synoptics than the usual default atlantic SW feed.

A terrific photo of an arcus cloud associated with a thunderstorm approaching Reading at 17.30 this afternoon. Photo courtesy of Simon Lee, Twitter @SimonLeeWx.

There is no way that the SE will have will have water shortages in spring, after all the channel lows and E'lys coming this winter with northern blocking sending the jet on a southerly track, the spring snow melt will give more than enough water.

Some lovely cloudscapes today, including this anvil.

Yes a real lively day weather wise 2 shots in between the storms on Esher Common skies looked more tropical than autumnal today !

Starting again with the tropical feature which had been shown to develop in the Atlantic during the first week of October, which we all now know is Hurricane Lorenzo which became the easternmost CAT 5 ever recorded https://weather.com/safety/hurricane/news/2019-09-26-hurricane-lorenzo-category-4-rare-eastern-atlantic https://www.metoffice.gov.uk/about-us/press-office/news/weather-and-climate/2019/will-hurricane-lorenzo-affect-the-uk and is now heading toward the Azores then toward the UK which I will get onto in a moment. Overall I think the ensembles done a good job with timing and positioning at this stage. There were also hints at a northerly across the UK which is on course to move in through tonight bringing some chilly air MJO did indeed move into phase 1 and is still in phase 1 so I would say a continuation of the current pattern remains likely with lower pressure in the Atlantic extending into the UK at times. Going back to Lorenzo I mentioned a track towards the UK, models appear to have firmed up on the idea (although there could still be some changes in position as is always the case with hurricane paths) of Lorenzo skirting the west / northwest coast of Ireland then moving eastward across Ireland before moving SE through the Central part of the UK / England effectively becoming a sliding low which IMO is an uncommon occurrence especially at this time of year when low pressures would be expected to be moving directly west to east. Actually a good example of the effects that blocking high pressure can have (especially during winter)

Some crazy skies today like something otherworldly, multiple deluges even a thunderstorm nothing mental... Rotherhithe PWS has seen 16mm today and I suspect they’ll be more to add to that total by midnight.

If only it were January, and the T850s were 15C lower!!!

And for anyone who'd like to learn, take a look at John's Skew-T guide in our shiny new learning area

Definite signs from the extended ECM ensembles of an improvement towards mid month.... Slp at this stage close to a 1020mb,with the mean temps around 5C. So perhaps some late bursts of sunny daytime conditions and cool misty evenings.... That would be some perfect sunsets and rises and a much needed rest for some of our waterlogged friends who are currently getting fed up with this non stop rain.... Bring it on I say.

Loads of very big puddles out there and Sainsbury's in Beaconsfield is closed due to flooding...and it's still raining. I put my winter duvet on today but left the window in the bedroom open to air. So much rain came in that said duvet, duvet covers and sheet are now in the tumble drier

this would do, great childhood snowy days

The next round of storms split around us so nothing as dramatic as earlier but the lovely cloudscapes and hints of storminess aloft continued.

Single figure maximum today at 9c with a fresh northerly wind and light showers.Quite a wintry looking sky across the Firth late in the afternoon. Twin calves inside for a couple of days to bond with mum and allow slighly smaller one to put some weight on. On the radar can see some pinks and greens in the showers over the higher hills so will look out in the morning to see if Ben Wyvis has a wintry cap.

No but will try and copy the very basic map and explanation and see if I can post it. On another topic, Lorenzo, this link is interesting, the Portugese forecast for the Azores area showing how they expect it to move over the top of them and on to Ireland? https://www.weather-forecast.com/maps/Azores-Portugal

Now that the track of Lorenzo is firming up, here's a GIF of the ICON 12z take up to T90: That change of direction as it presumably comes up against the block to the north north east and undercuts, it looks so odd, but most models are showing this.

I think you misunderstand the enormous complexity of the problem. Hurricanes and tropical storms have yet to be successfully modelled once they get into the North Atlantic. You can be assured that intense work is going on within the major forecast centres to try and solve this. So far with only very limited success.

An October 2008 repeat would satisfy me! We can all hope.

Now this is lovely! Had plenty of booms and pretty sure a few hours ago when a storm was to the north I had a positive strike, was nowhere near the cloud and it crackled like hell!

It actually loses it's fuel source as it leaves the main jet to the west and thus drifts SE and fills rapidly having undergone full transition

Rudely woken from my Afternoon nap by rumbles of thunder here in Lee, about 20 minutes ago. Some more intense cracks, a few minutes ago. Decided to abandon the idea of Orthopaedic Pillow hunting until tomorrow, which looks like being a much calmer Day on the Weather front. Patience of some of those Brontophiles amongst you, finally rewarded. Some very noisy Dinosaurs out there, crashing about at the moment!!!! Now downstairs with the wonderful aroma of my Wife's meatball sauce, wafting about. Regards, Tom.

Goodness me that was a few years ago. Thanks for that plug Paul. Do the illustrations still work I wonder-will have a look see. Seems okay with a quick glance, very basic diagrams but back then all I had was a very basic Microsoft paint box!

Buckle up lads looks like where in for a wild one.. And Hello everyone #winter2019-20

Damaging.

For anyone with an understanding of the skew-t diagram, the Camborne and Lwerick ascents clearly show how the UK is going from summer to mid autimn in 24 hours! http://weather.uwyo.edu/upperair/sounding.html

It s been nice and sunny here today too but there are a couple of light showers about now. 10.9C max but a definite chill in the Northerly breeze.

Two days in a row we've had lovely autumn sunshine here. Temp hit a chilly 3.4c during the night. The garden is getting the attention it so sorely needs and looks so much better for it. The weekend looks like utter keich and next week looks like we might be getting the first Autumn storm, depending on what forecast you read! We'll see. best get out and pull more weeds now!

Before Lorenzo arrives, looks like some nasty weather out west already. I decoded this image using a Software Defined Radio, Quadrifilar Helicoidal antenna at 38ft tuned to 137Mhz, a low noise amplifier, WXtoIMG decoding software and NOAA 18 satellite passing overhead. I hope to post more of these pictures tomorrow and next days ahead once Lorenzo is nearer the UK. Of course nowadays there's loads of up to the minute radars and loops but still good fun knowing this image was more live than any other image when initially decoded

I may have spoken too soon! Biblical, torrential, other 'als' rainstorms as we arrived for the lad's jujitsu class at Chessington Community College. Parents and kids were dripping their way through the building while mad footballers continued training on the astro turf. No thunder this time. The wind seems to be strengthening now.

But, alas, the GFS Operational is all on its lonesome, regarding that intense depression on Day 16! And, if those Average 2m Temps are anything to go by, 'same sheet, different day' would sum-up the 12Zs quite nicely!

Getting a bit concerned any blocking high is not going to be strong enough and just ends up leaving the already soaking wet UK to suffer more of this horrendous wind and rain.

Cheers John- So what method did they have - wasnt it based around coordinates of high pressure leading into developing a Scandi HP? UKMO 96 sizing an Easterly up-

Radar 15.20 (Lightning off) 16.00 (Lightning on)

I sat in the airport yesterday and worked my way up to page 255 Late February to early March really was something special. Was amazing reading it all, checking the historic charts and reminding myself at just how good a winter it was locally.

From Oct last year "It could herald the start of a four-month Polar assault with snow and sub-zero temperatures threatening to grip the nation until February." Rao UK weather forecast: Britain braces for ‘SEVERE snow’ - FREAK SOLAR STORM warning Oct 2018. It will be on automatic updates now 1st October - snow /winter story send at midnight.

Too many variables, thats the beauty of weather. Trouble is we still dont really understand how a lot of the interactions affect one another enough. If some of the most powerful computers on the planet cant agree then we have no hope! lol

Once Lorenzo's out of the way, the GEFS 00Z ensembles suggest a spell of uncertain autumnal nothingness will ensue...? Could be the SAD setting-in though?

October 1st tomorrow...glorious time of the year when the lovely blue colour appears to our North West, North and North East and begins it’s push South. Too early for us for anything exciting snow wise at low levels but great to see the Winter-esque scenes from Scandinavia and such. It almost brings a tear to my eye - up there with the birth of my son. ECM to +144 hours.

Ireland is a good shout 2 in 2 years Debbie 61 seems its the bullseye for anything coming from azores homework done Debbie (1961 https://en.wikipedia.org/wiki/Hurricane_Debbie_(1961) Ophelia (2017 https://en.wikipedia.org/wiki/Hurricane_Ophelia_(2017) Lorenzo (2019 to be continued?????????

Shame, I was 0.2 off. A great start to my CET career though.

September confirmed as 14.3c which is 0.6c warmer than 2018 https://www.metoffice.gov.uk/hadobs/hadcet/mly_cet_mean_sort.txt

Morning all, "Pinch, punch, First Day of the Month" and all that. Feels like I've been "Pinched and Punched" in my left shoulder, so decided to come downstairs and make myself an early Morning, cuppa. I prefer sleeping on my left hand side but as the pain was preventing me from sleeping any further, decided to get up. I have had a lot of "issues" with my left hand side, after my Haemorrhagic Stroke of four Years ago. Fortunately my dominant right hand side, remained unaffected by the event. Hoping to buy an Orthopaedic pillow on our travels today, which should help to alleviate the pain and allow me to get a reasonable night's, sleep. Oh, the joys of getting old!! So, sitting here relaxing and about to watch a recording MeteoGroup's extended Forecast, Stav Danaos on duty last night. Below is a BBC Video link to the Forecast, for those Members who'd rather not read my commentary: https://www.bbc.co.uk/weather/features/49872491 Stav began his Forecast by commenting on the amount of Rainfall we've seen over the U.K in the last two Weeks, especially England and Wales, where quite a few Rivers have broken their banks. Dozens of Flood Warnings remain in place, each Rain event exacerbating the problems. The area of Low Pressure that brought the overnight Rain, will continue to dominate the scene on Tuesday. We may well see some heavy and thundery Showers breakout over our Region today, given the proximity of that Low. Still quite mild for our Region, as there is some Tropical Maritime air associated with this System. a Max, of around 18c or so, for the London area. Overnight, cooler and drier air will move down from the North, pushing those heavy Showers away from our Region. A Min. of around 9c, for the London area. So, quite a chilly start to Wednesday Morning but fine and dry, under an area of High Pressure. It should remain dry for our Region but feeling distinctly chilly under a N/N.W. flow. sourced from the Arctic. Plenty of Sunshine on offer though and with Winds falling light, a Max. of 14c for the London area, shouldn't feel too bad. It should only be a brief spell of cooler Weather though, as our "old friend" Hurricane LORENZO starts to influence our Weather, as it moves closer towards our Shores. This feature is now moving North in mid-Atlantic, weakening as it does so. Computer Models are still having "issues", as to where this feature will end up? It looks as though it will amalgamate with an area of Low Pressure, to the South of Greenland. Current thinking suggests it will stay West of the U.K. There's more certainty though in the fact that, it will eventually drag up some much milder air from the S.W., pushing that Arctic sourced air, back towards Scandinavia. Thursday will probably stay dry over our Region and although Temps. will start on the cool side they will begin to rise, as we begin to import that milder air from the S.W., a Max. of 14c for the London area. Beyond Thursday/Friday, the Weekend and the early part of next Week, although Low Pressure will remain dominant in the N.Atlantic, bringing some rather unsettled Weather to the N.W. of the U.K., our Region should be more settled thanks to the proximity of High Pressure, over the near Continent. Stav ended his Forecast by suggesting that our Region has a better chance of staying more settled than the rest of the U.K. but there still remains a lot of uncertainty, further ahead. That's my interpretation of MeteoGroup's extended Forecast for our Region, seen through the eyes of, Stav Danaos. Looks like myself and my Wife may well be dodging some heavy Showers in the search for my Pillow, today. Regards, Tom.

Remember what I said last week around models gravitating to cold in the winter despite wanting to head towards mild- ( rem 09/10 & 2018 for example Not quite winter here but Central Europe would just be able to fit into that catagory look at the ensembles for Central Europe flip over 18 hours from mild to cold @carinthian