Leaderboard

ECM 168> 192 says hello to a new pattern for the end if October - AO heading south - Huge PNA + Pattern - Deep Scandi Trough - Retrograding Atlantic high...

It has been a while since my last posting about the stratosphere. I remember back in the days, I was trying to be a strat modelling pioneer, making graphics that people demanded but were rare to come by. I was among the first, if not the first in the world to produce fully public HD-3D/4D polar vortex animations. I am here again now because there is still something that people demand but it is hard to come by. It is seasonal stratospheric forecasts. Those are almost impossible to come by as far as I have searched, unless you have a fat wallet or you are full time professional. Thanks to the Copernicus project, I now have access to stratospheric grids of ECMWF and UKMO Glosea5 models. Configuration wise, those are the best two models in the world for seasonal stratospheric forecasting. The only one that could join them is the JMA-SEAS model. So I present you four graphics for now, monthly mean forecast. Considering it is just the October initiated forecast, so we have a long lead time, and its a monthly mean of 50 members, its actually impressive. The signal is visible. I will add more graphics with time and every month with new runs. I do plan to make a permanent home eventually for these graphics to be regularly updated on the Severe Weather Europe page where I am one of the admins. Will also add 500mb monthly anomalies there in the far future. The grids were in GRIB1 format with some non-conventional coding, so it took some trickery to produce it, but I have "cracked the code", so there is much more of this to come.

What a pretty picture... A tri-pronged attack on the trop vortex and a tanking AO

In the land of repeating patterns, the modelling over the past few days continues to promise much for coldies ..............

Half way through October. Time to stir.... Interesting reading RJS's comments in the seasonal forecast thread regarding extreme cold in central Canada and likely downstream trough from this event. If this can be given as a base state heading into the start of winter, then exact positioning of the long wave pattern becomes guessable. Note the MetO ENSO forecast As many forecasted several months ago we are heading into a weak Nino winter with consequent pressure applied to subvert sub tropical high pressure belts and therefore the possibility of a more southerly tracking or split jet. GLAAM is in a moderate to strong positive phase and the Nino imprint onto the atmosphere is clear from the GWO state which has been locked into the 5 - 8 orbit for weeks now For the foreseeable therefore a pattern that wont encourage flat westerlies, should instead see a good deal of jet wobble and curve, and an autumn that for now looks to remain fairly blocked. With an eastern US trough likely then the suggestions from a number of posters that a mid atlantic high may develop downstream looks about right to me in the context of the above. That might help to bring about a frosty and foggy passage into November.

Evening All So my second main post in relation to Autumn / Winter 18. Thus far the initial forecast for this first half of Autumn has been really satisfactory with some notable successes- The Anomaly chart for Sept 1 to the 13th has shown that the jet has been forced off way to the North allowing perpetual Southerlies / SE winds to invade the UK & indeed western Europe- * We have seen notable heat - nearly 80F on 13/10 Oct - * There havent been many 'westerly days' & rainfall has accumulated for some over short sharp bursts as opposed to the usual steady build up. ( Again highlighted in the first post ) * Also whats been a key player & also has close similarities with Summer is the depth of the blocking around the mid lattitudes - Record breaking High Pressure in July over Europe , & September sees record breaking High pressure over Alaska- Sept 1-Sept 15 Global Anomaly This anomaly thats lingered up until the tail of September has been the main reason that W Canada has had the very cold start to the Autumn & also why Siberia has been a little slow to start with snowcover - The ice anomalies & low thermal gradient this year are really allowing for Higher than average pressure to exist in 'situ' even at Northerly Lattitudes - Examples of these powerful highs appearing at high lattitudes started appearing in 2010- Note The december to Remember- The second spell started with a 'super high' What these High pressures create is intense areas of WAA on the western flank & the same with cold on the eastern flank- they also allow for more Northward / southward penetration of the warm/cold So the conditions they bring are deemed 'extreme' for the localities on the recieving end of the advection- Backing up this theory of Low ice / warmer arctic seas > Higher Arctic Amplification > Intense WAA/CAA is the range of the metric of AO which in the past 10 years has gradually been stretched scalewise up & down - This Late Autumn / Winter - seems the perfect platform to deliver more of the same - Exceptional warmth interlinked with some potential for exceptional cold ! There are unlikely to be any over riding negative signals this winter- - Neutral El Nino Signature - Downwelling westerly QBO unlikely to be to adverse to the pattern- With more emphasis on positive links - Weak to possibly 'very' weak stratospheric vortex including a possible early warming event December to weaken the vortex further - Stronger disconnect in terms of tropospheric & stratospheric coupling - again the very shallow gradient weakening the 'westerlies' - Very low solar activity supporting the westerly weakness - 'Super high pressures' migrating Northwards towards the pole creating sharp transitions / modality changes in teleconnection metrics ( AO / NAO / PNA & POL ) these will also create big Stationary patterns of warmth & cold around the mid lattitudes For me the signals are overwhelming & give us a range of solutions for Winter that strongly suggest a below average DJF with a high probability of at least a 1 monthly rolling period ( not to be confused with a recorded CET month ) being below 2c. Higher incidence of Northerly & Easterly outbreaks. I dont rule this out exclusive to DJF - but also with the pattern expected to flip towards the end of October we could see some of this blocking in place throughout November. My eyes have turned to the stratosphere, which has seen a burst of activity lately bringing the zonal wind up above average of about 22 M/S - however the ensemble suite has shown that this may well be the peak for the moment as we drop back towards 20 M/S again in November ( the average being 30-40M/S as we head towards December ) So there we have it- some late Autumn / Early Winter insight - - Big Flips in the AO with some decent negative values arriving - Super High pressures retrograding up towards the arctic Circle generating significant CAA & stationary cold patterns - Possible early warming Late Nov / Early Dec to really take any Westerly sting out of the Jet CIAO for now....

What a day 10 tease from the Ecm 12z just about to pull the trigger with all that bottled up arctic air poised to surge south...would love to see days 11,12,13 etc!

Its at the stage of and the dynamics of equitorial phasing.. Kelvin waving is on the board and the heat basin can be-seen even by large scale global'raw' models(gfs 3Dmonde) Oceanic waving ...based on pac(pacific runs)..with nina classic...even 'odd' Im loving the equitorial set via heat oomph..and then miss-match ..aiding 'again' a notable PAC-RIDGE... All in-set for a wreck and ruin of northern hemispherical confusion! Taking annoms @face value around the euro upper latt window..it a design for a classic set up for omega/arctic retro... With a vast cooling ...quickly overiden by warm-air-advection into otherwise normaly present sets! The northern most influenced equatorial fuse..ie ..iberia..northern Africa sst's..are alarming for such evolutions also .. I dare..and damn..to say...if your looking for a classic winter on the dice blocked pattern for ourselves,uk, and the north-western euro sector...then bookmark these early season snaps!.. The mjo phasing...is imo ..atm on a catch up phase...and will be of major interest when momentum align. Solar min-also taken into account..its disarray..for the organisation of the 'polar vortex'... And a circus for cold receptors' eyeing a home to spill into..

Its brilliant to see so many posters come out of their Summer Hiberanation, gearing up during this Autumn and to the coming winter! This place is buzzing tonight!!! But who can't get excited when your a coldie and the ECM teases you with this.... All fun and games of course just for now, cause we all know how fate likes to tease us and when it looks all too good to be true, its snatched away before our very eyes! But there is much to be optimistic about this year! Let the roller-coaster that is model watching, commence!

Late October fog = cold snowy winter. Simple as!

After the recent stormy and wet weather it’s looking a lot better for the UK. High pressure looks like taking over. The GFS 12 hrs looks a bit more like the ECM 00hrs, quicker to remove those lower heights to the nw . It throws in a mini tease around day 9 and 10, although the main cold looks a bit too far east . It could though bring some much colder nights . For coldies something to look out for if upstream develops a bit more amplitude in future runs . A bit too early to see anything of note but interesting to see whether the ECM might add a bit more amplitude into the mix .

Meanwhile back in the here and now so to speak. ^-14 days ahead and the anomaly charts, at least the EC-GFS version have pulled the predicted upper ridge back a shade allowing a colder flow, at least, down the eastern edge of the UK. I wonder if this will continue with, as some have suggested, the upper and surface ridge being far enough west fot colder air to spread into the UK? http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html The last couple of runs from NOAA do show the centre of +ve heights to be around 20 West. So maybe most of the country could get on the cold side. How much cloud is open to speculation until nearer the time with a flow around the high off the Atlantic probable. At the moment these charts do not suggest, even as a one of within the mean any major Polar outbreak. The NOAA 8-14 keeps the +ve height anomaly in much the same place as the 6-10 shows. Most of the models at 240h show something along these lines. Only GFS allows for a colder plunge from a more northerly area. http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

Tamara still pops in from time to time, like myself. You might have a better chance of catching her here: https://www.33andrain.com/topic/868-teleconnections-a-more-technical-discussion/ You were a tad early, but still largely right, with us now in a +EAMT event over the past few days. This as @Catacol states, we are in a +AAM phase, supported by the +EAMT and other torques. I don't expect the AAM to be very Nino-esque IMO, with SOI forecasts from the Met Office and ECMWF supporting a +SOI in Nov and Dec, supporting an atmospheric ENSO Nina-like phase. This would obviously translate to the AAM, and shows that there is potential for the Atmospheric ENSO component not to merge with Oceanic ENSO, which should be a weak-moderate basinwide event. This theoretically causes more NP-Jet extensions, which translates downstream to the UK, by methods of the GSDM. Context to this discussion here . And the +EAMT is helping a Pacific Jetstream extension over the next 10 days, according to GFS.

Every autumn we have the chasing of early season cold and away from the north and higher ground it is generally a waste of energy and time ! Patience is a virtue and the ec46 seems consistent with the height rises to our north and northeast through November with subsequent low surfer temps to our east in general the consequence. Ours recover slowly as the mean flow across w Europe becomes less continental from the east and more from the south as the Scandinavian high becomes more sceuro in time. The story of November would seem to be the lack of precipitation in n and e Europe whilst frost and fog are likely to be prevalent. the pattern is currently heading where most seasonal forecasts said it would ..... as Claudio once said .... 40 points, 40 points !!! No need to get ahead of ourselves looking for winter in late October ......

A generally pleasant spell ahead, with a rather ineffectual atlantic, thanks to significant ridge development over the UK, edging west as we move through the weekend, allowing frontal/trough to move down from the NW, bringing a spell of moderate rain for the NW, petering out as it moves into the ridge. Into next week both ECM and GFS consistent in showing the ridge holding firm to our west, and building which should maintain the generally calm conditions, risk of frost and fog and night, and a change in airstream will pull in some cooler air from off the atlantic as well, so maxima won't be far off average. As we approach latter stages of next week, indications the ridge may shift sufficiently west to bring down a much chillier airstream from the north, with some form of trough/frontal feature - it might slip to our east which would prevent a full on northerly, conversely we might see developments to our NW which would send the ridge towards Greenland and leave us exposed to a cold polar outbreak as we end the month. Late October can be a very stormy period full of wind and rain - this year it looks like being relatively quieter, with fog and frost probably the most notable feature.

Anyhow the net impact of the pattern could be huge scandi early snow cover building up, given relatively early falls occurring already.

Was just going to comment on the ecm but you beat me to it. Incredible northern hemisphere shenanigans going on to say the least. Just look at that WAA up into the western Canadian Arctic by day 7. Even more epic by day 8. Great synoptics going forward enhancing UK cold winter prospects.

Morning, as promised in the above post,I have an update this morning. Our portal service providers have given us a 30% chance of some significant snowfall in resort by 31st October . That in real terms equates to a relative high % prediction for 15 days out but as we all know is subject to change as we approach a more reliable forecast time. Their own model has hinted at a possible significant change in the weather pattern towards the end of October for a few days now as have some of the major global models. A powerful ridge over the North Atlantic to get established by the last week of October resulting in a more meridional flow into Europe ( as highlighted by the GFS upper flow chart below ). Of course the location of any dynamic weather will depend on the actual positioning of the ridge, so forecasting can change on a daily basis but Central and NE Europe looks favourites for a abrupt change from summer to winter type conditions.

Very settled outlook away from north east Scotland for the next ten days however hidden beneath the charts is a pleasant change of air-mass between days 5 and 6 which stays with us until day 10 (increased risk of fog or grass frost for some rural spots).

Further to my post last thusday evening about the hp cell developing in the Atlantic,the latest from the cpc 6-10 and 8-14 day 500mb anomoly charts shows even stronger ridging in that area,it will be interesting to see how amplified this ridge gets nearer the time and for the first time this season we see a forecasted neg NAO/AO>-2/-3 and the gefs/ecm ens(although the ecm doesn't go as far as the gefs),the gfs op clearly a mild outlier and the control clearly mild outlier so in summery we will have a few fine days to come with the Azures high nudging in from the SW then migrate west a little to allow a cooler west to northwestly but a NNW/N direction cannot be ruled out,it all depends on how far the hp cell retrogresses west,the gfs has been toying around for the last few days if not a bit longer with a possible northerly at or just before the end of October,interesting times are starting early this year.

With all due respect, you are wrong. A -EPO's downstream effects often create a Eastern trough. That is what it is known for doing, disturbing the polar jetstream up to Alaska, and bringing cold down to the Eastern Half of the United States. A -EPO if it stretches down towards the West Coast of America often gets called a joint +PNA and -EPO. So the assertion that a -EPO must go with a -PNA or vice versa is entirely misleading.

This is what I’ve been waiting for if all falls in to place we could have frosty bonfire night.

I realise I added to the case for an oceanic and atmospheric disconnect, but what if the ENSO is helping to signal, particularly with CP Nino regions being warm (along with EP Nino regions theoretically warming as well), and cold SST anomalies around Maritime Continent. This would help MJO and other equatorial waves to avoid Phases 4 & 5, and stay around Phases 7-8-1, particularly the former two phases. This is all for in terms of the winter, but can also apply to the present day.

That PD-OSCILLATION +sig-has done wonders for uk winters in times past... And with the equitorial situ...along with dire accomplishment of the 4segment polar vortex....and angular basis....that oscillation, looks defined for aid of blocking situ's around the mid/upper latts....and given the overall advevtive-sequence's ...id suggest a near...or clear colder than average winter...into NW-●EURO as a whole...obviously other dynamics are in the mix....but sometimes...the basic of cooking....makes the best eating!!! And the ingredients are certainly there.

The pattern looks increasingly amplified during the next 10 days with some unusually strong mid-latitude ridging around. Ties in well with some strong MJO activity in the western Indian Ocean of late and with a recycle looking to get underway in the coming days (though GEFS way more amplified with this than ECM), though Arctic amplification is probably adding at least a little more to the ridge-trough amplitude; the situation is just crazy up north of us. The MJO forcing will conflict with the current Nino-like state of the tropical Pacific SSTs - and in fact, it appears it (the MJO forcing) will be the more dominant factor, with the ridge tending more west of the UK during the final week of the month in a Nina-like fashion. Meanwhile, there are signs of further WWBs to help those tropical Pacific SSTs rise further. A big ocean-atmosphere disconnect evolving - but how long can it last?

The above summer forecast verified reasonably well in most cases, the prediction implied a top ten outcome and in fact the summer was around 3rd to 5th warmest on record depending on which data you used. The CET predictions of 16, 18 and 17 compare with 16.1, 19.1 and 16.6 for an average error of 0.53 C deg, and it has to be kept in mind that August was running close to 17 until around the 23rd with a very cool finish. The overall prediction was closer, with an average error of only 0.27 C (17.0 vs actual of 17.27). It was a dry summer in many parts of southern Britain and southeast Ireland. The magnitude of this drought was probably underplayed in the forecast. As for North America, it certainly did turn into a scorcher of a summer in the west with widespread fires in western Canada in particular. We were dealing with noxious smoke on an epic scale for much of August (although I was away on holiday in clearer skies down south) and the first week of September before the activity finally subsided. The tropical season has not been keeping pace with the forecast although it could still work out fairly close, and Michael alone is worth several ordinary hurricanes I suppose. ... well, I won't make a big deal about this forecast because basically I think almost everyone expected this sort of summer after the spring blocking, so it is now on to the winter of 2018-19 for the next instalment ... Long-Range Outlook for Winter 2018-19 As always, my forecast is based on a blend of traditional concepts and exclusive research into "index values" on the assumption that at least some variability in the climate can be linked to variations in the solar system magnetic field (a complex response to relatively small changes in solar wind output and effects on the earth's linked atmosphere and magnetosphere). It is looking quite cold compared to normal for Britain and Ireland, in particular later December and parts of January. However, this appears to be dependent on a strong jet stream either shifting far enough south or relaxing for periods of 1-2 weeks, and the intervals between the cold spells could be quite stormy at times when the jet stream is roaring at full capacity. The research index values in particular go far colder than I have seen them for the past several winters, indicating many analogue cases that were very cold winters. Looking through the analogues, I find that periods around late December into early January, and mid to late January, were favoured for the coldest weather. This is also favoured by assumptions made about lunar modulation of the pattern, which is how I have come to see the lunar influence, not as a driver so much as a shaper of larger signals from the other players at work. Another consideration is that we are well into a prolonged solar downturn and so there's nothing in the larger solar-weather paradigm to contradict the notion of this being a colder than average winter. We are in a similar position to the period 1819 to 1823 which had numerous cold winters but it's not a guarantee by itself to be in this sort of regime. I've seen some discussion saying that perhaps this won't be the widely expected "big one" and perhaps we'll need to wait another winter or two, but I have no way of choosing which one is the big one from the coarse assumptions that one is forced to make using only a solar-weather paradigm. The past summer season in the central Canadian arctic was exceptionally cold. Resolute for example had no month warmer than the 1.9 average in July, and that is the lowest such statistic on record in recent times (the record began in 1948). This has been followed up by a large-scale southward movement of a cold anomaly over central Canada that has people commenting that winter already began in the prairies in early September, with snow often on the ground. This anomaly is almost bound to be followed up by a persistent trough around 90 to 100 W longitude. That in turn would favour west Atlantic blocking and a downstream trough between 10 and 30 W. Although that's a little west of the "sweet spot" for a cold winter in Britain and Ireland, I feel that it may be a high amplitude pattern that will induce Scandinavian blocking highs, and cold outflow from those despite fairly high 500-mb heights in western Europe at times. And the pattern could oscillate east-west enough to place the trough over Britain and Ireland at times. So I am predicting a notably cold winter but with high variability possible leading to alternating spells of wintry cold and stormy fast flow situations. Another factor that may prove significant is that energy levels will be highly concentrated near the full and new moons this winter, perhaps more so than has been the case in most recent winters. I expect this to translate into alternating periods of very unsettled, stormy weather around those lunar dates, and relatively long settled intervals between them. The settled intervals are likely to be the times when blocking will deliver the colder air masses from an easterly or northeasterly source. But there may be some tendency for the disturbed intervals to remain cold and turn more northerly. This could add up to considerably more snowfall in the heart of winter than we've seen for quite a few seasons, in contrast to last winter's concentration of snowfall near the very end of the winter season (27 Feb to 2 March was very snowy in some regions). I am aware that this represents a high risk forecast, especially given the tendency of recent winters to resist opportunities to establish potent blocking. So it won't absolutely surprise me if the result is some kind of weaker compromise where some cold and some snowfall develop but longer intervals remain relatively mild. I don't foresee a really mild winter being likely given these background conditions, and I do have concerns that the volatility may produce some exceptionally stormy intervals. This pattern may persist well into late winter and March may not see a lot of change from it, except that by then the energy level considerations will be more evenly distributed into four peaks rather than two per lunation. That separation during February may lead to a peak in snowfall since the peaks will be somewhat less supported and that could be reflected in a more persistent blocking pattern. As to the dates of the stormy episodes, those appear most likely to fall around 19-22 December, 3-6 January, and 16-20 January, and there could be heavy rainfalls in the south during some of those intervals as colder regimes are pushed back to the north at least temporarily, but as time goes on the chances for snowstorms likely increases with each of these windows, then towards the end of January it may be more of a sea-effect snowfall opportunity with the storm track pushed much further south into Iberia and the Mediterranean. During the anticyclonic intervals that are likely to peak between those stormy intervals, we could see some unusually low temperatures especially if snow cover has been established towards the transition from stormy to settled weather. In the run up to the winter, I would expect quite frequent mild and unsettled patterns with the colder synoptics taking their time to appear, possibly in muted form around mid to late November so that perhaps Scotland will get the first round of this predicted wintry regime. In North America, I am expecting a winter dominated by intense cold over central regions, often extending out to both coasts, and a generally depressed jet stream but with weak El Nino tendencies likely to lead to frequent and heavy snowfall inland from the west coast over the Rockies about as far south as northern New Mexico. Parts of eastern Canada may be unusually mild with the storm track tending to run north from near Cape Cod into eastern Quebec province. I feel like this may be a very rough sketch of a winter that may contain some really unusual synoptics and bring conditions that are rarely seen at some times, and those are difficult to anticipate so would just caution that various extremes may be tested at times. I don't think it will be a dull or boring weather pattern for most of the winter, in any case. For verification, I expect the average temperatures to run as much as 1.5 to 2 degrees below recent normals and for this winter to be one of the colder ones in the past thirty or even fifty, and colder even than the longer-term averages which run almost a degree below modern 30-year averages. I somehow doubt that it could be an all-time cold contender to match the summer because that seems to be very difficult to achieve with the ice margins being as far north as they have set up in the North Atlantic in modern times. But as we saw in December 2010, anything is still possible and there could be some intervals of record breaking cold.

Indeed...and it must be noted that most of the legendary winters featured an early Canadian warming... Larry, this is not the place for 'inane drivel'

p-stamps...out @months end.... some really intresting mixes there. meanwhile the designs are firmly in place for a monster pacific/western seaboard-bite....or formation into large mass USA. bossing' any gain of the pv into usual territory....and ainding squeeze of smaller...yet significant arms of waa in and around the mid/upper latts... just a case of trough and cell segment exactions.....winter in the northern hem has kicked off....and ...and is eyecatching on many levels.....

Ah yes ... the land of repeating patterns ........ i’m late, i’m late for a very important date .........there’s another land of make believe ......fwiw, the theme that has been catching my eye is the diving troughing from the northwest ...... the high lat blocking we are also seeing is as likely to end up in the right place for cold nw Europe as wrong .........the diving troughs in the east Atlantic would be a more reliable indicator of potential nw European cold imo .........

A BA ramp is a rare beast indeed. Must crack open a beer and raise to that.

There's an index member in my research model with a period of about 6-7 years (it hits with relative precision at 13, 20, 33, and 46 years and needs a slight adjustment at the 6-7, 26-27 and 39-40 year intervals. Look how juicy this analogue set is (going back to start of CET) ... this is listed by the January of each case so years before these contain the Nov-Dec analogues ... and this includes only those cases needing adjustments of less than ten days ... because we're talking about retrograde index, the off-set pairs run earlier for first more recent, going back in time, and later for second of the pair, by about 10 days, e.g., the 6,7 set would include for example 2013 an earlier index by 8 days than 2019, and 2012 a later index by 7 days. It's similar for the 39,40 pairs. For example there, 1979 would be running later than 2019 by about 7 days. For the 26, 27 set, we are looking at the more recent of the pairs being 6 days earlier and the second less recent being 8 days later than 2019. (6,7) 2012,2013 ... 1966, 1967 ... 1920, 1921 ... 1874, 1875 ... 1828, 1829 ... 1782, 1783 ... 1736, 1737 ... 1690, 1691 (13) ...... 2006 .......... 1960 ............ 1914 ............... 1868 .............. 1822 ............. 1776 ........... 1730 ............. 1684 (20) ....... 1999 .......... 1953 ............ 1907 ............... 1861 .............. 1815 ............. 1769 ........... 1723 ............. 1677 (26,27) . 1992,1993 . 1946,1947 . 1900,1901 ... 1854, 1855 ... 1808, 1809 ... 1762, 1763 ... 1716, 1717 ... 1670, 1671 (33) ....... 1986 .......... 1940 ............ 1894 .............. 1848 ............... 1802 .............. 1756 ........... 1710 ............. 1664 (39,40) . 1979,1980 . 1933,1934 . 1887,1888 ... 1841, 1842 ... 1795, 1796 ... 1749, 1750 ... 1703, 1704 ... (before CET) (46) ........ 1973 .......... 1927 ............ 1881 ............... 1835 .............. 1789 ............. 1743 ........... 1697 ......... _______________________________________________________________ This slice of the past catches quite a few of the exceptionally cold winters, narrowly missing 1709 which only needs a 15 day adjustment towards earlier dates, but being out of phase entirely with a few like 1740 and 1963. However, the overall average of these winters when adjusted by the required number of days (where daily data available) produces a profile that reaches a minimum of 2.5 deg below the current average around mid to late January and runs generally below normal throughout the winter season. The notable cold winters in the set include 1684, 1716, 1763, 1795, 1829, 1855, 1881, 1947, 1979, 1986, This index value is rated as 10 to 15 per cent of total variability and is second most significant. It is related to inner solar system magnetic field flux changes associated with the planet Mercury. The one slightly larger index value components is related to Jupiter and the analogue set there is regarded as linked to progressive features so less associated with blocking, more to do with position of long-wave ridge and trough features. One other detail that I can report from the research is that retrograde episodes can be expected roughly every second month from this index value, and on a longer, slower time cycle, about every 7-8 months from a separate index member, and that one has analogues with winter 2010-2011 and also includes 1978-79 and 1962-63, also 1946-47. The episodes would be expected to occur 2-3 days later each eight years going back in time, and you start to lose well-timed analogues before about 1906-07, running into a different set timed for somewhat earlier running back from 1823-24, so that includes 1816, 1808, 1800, 1792, 1784 and 1776 as analogues for January. This does not look to be a dominant index value in the research, but it's good to see a reasonably low temperature index from that one combined with the principal retrograde member. If we can't build the cold blocking pattern out of these materials, then we seem to be losing our best chance but the long solar downturn may allow weaker analogue sets to succeed in the future. You have to wonder if we have a "big one" in our near future despite what we are allegedly doing to the boundary layer. It does concern me, but a signal of +1.0 C competing with all these others may be in over its head, we can only hope, right Fred?

One messed up vortex! But at the same time another strengthening vortex, in the stratosphere, here zonal mean zonal wind at 10hpa: Now poking it's nose above average and GFS taking it higher. So as we enter November and progress towards winter proper, it looks the two vortexes are almost totally disconnected. I think this gives the potential for some interesting cold weather early into winter or maybe before, depending on location (won't get IMBY in this post!). On the other hand, a disconnect between the trop and strat vortexes won't continue indefinitely so this will need to be watched #FrontLoadedWinter

In the run up to winter - revel in the good old days. Enjoy!

T240... commonly known as a "trigger low"... and on cue for perhaps the first date of the autumn when lowland snow would be possible It's not as if it's out of sync with the ensembles - but we need many more runs like this to get truly interested.

Hmmm, I also would have liked to see the next few frames of the ECM 12z, a sudden flip to cold around the change of the month is increasingly the form horse, how well it would tie in with this year as a whole! FV3, aka GFS parallel, shows a potent northerly blast here at T276:

The ecm gets a little carried away with itself from days 9 to 10. Days 4 through to 8 all good though. It's all about the building blocks at this time of year. The fun and games can start when they are supposed to.

Yes, was thinking we could do with a -AO to end October, don't want to bring that swearword October something index up again at he risk of derailing thread but not many stunning winters had a +AO all the way through October and what better part of Oct to have a buckled meridional NH pattern than the end of it.

Of course Whats very unusual is the depth of the high pressure into the pole for October in the PNA which then drives the trough further south - & the cold along with it- something I alluded to in the NH pattern thread yesterday-

TBH the deep scandi trough and not dissimilar pattern was advertised on a few GEFS not so long ago Steve.

I feel an immense sense of grief about the impacts of climate change and environmental destruction in general. I wonder if those that feel we cannot impact our environment are aware that we have dried out seas, are causing the 6th mass extinction, rainforest destruction, coral bleaching, plastic pollution not to mention climate change. It is clear we impact the Earth and it is clear we will be leaving it environmentally in a far worse state than we inherited it. We all know deep down in our unconscious the harm we are doing and I believe it is hurting us whether we recognise it or not. Grief can lead to lead to denial, anger, depression and all of these can be seen on this forum. On this forum we all share a common interest and passion for nature and the forces it creates and the beauty, wonder and power it demonstrates. I think we all know deep down inside that we cannot just keep on living, exploiting nature the way we are and that at some point something is going to give. Hopefully at least we can all agree on that.

Roger.. I have recorded 58.3mms to so far this month. (slap in the middle of England) I think it is places further West (particularly in Wales and the South West) which may just possibly increase these values for the aveages. Some areas of Wales recorded as much as 250mms over the weekend with the River Severn rising quickly, though to match that areas to the East had much lesser amounts. MIA

Only venture in that direction I've seen so far is here.. If you are hoping for cold then it's not a bad start. Back to the here and now, we're at a small campsite at Daviot at the moment and spent a large part of the day at Culloden in what was pretty pleasant weather. Off to Aviemore tomorrow for a couple of nights before we probably have to think of heading home.

As the front cleared east this morning: A view to the NW And to the NE And a spring flower round the back of the barn

A nice bright sunrise this morning, but sky from around 08.15 covered by a thin stratus layer, no wind, temp 2C and evidence of a grass frost overnight.

So an early look at my LRF for winter 2018/19. Before I go into it I want to say I believe a winter to rival a 20th century great will occur within the next 3 winters. Let’s start with why I believe this. Following taken from Spaceweather in relation to sunspot count. 2018 total: 165 days (58%) 2017 total: 104 days (28%) 2016 total: 32 days (9%) 2015 total: 0 days (0%) 2014 total: 1 day (<1%) 2013 total: 0 days (0%) 2012 total: 0 days (0%) 2011 total: 2 days (<1%) 2010 total: 51 days (14%) 2009 total: 260 days (71%) 2008 total: 268 days (73%) 2007 total: 152 days (42%) 2006 total: 70 days (19%) I compare 2018 to 2007 = 11 year cycle going forward. We know the winter 09/10. Potentially we could get an 07/08type winter...but I think we are past that as one can see we have still got 2 1/2 months to go and we are 13 more spotless days already....I think 190 but 200 is not insurmountable. I am also not of opinion of Gavsvid updates that this year ‘could’ be solar minima. 19/20 imo more like it. And if it continues as last minima.....moving on from this year we could be in territory not seen for over 200 years. (Interesting RJS mentions 1819/22) El Niño (weak?) so not unfavourable Will the cold Atlantic to our West be of relevance? As already posted as snippets I think winter starts early. So overall theme I feel prevalence of northern blocking with Scandi Blocking likely to be a player with at times an active jet bringing in LP systems but ultimately failing to upset the rhythm of winter. December - colder than average. I won’t put too much meat on bones yet but after a wintry first half I suspect blocking to be in place approaching Xmas and then an Atlantic trying to push in against a cold block that won’t give way (period of note possible). I say it won’t give way as I anticipate January to continue with the colder than average winter. January - colder than average - 1st 10 days earmarked for potential coldest temps of winter with cold block established over (if anticipated) snowfields are widespread. I think mid and backend of January to be potentially very snowy with LPs attempting to take over the ‘general’ pattern as I think the blocking will be at it’s most vulnerable as we enter February February - Average overall but wet. I think the rhythm eases somewhat and we could see winter wane. There is a possibility that jetstream holds on southerly track and wintry conditions elongate but Atlantic vulnerability I’ll call it. A winter to match a 20th century great over next 3 winters?...means I am saying it could be this one. For sure imo we have entered a period going forward where we could be in the game for some serious synoptic patterns. Serious cold and long is still very achievable and imo going to become ever more achievable. As always, with blocking if in wrong place then is a blow out......and Greece etc are locked into an ice age and we are distinctly average, bland even a touch mild....but better to have prevalent northern blocking to put us in the game for cold. I’ll add more with what I identify as ‘periods of potential most impact’ in Nov..... BFTP

Any Express weather article should go in the make us laugh thread

I think for now the most I am prepared to say about the long term (December onwards) is that the signal for a winter with a strong azores high presence looks rather weaker than most recent years. Nino wont help the azores high for sure, and the ECM probability forecast for sea level pressure suggests a year when we wont be plagued by high pressure bumping up from the SW. This is a long way away from suggesting an automatic high lat block and cold continental air source BUT it is a start.

Sunny Sheffield down to 12.4C +0.1C above normal. Rainfall 48mm 58% of average.

A very simplistic look at the overall patterns almost a year on from the unusual warmth, Saharan dust and afternoon darkness that was a talking point, I find myself in the garden with the tan being topped up again. To me the lack of any real 'ooomph' to the Atlantic driven agenda has been a theme for over a year now. Various strong HP cells dominating from all points of the compass in that time. AS was the case in March 2018 into April 2018, looking at a set up that took us from deep winter into high summer in the space of 3 weeks, Why would the reverse not be possible now? Given the general state of the NH pattern....