iapennell

You will find this in the Winter Prediction part of the forum

Early February will likely be cold and frosty, on the strength of the Sudden Stratospheric Warming now predicted for mid-January exteme minima across the English and Welsh lowlands will be somewhere between -5C and -10C, some frost-hollow areas are likely to be a bit colder than this. In the Scottish Highland's frost-hollows (places like Altnaharra and Braemar) the extreme minima are likely to be near -15C. However, don't expect widespread heavy snowfall unless you live near the North East and Yorkshire coasts, in the Pennines or in northern/ eastern Scotland. For temperatures to get below -10C right across Britain you ideally need three ingredients: Significant powdery snow-cover (over two inches), a very cold airmass in-place, then clear skies and light winds for the duration of at least one night (this leads to strong radiative heat loss). For this to happen you need (firstly) a cold enough airstream to bring widespread powdery snowfall that does not melt, followed by clearing skies and light winds with the very cold air being maintained. I cannot quite see how that is going to happen unless the frigid easterlies have a fetch to as far east as Russia, this lasts three or four days and then high-pressure ridges in from the north or north-east. The Norwegian Sea will likely remain too warm for a direct hit from the Arctic to bring daytime temperatures below freezing across the whole country necessary to sustain powdery snow-cover, a following ridge from a Greenland High will involve air being warmed over the far north Atlantic/ Norwegian Sea (due to northerlies falling light) and that could lead to daytime thaws before the clear still nights set in: Wet snow releases a lot of latent heat as it freezes due to radiative cooling- and such latent heat release, combined with the air above not being especially cold, would likely temper how far air-temperatures could fall. I have a hunch that Westerly influences off the North Atlantic will too soon become (or remain) a little too strong to permit the uninterrupted flow of air from northern Russia to the UK for three or four days that would be needed to establish widespread powdery snow-cover in the first place, let alone for this to then be followed by a high-pressure ridge then extending south-west from Scandinavia (to clear the skies and keep the airmass very cold with an east or north-easterly drift of air) to complete the frigid set-up.

@CreweCold Lets say I was presently surprised. Indeed the predicted SSW high over the Arctic is not what I expected, given that the Stratospheric Westerlies along 60N were almost record- strength in late November when I produced my forecast!

Yes, but you want that Greenland High to stretch across to the strong High over Russia with low-pressure (not high-pressure) to the south and south-west of Britain to set up for something extremely interesting! The warmer-than-usual Norwegian Sea has consistently been the "Weakest Link" in the (hopeful) High Latitude Blocking chain- its warmth has consistently attracted depressions into the area which- in turn- has the effect of cutting off supplies of Arctic or Russian air to Britain !

Firstly, a Happy New Year to Netweather Forum members and those eagerly watching the charts hoping for a very cold and snowy synoptic set-up. The weatheriscool website offers a forecast for mean winds to be up to 25 metres/ second (over 50mph) from the East along 60N by the 18th January, and given the tendency for Sudden Stratospheric Warmings over the Arctic (and the associated circulation) to work downwards into the troposphere over the following three weeks this does offer hope of a frigid easterly blast in early February. BUT... 1) The QBO in November (at the 30 mb level in the stratosphere high over the Equator) was on average over 11 metres/second (24 mph) from the West. 2) Most of the Equatorial waters are hotter than usual, even though there is an East/ Central Pacific La Niña (the worst possible place for Westerly AAM considerations as it strenthens the tropical easterlies to the west but any westerlies aloft wont touch the Peruvian Andes to be dissipated). A hotter-than-usual Equator overall means an active Intertropical Convergence Zone (ITCZ) and a healthy ITCZ means stronger north-easterly Trade Winds further north- busily pumping Westerly Atmospheric Angular Momentum (AAM) into the Northern Hemisphere general atmospheric circulation (thereby also increasing the sink for Westerly AAM elsewhere). 3) The Norwegian Sea and Barents Sea remain free of ice and are warmer than usual- as is the North Atlantic, but Canada/ Greenland are already very cold. This not only fosters cyclonogenesis in the north-west Atlantic but warmer-than-usual waters further east and north wont discourage the depressions moving into those areas. 4) There have been Westerlies over the Tibetan Plateau- up to 20 mph in recent days. But this is not enough to negate the Westerly AAM- increasing effects of 20 mph (and above) North East and Easterly Trade Winds most places between 30N and the Equator (which you can see from "Windy" website). Much Westerly AAM is being generated by North East Trade Winds, some of which will be offset by surface Westerlies over the Equatorial Indian Ocean. But most of the generated Westerly AAM will remain intact even after the sink effects of surface Westerlies over the Equatorial Indian Ocean and the limp Westerlies over Tibet are taken into consideration. The Westerly QBO over the Equator- feeding its influence down from the Stratosphere will add Westerly AAM to the tropospheric Northern Hemisphere circulation. This only leaves higher latitudes of the North Atlantic and North Pacific as sinks for this Westerly AAM- and (given the fundamentals of Canada-Greenland to North Atlantic baroclinicity and sea-surface warmth in the European Arctic) there is a strong likelihood that the UK and points west will be seeing those Westerlies. The Easterlies predicted for the Arctic Stratosphere can only make limited headway against these fundamentals. So, on the basis of such meteorological fundamentals, there will not be a January 1987 or a February 1986 style Great Freeze in the UK in Winter 2020-2021. There will (probably) be this coming week and another week in early February with some very cold east winds, some sharp night frosts and snow-showers (as the predicted Sudden Stratospheric Warming feeds its influence downwards) but no month-long freeze with nights below -10C and deep snow across Britain.

For cold snow-and-hard frost lovers (I count myself amongst them) it does not look like high pressure is going to remain extensive enough along the North Norway to North Russia axis (nor for long enough) to give the ultra- frigid -40C air over Siberia a chance to get as far west as the UK. The long-term charts suggest the North Atlantic Westerlies will re-assert themselves by about the 16th January. Although Stratospheric winds are very much Easterly (on average) at 60N on 18th January (offering a hint of something icy in February), mean winds are predicted to be over 20 mph (10 metres/ second) from the West on average at the 250 mb level along 60N on the 18th January. However, it would be great if those Arctic Stratospheric Easterlies happening (and predicted) did lead to some truly dramatic intense frost and snow: Unfortunately, the warmth in the Norwegian Sea, sea-ice below normal on he Russian/ Scandinavian side of the Arctic and the Himalayas failing to act as a sufficiently big sink for Westerly Atmospheric Angular Momentum to absolve more of the need for Westerlies over the North Atlantic and North Pacific to counterract the tropical and sub-tropical Easterlies (there have been 20 mph Westerlies on the Tibetan Plateau recently- they need to be stronger) means that whatever cold is likely to reach the UK is likely to have a) a short fetch to the north/east and b) liable to be swept aside by mild North Atlantic air. However, I would like to be proved wrong on this as winters devoid of hard frost/ heavy snow do rather fail to inspire me (and indeed many others who visit this Forum)!

It is a pleasant surprise to have a bit of an easterly for the next week, the fundamentals that I used in my Winter forecast- Westerly QBO, above- average sea-surface temperatures over the North Atlantic but very cold Canadian/ Greenland Arctic but warmer-than-normal Siberian Arctic (in November) did not suggest a Sudden Stratospheric Warming in early January over the central Arctic. Unfortunately it is likely to be relatively short-lived (see the weather chart for 18th January 2021): And -7C looks set to be the coldest we will get in the North Pennines (about the 10th January- we regularly used to get below -10C in the 1980's) :

Sadly, and I speak as one who likes hard frost and snow myself, the fundamentals in the large-scale circulation and the pattern of sea- surface temperatures just do not point towards any real spells of wintry weather affecting the UK this coming season. However, if one like gales and heavy rain and lives anywhere north-west of a line from Bristol to the Humber there will be no disappointment! It would be nice to be proved wrong with my forecast, but I am (sadly) confident that I will not be.

Dear Readers, I have, as promised, got a long-term 2020-2021 forecast for the United Kingdom based on information that I have about global and regional sea-surface temperatures, large scale upper wind patterns and the current phase of the ENSO cycle in the Equatorial Pacific. Firstly, the Quasi Biennial Oscillation. This is a (roughly) 27- month cycle of wind- fluctuations high up over the Equator - in the Equatorial Stratosphere. Wind levels at the 30 mb level averaged near 8 metres per second from the West and at the 50 mb level were just over 2 metres per second from the West during October 2020. These Westerlies gradually descend and enter the tropical troposphere about two months after their occurrence at the 30 and 50 mb levels in the Equatorial Stratosphere, then over the next few weeks impact on the entire global circulation- mainly affecting the winter circulation. This transfer of Westerly momentum from the Quasi-Biennial Oscillation circulation- magnified as air moves into higher latitudes would imply stronger higher-latitude Westerlies (of 2 to 3 mph) during January and February. Currently there is a Lá Niña type circulation in the Pacific Ocean resulting on sea-surface temperatures about 1 to 2C cooler than the seasonal norm from the West Coast of South America right across to the Western Pacific (Polynesia area). Other things being equal cooler-than-normal waters along the Equator around at least one third of the Earth's circumference ought to result in weaker north-east Trade Winds from the Northern Hemisphere arising from a weaker Hadley Cell. However, the Equatorial Atlantic and Indian Oceans are 1 to 2C warmer than usual, which would lead to greater convection along the Intertropical Convergence Zone (ITCZ), a stronger Hadley Cell, and stronger north-east Trade Winds from the Northern Hemisphere. There is therefore a small net effect of hotter-than-usual conditions beneath the (likely) winter position of the Intertropical Convergence Zone leading to a stronger Hadley Circulation and (therefore) greater transfer of Westerly atmospheric momentum into higher latitudes of the Northern Hemisphere. Moreover, with this setting, relatively cool waters over the eastern and central Equatorial Pacific lead to stronger easterlies near the surface of the Pacific (where winds blow west from the cool waters where surface pressure rises towards hotter seas across the westernmost tropical Pacific). That leads to greater Westerly atmospheric momentum transfer into both the Northern and Southern Hemispheres aloft. The North Atlantic is substantially warmer than usual at present, whilst early snowfalls have resulted in Canada cooling down fast. Arctic sea-ice levels remain below normal but are recovering quite quickly from record-low levels seen during October 2020. Arctic ice-cover is recovering fastest in the Canadian Arctic but large areas north of Norway and Arctic Russia remain ice-free to date (if Britain is to have very cold north and east winds, due to blocking patterns further north it's best to have ice-growth north of Norway and northwest Russia): A very cold Canada and Greenland, but a warmer than usual North Atlantic sets the scene for a strong atmospheric temperature and pressure gradient across the far north-west Atlantic, one that would favour deeper North Atlantic depressions and a strong North Atlantic jet-stream heading towards the United Kingdom. In the shorter term, both the fact of a continuation of an exceptional North Atlantic hurricane season, and fact that the upper winds in the stratosphere high above 60N are predicted to be stronger than usual out to 16 days' hence by all 31 atmospheric modellers (http://weatheriscool.com/) points to strong Westerlies heading towards the UK throughout the following month (and covering the Christmas period). The circulation in the stratosphere above 60N takes two to three weeks to impact on the weather near the surface across northern Europe and North America. The Sun is still in a quiet phase at the start of Sunspot Cycle 25, among other things that ought to mean a cooler Sun, a sluggish Hadley Cell and less transfer of heat and Westerly atmospheric momentum into higher latitudes. However, the deep tropics are still warmer than usual and the Westerly QBO in the Equatorial Stratosphere will have other impacts. There are also signs that the Sun is becoming more active in any case (see here: https://www.nasa.gov/feature/goddard/2020/new-sunspots-herald-increased-solar-activity-cycle-sdo and here: https://earthsky.org/space/photos-sunspots-ar2781-solar-cycle-25 ) . If, as seems likely, the Sun is growing active it will be stronger and produce more heat to power the Hadley Circulation -and cause more warmth and Westerly momentum to shift to higher latitudes. Lingering hurricanes and typhoons mean that strong easterly winds to the north of them (and westerly Atmospheric momentum being thrown northwards aloft) will also contribute to a greater transfer of heat and Westerly momentum into higher northern latitudes- leading to stronger Westerlies in higher latitudes in the run-up to (and over) Christmas. The conclusion of this analysis is a dire one for lovers of snow and hard frost, since all these macro-scale influences on Britain's prospective winter- weather weigh heavily towards Winter 2020-2021 being a mild, wet and (yes) potentially stormy one. This is particularly likely, since the strength of the south-westerlies through November has prevented the advance of continental snow-cover westwards of the Ural Mountains. This, along with the persistent south-west flow will prevent very cold air and snow-cover building up over Scandinavia an north-west Russia (crucial if strong blocking highs are to form in the area). It is, instead, eastern Canada and Greenland that have the intense cold and snow-cover, which will help generate some intense North Atlantic baroclinicity and cyclogenesis. The North Atlantic, being warmer than usual, will also limit the likelihood of really cold air reaching the UK. Sea surface temperatures around Britain are warmer than normal after a slightly milder than usual autumn overall and (even were there to be a fortnight of very cold northerly or easterly winds, which is very unlikely) sea- surface temperatures around Britain will remain warmer than usual. This will ameliorate the impact of any cold air-streams from north or east. For a bit more detail to my prediction December is likely to be dominated by persistent south-westerlies, with plenty of wind and rain. Stormy conditions can be expected during the second half of December across Scotland, Northern England, Northern Ireland and North Wales. There will be snow in the mountains at times, interspersed with mild strong south-westerlies that remove all traces of snow (except perhaps on Ben Nevis and on the Cairngorms). The south of England will be drier, but still quite windy. Temperatures of 15C can be expected on some days in the South and Midlands. Frost at night will be rare except in northernmost mountain areas. January 2021 will continue the wet- and at times- stormy theme. Expect something like January 2014- it will be cold enough for snow at times in the uplands of Scotland and across Northern Britain, but don't expect widespread snowfall across the lowlands. There will be some frosty nights with clear spells following colder west- northwest winds, but nothing of any severity anywhere. The Midlands and South will get the driest and brightest weather, and with mild south-west winds at times air temperatures will still reach 13C widely. February 2021 will continue the unsettled theme, but it will not be as wet and stormy as in February 2020. With Canada and Greenland by this time very cold and the north Atlantic approaching its coolest, February will bring the highest chance of any cold weather. Tropical cyclones will be happening by then in the Southern Hemisphere (over the Indian Ocean and western Pacific south of the Equator where the seas will likely be very warm by then); these will by this time impact the general circulation in the Northern Hemisphere in the opposite manner to hurricanes north of the Equator- as the Easterlies high up on the equator-wards side of these Southern Hemisphere tropical cyclones will enter the Northern Hemisphere circulation, this time reducing Westerly Atmospheric Angular Momentum: This will lead to some weakening of the Atlantic Westerlies. Thus, we can expect a week of more of dry fine weather with colder north-westerly winds, which may become easterly as the high-pressure drifts into northern Europe. This will mean widespread night frost for a time and some bright cold days. However, a nationwide severe wintry spell with lots of snow is not at all likely as the fundamentals will still be against this- the Westerlies are likely to shift north of Britain across the still relatively-warm Norwegian Sea so this will preclude frigid Arctic or Siberian air reaching these shores. The best likelihood of seeing any snow will be in the mountains across northern Britain with the squally colder Westerlies following the passage of depressions. So to conclude, a mild rainy, windy and unsettled Winter 2020-2021 with snow in northernmost mountains at times, with the best chance of brighter colder weather in February, looks to be on the cards.

Hello lassie23. I will see what I can do, but it won't be more than a few paragraphs. I can say with some certainty that I don't believe that it will be a very cold winter- and the next month looks set to be a continuation of the mild, wet and windy theme.

Hello all. Ian Pennell here from the wild and windy North Pennines. Just to let folk know that I have returned to this Weather Forum after a three-year absence. I have been increasingly busy with my new business and caring for my increasingly frail mother. Not been much time to do weather forecasts!

Blame those wretched South-Westerlies that "Have to Blow to Stop The Earth Slowing Down"! They can be very effective at Keeping Cold From Britain. This is what happens with the "Ferrel Westerlies": Winters as bad (or worse) than the one described in Enid Blyton's "Island of Adventure" (from the 1950's) where Jack, Philip, Dinah and Lucy-Anne (and Kiki, the parrot) lived in a cave for six months! Descriptions of November being "some days were wet and windy, other days the children went out to bask in the Sun". And December, "wet muddy roads", "the Sun breaking through a thin mist in the east" .....not a mention of frost or snow in the story! A December with No Air Frost and Not A Trace of Sleet Or Snow- how disgusting. Of course, the 1930's to 1950's (the period from which Enid Blyton wrote about in her children's books) were a period of global warming before the cooling of the 1960's and 1970's when numerous scientists expressed alarm over a new "Little Ice Age". During the 1930's, in particular, there were some very mild winters - and some warm summers in the south of England.

That is do-able. There's the Greenland Ice-cap just a bit further north -to be used for that very purpose.

See Project (2) about the Large Floating Wall along the North Atlantic from Cornwall to Newfoundland (near top of this thread). This would stop the Gulf Stream, help cool the northern North Atlantic and encourage depressions to take a more southerly track towards western Europe. That would increase the likelihood of cold and snowfall brought in on icy northerly or easterly winds. If the North Atlantic north of 50N was colder we would (of course) get snow and freezing temperatures on westerly winds too!

The next best thing might be a giant pump to pump all the near- freezing water deep down in the north Atlantic up to the surface. With the surface waters of the North Atlantic several degrees colder that would at least increase the chance of the Westerlies being cold enough to bring snow to much of the country.

Seems as it is Christmas, I decided to come back to wish all on here a "Happy Christmas". I have been busy the last few months. If there was some way of weakening the Westerlies that blow in winter into western Europe, it would increase the likelihood of persistent snow-cover and very low temperatures in winter across the continent. I was shocked to see just how mild it was right across Germany and into Austria over the last week. 14C in parts of Germany. Those Ferrel Westerlies do need curbing!

@johnholmes All of the proposals mooted above have glaring problems with them, not least the financial costs and possible adverse side- effects. The SO2 solution could cause disruption to the ozone layer and although greatly reduced by putting the SO2 it in the Stratosphere, some of it could find it's way into the troposphere leading to possible acid rain or snow (that risk is not 0%). Covering the equatorial oceans with giant floating mirrors would upset a good deal of marine life in the areas affected. The alternative is that we don't do anything. Carbon dioxide levels continue to increase and (notwithstanding that we may be at the start of a Maunder Minimum type period with a quiet Sun and cooler global temperatures for a time) in 25 to 30 years' time global temperatures will be such that the West Antarctic and Greenland ice-sheets start to melt rapidly, methane will be released from the thawing tundra...and it will soon be too late to prevent major ecological crises far worse than a possible bit of acid rain or the renewed Ozone Hole could cause. In the meantime Britons will be faced with plenty more naff winters with wind and rain. Coastal storms will get bigger and coastal erosion a serious threat to countries such as the UK, Norway, Canada and Ireland. Each December we face more gloom with depressions lining up to pass south of Iceland (there is a likelihood of some colder winters from 2020 to 2035 due to the Quiet Sun but this will still be hit and miss). There will be more Climate Summits but, since governments around the World are not willing to impoverish their populations to "Save the Planet" not much will happen to CO2 emissions. In the longer term our winters will get worse (i.e more persistent mild, wet and windy) and Coldies will be tearing their hair out in despair- "If only something were done about it!". But nothing will get done about it because any discussion about geo-engineering always gets shot down in flames. Millions of cold- weather lovers, who would like their Christmases to be snowy and sparkly (and those who hope for such weather at some point each Winter) will suffer exasperation! In 2035 Coldies will still be looking at the Weather Charts on Netweather Forum at a High in the NE Atlantic in January, hoping it will edge just a bit further north to encourage cold easterlies: They will have their hopes dashed as (close to the forecast time) the High collapses south- to be west of Spain and those Damp Mild Ferrel Westerlies blow in 'round the top to affect the UK. Snap-shot of the future: January 2045- A deep depression (one of several so far in winter 2044/2045) pushes over the Faeroe Islands with a central pressure of 916 mb whilst the Mediterranean High is 1040 mb over Lisbon. Savage gales and torrential rain batter Britain's coasts with a full moon also leading to high tides. Huge waves over- power the small town of Stromness at the south-west end of the mainland Orkney Islands and several houses collapse into the raging North Atlantic. Over 220 local Orcadians are confirmed dead. Meanwhile, the River Clyde overflows its banks, helped by over a foot of rain on the Scottish Southern Uplands in 24 hours and the storm surge off the Scottish Coast. Sea- levels globally have risen one metre in the last year and catastrophic flooding has been widespread. The massively-flooding River Clyde combined with destructive gales has left over 100 Glaswegians dead.....This disastrous episode follows last summers record heatwave (temperatures topped 40C in London in July) that has led to 25,000 excess deaths in the UK. This was the largest weather-related cause of death over a short time period in Britain's history........If only action had been taken sooner to prevent such weather-related catastrophes which has affected many countries around the World over the last twelve months. Unfortunately a collective amnesia and fear of doing anything seems to have gripped the governments of the USA, China and other countries around the World so that they could not contemplate any sort of action to prevent a global Climate Disaster- whilst CO2 levels (now at over 600 ppm by volume) continue their march upwards.

@johnholmesMost folk on Netweather's wonderful Forum express their frustration at the mild south-west winds that have come to predominate most winter's in recent years, particularly December when folk are hoping for something a bit more "Christmassy". What is "Christmassy" about endless mild weather, wind and wet? Surely, a discussion of (possible) projects to help reduce the likelihood of future winters being so relentlessly mild and wet in Britain (and other locations on the west coasts of continents at mid- latitudes), to provide some assurance of at least one decent cold spell in each winter whilst ameliorating Global Warming is a discussion whose time has come. I admit that most of the ideas mooted would stretch Government budgets around the World (maybe a global Crowd-funded initiative would be required) and some would be impractical but I did want to get folk thinking about the feasibility of some of the measures- and to discuss others. The root of the Problem with the Winter Weather in Britain (from a Coldie's perspective) is the Law of Conservation of Angular Momentum on our rotating Earth and the logical Need (that follows on from this) for the atmosphere to rotate with the Earth around it's axis of rotation: Easterly winds in the tropics, subtropics and at very high latitudes must be counterbalanced by Westerlies (or to be more precise, the force of all the easterly- quarter winds in the world must be counterracted by that of Westerlies). If there are practical ways of increasing the sink for Westerly AAM in other ways by increasing the surface friction of the underlying surface, that would weaken the Westerlies: That would increase the chances of more agreeable weather in Britain. Of course, there are people who don't like cold weather but a number of such folk don't like wind and rain either: Frosty weather in winter kills bugs and reduces the likelihood of pestilence, less storms mean less coastal erosion and such folk could be persuaded of the benefits of colder but drier weather with less bugs. That's assuming that there are geo-engineering means of modifying the Westerlies that are affordable and practical. All the best this Christmas and in 2019. @Ed Stone Indeed, why don't we? The project of planting millions more trees (including artificial ones, that also take in CO2 on the Rockies) would also help remove CO2 from the atmosphere and help to eliminate further Global Warming. Sadly, governments around the World are taking control of CO2 less seriously: In particular the USA has pulled out of the Paris Agreement and China is building lots more coal-fired power stations so mankind will probably have to consider some sort of geo-engineering project sooner or later. Plans to put dust or sulphur dioxide into the Stratosphere have been given consideration as a means of reflecting sunlight from the Earth and keeping the Earth cool (see here: https://www.technologyreview.com/s/511016/a-cheap-and-easy-plan-to-stop-global-warming/). This would be most effective in the Stratosphere at low latitudes where it could help weaken the Hadley Cell and, in the process, lessen the transfer of Westerly AAM to higher latitudes (and it's the latter that causes us grief each Christmas). In seriousness, there does need to be a greater incentive for developing (and other) countries to reduce carbon emissions further, like carbon credits but there being much more of an incentive for countries to change course. Governments around the World will not willingly tax their citizens more and tip their economies into recession in the name of fighting global warming, which is precisely why the governments of the USA, China and India are dragging their feet. Money talks, so an organisation like the IMF should dole out grants (not loans) to countries that reduce their CO2 blue-print. If the IMF won't do it then the British Government could build up a big chest of £1 trillion in five years to help our own economy become carbon neutral but also incentivise other countries to do so. As to how to build up such a War Chest to fight Global Warming a global "Crowd-funding" Programme, issuing Cool Earth Bonds to the British people and filling the gap by selling the Shetland Islands to Norway- so that the Norwegians give us some of their Sovereign Wealth Funds for such a good cause (how serious are we) and cutting (other) Foreign Aid? If the objection of many countries to being serious about fighting Global Warming is that they want their economies to grow to their citizens have better lives, we find ways to compensate them for their economic losses if they reduce CO2 emissions, or indeed do other things to help mitigate global warming. Putting sulphur or dust into the Stratosphere over the Equator is a possibility, the ecological down-sides of acid rain are greatly eliminated when SO2 is put into the Stratosphere- above the height of clouds that precipitate rain or snow: Dust and sulphur in the Stratosphere would help cool the global climate and weaken the global winds- a win win for those who hate mild wet weather in Britain! Planting trees on a massive scale is another possibility, and if these are planted at mid-latitudes they help weaken the Westerlies by greatly increasing the friction of the surface. If we were able to pay other countries to do some of these things (and reduce CO2 emissions) we might get some of our cold frosty winters back! Whatever the weather, I wish you and your family all the best over the Christmas period and a prosperous 2019.

Blame the Ferrel Westerlies. Something needs to be done about them!

The cheapest (and most economically practical) solution to dismembering the dratted Ferrel Westerlies would be the creation of millions of tonnes of sulphur-dioxide to be released from high- flying aircraft in the Stratosphere along the Equator. There it would substantially reduce solar input to the surface, weakening the ITCZ and the NE and SE Trades (and with it the frictional production of Westerly AAM to be transferred to higher latitudes). By putting SO2 into the stratosphere, it is above the elevation where rain or snow could wash it out of the atmosphere. If SO2 is considered a bit risky for ecological reasons, billion of tonnes of very finely powdered salt (extracted from sea water) distributed along the Equatorial Stratosphere would also help block out the Sun's heat where it was most intense. This too would lead to a weakening of the global winds: It might even help stop global warming as well as lead to Weaker Westerlies (with frosty snowy easterly and northerly winds being given a better chance) in the UK in winter. Without any major excavations, or manufacture of materials (both SO2- from volcanoes, and salt occur naturally) the cost comes down to around £100 billion. It's just a matter of getting enough modified aircraft into the Stratosphere with finely powdered salt (or SO2) to reduce the heating of equatorial lands and seas, so that the Global Winds are weakened.

@Lettucing Gutted Firstly I hope that you are having a good Christmas with your family, all the best for 2019. Indeed, the 10 million square kilometres of giant floating mirrors over the equatorial oceans would be effective (and may help to reverse global warming), but the cost of ££ trillions would make this plan a non- starter. Even if governments around the World doubled their tax- rates (which would plunge the World into deep recession and actually result in less revenue) it would not be enough to pay for such a huge geo- engineering scheme. A much cheaper (and almost as effective) alternative plan would be to manufacture trillions of tonnes of white paint to spray on a large belt of central Africa (all land between 5N and 5S) and northernmost South America (again, all land between 5N and 5S). This would be an oil- based paint that would not wash off in water. Millions of Africans, Brazilians, Colombians and currently hard- up Venezuelans would be paid to manufacture and spray this paint. They would be able to buy food from areas not covered in white paint and the economies of the other areas growing such food would thrive. The ecological impact of this massive Equatorial Land Painting exercise could be mitigated by evacuating a whole range of animals from the Amazon (and elsewhere) to locations further north and south. The result would be much solar energy reflected away from Equatorial regions, leading to a weakening of the ITCZ and a big weakening of the NE and SE Trades: this in turn would greatly reduce the "Need" for Westerlies in higher latitudes to counter- balance tropical easterlies. This would lead to colder frostier winters and warmer drier summers in the UK, Ireland, British Columbia- and other areas that suffer from too much persistent wind and rain during their winter half- years! So much white paint reflecting the Sun's heat from regions of the World where it is strongest would also counter Global Warming- even allowing for the fact that the mining of raw materials and manufacture of so much white paint would emit large amounts of CO2! Cost of this project: £500 billion initially. Huge purpose-built factories would need to be built to make the paint (which could be done locally) and materials mined extensively to manufacture enough paint. There would also be side effects- brightening (and thus cooling) the deep tropics so as to weaken the ITCZ would lead to the virtual elimination of rainfall in the deep tropics and severe droughts would grip many areas on a scale not previously seen. The Amazon would be much drier and that could adversely impact the local ecology over a wide area. Perhaps, as part of such a big project, extensive water- desalination units would need to be built and set up, so as to mitigate the effects of drought (the impact of growing food in such areas to feed people in regions covered in white paint and to help local populations and ecological systems). The final cost is likely to exceed £1 trillion, and rather more when allowing for impacts on regional economies! Another much cheaper plan that would impact directly on the Westerlies would be the planting of forests on a grand scale in western Scotland, Ireland, British Columbia and Washington State. Artificial trees could be manufactured and "planted" in the colder windier locations where trees cannot grow naturally but where they would be most valuable in intercepting the Ferrel Westerlies (and acting as a better sink to Westerly AAM); special cup- shaped frames up to 500 metres above the surface with the "cups" facing west should be "planted" along the tops of the Rocky Mountains above 3000 metres' elevation and on the highest northernmost parts of the Tibetian Plateau (i.e. those areas likely to get strong Westerly winds in winter). Millions of such "trees" also need to be planted into the Rockall Rise (where the North Atlantic is relatively shallow) with thie "cups" up to 500 metres above the ocean surface and pointing south-west to absorb the full force of Atlantic gales and thereby weakeing depressions before they bring their wind, rain and mild south-westerlies to the UK. Cost: £500 billion needed to do this on a grand enough scale to seriously weaken the Ferrel Westerlies to the extent that Britain's Winters get reliably cold enough and dry enough for folk on the Netweather Forum! Weakening the south-westerlies blowing into the NE Atlantic would also have the added benefit of weakening the North Atlantic drift which flows northwards into the Arctic- helping to preserve the reflective Arctic pack-ice and thus to help prevent Global Warming!

Sadly that is true!

@Frost HoIIow Merry Christmas to you and your family, and all he best for 2019. Unfortunately I cannot see a winter as cold as that of 2012/2013 developing. The SSW over the high Arctic is not as intense whilst Europe is too warm. Canada/ Greenland very cold but north Atlantic warmer than usual overall- plenty for strong baroclinicity to drive deep Atlantic depressions past Iceland for the remainder of the winter. QBO turning Westerly again is not a good sign either. There will be a couple of cold spells in late January/ February but nothing out of the ordinary nor lasting more than a few days at a time.

@cheeky_monkey What kind of points system do you have in Canada for those wishing to emigrate from the UK? I'm thinking of doing so, considering how naff the winter weather has become in my corner of the world: I live at over 400 metres' elevation in the North Pennines and even now we have not yet had our first real snowfall of the winter!!

To add, there may be other (more practical) ways of weakening the Ferrel Westerlies- so we can perhaps consign persistently mild wet autumns/ winters in Britain to history. You are welcome to discuss any of the following: 1) A mile high wall (200 metres across) built along the west cost of Ireland, certainly this will catch the low- level jets that blow along warm and cold fronts. This would create a higher- up sink for Westerly AAM. Put wind-mills on the top of the wall to a) provide extra resistance to the wind and b) generate electricity for all of Ireland. Cost about £500 billion. Spending all the money Britain saves by not having to pay into the EU budget each year plus a Land Value Tax on high- value land/ property in Britain should pay for this over thirty years. The Irish should be eternally grateful for the jobs this will provide it's citizens and for the prospect of a drier climate with proper seasons into the bargain. This measure would create a near- permanent upper level ridge over the UK, depressions would be diverted towards Iceland or south-eastwards towards Spain. It would sharply increase the likelihood of dry bright frosty weather in winter and warm dry weather in summer over the UK. The western Mediterranean may get more winter rainfall- reducing the risk of severe drought there. 2) A large floating wall up to 100 metres deep extending east to west along latitude 50N from Cornwall to Newfoundland, made from large hollowed- out aluminium cubes. This may be a preferable option by stopping the Gulf Stream extending to high latitudes. The resulting cooling of the northern North Atlantic and Arctic Oceans would help the Arctic ice-cap to grow, rather than shrink. This greater reflectivity of the Arctic area would then help forestall global warming. Colder northern seas would also push the main baroclinic zones further south so that the Ferrel Westerlies give more winter rainfall to the parched Mediterranean and Middle East, whilst Britain and most of central and northern Europe get more very cold northerly and easterly airstreams bringing snow. The only drawback is that depression tracks would push further south throughout the summer too, leading to record cold wet summers across central and southern England. Western Scotland would get more bright but cool summer weather with north- east winds and a chillier drier climate would mean less midges! Cost: £1 trillion up-front and the aluminium hollow cubes would need replacing every 20 years, at similar cost. Huge logistical problems. 3) A 7 km high wall extending north- south across the Tibetian Plateau, itself above 5 km high across an extensive area. It would cost over £800 billion. Logistical problems of getting all the building materials onto site in remote locations despite it being little over half the height as the Californian wall of 12 km high. Atop the wall, intercepting the subtropical jet- stream 12 km above sea- level sturdy win- mills could be erected and given the strength of the subtropical jet-stream in winter they could provide China with much of it's electricity. The wall would, of course, need to be at least 100 metres thick at the base to minimise the chance of it collapsing. As with the 12 km high wall in California, this wall would intercept the subtropical jet-stream, removing Westerly AAM from the atmosphere so that there is little "need" for Westerlies elsewhere in the northern Hemisphere. 4) A variant of (3), at a fraction of the cost: 10,000 huge steel poles ten metres' in diameter 100 metres apart in a north- south direction on the Tibetian Plateau, each joined together with beams and each extending 1 km down below ground- level and extending up to 12,000 metres above sea- level. At the top of each 8,000- metre tall pole there would be, facing west, ten very large steel "brushes" pointing outwards: Cost over £500 billion because of the huge amount of excavation needed to drill 10,000 ten-metre diametre holes 1000 metres down into the Earth. Then there's the small matter of manufacturing enough steel (probably requiring a steel-works set up on the Tibetian plateau) and the practicalities of employing enough people to work in bitter conditions stop this plateau. The same applies to (3). 5) Cover 10 million square kilometres of the equatorial Pacific and equatorial Atlantic Ocean (between 5N and 5S) with giant floating mirrors. This would cool the equatorial oceans, help make like bearable for millions who live in the steamy deep tropics and (most importantly) greatly weaken the Intertropical Convergence Zone (ITCZ) and with it, the Hadley Cells of both the Northern and Southern Hemispheres. Thus the NE and SE Trade Winds are greatly weakened and (with it) the creation of Westerly AAM to be transferred polewards aloft to maintain the mid- latitude Ferrel Cells in both Hemispheres. Britain, Ireland, New Zealand, British Columbia, France and southern Chile would all enjoy drier colder climates with proper winters. As an added bonus, the giant mirrors covering much of the equatorial Pacific and Atlantic, would reflect almost 100% of insolation straight back to space- from locations where the incident insolation year- round is strongest: This would help fight global warming. Unfortunately the cost would be immeasurable- £ several trillion, particularly as the giant mirrors would need replacing periodically! If you have any other ideas as to how we could effectively fight the Ferrel Westerlies that wreck so many of our Christmasses do share them here! Have a great Christmas and a prosperous 2019. Ian Pennell