North-Easterly Blast

I am not saying that it is likely that we shall see anything like Dec 2010, but I would have hoped that a weak to moderate La Nina would have increased the chances of early cold spells compared to recent years.

It is very worrying that many of the charts are now showing a flat jet and mostly mild zonal. I am not saying that it is likely that we shall see anything like December 2010 at the start of this winter, but many would have hoped that a weak to moderate La Nina would help the chances to be better than they have been for a number of years, of early cold spells this winter season.

For a westerly QBO winter 2020-21 was actually a fairly decent winter for cold - at least by the standards of recent years - obviously nowhere near as cold as 2009-10 but it was colder and a bit different to most, if not all winters since 2012-13. The only other winter since 2012-13 that was as cold as 2020-21 was 2017-18.

I would not call winter 2000-01 a particularly cold winter. It was really fairly average overall for the south after the mild first half of December, although it was colder in the north as many colder spells that winter were more focused on the north. I would put winter 2000-01 as a winter that was in some ways, a bit similar to 2020-21 more recently. Admittedly winter 2000-01 was colder than many winters of the last 35 years, though in the grand scheme of things it was more of an average winter.

Now ten days (very nearly a third of the way through) into the month, and the running CET has now gone above 18*C, and with the next four or five days looking very warm or hot, a final CET finish below the 17s is now looking very unlikely. The warmest August CET of recent times was in 2020 at 17.6*C (legacy) , and we have to go back to 2003 for one warmer. In actual fact notable heatwaves have not been common in August in recent years (even the notably hot summer of 2018 fizzled out after the first week of August), and overall high August CETs have been rare since 2003. On top of that, the warmest August of recent times in 2020 was also a wet one overall. It is now looking likely this month that the first significantly warm (and also dry) August since 2003 may be happening. `

It is a complete shambles that news reports said that Coningsby and Heathrow got to 40.3 and 40.2 respectively, and then at the end of the day posting information on the observation map extremes page that the highest day temperature was 39.9 at Scampton, which is making out that the Coningsby and Heathrow readings were not reliable or even true, and at the very least it implies that the readings quoted on the Met Office twitter site are not validated. I hope that the Met Office make a post or statement in the days ahead as to what the highest officially validated reading was for the UK's hottest day ever. If we were talking of a more modest hot spell where the highest maximum mentioned was something like 30.3 and the observation page extremes section quotes 29.9 then it would be less important to investigate it properly but when we are talking about the UK's hottest day in recorded meteorological history then it is clearly important that an official statement is made as to what the highest official reading was.

UK observations map - Met Office WWW.METOFFICE.GOV.UK Weather observations for UK over the past 24 hours including a map to view recent weather data, timeline and observations table If you follow the above link, at the foot of the observation map, at around midnight at the end of each day the UK extremes are published, and it quotes 39.9 at Scampton as being the highest day temperature for the 19th. From this it appears that there is a chance that 40.0*C or more was not reached. Based on this, I think an investigation needs to be carried out as to if the 40.3 at Coningsby and the 40.2 at Heathrow are reliable readings.

It has just been posted on the Met Office hourly observation data that the highest day value for the 19th was 39.9*C at Scampton, so it appears that no reading above 40.0*C has been validated. It was posted on various news reports that the highest observed reading was 40.3*C at Coningsby, Lincolnshire, plus that Heathrow got to 40.2, and a couple of other sites in the London area got over 40.0. I think that all the above matters need investigation - given that 40.2 and 40.3 were widely remarked upon as being the highest values for the now hottest day ever in the UK, they really need investigating as to how they were measured and recorded - now the Met Office are saying that the maximum was only 39.9 at Scampton - so there now looks to be a chance that nowhere in the UK got to 40.0*C+.

So far today the highest temperature that I could find reported was 38.1c in Cambridge, so at the very least we can be sure that today has marked the fourth occasion that temperatures have exceeded 100*F somewhere in the UK. As of 4pm we are 0.6c short of the UK's all time record. As 850s are still rising I believe that there is still a chance of temperatures rising, but it looks touch and go now as if today will beat the 38.7*C set in Cambridge Botanic Gardens on July 25th 2019. Another record that we probably more likely to beat today is the all time highest maximum daily CET on record, as 35*C+ has been widespread across a large part of England today. The highest ever daily CET maximum that I could find in the records was 34.1 on the legacy CET version on 25/7/2019, or 34.2 in the new revised CET version on the same date. It looks almost 100% certain that we will beat this record today and may even have a chance of the first ever 35*C CET maximum day. Another CET record up for grabs tonight is the warmest ever CET daily minimum on record. The highest daily CET minimum that I could find in the records was 19.4 on 20/7/2016 in the legacy version, or 19.5 in the new revised version on the same date. I believe that tonight we have the chance of recording the first ever 20*C+ daily CET minimum.

The only way that I believe that you can get different values for the new version of the CET and the legacy version is if the new version of the CET uses different stations to calculate the daily CET compared to the legacy version. As far as I was aware, the legacy version used stations ranging from Rothamsted, Pershore and Stonyhurst to calculate the CET. If different stations are used to calculate this new version of the CET then it is inevitable that slightly different values would be achieved. For the sake of the legacy version of the CET, given that its daily values date back to 1772 and monthly means date back to 1659, using a particular range of stations to calculate it, then I would prefer it if the legacy version of the CET could continue to be updated using the same stations as were used before.

We may have had a significantly above average May but without any significant spell of particularly warm weather; really warm days were isolated briefly around mid-month; apart from that for the rest of the time it has not felt particularly warm.

Will the legacy version be updated with the month's final figures? It appears that another version of the CET has come out which in recent decades has slightly different figures in general to the legacy version. I notice that the legacy version has the daily values up to the end of April, and the monthly means up until then as well.

I meant to say backloaded winters in recent times - there have been very few since 1988 - the only good example of one in recent times that I can think of is 2012-13. All the other backloaded winters that I can think of were before 1988. You are correct about those earlier examples like 1946-47 in terms of when the severe spell occurred; 1955-56 was a good example as was 1954-55, and 1953-54 to some extent as well. 1985-86 was a great example, starting off mild then it got colder for a while in late Dec / early Jan then got a bit milder for a while before turning cold in late January leading on into the very cold February. Before 1988 backloaded winters were relatively common as in the above examples but since 1988 we have only really had 2012-13. I would not call winter 2005-06 consistently chilly throughout - it actually wasn't particularly cold - for most of the winter it was consistently fairly average with HP often close to the UK and never really setting up into favourable HLB to bring cold northerlies and easterlies to the UK and the really cold air never really quite made it to the UK that winter, although the pattern did come together into HLB with winds in from a northerly or easterly quarter for a time in late February and through a good part of March. Winter 2005-06 was more like a failed cold winter = the building blocks were there but mostly did not set up favourably for us in the UK, although I think that north and east Europe saw some good cold spells that winter. 05-06 is an example that even if there is blocking over northern Europe, the pattern still has to fall favourably for us in the UK, and in that winter it just did not quite come together.

Winter 1996-97 effectively ended around January 11th - it was another pear shaped winter in some ways similar to 2010-11 - in 1996-97 December was cold (though obviously nowhere near as cold as December 2010) , then a cold spell lasted into the first third of January then it all went belly up and that was it - the cold was never to return during the rest of the winter, whereas in 2010-11 it was the severe spell from late November and through December 2010, but once the cold abated at the end of December that was it, the cold never really returned during the rest of the winter and in 1996-97 and 2010-11 both the Februarys were ridiculously mild. Another so called pear shaped winter was in 1981-82 - that was another winter that effectively ended in mid-January and the rest of the winter was not up to much. You are right that winter 1995-96 was a good example of a winter as a whole being good for cold spells - with cold spells in it from start to finish. In some ways winter 2009-10 was also cold as a whole; the period from the middle third of December to the first third of March overall was cold. In fact although winters 1996-97 and 2010-11 had cold starts that deteriorated into nothing, there have been very few examples of "back loaded winters" in recent times - the best example that I can think of is 2012-13, which had that notably cold March, and in that year the period from around January 10th through to early April overall was cold.

I would not by any means call winter 2017-18 particularly cold or special. I would say that yes it was good from a cold perspective compared to most winters in the UK since 2012-13, but in the grand scheme of things 2017-18 was a fairly average winter by UK standards, and not memorable in the way that 2009-10, Dec 2010 or 2012-13 were. It is just very concerning to think that winter 2017-18 and winter 2020-21 may be the modern versions of 2009-10, Dec 2010 and 2012-13, and that the winter spells in these years may well be consigned to the history books.

1982 looks a bit of a non-descript year after the cold of December 1981 and the first half of January 1982 had passed - with no month much below average for the CET, and most months above the average though never by more than around 0.5*C, apart from November being just a little more than 1*C above. 1982 in my opinion is a year that does not really stand out as being much out of the ordinary weather-wise, apart from the cold spell at the start of the year following on from late 1981, though it did have a very thundery and quite warm June. The following year 1983 does stand out as being a warm year overall (by pre 1988 standards) and having what is now the second hottest July and also the second hottest of any calendar month on record, though it still contained a cold February, April and May.

I thought that August 2020 was a pretty close match to August 2004 - they both had a similarly warm overall CET but both Augusts were wet months overall, although I think that August 2004 was the wetter of the two. In fact summer 2020 was a very similar summer to 2004 overall; the CETs of June, July and August were very similar in 2020 to 2004 almost exactly month by month, and both summers had a wet August overall, and in fact rainfall in July 2004 was very similar to July 2020. It is not often in the British weather that you get a three month season exactly alike to another year, but I think that summers 2004 and 2020 managed to be almost exactly alike. Another example of three month seasons almost exactly alike in two different years was summers 2006 and 2018. Both these summers had a very hot July, and started with a warm and dry June, but both summers moderated somewhat in the August with something closer to average. When you look at it, the summer of 2018 had CETs month by month very similar to 2006, and also similar rainfall month by month as well. So in 2018 and 2020 we had summers that were an almost mirror image of 2006 and 2004 respectively.

Summer 2004 was a fairly warm but wet summer - especially August - but summer 2005 was a bit drier and more settled as well as being on the warm side. Summer 1996 was a fairly dry and often settled though at 14.4, 16.5 and 16.5, the CETs were nothing particularly warm, just fairly average to slightly above.

Summer 1985 was a particularly cool summer overall, with an overall CET of only 14.5; June and August were much cooler than average, although the July I believe was not far from average; there was not much heat about that summer at all; I think that summer 1985 produced only isolated warm days or maybe two or three in July, but apart from that it was cool and often wet. September 1985 though was fairly warm I believe, with a notably warm spell late in the month that lasted into the start of October, which went on to be a very dry anticyclonic October. September 1985, at 14.6c CET, is actually the warmest September that I can think of in recent decades or even in the last century, that led on into a cold winter. You are correct that 1985 was a cold year with a particularly cold January to March period, and the overall coldness of 1985 lasted through most of 1986 as well.

It possibly depends on how cold Europe is as to how cold an easterly is. To get the coldest air to the UK from an easterly, you really need an easterly to develop out of a high from the Arctic / northern Scandinavia that spreads across Europe turning northern and central Europe very cold and the easterly to go on to reach the UK, then it will be cold in the UK, but if Europe is not particularly cold then an easterly will not have the same bite in the UK.

I will add in that November 1994 holds the record for the warmest November CET on record, at 10.1*C. February 1994 saw probably the best cold wintry / synoptic spell between February 1991 and the 1995-96 winter. The middle to latter half of February 1994 did see a good easterly setup (although not on the same scale as the Feb 1991 easterly) and it did give a pretty good two week cold spell for many parts of the country. A notable feature in 1994 was that the temperature never really changed much from September until December.

In actual fact after February 1961, there was not a notably mild February CET until 1990. In that 29 year period there was not a February CET above 6.0*C. The fact that there was no February with a CET above 6*C between 1961 and 1990 helped the 30 year average for 1961-90 to be only 3.8*C, although that was still slightly above the 1951-80 and 1941-70 averages for February. February 1961 at 6.9*C, had the ninth highest February CET on record from 1659, although 1867 and 1872 were tied with it, so it could be considered to be in 10th or 11th highest place for the CET. Interesting to note that February 1779 as having the highest February mean temperature ever is quoted in the newspaper article.

Any news on the areas that are more likely to get snowfall tomorrow? I still think that Scotland and higher levels in England north of the Midlands have a good chance of seeing some snowfall this Thursday February 24th.

I think that between 1894-95 and 1939-40 that there were also a small number of other winters that could be regarded as reasonably cold (CET below 3.5), even if not especially so, but as you say anything that could be reasonably described as being a relatively cold winter let alone very cold was pretty rare in the 1895 - 1940 era. In that period I would say that winters 1899-1900, 1901-02, 1906-07 were all fairly cold, as was 1935-36 later on in that period. I think that 1933-34 was relatively cold but different, as I believe that much of the cold in that one was from a mid-latitude block over the UK giving surface cold, rather than deep cold Arctic air / proper cold synoptics.

I have just looked at that; all the winters from 1910-11 to 1915-16 all had CETs between 5.0 and 5.5, so these were all above average and definitely not cold, apart from 1914-15 which was possibly a bit nearer average. 1915-16 was a very strange one in that although it had the mildest January CET on record, there was a lengthy spell of cold weather in late Feb into March in that one, and I believe that the previous November 1915 was something like the second coldest on record for the CET. So all in all 1915-16 was really an example of a winter having an extended notable mild spell in the middle that was bookended by cold spells early and late. That said although none of the above six winters were cold overall, I am sure that most of them had little shorter cold outbreaks at times, unlike a number of recent mild winters that were devoid of any cold outbreaks at least from the north or east from proper cold synoptics all the way through. Which four of the great severe winters since 1900 happened near solar maxima? If that was the case I would think that just before solar maximum may be slightly more favourable than just after.