North-Easterly Blast

In actual fact this February would only need a CET of 4.3 or below to make winter 2022-23 the coldest winter since 2012-13. The coldest winter so far since 2012-13 was 2017-18 which had a CET of 4.33 on the legacy series. 2020-21 was not far behind with an overall CET of 4.4 on the legacy series. If winter 2022-23 could manage to be the coldest winter overall in ten years even though it will not be a particularly cold one, it would certainly put into perspective how poor the UK's winters have been from a cold perspective since 2012-13.

I think that in winter 1985-86, the pattern was very flip flop and the cold was "on-off" in the early part of winter, starting early with the coldest November since the 1920s I believe, then at the start of December 1985 it switched to very mild, which lasted for the first three weeks or so of December, then we did have a cold spell from around December 26th 1985 to around January 10th 1986, then it got a bit milder for around another fortnight, before the cold again set in for the last week of Jan 1986, which then developed into the very cold February.

The last time that happened was in 2013, and before that in 1962, but it is very rare to get a March that is colder than both the preceding January and February. In actual fact in 2013 the March was colder than all three months before it. That said that chart is over a month away so it cannot be taken too seriously. On top of that a cold early March does not guarantee a cold month overall - back in 2005, March looked promising for a cold month early on with a pretty cold first fortnight, but then the very mild second half came along and pushed the month above average overall.

We any of the SSWs in the 1960s to 1980s followed by a significant cold spell in the UK shortly afterwards? Apart from the SSW in January 2009 leading on to the cold spell in early February that year, I do not think that any of the other SSWs in the 2000s were followed by much in the way of a cold spell shortly after, so unless we know when all the SSWs were, and if the UK did get a cold spell soon after, we do not know how favourable SSWs are in bringing a significant cold spell to the UK.

Many thanks Kevin for the information - as you rightly put it; those four winters that you quote were a bit like back to front versions of the 2010-11 winter, and where a winter starting with a notably mild December did not preclude a cold February to follow or preclude the rest of the winter in delivering anything cold. You may have posted four good examples of notably mild Decembers then turning much colder later in the winter, but this is clearly the most extinct weather pattern in the UK since at least 1988 that I can think of. There are a few other examples of winters as a whole that I can think of that had significantly mild Decembers but then turned significantly colder, which are 1900-01, 1918-19, 1953-54, 1954-55, and we have certainly not had any winters like this since at least the 1980s that is for sure. The 1872-73 winter that you mention is interesting in that the January had a very mild first half then a colder second half, then February 1873 was cold. December 1872 was slightly above average by today's standards, although nowhere near the 7*C CET category. In some ways winter 1872-73 was a bit similar to a more recent case in 1982-83, where the winter had a cold February after not much going on from a significant cold outbreak perspective in December and January as a whole. 1872-73 and 1982-83 are among the best examples that I can think of that had a cold February after not much in the way of cold weather in the earlier part of the winter, but those types of winters are few and far between. Most cold (sub 2*C) Februarys that I can think of, have mostly been preceded by a significant cold outbreak for a while in the first half of winter, even if it is not continuously cold. Generally in my view, the absence of a significant cold outbreak for a while in the first half of winter does not bode well for a really cold February (sub 2*C CET).

I think that the type of fog that you are referring to was smog, which was where particles of smoke stuck to the droplets of water in the fog creating a dirty smoky fog, hence the name smog (the first two letters of smoke and the last two letters of fog).

January 2021 and the first half of February 2021 had more in the way of cold outbreaks than many other recent winters have had even if they were not exceptional in cold spell terms, so a SSW in Jan 2021 obviously helped to some extent as although winter 2020-21 wasn't particularly cold in the grand scheme of things, it was still one of the better winters for cold in the UK since 2012-13.

I have said many times before, that a SSW only increases the chance of a significant cold spell in the UK, but it does not guarantee it, everything still has to fall favourably for us in the UK, as the dice of luck still has to land for northern blocking to set up favourably to direct cold airmasses into the UK. The stratospheric warming is modelled to begin in a week's time, and to be complete by the 18th, so anything can happen beyond that time and it is a situation where it is impossible for the models to give any trends.

My point is that fog has traditionally occurred during the winter season and fills the air white - so fog in my view is the white stuff that fills the air away from where there is any surface to stick to; snow falls and sticks to the ground and surfaces, and frost forms on the ground and on surfaces, so in reality frost, snow and fog are all different forms of the white stuff. "Winter white" from fog is visible in the air above the ground and surfaces. To make the air white it has to be foggy, whereas snow forms in the sky and falls to make the ground and surfaces white, and frost actually forms on the ground. Compared to fog, frost and snow do not really make the air white in the same way. Away from the winter season it is rare to see fog, at least away from high ground and near coastal areas.

Winter 2022-23 so far looked to promise so much at the start, at least compared to recent years anyway, with a potent 11 day cold spell in December, but when this broke just after mid-December, the rest of this winter so far has produced little in the way of significant cold outbreaks, with just a week or so that was colder (though nothing overly dramatic) just after mid-January. If the rest of this month and even into early March does not deliver something from a cold perspective, then I think that winter 2022-23 could in some ways be seen as a pear shaped winter, joining the list of the likes of 2010-11, 1996-97, 1981-82, that were cold early on but went downhill and were followed by next to nothing, albeit with a shorter cold spell to begin with, meaning that 2022-23 could turn into a less extreme version of a pear shaped winter than the others above. There is still time for a spell of colder weather to show up (whether that be significant / intense or modest / less dramatic) before this month is out, but if we are to see any chance of that, we would need to see it appearing in the computer models soon. I think that if a cold spell did materialize before this month is out, then I think that winter 2022-23 could still be seen as a fairly average winter, but if this month does not deliver anything from a cold perspective, then winter 2022-23 will really go down as a pear shaped winter, but just one that is not as cold to begin with as 2010-11, 1996-97 and 1981-82. You never know, February 2005 is one example that I can think of where the second half of February did deliver a pattern change to a cold spell of weather after there had been limited cold in January and the first half of February, though I cannot think of any examples since 2005. I have done my calculations, and I will say that this February only actually needs a final CET of 4.3 or less to make 2022-23 the coldest winter since 2012-13. If we could manage to achieve that, then although winter 2022-23 will not have been particularly cold overall, it will still be seen as an improvement on recent years if it could still manage to be the coldest winter overall in ten years. It has been said numerous times before, that winters like 2017-18 and 2020-21 could be the modern versions of 2009-10, 2012-13, and December 2010, and that we are now in an era where winters like 2017-18 or 2020-21 are now the greatest depth of cold for a winter in the UK that is now realistically possible to develop, and if we get a further cold spell before this winter is out then winter 2022-23 could join the list with 17-18 and 20-21, but if there is no further cold spell this winter then 2022-23 will likely be seen as another milder than average winter.

I do actually believe that this winter has so far seen more in the way of fog compared to recent years. The cold spell in December did see some fog on some days in places, and there was also some fog at times in the spell of colder weather that we had after mid-January. Fog has certainly been another aspect of winter weather that appears to have all but disappeared in recent years in most parts of the country.

Since 2018, I believe that there was also an SSW in Jan / Feb 2021; could someone please correct me if I am wrong? I think that this led to some of the colder spells in that winter.

Another February passes by without being notably cold - it is now 32 years since the last time we had a significantly cold February (1991, at 1.5 CET on legacy series). On a handful of occasions in more recent times we have been 0.5 to 1*C below the 1961-90 average, in 2010, 2013 and 2018, but there has not been a proper notably cold February (sub 2*C CET) since 1991. We are long overdue a proper cold February. I have looked at the patterns of the earlier parts of winters preceding a really cold February, and it appears that in most cases there has been deep cold air close to the UK for a while, or a significant cold outbreak, in the earlier part of the winter, even if the earlier part of the winter is not continuously cold. It appears that it is rare to get a cold February if the earlier part of the winter has not seen much in the way of cold outbreaks, although an exception that I can think of is the cold February of 1983 came after not much in the way of cold outbreaks in the earlier part of the winter, and I wouldn't say that 1990-91 really had much in the way of cold spells in the earlier part of the winter, apart from that it did have quite a cold spell in the first half of December 1990 with a significant snow event from Yorkshire down to the Midlands, though mid to late January 1991 was chilly at the surface though under an anticyclonic block and not proper cold synoptics.

What I meant to say was that, I acknowledge that the cold spell in December of this winter was nowhere near on the same scale or longevity as December 2010 / 1981, or the one in late Dec 1996 / early Jan 1997, but if the rest of winter 2022-23 does not deliver anything from a cold perspective, then winter 2022-23 will go down as a less extreme example of a pear shaped winter (a winter having a much shorter and less intense early cold spell that deteriorated into nothing) than 1981-82, 1996-97 and 2010-11. You never know, February 2005 is one example that I can think of where the second half of February did deliver a pattern change to a cold spell of weather after limited cold in January and the first half of February, though I cannot think of any examples since 2005. As posted above, this February only needs a CET of 4.3 or less to make this the coldest winter since 2012-13, and if we can manage to achieve that, then although winter 2022-23 will not be particularly cold overall, it will still be seen as an improvement on recent years if it can still manage to be the coldest winter in ten years.

The NAO is simply a difference in pressure between the Azores and Iceland - +NAO is higher pressure over the Azores and lower over Iceland. A -NAO is the reverse - high pressure over Iceland and lower pressure over the Azores. A -NAO is by no guarantee of colder conditions for the UK - you could have a -NAO but be more west based and the UK left on the milder side, or a high over Europe but low pressure over the Azores with the UK left on the milder side. Even with a -NAO, everything still has to fall favourably to get the cold air into the UK. On the other hand, a +NAO usually leads to milder conditions in the UK during the winter months, but although it unfortunately rarely happens at least now and in the last 35 years, it is still possible to have a +NAO and get some colder air into the UK - you could have higher pressure over the Azores but a bit further west, and low pressure over Iceland and have the jetstream tracking NW-SE, which would be cold polar maritime zonality - the best example above all others that I can think of is January 1984, but in recent years I can think of less impressive examples in mid to late January 2015, and in mid-January 2018, where in a +NAO setup colder polar maritime air fed into the UK. Winter 2022-23 so far looked to promise so much at the start, at least compared to recent years anyway, with a potent 11 day cold spell in December, but when this broke just after mid-December, the rest of this winter so far has produced little in the way of significant cold outbreaks, with just a week or so that was colder (but nothing overly dramatic) just after mid-January. If the rest of this month and even into early March does not deliver something from a cold perspective, then I think that winter 2022-23 could in some ways be seen as a pear shaped winter, joining the list of the likes of 2010-11, 1996-97, 1981-82, that were cold early on but went downhill and were followed by next to nothing, albeit with a shorter cold spell to begin with, meaning that 2022-23 could turn into a less extreme version of a pear shaped winter than the others above. There is still time for a spell of colder weather to show up (whether that be significant / intense or modest / less dramatic) before this month is out, but if we are to see any chance of that, we would need to see it appearing in the computer models soon. I think that if a cold spell did materialize before the month is out, then I think that winter 2022-23 could still be seen as a fairly average winter, but if this month does not deliver anything from a cold perspective, then winter 2022-23 will really go down as a pear shaped winter, although not as cold to begin with as 2010-11, 1996-97 and 1981-82. For winter 2022-23 to be the coldest winter since 2012-13; I think that February needs a CET of 4.3 or lower to beat winter 2017-18, and to get a winter CET similar to something like the average 2005-06 winter, I believe that February would need a CET of something like 3.8. For winter 2022-23's CET to beat winter 2012-13, then the February CET would need to be 2.8 or below, which is now very unlikely. A CET for this February that is anything above 4.4 will mean that winter 2022-23 is milder than 2017-18 (which is so far the coldest winter since 2012-13).

Well in all Februarys since 2017, only 2018 was below average, and all of the other five have been mild or very mild and not one even close to average, though 2021 did have a cold spell in the second week.

This odd year January looks unlikely to be colder than last year's even year January, but as you say, since 2007 / 2008 consecutive January CETs have not been within 0.5 of each other, but in my opinion there now looks to be a good chance that this January CET may end up very similar to last year's figure or just a touch above it, so this year it looks to be the case that consecutive January CETs are within 0.5 of each other for the first time since 2007 / 2008. This month's CET could still dip under 5.0*C if the last few days of the month are cool enough.

Yes I noticed that, 2011 was the last odd year January that had a higher CET than its preceding even year January, and 2010 was the last even year January to have a lower CET than its preceding odd year January. That checkerboard pattern was the case right up to last year. This CET this month looks unlikely to fall below last year's figure, so it is now looking as though that checkerboard pattern will not be the case this year.

The January 2022 figure of 4.7 has been revised upwards from 4.6 in the legacy version. January 2022 was about the most recent 91-20 average, although still a mild month by 61-90 standards. The most modern 1991-2020 average CET for January is 4.66*C. Compare this with the 1961-90 average which was 3.81*C. These figures are using the legacy series. There is still a chance that the final CET for this month could fall into the 4s, but if we do not manage to get much colder air over us in the last week it could finish above 5*C. So yes January 2023 is likely to end up above average by the most recent 1991-2020 average, and it will still be a mild month by 1961-90 standards. Yet again we avoid a cold January. We have only had one January (2010) that was significantly cold since 1987; since even before any figures were included in the 1991-2020 average. On a handul of more recent occasions we have been slightly below the 1961-90 average (low to mid 3s), in 2021, 2013, 2009 etc, and 2011 was under 4*C.

Where do you get the information on an uptick in sun spot activity from? I do not know of a website with the current sun spot activity on.

It is now 100% certain that another January is passing by without being notably cold - only one January was significantly cold since 1987 (36 years ago), and that was January 2010. On a handful of occasions in other recent years we have been slightly below the 1961-90 average (2021, 2013, 2009, 2001), but it is a truly appalling show for winter weather in the UK, to think that only one January in 36 years has produced a significantly cold CET. On another hand, April 2021 is the only significantly below average April CET since 1989, but the statistics for January look just as poor as this with 2010 producing the only significantly cold January since 1987.

I think that January 1992 was colder in the latter half due to an anticyclonic block sat over the UK giving surface cold, and not deep cold Arctic air or proper cold synoptics. January 1997 started with a continuation of a cold easterly spell that had begun in the later part of December 1996, and it lasted until 10th January 1997, when that winter effectively ended, and the cold was never to return, as the rest of Jan 1997 was fairly average, non-descript and anticyclonic, and Feb 1997 was more or less very mild all month. Since then you are correct that on a handful of occasions over the years such as in 2001, 2009, 2013 and 2021 the January CET has been slightly below the 1961-90 average but only January 2010 was significantly cold since 1987.

We have only had one significantly cold January since 1987 (the last 36 years), and that was in 2010 with a CET of 1.4 (on the old legacy series) More recently in 2021 we have been a little below the 1961-90 average, and 2013 was also a little below average I think. You are dead right, most Januarys since 1987 have basically seen no proper cold.

January 2020 had a CET of 6.4. Prior to that we had January 2007 with a CET of 7.0 and then January 2008 with 6.6, so that is what I would call three notably mild Januarys in the last 20 years. January 2005 also had 6.0 in the old legacy series, although it has been revised down to 5.9 in the new series. Personally I think that a January CET over 6*C puts it in the notably mild category. Although it is still only the 4th, it is already difficult to see this month being anything other than above average.