Thundery wintry showers

A few rumbles in west Lincoln, and some torrential rain.

I'd say it's pretty springlike out there today in Lincoln, 16C max so far, about average for this time of the year, with sunshine and some sharp showers, and that nippy feeling that's been there almost constantly since the beginning of April has gone. Spring has a reputation for being showery so I wouldn't call the intermittent downpours unseasonal either. There were some sferics just west of here about half an hour ago, though I didn't hear any thunder, perhaps it was a little too far away to the west.

Today I'm agreeing more with those who aren't keen on this type of weather, a warmer version of a dull damp November day, but I fully expect to welcome the shift back into a sunshine-and-showers regime starting tomorrow with temperatures up at around where we'd normally expect at this time of year. I thought April was an interesting month, a refreshing change from the run of warm ones we've had recently, no doubt helped by its emphasis on sunshine rather than raw dull wet weather, and was quite excited by the rare (for recent years) chance of snow in May, but if the cold regime had gone on much longer it would have outstayed its welcome even for me.

I've been watching out for sleet/snow in the showers but I think Lincoln has been marginally too far south for that - the nearest I got was rain and 5C yesterday evening. But there was some thunder and lightning just to the north/north-east on Wednesday, and there was hail on Tuesday and I saw another hail shower about half an hour ago today. Today is the fourth "convective day" in a row here and possibly more to come next week after we get the wet and windy weather of Saturday and early Sunday out of the way. It may well feel very different next week with temperatures close to or even slightly above the seasonal norm.

Some photos of the cloud that brought thunder and lightning just north/north-east of Lincoln on the 5th (Wednesday):

I've seen Christmas Day 1987 mentioned quite a few times over the past few years. I think it sticks out for many because the period around Christmas 1987 was generally mild and very dull with tropical maritime air, but Christmas Day was clear and sunny in many parts of the UK, due to an incursion of returning polar maritime air. It wasn't exceptionally mild, but would have felt warm in the sunshine. It would have especially stood out due to the lack of sunshine on the surrounding days and then the abundance of it on the big day. Christmas Day 1988 was warmer but might not have felt as warm because for most parts of the UK tropical maritime air dominated and there wasn't much sunshine.

It's a right mixed bag here, feels springlike in the sun and out of the wind, then feels wintry when the showers come over and the wind gets up. I haven't noticed any sleet or snow yet during this spell, Lincoln appears to have been a little too far south for that, but there's definitely been snow to low levels in Scotland and parts of the north-east of England.

I recall that at one point during April (sometime between the 20th and 25th) Lincoln got up to 17-18C on a couple of days with sunshine, although the minima were still close to freezing. Yes, the Met Office map doesn't lie, for many parts of the UK mean maxima were close to or even just above the 1961-1990 normal, and not far below that for 1991-2020 - only in East Anglia and the SE were maxima notably low. (This does, though, bear out comments from London that the maxima were low). It was the minima that were exceptionally low nationwide.

I was thinking quite recently that in England and Wales (but not Scotland or Ireland), 1994 was quite a good example of a "regressive" spring. March was warm and windy, April had close to average temperatures and May was cool, and it was mainly the second half of May that was dull, unusually cool, and wet for much of central, southern and eastern England. Then there was 1981, when March was warm (albeit dull and very wet), the first half of April was warm, and then the second half of April had an exceptional northerly outbreak with lying snow to low levels even in places like Exeter. May 1981 started cold, then turned quite warm but very changeable, not dissimilar to the synoptics that we've got on offer right now. I guess that towards the end of April 1989 perceptions of that spring would've been similar, but things then turned around dramatically in early May that year. 1998 and 2000 also had a warm March followed by a fairly cool and at times wintry April, but again in both cases it warmed up somewhat in early May.

This spring has been cold for recent years, and April unusually cold by night, but at the same time I get a sense that when the majority on here say they want "spring", it's an idealised version that sees a marked cut-off point sometime in March followed by a slightly cooler version of summer with no frost or snow for the remainder of the season. Historically, even a warm spring has tended not to manage that. I've seen 1982 mentioned as a season when a cold winter abruptly gave way to a warm, sunny spring, but even then, while it was generally that way, we had northerly outbreaks coinciding exactly with the Easter and early May Bank Holiday weekends, and sleet/snow showers were fairly widespread in the first week of May (though less so than in 1979). I'm sure that if that had happened this year, the warmth elsewhere in the spring wouldn't have stopped a spate of moaning about the "awful", "horrible" start to May. 1990 - another warm sunny one - had a cold snap with sharp frosts in early April, and some wintry showers in the north around mid-April. It's only really in recent years that we've managed to see out April and May without frost and snow, and then only in a minority of years. Last year's sunshine fest didn't manage it, as there was a cold snap in the second week of May. I guess that this spring my perceptions have been skewed a bit by celebrating being in Lincoln rather than Exeter and therefore being rather less sheltered from temperature variation, snow and thunderstorms than has been the case for quite a while. Yesterday was my first thunder-day of the year, there has been hail on a few occasions previously, and snow on 11 April. But having said that, I probably wouldn't be moaning too much if I was still in Exeter for as Evening thunder mentioned the weather there hasn't been too bad recently.

Showers have mainly skirted around Lincoln today, just caught a few light showers on the edges of them, but have just had thunder and lightning from the latest shower passing just to the north, I saw 4 flashes from the cloud as well as hearing thunder.

Looking over some recent comments, I decided to check out my old photos from April/May 2013 (in a spring that was consistently cold even relative to the old 1961-1990 average) and yes, for example in this picture from the University of East Anglia, Norwich, on 2 May 2013, some of the trees were only just starting to come into leaf. An indication of the warming climate is the observation that Spring 2021 has so far been close to the 1961-1990 average, with the warm March and cold April almost exactly counterbalancing each other, though the cold weather occurring later in the season means that vegetation is probably currently running behind the 1961-1990 average. I'm left wondering how backward things would've been in early May 1979, following a cold winter and March, a near average April (relative to 1961-1990) but with wintry showers early and late in the month, and then an unusually cold snowy start to May. 1917 and 1951 are other years that were unusually cold up to this point in the year. One thing that sticks out from Roger J Smith's CET analysis is that the first four months of the year have warmed faster than every other month apart from November, warming by about 1C between 1961-1990 and 1991-2020 (whereas the annual mean has gone up by just 0.7-0.8C). Thus, a colder spring will tend to particularly stick out.

Hoping for some good convection & cloudscapes in Lincoln tomorrow, the forecast looks pretty favourable, a lesser chance on Thursday & Friday also. Slight chance of some sleet/snow if any particularly heavy showers turn up, but lowland sleet/snow will probably be mainly confined to Scotland I reckon. Today had a window of brighter, showery weather in the afternoon with one heavy-ish hail shower, but otherwise was mostly cloudy with some rain, being just a little too far north for most of the day.

Still eyeing up possible wintry showers for the next three days, Lincoln might be a bit too far south unless we catch some particularly heavy showers here, but certainly Scotland and the far north of England could see sleet/snow to low levels. I think this evening's GFS has gone off on one- that's a distinctly autumnal looking run, that low around T+210 would be unusual even in autumn or winter, let alone in May when the Atlantic is traditionally at its weakest. The UKMO and ECMWF are consistent in their projection of a warmer (albeit mostly around average, rather than particularly warm) changeable regime and that's what I'm currently expecting.

I've had a rather more positive view on this spring than most, especially the unusually cold dry sunny April. I can't argue with the majority re. condemning today's autumnal Bank Holiday weather though! We've had quite a few unusually warm, sunny Bank Holidays recently (notably in 2018) so I guess this is the weather's way of evening it out, but it does feel like a parody of a stereotypical British Bank Holiday out there.

SummerShower might be remembering Easter Monday 1994, which was indeed cold and windy with wintry showers. May Day 1994 was fairly warm, though there was indeed a spell of cold north-easterlies leading up to the second May Bank Holiday in 1994, with some unusually cold nights over that weekend as high pressure moved close to the west with a slack northerly flow.

In 1997 the snow fell the day after, but maxima on the Bank Holiday Monday were lower in many parts of the UK because it was dull and wet, whereas Tuesday 6 May 1997 had plenty of sunshine. I think May Day 1979 was right at the end of a succession of days with wintry showers, but it was not as cold by then as it had been in the first five days of the month. Certainly those two are candidates.

10.8C and 87.4mm.

Had some quite heavy showers in Lincoln yesterday with hail at one point, but only light showers today, and quite cloudy with a fair amount of "infill" cloud. Two more showery days coming up, but then Monday looks like being a washout, in contrast to many recent Bank Holiday Mondays. I'm keeping an eye on the possibility of wintry showers penetrating into the northern half of England on Wednesday.

Some disagreement from the UKMO/ECMWF vs GFS for this coming Tuesday after the Bank Holiday Monday washout, with GFS going for a quick change to a showery north-westerly but UKMO/ECM keeping the deep low in the North Sea giving a strong northerly which is likely to be pretty chilly and probably grey for eastern areas: At present all three of the main models agree that there could be snow showers to low levels in Scotland on Wednesday with 850hPa temperatures of around -6 or -7, perhaps more locally in the Midlands and north of England in any heavier showers. Northern Scotland is especially likely to see snow: Thus, potential for the most widespread snow event in May since 2010, and maybe since 1997 - one to watch. Beyond that, the disagreement returns, GFS looks mostly showery with sunshine, but the ECM brings in more southerly tracking lows which would give dull wet weather at times for much of England and Wales, sunshine and showers more likely for Scotland. Signs are that temperatures will move closer to the long-term normal in the 7-10 day range, but no particularly substantial change of pattern - I wouldn't be too confident of the GFS bringing the Azores High in at T+240 plus. The 8-14 day outlook from NOAA implies a generally westerly flow which would bring changeable weather and temperatures close to or just below normal.

Here's what I can piece together as a summary of January 1959's weather: North-westerly winds prevailed on the first four days bringing progressively colder temperatures and some wintry showers, but nothing major. Then between the 5th and 7th, fronts moved across much of England bringing snow on their northern flank, particularly to the Midlands and northern England. Some southern areas also had some "backward edge" snow as the Arctic air mass came in behind the last of the fronts. For Scotland, it was brighter while turning increasingly cold as the north-westerlies were replaced by a direct northerly flow. From the 8th to 11th it was generally cold and sunny for most with a northerly flow but there was frequent snow for northern Scotland and some troughs in the northerly flow brought snowfalls to other parts of the country as well. Maxima were widely below zero. On the 11th/12th a low pressure system intensified in the North Sea as less cold air entered its circulation, bringing widespread snow but many areas reported a wintry mix for a time as the less cold air took hold. This might have resulted in the snow cover turning more icy as the cold air quickly re-established afterwards, but areas that had snow cover generally held onto most of it. Then from the 13th-15th the cold air intensified, with depressions bringing precipitation - probably again snow on its northern flank - into southern areas at times, and cold sunny weather elsewhere, with sharp night frosts and freezing fog. The northerly flow finally ran out of steam on the 15th/16th, and this was followed by a temporary change to much milder weather as pressure built to the south-east and we got southerly and south-westerly winds, bringing increasingly wet and windy weather. However, pressure remained high over Greenland. Then a cold, showery north-westerly set in with sunshine and wintry showers, although snow cover from this wasn't particularly widespread. Then the last week was anticyclonic and quite cold. Most areas again had plenty of sunshine during this spell, with high pressure favourably placed to bring little in the way of cloud, but frost and fog occurred widely at night. This led into a very anticyclonic February, although in February a slack south-easterly flow often brought more in the way of cloud into many parts of the country. Overall January 1959 remains the sunniest January on record for the UK as a whole, assisted by the high frequency of cold, clear northerly and north-westerly types and the anticyclonic last week. The cold first half brought 10-15 days of lying snow to a large portion of the country, and northern Scotland was particularly snowy.

What about 1990? 1995? 2003? 2006? I recall they were all dry Aprils.

If your Oregon Scientific weather station was around the £300 mark then I would definitely recommend the Davis Vantage Vue as a replacement (it's priced about the same but in my experience it is much better quality). It gives accurate temperature readings, wind, humidity, and rainfall to within 0.2mm (rather than the 1mm of my old Oregon station). I'm not very up to date on the less expensive stations (say £100 or less) though.

Yes, the first half of March 1995 was quite "westerly" with a gale on the 17th but from then until late May we mainly had a mix of anticyclonic and northerly types. The Atlantic pushed in at times from late May through to late July but never took hold for long, with anticyclonic and northerly types dominant in June and southerlies in late May and July. August was famously very anticyclonic. September 1995 started cyclonic rather than Atlantic-driven. There were again short-lived bouts of westerlies in late September & October but October 1995 was a southerly month with high pressure to the east keeping frontal systems mostly restricted to the north-west. November 1995, though unsettled and quite mild, was a blocked month with blocking mostly in the wrong place for cold/snow except for a northerly on the 17th. In the winter of 1995/96 the Atlantic was largely absent in December 1995, it made some inroads in early to mid January 1996 only to be pushed away by a large Scandinavian blocking high, and it made only short-lived arrivals in February 1996 (one of which brought a major snow event at the end of the first week) and it was absent again in March. There were brief Atlantic-dominated spells in late April and late May of 1996 but otherwise anticyclonic, southerly and easterly types featured in April and persistent north-easterlies in May, which weren't far short of giving us our coldest May on record. There were also only short-lived Atlantic-dominated spells in the summer of 1996, with a significant anticyclonic spell in the middle of all three summer months. September 1996 was anticyclonic/easterly. So from my recollections, after mid-March 1995 we didn't have a lengthy Atlantic/westerly spell until October 1996! OK, so that's quite a lengthy historical post, but it illustrates that it's not unprecedented for the Atlantic to be largely quiet even over a period of a year and a half. In spring and early summer it is fairly common for it to be largely absent for long periods (I don't remember much in the way of westerlies in April/May in 2010, 2016 or 2020 either). So the upcoming outlook, with high pressure giving way to northerlies, is not out of the ordinary, although the persistently cool weather of April has been notable.

Looking at the latest model outputs, a couple of warmer nights should raise that figure a little, so even allowing for a downward correction at the end of the month I don't expect April 2021 to beat or equal 1917, but there's certainly a good chance of it making the top five coldest for minima. It reflects my earlier points about dry sunny cool Aprils having been surprisingly rare. Many cool Aprils in the past have been wet and/or cloudy (e.g. 1986, 1989) which has kept the minima relatively high.