Thundery wintry showers

A warmer pool of air will move south after midnight, so I expect the peak time for wintriness in the showers to be this evening- it will probably warm up a bit after midnight.

I'm rather further inland now at Sandhutton but there have been a few rain showers here, with the temperature at around 5C. I think for snow here, heavier showers would have to penetrate inland, which seems unlikely, though it is promising for later in the winter if showers are getting this far inland off a direct northerly.

Indeed, one paradox of coastal climates is that although lying snow is comparatively rare due to the warming effects of the sea, the sea is also a source of moisture, meaning that when it snows, sometimes it really snows. North Sea areas are more favoured than the other coasts of the UK due to the tendency for winds off the North Sea to be associated with our coldest airmasses, resulting in very potent "sunshine and snow showers" situations, although on the other side of the coin, particularly in marginal frontal situations, sometimes eastern coastal areas get rain/sleet while inland areas get snow.

East Anglia is probably a bit too far south in my opinion but I think sleetiness to low levels is possible as far south as Lincolnshire, with the winds set to veer slightly east of due north which should help to bring wintry showers inland on Friday afternoon and overnight Friday/Saturday.

In the Tyne and Wear/Northumberland/Durham area June 1997 got off to quite a "summery" start, reminiscent of the previous three summers. The 1st and 2nd were plagued by low cloud off the North Sea but the easterly wind eased on the 3rd-5th which allowed dry sunny weather to take over, and it became quite warm. The 6th-10th were showery but quite sunny and warm, with most of the showers restricted to the evenings, and the 7th had some thunder. But then from the 11th onwards the weather turned progressively cooler, cloudier and wetter (I think the cooler weather didn't spread into central and southern England until around the 14th/15th) and it then became exceptionally dull, cold and wet from the 25th June to the 1st July inclusive, with only about ten minutes of sunshine in that 7-day period and frequent moderate to heavy persistent rain. Statistics will show that June 1997 was considerably wetter than the Junes of 2007 and 2012 in the Tyne and Wear/Durham/Northumberland area, but not quite as dull. However NE England was particularly heavily hit by the persistent frontal rainfall and lack of sunshine from the 25th onwards and most other parts of the country were drier and somewhat less dull than in June 2012.

Re. Gibby's post, I think the Scandinavian blocking high is indeed a more reliable source of cold weather for most of the UK (the west-based negative NAO with Greenland blocking is a good case in point) but whether it's more reliable for widespread snowfall is another matter. I remember a lot of cold dull dry spells with limited snowfall associated with Scandinavian blocking highs, usually when they are too far east/south to send arctic continental airmasses our way and we instead get a combination of cold surface air and mild upper air heading up from the eastern Mediterranean, with stratocumulus trapped under an inversion. That said, when the Scandinavian high ridges westwards towards Greenland/Iceland (a scenario that Gibby mentioned) then it is very rare not to get widespread snowfalls as a result, via snow showers heading well inland from the North Sea and/or fronts pushing up from the south and stalling against the block. Meanwhile, the cold snap for the upcoming week has been toned down substantially, with the main initial cold blast going out into the continent and subsequent cold blasts being sent into the mid-Atlantic. Nonetheless, there will be some wintry showers in counties bordering the North Sea on Friday. Friday afternoon and evening will probably see rain showers over eastern England with sleet and snow to near sea level in eastern Scotland, then on Friday night we may see sleet and snow penetrate as far south as Lincolnshire. The -5C 850hPa isotherm struggles to penetrate as far as East Anglia, so although showers will continue over East Anglia for most of Saturday, I think they will continue to fall only as rain or perhaps hail locally. Re. the possible Monday/Tuesday snow event, it looks to me as if the main thrust of cold air will be out to the west. After that, the ECMWF has low pressure rooted to the north-west of the UK bringing sunshine and showers and temperatures near or slightly below average, but the GFS sends the low southwards to the west of Britain. From previous experience of these setups I feel that the GFS will probably be nearer the mark with this one, but I'll wait until I see tomorrow's runs before reaching any strong conclusions.

Indeed, Oslo and Helsinki are about as cold in an average October as northern England is in an average November. Then when we get around to November, the mean is well below typical British January values. Coastal fringes may be exceptions, and Stockholm is slightly warmer but even in Stockholm, Novembers are a lot colder than we are used to.

Before we get to this upcoming cold snap/spell (length is still yet to be determined) we have a few days coming up which, for most of us, would be best described as mild and muggy. We will have high pressure in charge of the weather but a weak slow-moving front, which will bring grey skies and drizzle northwards tomorrow, and those grey conditions will hang around for most of us on Tuesday and Wednesday- the weak late-October sun probably won't make much of an impression on the cloud sheet although the drizzle will tend to fizzle out. The exception will be central and northern Scotland, where a mix of sunny spells and fog patches can be expected, and chilly nights- in these setups some places will see plenty of sunshine while others will have persistent fog for much of the time. Most of the model runs that I've been seeing recently showed notably cold weather for late-October, but mainly dry due to the proximity of high pressure. The UKMO at T+144 is one of the snowiest-looking charts that I've seen progged in the last week, and certainly the first chart inside T+168 that could well produce widespread snowfall. I think one or two Arctic incursions, bringing notably cold but mainly dry weather, and lasting a couple of days, is quite a probable scenario- for widespread snowfall the high pressure would need to be further west than most recent runs have shown, as illustrated by the latest Met Office run.

There have always been extremes of weather across the globe, but when the frequency of extremes above a certain threshold increases (to a degree that reaches at least the 95% confidence level, as defined by various statistical analysis methods) then there is a strong implication that the climate is changing. I don't think the evidence for human impacts on rainfall patterns and extremes is as compelling as it is re. temperature, but then again, there's the issue that a significant change in the mean global temperature is likely to impact on atmospheric circulation and therefore rainfall.

One past summer month that I would love to get the chance to re-live would be June 1975. Cold showery northerlies lasted until the 4th and brought unusually widespread snow on the 2nd, but an abrupt switch to southerly winds brought widespread temperatures of 25-28C by the 7th. High pressure then brought a dry sunny spell until the 13th, followed by a few cool showery days with fairly widespread thunder and hail. A brief south-westerly spell followed on the 18th-20th with a traditional NW-SE split, then high pressure dominated during the last third of the month (yes, ideally timed for Bottesford's wedding!), and generally in the right place to promote abundant sunshine. It got quite hot again for a time, but the last few days had some unusually cold nights due to a sluggish incursion of Arctic air. I doubt that we'll ever see a summer month quite like it again- to have a day of widespread snowfall, two frosty interludes, two heatwaves, exceptionally high sunshine totals and a general shortage of rainfall, all in the same summer month, takes a lot of doing.

I remember Winter 2007/08 for the anticyclonic spell from the 8th-20th February, which in Norwich produced an exceptionally sunny spell, with just one brief interruption. The start of that spell was notably warm and springlike by day (as high as 16C on one of the days) with chilly nights, then the second half of it turned colder, with overnight frost and fog, hazy sunshine by day, and some very spectacular sunsets. There was also a brief snowfall in Norwich on the evening of the 1st, though most of the snow melted the next day. Mid-January 2012 produced a few days of sunny, anticyclonic weather with spectacular sunsets that reminded me of the February 2008 spell, although it didn't last as long. The strong association between high pressure and "anticyclonic gloom" during the winter months is partly what makes those largely cloud-free anticyclonic spells so notable, and the development of mist and fog outside of daylight hours can help to enhance the sunsets.

I vaguely remember wet snow falling at Cleadon (Tyne and Wear) at a Bonfire Night party on the evening of the 5th November 1991. http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119911105.gif Snow wasn't very widespread on that day though, and I can't locate any instances of widespread snowfall on the 5th November in the twentieth century.

An unexpected minor thunderstorm at Sandhutton (N Yorks)- had four rumbles of thunder so far, and seen fork lightning out to the west- caught me rather by surprise! Edit: thunder every minute or so now.

My feeling about this possible northerly is that there almost certainly will be a southward surge of Arctic air north of 60N, but at this range, it is unclear whether it will penetrate south of that and, if so, whereabouts. I quite often see these blasts shunted to the west or east as we get nearer the time, and with it only being October, the setup has to be absolutely spot-on to bring widespread UK snowfall away from the high ground of Scotland. My current feeling is that the northerly blast will end up too far east, as we keep a weak trough in the mid-Atlantic with high pressure over the top. Over the last couple of days there has been a trend for a westward movement and toning down of the Atlantic trough towards this coming weekend and early next week. However, it looks like there will be a slow-moving front stuck somewhere over the eastern half of the country, with a mix of sunshine and declining shower activity to the west of it, and the warm dry sunny weather over the near-Continent struggling to make it into our shores. The positioning of the front is subject to revision but it looks to me as if many western areas will get a sunny and mostly dry spell of weather but many parts of eastern and central England may end up grey and drizzly.

I think this is a popular misconception, caused by the lack of potent cold spells in February in recent years. Note that the Marches of 2001 and 2006 both produced cold spells that were arguably more potent, in terms of cold temperatures, than anything we've seen in February since the 5th-7th February 1996. Sub-zero maximum temperatures were very widespread during the famous "easterly" outbreak in February 1991, and three years later, I remember a spell with sunshine and snow showers around the 20th-22nd February 1994 in the Tyne and Wear area, when the snow hardly thawed at all in the sunshine in between the showers, and maximum temperatures barely exceeded freezing. There was also a potent cold spell around the 14th-16th February 1994 due to a south-easterly flow bringing a cold pool in that had accumulated over the Balkans.

Out of 2008/09, 2009/10 and 2010/11, I would give 2009/10 the nod, mainly because I remember 2010/11 being very uneventful after Boxing Day. I remember being rather disappointed overall by February 2010, but the period from 17th December to 9th January was pretty unforgettable. Of the historic past winters I would quite fancy reliving 1954/55 and 1968/69. Both of those winters had some exceptionally cold northerlies with widespread snow, but were not constantly cold (December 1954 and January 1969 were pretty mild). 1954/55 was the "Operation Snowdrop" winter in northern Scotland, with mid to late February particularly snowy via northerly and then easterly winds, while 1968/69 contained an unexpected white Christmas for many places including much of NE England, as well as a very wintry February. The historic winter month that I'd probably most want to relive would be January 1958- it had pretty much everything, a cold snowy start, then a long Atlantic-driven spell, then a quiet frosty spell, then a notably cold northerly outbreak with polar lows and troughs giving widespread snow even to south-east England, and then a sudden switch to exceptionally warm southerlies.

By my calculations, the UK areal average sunshine (according to the Met Office) over 1971-2000 was 172.4 hours. By this measure, it's been even more grim than that for sun-lovers- other than the exceptional one in 2006, we have to go back to 1999 for the most recent sunnier-than-average July! That said, those of 2008, 2009 and 2011 came out within five hours of the long-term average.

I thoroughly enjoyed Summer 1996, and also that of 1994- both have indeed been largely forgotten in the minds of many because of how exceptional 1995 was. I think the same could be said of 1975 being eclipsed by 1976, and to a certain extent 1989 being eclipsed by 1990 (1989 was generally the drier and sunnier of the two summers, but 1990 is remembered more often because of that phenomenal heatwave around the 3rd August). 1975, 1994 and 1996 all had a good deal of variety as well as above-average warmth & sunshine and below average rainfall over most of the country.

I must admit that I sometimes find it rather contrary on a forum populated by many weather enthusiasts, when the model output thread becomes focused exclusively on the prospects for sustained dry, settled weather. Having said that, I've noticed that I tend to view those spells with largely clear skies and unusual warmth as notable weather events in themselves, perhaps partly due to their rarity in the UK, and so I don't get much of a sense of there being no "weather" to look at. I'm not sure if this is common among hardcore weather enthusiasts, but I particularly noticed it working that way for me during the late-May spell. It's more those non-descript settled spells with cloud, a bit of sun and the odd bit of drizzle that leave me feeling that notable "weather" is hard to find. However, in fairness, there was a remarkable amount of that type of weather during the low pressure-dominated spells of June and July this year in between the deluges!

Re. those who are talking about current cold pooling having a significant bearing on the upcoming winter, think of the occasions when we've had major cold pooling on the near-continent and near-missed easterlies, only for us to get a full-on easterly after the continent warmed up. Or think late November 2010, when most of continental Europe was exceptionally warm, but the amount of cold pooling increased dramatically after just three days of north-easterly winds. The main point is that cold pooling can be a very short-term thing and is sensitive to changes in the synoptic setup. Similarly I am not aware of a statistically significant correlation between northern blocking in the autumn and northern blocking in the winter. What we have coming up is essentially a west-based negative NAO setup which would probably disappoint a lot of snow lovers if it was to arise in winter, due to the mean trough being sat to our west and forcing cold arctic airmasses to head a long way south in the Atlantic before "returning" to us from the south-west. As a result, fairly standard autumnal weather can be expected with temperatures perhaps a little bit below the seasonal average. A fairly quiet spell of weather is suggested through to Monday for most of us, before the weather turns progressively wetter and windier from the west with secondary depressions giving active rain belts at times.

I think it is easy, when having a strong desire for something (e.g. "when is it next going to snow?") to get fixated on it- I know, I've been there! Also, there are many members who are interested mainly in one or two types of weather, of which cold and snow in the winter appears to be most popular. Regarding the question, I find it to be a combination of the white landscape, the extra pleasurable activities like snowmen, sledging and snowball fights, and above all, I find those sunshine-and-snow-showers setups very exciting to watch (having moved inland I'm not quite as well-placed for those as in Tyneside or Norwich, but inland North Yorkshire still tends to pick up a lot of snow showers when we have a good blow from the east or north-east with 850hPa temperatures close to or below -10C or, more rarely, a particularly cold north-westerly). The winters of 2009/10 and 2010/11 showed me that my tolerance for prolonged cold snowy weather is pretty high- the only exception seems to be when the snow turns icy for a long period. Nonetheless, I would still prefer a mixed winter with cold snowy spells interspersed with milder ones, rather than a repeat of 1962/63. For me, there are plenty of other types of winter weather that can also be exciting in their own way (including some that involve warm temperatures), just as long as they don't dominate for almost the entire season.

1. Anticyclonic spells to be predominantly dry and sunny, rather than cloudy, and cyclonic spells to be predominantly bright and showery with some thunder, rather than dull and wet. 2. A high frequency of setups with a Euro high and Atlantic trough. 3. A recognition that you can like certain types of unsettled weather (e.g. warm sunshine mixed with thundery downpours) without being "anti-summer" or being a fan of all unsettled weather. I tend to get irritated when I see a change from persistent rain and 14C to sunshine, thundery showers and 23C described as "more of the same, miserable and unsettled with rain or showers". I see that Bottesford is getting married on my birthday (22nd June). I generally hope for a mix of sunshine and convective activity on that day, although one work-around is to have the downpours hit my location and miss the location of the wedding. However, there isn't really much of a clash as a dry sunny day is generally my second preference (the 22nd June 2010 was particularly good on that front) and so I wouldn't be complaining if we did get a large and reasonably 'clean' anticyclone on top of us.

Just a response to the comments about charts like the following being ideal: http://cdn.nwstatic..../ecm500.192.png The success rate of that setup re. widespread snowfall is strongly dependent on the amount of cold air that accumulates over south-eastern Europe beforehand, as the airmass source is essentially from around the Balkans. If there is a lot of cold pooling to tap into, that setup can produce widespread snowfalls (take mid-February 1994 for example) but in the second week of December 2002, when cold pooling was concentrated over north-eastern Europe, we got a prolonged spell of dry cloudy weather and only localised snowfalls. A "stonewaller" for widespread snowfall would ideally have stronger "undercutting" into south-eastern Europe and a stronger westward ridge from the Scandinavian High which would send colder air westwards from eastern and north-eastern Europe. This would increase the chances of widespread snow (rather than a marginal rain/sleet/snow mix) from southerly-tracking frontal systems as well as significantly increasing the potential for snow showers heading well inland from the North Sea.

Looking at the model outputs it seems that the quiet spell for central and northern areas will move away eastwards on Thursday as the next set of low pressure systems move in from the west, although initially they will be quite weak. Late on Thursday and into Friday it could well become very wet for a time with a slow-moving frontal system progressing north-eastwards (I don't think the rain will be all that heavy, but it may be very persistent). Something to watch out for, perhaps, in the areas that are currently at risk of flooding following the deluge around 23-25 September. Pressure does look like rising over Scandinavia, but as so often happens in the winter, it is unclear whether the cold continental air will make it this far west- we may well stay under the influence of the Atlantic. If we do get an easterly incursion, daytime temperatures will fall below average but overnight minima will probably rise in the east due to cloud cover off the North Sea, so the average may not be especially cold, with 850hPa temperatures close to the 0C mark. Although there have been very rare instances of "easterly" October snowfalls, generally in October the vast majority of snowfalls come from the north, with "easterly" snowfalls not becoming relatively common until late-November when the continent often cools down significantly.

Here's waiting for you getting a series of totals of £19.89...