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WINTER 2020/21 FORECAST

Headline: Temperatures around average, rainfall average or a little below, greater chance of snowfall compared to last winter but a severe winter unlikely.

It’s that time of year again when Twitter weather accounts like myself dish out our long-range thoughts on winter in forecasts that you’ll either never hear about again (if it doesn’t go to plan) or you’ll never hear the end of. In reality, even the professionals and the Met Office cannot confidently predict the weather one month ahead – let alone three – so whilst a lot of thought goes into these forecasts concerning background signals and so on, it is pretty much just for fun.

Before getting to the main forecast summary at the end, I will run through a bit of info on some of the background signals considered within the forecast outcome. I will *try* and make it as simple and brief as possible, so not to drag my own time or yours! I will also point out as ever, I am only an amateur – not a meteorologist – and I don’t know everything!

Long-range seasonal models

Several different meteorological agencies release long-range anomaly charts for the months/seasons ahead, indicating a general synoptic trend. For the UK, the key thing to look out for is whether they’re more suggestive of a +NAO or -NAO pattern, this means looking at height anomalies across the North Atlantic from the Azores up to Iceland/Greenland alongside trends in Europe. Whilst it isn’t totally black & white; +NAO generally means ‘zonal’ – so Atlantic / mild / wet – whilst -NAO generally indicates ‘meridional’ – so a greater chance of colder & drier weather and increased snow risk.

The chart posted above is the Met Office GLOSEA5 November update showing predicted height anomalies for the period December to February (D/J/F). Whilst it isn’t as strong a signal as last winter, with positive anomalies over the Atlantic and into Europe coupled with negative anomalies over Iceland & Greenland, it is indicating a +NAO winter overall.

Posted above is the same as discussed before but this from the ECMWF seasonal forecast – again showing anomalies for the D/J/F period. This one is a little more interesting… yes it does have the anomalous heights over the Atlantic/Azores and into Europe but this also extends to the east/north-east of the UK over East Europe/Scandi. It also has only a very weak negative anomaly over Iceland/Greenland with largely no strong signal. I wouldn’t consider this a great chart but it isn’t the worst you’ll ever see.

More interestingly, when we push it forward to the January to March period (J/F/M) (therefore dropping December) – the signal becomes somewhat more strongly +NAO (not that the previous wasn’t also +NAO)… this suggests the ECMWF is going for a ‘front-loaded’ potential, with December seeing a high pressure influence before zonality increases into January and February.

I won’t post & discuss all of the seasonal models but the general theme does appear to be indicating a +NAO winter. Last winter these models were on the money, that doesn’t mean they’ll be right every year but they also shouldn’t be dismissed.

ENSO (La Nina)

The equatorial Pacific is currently in a La Nina state and has been for some months since late summer / early autumn when the 3.4 region SST anomaly dropped below -0.5. This is the ‘cold phase’ with El Nino being the ‘warm phase’. It looks like this La Nina will persist into 2021 and likely throughout our winter. Its link with UK winter weather is often subtle and indirect but historically there are some correlations, the most of note is a weak/moderate La Nina favoring a ‘front-loaded’ winter with an increased chance of high pressure/blocked patterns.

Looking at the Nino 3.4 region SST anomaly index, you can see there was a period of steep cooling in late October and into early November with the index dropping below the -1.5 ‘strong La Nina’ threshold, peaking at near -1.7. A strong La Nina is considered a poor signal for UK winter weather. Since then, waters have warmed a little and in recent weeks we have plateaued comfortably within the ‘moderate La Nina’ range (-1.0 to -1.5) which is considered more favorable. I wouldn’t like to say for certain just yet that the -1.7 in early November was the ‘peak’ of La Nina cooling but at the moment it appears a moderate La Nina winter is more likely than a strong one. The latest index value 05/12/2020 is -1.246.

Solar activity

Always worth throwing in a mention to solar activity and the recent solar minimum, we very recently came out of the cycle 24 solar minimum (as you’d easily guess, indicating very low solar activity) and we now know we are entering solar cycle 25. These cycles take around 11 years so we expect solar activity to increase over the next few years towards solar maximum and the next minimum is over a decade away!

It’s also worth noting just how weak cycle 24 was, in fact it was one of the weakest cycles ever recorded (although not as weak as the Dalton Minimum cycles 5 & 6). Cycle 25 is expected to be just as weak if not slightly weaker.

For the UK and winter – there is a credible link between the solar minimum period (especially the year or two after) and increased amounts of high latitude blocking with meridional ‘wavy’ jet stream – this opening up the likelihood of more anomalous weather (possible reason behind the frequent hot plumes & record temperatures in both summer 2019 & 2020?). That all said, it is only an increase in probability – suffice to say we won’t have continuous high latitude blocking for the next 24 months!

Quasi-biennial Oscillation (QBO)

Another background signal we look at is the QBO, essentially it’s a cycled variation in the winds that circulate high up above the equator. Once every 14-ish months, these winds switch direction and this change can have an impact on the jet stream. When QBO is positive/westerly, the UK is at a greater risk of Atlantic zonality with a stronger jet – meaning more in the way of mild & wet winter weather. When QBO is negative/easterly, the jet stream can become somewhat weaker which allows for a greater chance of cold weather, less rain and also a heightened risk of PV (polar vortex) disruption and/or an SSW (sudden stratospheric warming) event.

QBO is usually known for being quite uniform in its cycles – but of course in 2020 it had other ideas. QBO transitioned from westerly to easterly back in January (2020) when the monthly index value went negative (+1.66 in December 2019 to -2.51 in January 2020) and this winter was supposed to be a straightforward QBO-easterly winter. In April the 30mb zonal winds were still negative, down to -5.03, but by June they’d reverted back to westerly and the QBO index reached +0.34. This increase in westerly zonal wind at 30mb has continued ever since – the November index value was +11.15… far from easterly!

There does appear to be some conflicting opinions on where we stand with QBO at the moment. As shown in the chart above, easterly winds in the far upper levels of the stratosphere (shown as those blue colours in the far top right hand corner) are now slowly starting to descend down through the stratosphere again. However, at 30mb where the index is measured (you can see the faint line running across the chart, that marks 30mb) we are still very much seeing westerly winds (as shown by the brown…or yellow?…gold? whatever colour – those are the westerly winds). It looks to me like QBO is westerly and will remain westerly for the duration of this winter – possibly transitioning to easterly late in the season which won’t be of much use. Some are theorising those uppermost level easterly winds between 10mb and 20mb could still have some impact on the jet stream (which has been rather tame in recent months, it’s worth saying) thus still maybe helping increase the probability of less wind/rain/mild and something more blocked this winter.

Sea surface temperatures (SSTs)

Looking at sea surface temperature anomalies – there are as ever three areas of interest; the equatorial Pacific, the north & north-east Pacific and the North Atlantic Ocean.

Not too much to say regarding the equatorial Pacific – it’s displaying the signature La Nina look with cold anomalies extending from South American coasts all the way towards Southeast Asia.

The first thing I noticed which is of some concern going into winter is the presence of notably warm SST anomalies across the north-east Pacific to the south of Alaska and west of Canada. This has been a persistent feature in recent years/winters and is a negative for those not wanting a mild/stormy winter. As things stand, I don’t think the winter as a whole will be dramatically mild/stormy but if it were to end up so, this would likely be taking a lot of the blame. Warmer waters around the north-east Pacific promote higher pressure in the area thus sending the jet stream on a north-west to south-east trajectory through the States, pulling down cold Arctic air into the eastern States which can in turn fire up a more powerful jet exiting into the Atlantic.

The North Atlantic SSTs look rather mixed but there isn’t the presence of the desired ‘tripole’ and colder than average waters sit not far to the south of Iceland & Greenland (although there is some anomalous warmth in the Labrador Sea between Canada and Greenland).

Eurasian snow cover extent

Something we watch closely in October is the expansion of snow cover across Eurasia. It’s believed that the greater the snow extent in October, the higher the chance of a weakened PV and negative Arctic Oscillation (AO) later into winter. The theory is; the more vast the snow expansion in October, the stronger the Siberian High going forward – thus eventually weakening the Stratosphere PV, this propagates down into the Troposphere PV and we end up with a -AO (blocked) pattern.

This October, after a slow start, snow cover expansion was healthy from mid and towards late month but some losses in the final week – including on the final day – left the October 2020 final result at a decadal low. Snow cover across the rest of the Northern Hemisphere was in contrast very healthy – at times sitting at a decadal high.

Forecast summary….

First and foremost, I want to point out this forecast is based on the assumption we do not see a sudden stratospheric warming (SSW) event this winter. At the time of writing this, zonal mean zonal winds @ 10hPa 60N are very strong compared to the climo average but all modeling is consistent and in agreement for these to weaken towards mid December – possibly to below the climo average. Whilst there is some stratospheric interest going forward, at this stage there is no major SSW (zonal wind reversal) ‘expected’. As I say, this forecast is based on the assumption one will not occur. If one does, more significant anomalous weather – both milder or colder – would be likely in the weeks after.

My forecast is for temperatures around average across the winter as a whole (UK mean anomaly -0.5C to +0.5C) with a very slight favour towards a little above. I’d consider both a significantly milder or colder than average winter (greater than +1.5C or -1.5C anomaly) rather unlikely. I’d lean towards December being a little below average, January closer to average and February possibly milder than average, but not significantly so. Greatest chance of cold spells into January.

Precipitation; average or a little below. December in particular looks to be drier than average – even if things turn a little more zonal for a time. January & February more mixed but possibly not delivering us a deluge. I’d put February as the month to most likely be wetter than average. UK winter as a whole rainfall %….85-105%.

…..and snow

Whilst I don’t think Winter 2020/21 will be historical and remembered for decades to come for severe, harsh & snowy weather – I do think it’ll offer up more potential snowfalls compared to the previous two. In all honesty, that really isn’t a huge prediction to make as the last two winters have been close to snowless. A greater chance of cold spells, hopefully some snow for us all (strongly assuming hear that everyone reading this is a snow lover, apologies if you aren’t!) and hopefully a lot less of the record strong polar vortex that dominated last winter. As for the whole ‘loaded’ thing, I’d stick with saying front-loaded more likely than back-loaded (cold/snow more likely Dec/Jan rather than Jan/Feb) but I don’t think it’ll be overly pronounced on either side – more of a mixed bag.

Thanks for reading… I’m not quite sure I achieved that “as brief as possible” goal but I’m not surprised 🙂 …. Nick

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Update: Storm Alex, significant rain event

Published: October 2nd 2020

Just a quick update from me looking at the latest model output for accumulative rainfall over the coming days between now and late Sunday with some parts of southern England likely seeing well over a months worth of rain (locally over 100mm) in just 3 days.

Note that some places started seeing persistent rain yesterday and last night, so the most recent model output will be ‘beyond’ this, thus showing a little less rain in total for this rainfall event.

Some southern coastal counties have already seen a deluge, posted below is the radar-estimated rainfall total over the last 12 hours up to 10:10 this morning, well over an inch of rain has already fallen in parts of south Devon, Dorset & south Hampshire – the ‘epicentre’ of the rain so far looks to be in the Southampton area where some personal weather stations have exceeded 40mm with a lot more to come.

At the time of writing this, the Met Office severe weather warning remains at yellow – I am really quite surprised an amber hasn’t been issued for Dorset, Hampshire & Somerset.

Above is the rainfall accumulation chart from this mornings ECM 00z run showing expected rainfall out to the end of the day on Sunday. It does seem likely that this particular run is going over the top with the northern extent of the highest totals, suggesting over 100mm as far north as Oxfordshire, an outlier among the rest of the models. For the far south, it has the focus of the rain over Dorset, Hampshire & the Isle of Wight where 90-110mm is expected, more widely 2-3 inches of rain (50-75mm) from Somerset/Gloucestershire eastwards to Sussex.

Above is the same but from the GFS model. The main focus of the highest rainfall totals on this run sits around the Somerset & Wiltshire area with a maximum total of 116mm, more widely over 80mm from a zone north Devon eastwards into Hampshire, Surrey & Sussex. Notice across all the model output, Cornwall does look to escape the worst. Also worth pointing out parts of south Wales where 2 inches or more of rain is likely, especially over the highest ground.

Same again but from the ICON model. I do feel this run is underestimating the rainfall totals for Dorset & Hampshire – this area has already seen 30-40mm quite widely, this run suggests totals of only 50-75mm. Again Somerset & Gloucestershire the focus of the highest totals with over 100mm. Notice all of these models are also giving a solid 50-60mm for the London area, that’s quite a lot for this part of the country over only a 3-day period.

…and finally from the ARPEGE model. This does seem quite significantly underdone, suggesting no more than 60-70mm in the wettest spots – some places have already seen half of that and there’s still a weekend of rain to come!

So it does look like the highest rainfall totals will be in the Hampshire area westwards into Dorset, Somerset and possibly Gloucestershire too. 80-100mm looks quite achievable in this zone with over 100mm over any higher ground. Model output seems more variable for Wales but I suspect the higher ground in the south will see a lot.

Quite concerning from the Environment Agency, they now mention “significant surface water flooding is probable across parts of Wales and England this weekend” and “possible from river flooding”

As discussed a few days ago, river levels across the south have been generally around normal – not close to any level of concern – but they do fluctuate rapidly and a prolonged rainfall event of this nature is perfect for rivers to quickly reach notably high levels. I would still say the risk of significant river flooding (rivers bursting their banks) is rather low (but not out of the question) this weekend with the main flood threat being surface-based flooding both over fields/countryside in rural areas and also urban flooding on prone roads in towns/cities.

Speculating further ahead, we are still in the first half of autumn with a good few months of our ‘wet season’ ahead, some rivers will likely be pretty swollen by the start of next week, this does mean any further rain events going forward through October will bring an escalating flood risk – similar to autumn last year…. so fingers crossed for a drier spell after this coming deluge!

… … … useful links below … … …

Met Office warnings: https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings#?date=2020-10-02

Environment Agency flood warnings (England): https://flood-warning-information.service.gov.uk/warnings

Natural Resources Wales flood warnings: https://naturalresources.wales/flooding/check-flood-warnings/?lang=en

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Autumn kicks in, disruptive weather ahead to start October, Storm Alex

Published: September 30th 2020

For the majority of the UK, the vast majority of September was dry, settled & fairly warm. There were exceptions as ever, and the final week of the month was more changeable with some rain and a cooler feel – but as often seems to be the case, September was more a month of extended summer rather than the onset of autumn. At the time of writing this we are just hours away from the start of October… So, will October continue much the same? Well…….

……………..No

As the final few days of September have hinted, big changes are afoot and I think it’s safe to say, autumn is well and truly arriving. Gone are the days of 20c+ and sunshine? You can never rule it out in October, but for the coming fortnight at least – I think we can. The ‘official’ (and rather subjective) definition of an ‘Indian Summer’ is a settled/warm period of weather in October or November after the first frost. Recent days have delivered us some notable low September minima with quite widespread frosts – even in the south. You could argue “how widespread is widespread?” … does your location have to see a frost for you to have an Indian Summer? Blah blah, we are now in October (in a few hours) and we’ve seen some frosty nights so as far as I’m concerned, any settled/warm spell from here on in will be considered an Indian Summer. So how likely is one this year? Who knows what November will bring but I think it is safe to say October offers only a very slim chance. The coming 10 to 14 days taking us out to mid-month look wet – potentially very wet – as well as rather cool.

The general outlook for the first week to 10 days of October has been known for a good few days now. Models have been consistent in the wet/unsettled low pressure dominated theme and the change in track of the jet stream diving to the south of the UK has been well forecast. I’m quite confident in saying the first fortnight of October will be wetter than average, given the southerly tracking jet, the greatest anomaly (and probably the greatest amount of rain overall too) will be in the south across southern England & Wales. It’ll be far from settled further north, but you should avoid the worst of the deluge(s).

Below I have posted the most recent GFS ensembles from this mornings 06z run for Southampton (this gives you the general idea for much of the rest of southern England) out to October 16th. The top row of lines shows the ‘850hpa’ upper air temps. These aren’t the surface temps we experience on the ground, but show us how warm or cold the airmass is further up… and this correlates down to the surface (with added variations from time to time) – but the general idea is, if you’re under a cooler than average airmass, more often than not you’ll have cooler than average temps at the surface too. The bold red line shows the 30-year average, what we’d expect at this time of year. The bold white line is the mean/average of the 30 different GFS members (all the other coloured lines). Quite evident to see we will have a notably cool airmass to start October (down to 0c at 850hpa in south UK, daytime temps at this time of year low double figures at best) and that the general trend progressing into the second week of October remains cool. No sign of that Indian Summer. The bottom row of lines shows rainfall, the more ‘rainfall spikes’, the wetter the outlook. Notice the intensity of the spikes for this coming weekend from October 2nd (Friday) to 4th. Quite a deluge is expected across the south, some models suggest up to 100mm of rain or more over a 2 to 3 day period – that’s concerning.

If you’re wondering why it is the southern half of the UK facing the wettest weather rather than the typically wetter north, that is down to the position of the jet stream. The jet stream ‘default’ is to sit over the north/north-west of the UK or just to our north, leaving the south/south-east driest. Over the coming week, the jet stream will be positioned to the south of the UK, locking us in under low pressure, keeping things cool & wet. The jet stream is currently in a blocked, meridional pattern thanks to heights (high pressure) up in the higher latitudes – this basically means it is running north to south rather than the more common zonal (west to east) pattern. In the depths of winter this can (when blocked and positioned favourably) allow the cold Arctic air floodgates to open south into the UK and Europe, but… it’s early October, so chilly & wet it is. Below is the North Atlantic view of the jet stream winds for Friday 2nd showing a powerful (bright colours) and southerly tracking jet enhancing the development of a low near the UK.

Just to add, this meridional jet stream pattern is not “unusual to see” or “behaving oddly” – it happens most years at one point or another; the Polar Vortex (PV) is currently very weak (climatologically) so high latitude blocking isn’t that unusual. Nor is it “a sign of a cold winter coming”… we had a similar pattern to this last autumn in both October & November (remember the deluges and flooding?) and the PV still ruled the roost come actual winter! Of course, if it were still to be the case in another 6-8 weeks time then yes, that would be of interest… but at the moment it means little to nothing. It could also be theorised as linked to the recent solar minimum… yes, maybe – but still of little interest from a cold/snow fans POV till November at the earliest. Rant over 🙂

On the left is a ‘zonal’ jet stream, on the right is a ‘meridional’ jet stream

On to the severe weather this coming weekend; a vigorous and deepening area of low pressure will be sitting to the south of the UK on Friday, centered over NW France or in/around the English Channel. Models have been inconsistent with the exact placement and track of this low, so forecast confidence in recent days has been low. It does now appear the track will indeed be to the south of the UK initially, thus keeping the greatest wind impacts away from the UK and giving greater worry to France. Model output in recent days had suggested greater wind impacts for a larger swathe of England, especially the south-east. Just in the last few hours, the French Met department have named this system ‘Storm Alex‘ for wind impacts across northern France where damaging gusts are expected. For the UK, the UK Met Office have issued a severe weather warning for Friday (for both wind & rain) covering south & south-west England, along southern coastal counties as far east as Sussex.

Met Office severe weather warning for Friday
It will be windy for S/SW UK but less severe than the winds expected over NW France
ECM currently suggesting gusts of over 100mph from Storm Alex

Whilst wind will be of concern across southern counties on Friday with gusts 50-65mph; enough to down trees (many still in leaf), cut power supplies and cause travel disruption – arguably of greater concern looks to be the rainfall totals on Friday and beyond into the weekend. Whilst river levels in these locations are broadly around normal or even a little below, that doesn’t mean flooding won’t be an issue – remember river levels fluctuate rapidly… if rainfall totals currently suggested by models come to materialise, I’d expect some of these rivers to reach high, notably high or possibly even exceptionally high by the start of next week.

The main focus of the rain will be in roughly the same zone as that of the strongest winds – so south-west England and southern coastal counties. There does remain uncertainty around the extent of rainfall for counties further south-east; London, Surrey, Kent etc, but significant rainfall totals are quite possible here too. The main zone for this deluge looks to be from the West Country (Devon/Somerset) eastwards into Dorset, Wiltshire, Hampshire & IoW. Models seem quite confident now on this ‘wet zone’ but finer details i.e exactly how much rain, is still variable from model to model.

Above is the accumulative rainfall total chart for between now and the end of play on Sunday from the ECM model. Worth bearing in mind, this is falling over a 3 day period from Friday and across the weekend, but it is still a serious amount of rain. Suggesting over 100mm for parts of Somerset & Dorset, that’s more than a months worth of rain – even for October (which I believe is the wettest month for the UK as a whole, on average). Notice more widely – even beyond the Met Office warning zone – 50mm+ rainfall totals are expected widely.

GFS output is along the same lines; again out to end of play on Sunday, again suggesting over 100mm in places and 50-70mm more widely. I do think the Met Office warning could and should be extended further east into Kent and maybe the London area too (or just south) given the current output. I’d also consider extending into parts of South Wales.

Rainfall Outlook from UK Weather Updates (Twitter: @UKWX_)

Above is a Rainfall Outlook issued by UK Weather Updates (Twitter: @UKWX_) for the period today (Wednesday 30th) out to Sunday 4th October – I’d say overall I’m in agreement with the graphic both in terms of rainfall amounts and the zones shown.

So quite a severe spell of weather to come after a settled & benign September courtesy of Storm Alex. Gales or severe-gales on Friday followed by a washout weekend as low pressure drifts close to or over the UK – main emphasis on southern regions. Staying windy and pretty chilly too. Less going on further north but it won’t be dry, settled or warm! Remaining unsettled over the coming 10 to 14 days with low pressure dominating.

Thanks for reading 🙂 I plan to update this blog a lot more over the coming autumn & winter season, early October I will be doing a post discussing the factors behind forecasting the winter ahead and how things are currently looking. There will also be a full winter forecast at the end of November as well as possible weekly updates from December onwards. If you’re reading this having seen the link on Twitter, please give the tweet an RT if you can, I’d like to gain a bit more of an audience in time for winter. Also feel free to ‘follow’ my blog (which I believe gives you e-mails when I publish a post?) and also any comments welcome.

Nick ( @Official_WXUK that Twitter so kindly suspended for no good reason back in May 🙂 )

A Year In Review: 2019

2019 is a difficult year to summarise… in terms of exciting, eventful & seasonably desirable weather – I don’t feel it came close to 2018. 2018 hosted the Beast from the East/Blizzard Emma and the long, hot summer with weeks of high temperatures, masses of sunshine and little to no rain. 2019 did not deliver the snow, unless you were in Basingstoke and surrounding areas in early February… and it didn’t really deliver much of a classic summer either – some endured a washout and heat was limited to short bursts. But what 2019 did deliver was several all-time records, including the warmest winter day & hottest summer/ever *on record* day, exceptional to see both in the same year. Record smashing 850hPa ‘upper air’ warmth in both June & July too. This was then followed by a washout autumn, the wettest on record for parts of Yorkshire with severe flooding. So I’m left feeling it was quite a ‘meh’ year but very much memorable from a statistical POV thanks to some impressive new records.

I have tried to pick out a weather highlight from each month of the year, but some months were rather lacklustre. I am typing this at 2am – so please forgive any grammatical errors 🙂

January:

THAT failed ‘Beast from the East’ *sad face emoji*

The weather itself in January was far from memorable, in fact you’ve probably already forgotten… UK mean temp was bang on average, it was overall very dry & settled, cold & snow was limited to the final days of the month (-14C in Highland Scotland on the 31st). January will more likely be remembered for what could have been as models increasingly pointed towards a very cold E’rly spell which was due to start around 24th. I seem to recall there was a lot of model flipping and inconsistency with the GFS & ECM struggling to agree, but the overall picture was looking promising from mid month and into the third week.

Output was still impressive by 18th/19th with a ‘Beast from the East’ seeming probable; -10C 850hPa temps with heavy snow showers piling into the UK from the east as low pressure placed to our south, high to our north. Twitter was buzzing with excitement… and then the whole thing collapsed by 20th as model output switched to a mild set-up just 4 days short…thanks Azores high!

Just to add insult to injury, the day that was expected to see -10C 850hPa temps reach the UK with heavy snow – 25th – ended up being the mildest day of the month with a SW’rly airflow… +14C was recorded in Devon.

February:

The only worthwhile snow of the year

February started very cold with heavy snow across parts of the UK… it wasn’t the widespread & severe ‘Beast from the East’ that January modelled but for parts of southern England it was the first…last…and only notable snow event during winter 2018-2019. The temp dropped to -15.4C at Braemar, Aberdeenshire on 1st – the coldest night of both winter 2018-2019 and the year 2019 and lowest UK temp since 2012.

Heavy snow showers brought disruption to parts of Scotland and the NE of England but the main area of heavy snow was across southern England; initially for parts of Wales & the West Country before moving slowly eastwards and stalling across central & southern counties, focusing on parts of Hampshire, Berkshire & Surrey where some places had over 24 hours of persistent snow.

The greatest snow depth officially measured was 33cm in Tomnavoulin, Morayshire, Scotland on 2nd. In southern England, 19cm was the measurement from Odiham in Hampshire, however some parts of north Hampshire, particularly around the Basingstoke area where disruption was severe, did see as much as 20-25cm settled snow. Copley in County Durham had a snow depth of 16cm – just over half a foot – while 9cm was the greatest snow depth in Wales.

March:

March was a nothing much month – back to February with that record-breaking ‘winter heatwave’

March was a rather meh month; UK mean temp was 1.3C above average (10th warmest March since 1910) & rainfall was 140% (5th wettest March since 1910) — so we’ll instead look at the incredible late February ‘winter heatwave’ – quite possibly the most impressive new record set in 2019 (yes, ahead of the all-time new record). Prior to February 25th, the UK record for highest temp in February and the winter season as a whole was 19.7C (1998)

On 25th, with high pressure centred over central & eastern Europe drawing up warm air on a S’rly flow from N Africa and the Mediterranean toward the UK, the temp soared to 20.6C at Trawsgoed in Wales – helped by the Foehn Effect – a new UK Feb/winter record – the first recorded UK winter 20C. Northolt in London also exceeded 20C.

On 26th, the same synoptic pattern allowed for the new record to be broken again, warm S’rly winds & wall-to-wall sunshine – the temp peaked at 21.2C at Kew Gardens in London, smashing the old record of 19.7C, breaking both the 20C & 21C barrier…incredible warmth for a winter month. At 70.2F it was also the first recorded UK winter 70F. Wales also set a new record again on 26th with 20.8C whilst a few days prior, Scotland set a new Feb record with 18.3C in Aberdeenshire on 21st.

Despite the cold & heavy snow at the start of the month, February ended up overall 2nd warmest on record since 1910.

April:

Perfectly timed Easter weekend warmth

April 2019 will be remembered for delivering a perfectly timed spell of very warm weather which coincided with the Easter weekend. The first half of the month was rather cool with temps average to below, however a warm continental E to SE’rly airflow arrived in time for a BBQ weekend. As the April daily max temp chart above ^^ shows, the 4 warmest days of the month were from Good Friday 19th to Easter Monday 22nd.

On Good Friday 19th, the temp soared to 25.8C at Treknow in Cornwall – the highest temp of the month – whilst widely across the UK (away from the fresher east coast) temps peaked in the low to mid 20’s. Saturday 20th was another very warm day widely into the 20’s – 25.5C in Hampshire while Scotland & N Ireland had their warmest ‘Easter Saturday’ on record (worth noting, the Easter weekend dates vary year on year).

Easter Sunday (21st) saw a high of 24.6C at Heathrow in London whilst Wales, Scotland & N Ireland all recorded their warmest ‘Easter Sunday’ on record with 23C, 23C & 21C respectively. The warm spell culminated on Bank Holiday Monday (22nd) with the UK and all 4 home nations having their warmest Easter Monday on record; 21.4C – N Ireland, 23.6C – Wales, 24.2C – Scotland & 25.0C – England.

May:

Mundane…

May was an uneventful month, not much to say really. UK mean temp was 0.3C below average… rainfall was 93% of average overall – driest across Wales and the SW – and sunshine 101%. I’ve added a picture of a baby duck, didn’t know what else to add!

June:

Late month heatwave – record smashing 850hPa temperatures

Late June saw the first notable hot spell of the season with temps reaching 30C on both 28th & 29th. With high pressure centred to our NE giving continental E’rly winds on 28th, western regions were hottest whilst eastern coasts remained cooler ~ 30.0C was recorded in Achnagart, Highland Scotland. Meanwhile in France, a record shattering 45C was achieved. On 29th, the centre of the high drifted south a little, allowing for hot S’rly winds to reach the UK ~ 34.0C was recorded at Heathrow & Northolt in London.

Whilst surface conditions did get very hot on 29th thanks to the loss of the strong & cooling E’rly wind off the North Sea, far more impressive from this spell were the record breaking 850hPa ‘upper air’ temps. Due to the strong surface wind, these exceptional airmass values didn’t reach full potential – had the winds been light & more S’rly, temps would have been 2-3C higher.

The pre-2019 UK record for highest 850hPa temp value was 22.4C set in 2003 at Herstmonceux, Sussex. On June 28th, this record was smashed with a sounding from Camborne, Cornwall of 24.8C – extraordinary for the UK.

July:

Another late month heatwave… another pulse of exceptional 850hPa warmth… UK hottest day on record… 40C model output

UKV forecast 2m temp chart showing 40C as a possibility just 24 hours before the record breaking day…

Then came late July, another wave of exceptional warmth at 850hPa but this time with the ideal synoptic set-up to match which allowed for record breaking historic temps with the all-time UK record broken.

At 850hPa, a sounding of 23C was recorded at Herstmonceux, Sussex on July 25th, falling short of the June-Camborne record but surpassing the old 2003 record from the same location.

The heatwave began on 22nd with a very warm SW’rly airflow, 30.5C was recorded in Cavendish, Suffolk. On 23rd, the airflow became more S’rly with a plume of even hotter air reaching the UK, Northolt in London hit 33.7C whilst 30-32C was seen widely across central, southern & eastern England. Temps reached 28C in NE Scotland. The 30C+ heat was temporarily more limited to East Anglia & SE England on 24th where 34.3C was recorded in Writtle, Essex. The heatwave culminated on 25th under an exceptionally hot S’rly airflow, temperatures exceeded 30C widely across the UK – even in Scotland – with record breaking heat up to 35C as far north as Yorkshire. Stations across southern & eastern England were into the 30’s before midday, peaking as high as 35-38C in some locations. The pre-2019 record for all-time UK maximum temp was 38.5C set in Kent in 2003… this was broken when it was confirmed Cambridge Botanic Gardens reached a new high of 38.7C. Dozens of stations across the UK set new all-time records as the exceptional heat pushed unusually far north – 31.6C was recorded in Scotland.

Whilst 38-39C was always the most likely maximum temp on the day, some model output did suggest the possibility of 40C being achieved for the first time in the UK which seemed a credible possibility given several countries in mainland Europe to our SE had broke their all-time records by 2-3C and exceeded 40C for the first time.

August:

Hmm, another late month heatwave – new Bank Holiday heat record

Yet another notable heatwave occurred in August – again during the latter stages of the month – although this time far less exceptional than those previous. High pressure once again centred over Europe allowing a hot S’rly plume to move north over the UK. The temp peaked at 30.7C at Heathrow, London on 24th. Temps exceeded 30C more widely across England on 25th, peaking at 33.3C again at Heathrow. 26th was another hot day into the low 30’s across the east & south-east, Heathrow again at 33.2C. The heat persisted for one final hot day on 27th (Bank Holiday Monday) with a heatwave maximum of 33.4C recorded at…..Heathrow (again) – setting a new record for hottest late August Bank Holiday.

September:

Meh then a very wet final third with flooding

Not a huge amount happened as we went into autumn apart from things became increasingly wet with numerous deluges which meant an ever increasing risk of flooding, especially for those parts of Yorkshire & N England that suffered flooding rains earlier in the summer.

September was looking like a drier than average month up until around the 20th, the final third of the month saw several bouts of heavy, persistent rain with mounting totals. Parts of England & Wales saw flooding on 23rd and again on 28th, especially across mid/south Wales & Yorkshire. Further heavy rain on 30th culminated in the River Ouse in York bursting its banks.

Locally, parts of SW England, Wales, Yorkshire, N/E Midlands & N England saw more than double their average monthly rainfall (200%+)

October:

More rain…

Another month, much the same… yet more rain and more flooding issues. Thanks to a southerly tracking jet stream, it was once again southern & eastern UK seeing the most frequent unsettled wet weather while Scotland & N Ireland escaped the worst. On 6th, torrential rain led to flooding across parts of Norfolk & Suffolk where an amber rain warning had been issued – some roads & homes were flooded. Further flooding hit parts of Wales, the Midlands, N England & Yorkshire during the course of the month.

East Yorkshire, the E Midlands and locally in Norfolk/Suffolk ended the month with more than double their average monthly rainfall (200%+) while for a second month – Scotland ended up drier than average.

November:

Southerly tracking jet, more rain & flooding for England

November continued much the same with an often southerly tracking jet stream, most unsettled in the south whilst somewhat drier further north & north-west. There were drier and more settled periods and also some colder spells, November ended up 0.9C colder than average with parts of Wales & the West Country seeing snow over higher ground.

Flooding continued to arise during periods of heavy rain whilst severe-gales caused damage early in the month as a deep area of low pressure which the Met Office couldn’t be bothered to name caused widespread travel disruption across the south & south-west; hundreds of trees were downed, thousands left without power, some structures were damaged and one person died.

Torrential rain on 7th & 8th saw rivers burst their banks giving way to severe flooding across large parts of northern England; Sheffield & Doncaster were badly affected – the River Don burst its banks – whilst floods also hit parts of Derbyshire, Lincolnshire, Leicestershire and the wider Yorkshire area flooding hundreds of homes.

For Yorkshire and the Midlands, November was a third consecutive month with rainfall totals more than double the norm whilst parts of NW Scotland saw less than 25% of average. For the autumn (Sept to Nov) as a whole, a large swathe of Yorkshire and the Midlands ended up more than double the rainfall norm – locally some places had their wettest autumn on record including in Sheffield where records go back to 1883. Scotland’s drier than average autumn is thanks to the positioning of the jet stream, an unusual respite from constant rain for that part of the world!

December:

Crap.

This apparent ‘winter’ month has given us no winter weather – milder than average and for some wetter than average too – we’ve seen more flooding in recent weeks with the focus further south across the SW & SE of England. Apart from a dry, sunny & frosty few days to start… its been a pretty crap month – although this was half expected. The wait for winter weather goes on into 2020……

Winter 2019/20 Forecast

Published: December 2nd 2019

Long-range seasonal outlook for December, January & February 2019/20 from @Official_WXUK

Mad how time flies, only seems like a couple months ago last winter ended and now here we are 9 months later looking ahead to yet another winter season. I’m sure the usual frustrations lie ahead, for those who want snow and those who don’t – it is the impossible to predict UK climate after all. We’ve had even higher than normal levels of speculation about this winter for a number of reasons I’ll mention shortly, lots of conflicting signals & opinions…as always, these long-range forecasts are for the most part just for fun, we are talking about weather for the next quarter-year, all we can do is speculate on possabilities & probabilities.

Headline: Average to slightly colder, greater chance of snow

I am forecasting an around average to slightly colder than average winter season across the 3-month period with rainfall close to average or a little above. I am expecting a greater snow potential for the UK this winter compared to in recent years, potentially the best since 2012/13. Usually, colder winters are also somewhat drier (as a rule of thumb) but I am expecting quite a mixed & variable winter which may allow for colder/drier periods to be balanced out with milder/wetter periods. Also worth emphasising the forecast states average to slightly below, so not dramatically colder, overall. I also suspect we will continue with the wide regional variations theme which has been prominent this year, especially in terms of rainfall.

Taking a punt at UK-overall winter season stats, I’d say mean temperature finishing up at 0.1c to 0.5c below the 1981-2010 average & rainfall at 100% to 120%.

What’s been looked at to determine this forecast….

One of the big talking points in recent months has been the huge difference between long-range/seasonal model output and the various background signals. A number of meteorological agencies release long-range charts for the months ahead, indicating general synoptic trends. In recent months, the vast majority have been firm in indicating a positive North Atlantic Oscillation (NAO) which generally means a notable lack of high latitude blocking (HLB) and a likely presence of the Azores high not too far away…which for us means unsettled, wet, mild, Atlantic-driven weather and a struggle for snow.

The Met Office’s GLOSEA5 November update for the months Dec/Jan/Feb indicating a strong +NAO signal with low pressure to our north and high pressure to our south, giving westerly winds.

On the face of it, you’d say the signal is strong – it’s been consistent and across the board…but there are issues. The track record for these seasonal models is poor. Many were indicating a cold signal this time last year for the winter just gone and whilst HLB did occur, we ended up with the 8th mildest winter on record. More recently, these models were suggesting a very mild November 2019…yet November ended up a rather chilly month, colder than average. Furthermore, they do not factor in potential events such as a Sudden Stratospheric Warming (SSW) which can certainly hold potential to make current mild/wet output look rather foolish…and furthermore again, you cannot look at one chart for a 3 month period and not expect variation from the given theme – you can have a mild/wet +NAO winter with a Beast from the East thrown in for good measure.

My thoughts? I wouldn’t like to *totally* disregard them, with such numbers there could be *some* weight to it…but I do feel they often hold a strong +NAO bias (possibly by default) and given their iffy track record, I feel they’re worth only a glance rather than a study.

The ECMWF Seasonal Forecast November update suggests warmer than average temperatures for the UK this winter with a similar story for much of the rest of the Northern Hemisphere.

Whilst the seasonal models reek of a mild, snow lacking winter – a lot of the ‘background signals’ say otherwise. October saw a respectable expansion of snow cover across Siberia, something we watch closely as some have theorised it can lead onto a weakened Polar Vortex (PV)/negative Arctic Oscillation (AO) later into winter. The theory is; the more vast a snow cover in October, the stronger the Siberian High going forward – thus eventually weakening the Strat PV, this propagates down into the Troposphere PV and we end up with a -AO pattern (HLB = greater risk of cold/snow). The theory isn’t concrete, but it has some backing. As I said, this year was a good year…so it’s backing a greater cold potential.

October Eurasian snow cover extent anomaly graph from Judah Cohen showing October 2019 saw above average extent, similar to that of 2013.

Another background signal potentially hinting at a colder winter is the Quasi-biennial Oscillation (QBO) – a cycled variation in the winds that circulate above the equator. Once every 14-ish months, these winds change direction and this can have an impact on the Jet Stream. When QBO is positive/westerly, the UK is at a greater risk of +NAO/a strong Jet, milder and wetter winters. When QBO is negative/easterly, the UK can see a weakened Jet, less rain, greater chance of cold and also a higher chance of SSW events. Right now, QBO is transitioning from W to E (+ to -) having reached peak W phase in May/June. Monthly index values have since been falling; 8.25 in Sept & 7.27 in Oct (no Nov value as yet). Transition has so far been slow, but it does appear likely this winter will be a transitioning W to E QBO season with the prospect of reaching E phase later in the winter…another factor which could lead to something cold.

How could I not mention Solar Minimum (SM), the very low solar activity which holds a credible link with increased amounts of high latitude blocking which is a big thumbs up for the UK cold & snow risk with a more meridional jet stream pattern. We are at SM right now – this year – after coming to the end of Solar Cycle 24 (these cycles last around 11 years)…

Monthly sunspot numbers since 1960 showing Solar Cycles 19 to 24, each solar minimum indicated by very low sunspot numbers.

Without wanting to hype, it’s worth noting just how weak Cycle 24 was, in fact it was one of the weakest cycles ever recorded (although not as weak as the Dalton Minimum Solar Cycles 5 & 6)…and as of the day this was released (02/12/19) we are only 8 more spotless days away from matching 2009 & 16 from the 2008 minimum, well on course to recording the quietest year for sunspots of the space age.

The last SM occurred in 2008 with activity remaining minimal until early 2010 – as I’m sure you’re aware, the period 2008-2010 saw consecutive cold/snowy winters with notable severe cold spells including December 2010, the second coldest December in the last 350+ years, all thanks to significant amounts of HLB likely linked to the SM. Going further back, there have been other examples of severe cold spells coinciding with periods of low solar activity and it is strongly acknowledged that there is an increased likelihood of blocking weather patterns during these times.

Another point of interest is this years persistence of a -NAO pattern, we are on course to finish this year with one of the most negative NAO indexes on record (2019 at -0.53 sigma at last check, behind only 3 other years) – whilst earlier this year we had the greatest longevity -NAO on record. A -NAO set-up, especially when coupled with -AO, can deliver us real winter weather. Whilst there’s nothing to say it won’t flip to a +NAO pattern into this winter, for quite some time now it hasn’t wanted to remain + for very long, maybe an interesting persistence that’ll continue?

As if that wasn’t enough, there’s also an increasing likelihood we could see some Stratospheric Warming or even a Sudden Stratospheric Warming in the weeks ahead, the GEFS has been on/off flirting with the idea for a little while and is currently indicating the potential for later this month (December)

As we know, an SSW doesn’t guarantee snow, impacts in the weeks & months following can bring about blocked weather patterns and this certainly increases our chances of seeing cold/snow as the Polar Vortex splits/displaces and floods cold air southwards from the Arctic region down into parts of the Northern Hemisphere, but at the same time – other places on the ‘wrong’ side of blocking will end up very mild. The March 2013 severe cold/snow and 2018 Beast from the East both followed SSW events, however we also had an SSW event earlier this year and that played a part in the record warmth in late February. Something to watch very closely as ones occurrence could make January and/or February very interesting.

Latest GFS/GEFS once again hinting at an SSW event taking place later this month.

One thing that does stand out against the cold favouring background signals are the current sea surface temperatures (SST’s) which don’t look overly favourable for a cold winter scenario. Below average anomalies across the north-eastern side of the N Atlantic around UK/W Europe with a notable gradient as seas are much warmer than normal off the US East Coast, this sharp gradient – if it persists – could fire up a strong jet stream near/towards the UK. The Pacific also doesn’t look ideal, much warmer than average SST’s in the NE Pacific to the south of Alaska have been persistent for much of this year and anomalies remain very much + right now… this could send the jet stream on a north-west to south-east trajectory through the States, pulling down Arctic cold into the eastern States and thus potentially firing up a powerful jet exiting into the Atlantic. I know a lot of people put a lot of weight onto SST’s when it comes to winter forecasting, so this could be the biggest negative.

Global SST anomalies as of the end of November 2019.

All in all – some promising signs for those wanting a more seasonal winter, I am confident we will see more outbreaks of cold/snow this winter than last and possibly the best overall winter on that front since 2012/13. I also don’t expect a deluge/washout winter, although given recent flooding, a renewed risk will arise during wetter periods. For those less keen on the snow, at least the seasonal models are on your side.

Monthly summaries….

I am expecting December to be quite chilly at times but with rather limited snow potential for many, any cold coming from the north and not being overly prolonged but equally any milder periods also rather transient. Rainfall around average to a little above. I would expect some northern snow – especially later in the month – and I’d also be surprised if we didn’t see at least one named storm.

January holds potential for some cold & snowy weather, more especially if we see a December SSW. Regardless, I am expecting a meridional jet stream pattern at times which should allow for colder periods from the north as well as a greater snow risk. Temperatures widely variable with some milder intervals but overall finishing up average to slightly below average. Potential for a notable cold spell but that’s far from certain, most likely latter month. Rainfall around average.

February a difficult one to call, again quite key is whether we see an SSW occur or not. Potential for some colder periods, especially early on – possibly a more zonal month than the previous two with more in the way of mild/wet weather, especially later. Chance of snow, but that’s not saying much given its winter. A difficult forecast but I would emphasise the maybe greater than normal potential for worthwhile snow. Rainfall average, maybe a little above and regionally variable.

…and that’s about it, I think. Thanks for reading, especially if you read it all from start to finish 🙂 & feel free to leave a comment/feedback.

Autumn 2019 Forecast

Published: September 3rd 2019

Long-range seasonal outlook for September, October & November 2019 from @Official_WXUK

Photo from @victorthevole

Its time for the Autumn 2019 forecast, the warm-wet Summer of 2019 is now behind us, the slow descent into Winter begins. The season some love and others hate, the widely variable weather during this transitional season plays a big part. Autumn colours, trees shedding leaves, first frosts, slowly darkening evenings, cosy nights in with a howling windstorm outside — some love it, others loathe. September summer extension? Dull November days or crisp, sunny & frosty — there’s no Autumn rulebook in the UK.

Headline: Milder & a little wetter than average

As always, blah blah blah its a three-month long range forecast so in many ways this is just for fun — numerous players are considered but these often throw contradiction to one another so confidence past the first few weeks slips to low and past month one its virtually non-existent.

The Official Weather UK Autumn Forecast is going for an overall (across the 3-month period) milder than average & slightly wetter than average season — UK mean temperature average or above for all three months, rainfall variable but generally average or above, especially later in the season.

September 2019

Photo from @Liam_Ball92 / Liam Ball

Temperatures: Average to slightly above average

Precipitation: Near/around average

Autumn starting on a very autumnal note, temperatures average to below so quite cool for the time of year, especially in the north. Quite a changeable to unsettled first half of September; coolest, dullest & wettest in the north & north-west with rainfall above normal closest to the low pressure systems passing over/to the north of the UK – windy at times too. Somewhat less poor weather further south & south-east but temperatures still a little below par on most days, far from a washout with some dry/bright days but some rain/showers too. Overall; cool & rather unsettled. Subtle changes are likely from around mid month into the third week of September, high pressure becoming more dominant allowing for more settled conditions. The far north-west of the UK likely staying a little cooler & wetter on balance, but for the bulk of the UK becoming drier & warmer, temperatures returning average to above so in any sunshine – pleasantly warm. Overall, temperatures more likely finishing up (+) average rather than (-) average but only marginally 0.1-0.5C. Precipitation near to around average; 80-110%.

October 2019

Photo from @PhotographyWx / @SnowbieWx

Temperatures: Average to slightly above average

Precipitation: Average, maybe a little above

I won’t go into week-on-week details for October & beyond as there’s little point but the general theme I’m expecting is often changeable, quite a zonal month at times but with useable drier periods (hence the word changeable) – wettest in the north & north-west, rainfall across the month varying from region to region, possibly a little drier than average further south/south-east but overall finishing up average to a little above; 90-120%. Potential for some wet & windy bouts of weather, typical for October which I expect to be a fairly standard autumnal month. Temperatures often on the mild/very mild side with winds predominantly coming from the W or SW, limited risk of cold/frosty nights although brief chillier periods from transient N/NW airflows could see frosts occur. ‘Warm’ conditions still very much possible in October, especially early on, so still some pleasant days to be had. Overall a mixed bag month, probably quite a forgettable one although one or two named storms could bring something notable. Temperatures for the UK as a whole finishing up average or a little above, lesser likelihood of a colder than average October.

November 2019

Photo from @chris_alpacas / Christine Mitchell

Temperatures: Above average

Precipitation: Above average

I am expecting a mild & wet November, temperatures often above average, very mild at times with winds from the SW, overall finishing up above average – possibly by over a degree or more. A wet or very wet month, this wet weather affecting all parts of the UK, rainfall likely above average for large parts of the country, risk of windy/stormy weather at times too with a very active jet stream firing up deep areas of low pressure towards the UK. With this type of set up, brief colder northerlies are likely as low pressure clears E and winds turn N, occasional chilly days with a risk of northern hill snow would be possible, but overall I’d put the chance of wintry weather this November at small. A zonal month – mild & wet, a few named storms too.

Overall a mild Autumn, any cold weather very limited and temperatures frequently above the norm…a wetter than average season, but not massively so – rainfall not much above the norm prior to November but I don’t foresee any notably drier than average month over the season ahead. Snow? Not much….maybe some northern hill snow by November but no November 2010 repeat, not even close.

My Winter Forecast covering December, January & February will be issued on the final day of November or first day of December!

July 2019; everything but the kitchen sink…

After a relatively lacklustre start to the summer with a rather poor June giving both plenty of rain & unremarkable temperatures up until the one-day heatwave at the months end, July arrived and given us a bit of everything. Many found the weather equally as uneventful in the first few weeks but it was dry, very dry in-fact with some places seeing no rain by mid-month. However, the dry spell came at a cost…but before then we turned on the blowtorch for a week of furnace heat which culminated in a record breakingly hot day for the United Kingdom. This was followed by a breakdown and thunderstorms, the wait for many was finally over…and then it rained, significantly – the month ended with flooding in the north of England as torrential rain over several days dumped up to two months worth in places. It’s been very dry, very wet, very hot and on one particular night very thundery too – this was July 2019;

The month started on a cool note with a north-westerly airflow giving us showers & below average temperatures. Building high pressure from the SW in the following days allowed for drier & sunnier conditions – especially across England & Wales; London reached 27C on 4th & 28C on 5th. Further north, the first week of July was rather cool & cloudy, some rain but no washout. The second week and towards mid-month saw changeable & variable weather, some cool & cloudy days with showers, some warmer days with sunshine. The first half of July was notably dry for some despite never turning hot; some places had recorded little to no rain by 15th – here in Penzance my rainfall total was just 2.2mm. Far from eventful, but it was often dry with perfectly useable weather.

The third week of July saw the dry period come to an end; low pressure dominated with frontal rain bands giving wet weather from 17th to 19th. It was windy too for the north of the country, cool under any rain/showers with a west to south-westerly airflow off the Atlantic limiting any warmth to the south-east.

Things turned more interesting from 22nd, Monday 22nd was the first hot day in what turned out to be an exceptionally hot week. Initially with a warm & humid south-westerly airflow; 30C was reached in Suffolk. Hot & sunny weather extended across most of the UK by Tuesday 23rd; 30C was achieved widely with 34C in London as the flow became southerly off the increasingly hot continent. By this stage, model output was suggesting record breaking heat for the Thursday; the Met Office began hinting at 38/39C while numerous model runs shown 40C in the east & south-east.

Wednesday 24th was another hot day as low pressure to the SW of the UK continued to draw up a hot southerly plume. 30C was reached widely in the east & south-east although a little less extensive than Tuesday, the max was again 34C this time in Essex. The heatwave climaxed on Thursday 25th; multiple European countries smashed their all-time records and hit 40C for the first time on record, the UK was sitting under exceptional 850 hPa values with 23C for a time in the south-east and temperatures soared from sunrise – many into the thirties by late morning. Initially it looked like the UK fell short of a new all-time record, 38.1C was the known high on the day…however, within a week it was confirmed we reached 38.7C in Cambridge – beating the old record of 38.5C from 2003. The day ended with a breakout of thunderstorms across the eastern side of the country which was followed by an exceptionally warm night 25-26th; the minimum was just 22.6C in Carlton.

Friday 26th saw a cold front bring cloud & patchy rain eastwards, there were a few thunderstorms from the south too, whilst the far east of the country managed one final hot day with 29C the high in East Anglia. Backtracking a little, the week wasn’t without it’s final required element for weather enthusiasts – thunderstorms. On the evening of Tuesday 23rd, storms moved into the south-west and spread north-east overnight affecting large parts of the country; over 45,000 lightning strikes were recorded.

The weekend 27th/28th was a poor one for much of the country, cloudy and wet with heavy & persistent rain across the spine of the UK. The best of the weather was reserved for south-west England – sunny & warm – while further north & east flooding issues began to arise; 67mm fell in Lancashire on 28th.

And then it all dried out to end the month? Not quite. The final days of the month 29th-31st were dominated by a vigorous area of low pressure which had taken a southerly track from the Bay of Biscay. Conditions deteriorated from the south-west on 29th with frequent, heavy & thundery showers – windy too with 58mph at Berry Head in Devon. Heavy rain & thunderstorms became more widespread across the UK on 30th and continued into 31st, initially windy across the south while for parts of Lancashire & Yorkshire in particular, mounting rainfall totals in excess of 100mm led to significant flooding. A very wet & autumnal end to July, a stark contrast to the prior weeks of very dry weather and previous weeks extreme heat.

For the month of July – across the UK as a whole – the provisional mean temperature was 16.4C which is 1.2C above the 1981-2010 average, this makes it the 8th warmest July on record (since 1910) which may come as a surprise to some. However – it wasn’t as warm as last July – that should come as no surprise! For most of the country the anomaly in temperature was +0.5C to +1.5C but across Scotland & eastern England it was +1.5C to +2.5C. Highlighting for those who have commented on how warm nights have been recently, looking at mean minimum temperatures; July saw the joint 4th highest mean minimum temperature on record.

Below is the UK mean temperature anomaly chart for July 2019

Rainfall for the UK across July; the month ended with a UK percentage of 114% making it slightly wetter than average. For those like myself who forecast a drier than average July, you may be feeling a bit cheated because up until the final couple of days this percentage would have been comfortably below average. The first half of the month likely saw percentages below 10-20% and even up to the latter stages of the month, many places were drier than average. Quite unfortunate for those who went with a dry July but it shows just how much rain can fall within a few days, masking stats on the other end of the scale. In more detail, rainfall across the UK was widely variable; it was a drier than average month for Wales, south-west England and parts of East Anglia & the south-east while for the north Midlands, northern England & Scotland it was wetter than normal – especially so in the area from Manchester to Leicestershire where anomalies exceeded 200%.

Below is the UK rainfall anomaly chart for July 2019

As for sunshine amounts across the UK in July; provisionally it was 100% – bang on average. Large swathes of the UK ended average 90% to 110% – some parts of Scotland & Northern Ireland were a little below at 70 to 90% but this was balanced out by parts of south Wales & south-west England being slightly sunnier than average at 110% to 130%. The lucky extremities were the far western tip of Cornwall & north coast of Devon where sunshine anomalies ended 150% to 170%.

Below is the UK sunshine duration anomaly chart for July 2019

And finally; here’s the lightning strikes map for the UK & Ireland for July 2019…

Summer 2019 Forecast

Published: June 1st 2019

Long-range seasonal outlook for June, July & August 2019 from @Official_WXUK

It’s that time of year again when we look ahead to the potential weather prospects for the summer months, after last years record breaking long, hot classic summer can this summer match our heightened expectations? Spring has been anything but eventful, a very “meh” season; dry but with the only notable feature being the Easter Weekend warmth in April. Following a very dry 12-months, we are also monitoring possible drought concerns across the east & south-east of England, maybe a washout summer is what we need? Dry? Sunny? Wet? Warm? Keep reading to find out my thoughts…

Headline: Drier & warmer than average but no repeat of last summer…

Before I start, just remember as with all long-range forecasts looking more than a couple of weeks ahead it is for the most part JFF (just for fun) that doesn’t mean it’s all a total guess – knowledge, important factors & trends are considered – but please don’t go booking your wedding date off the back of this, confidence is little to none and past the first fortnight just about anything could happen!

The Official Weather UK Summer Forecast is going for an overall (across the 3-month period) drier than average & warmer than average season with a likely continuation of the drought concerns in the E/SE. However, I’m pretty confident in saying I do not believe it’ll come close to matching last summer in terms of lack of rainfall or the longevity in hot weather. A pretty decent summer but maybe feeling rather underwhelming off the back of last year?

June 2019

Temperatures: Average to slightly above average

Precipitation: A little below average

Given there’s already an idea on how the weather will pan out over the next week or two, I won’t go into too much detail. Initial warmth, a quick thundery breakdown followed by a cool and rather unsettled first week to June – wet & windy at times, wettest further N and W. We know this already. It now looks like staying unsettled into the second week of June, no washout but some fairly wet weather is possible at times in the form of both frontal rain and possible thundery showers. Temperatures initially around average but possibly warming up towards mid month. More uncertain, but I expect things to improve from around mid month onwards, a drier third week of June with rain mostly limited to the N and W of the UK, staying dry in the SE. Temperatures generally above average, possibly very warm/hot for a short time. Month ending much the same, I expect a high pressure dominated final week of June, largely dry & settled, often warm but positioning of the high pressure being key. Overall, no exceptional heat with any hot weather being limited to a couple of days, but no prolonged cool spell to drag the UK-average below normal. Drier than average overall but not significantly so.

July 2019

Temperatures: Above average

Precipitation: Below average

Of course by this stage, confidence is little to none so take this with a pinch of salt – but – my feeling is for July to be by far the best month of this summer in terms of both overall conditions and also in providing the best “spell” of weather. I expect a warmer & drier than average month, you could argue somewhat comparable to last July but certainly not to that degree. If we were to set up some sort of blocking/Scandi high pattern – which I’m thinking we will – July could be a very dry month for parts of the UK with any precipitation coming only from occasional thunderstorms as the Atlantic influence is cut off. In this set up, it could actually be the E and SE that sees the most rainfall, although still likely below normal. This would also see winds predominantly coming from the E or SE, a very warm/hot source of air by mid summer so likely a month with frequent above average temperatures and possible bursts of heat, nudging the low thirties across England. I would expect some decent thunderstorm potential too, as and when breakdown(s) occur. Overall, sounds great – lets hope it comes off!

August 2019

Temperatures: Average to slightly above average

Precipitation: Average to slightly above average

I don’t need to repeat myself, pinch-salt… looking ahead at August, I’m expecting a funny old month, possibly warmer than average but wetter too – not significantly so on either factor but a combination I don’t think we’ve seen in a little while. Initially starting dry & warm with the blocking high pressure weather pattern holding on, keeping the Atlantic at bay. However I do expect this to eventually give way and allow for a final, thundery breakdown followed by a wetter regime by early to mid month, low pressure bringing spells of rain in off the Atlantic and temperatures briefly dropping to average or a little below. For the second half of August I’m expecting fast changing and quite dynamic weather with bouts of rain off the Atlantic giving way to brief very warm or hot E/SE/S winds allowing for spells of summer weather to return, best of the weather for England & Wales, closer to the less warm and wetter weather for Scotland & NI. This set up would also create a thunderstorm risk. With a warm start and warm or very warm second half, I expect a warmer than average month (not significantly so) but with a persisting risk of thunderstorms from hot spells, as well as some Atlantic influence, I also expect rainfall to be average-above.

Overall: An okay – nothing eventful – June… A very good July – if dry/sunny/warm weather is your thing – if not, dreadfully uncomfortable with no sleep… A messy August – some continental heat, some Atlantic rain – oh and a few thunderstorms…

Hmm, what to call this? A welcome introduction?

Welcome!

Yes, this is a hello & welcome blog, I’ve got no idea who’s going to bother reading this but if you are – thank you!

I suppose I should use this blog post as an opportunity to tell you a bit about myself, as well as why I’ve decided to create it. The latter is quite simple, this will become home to somewhat more indepth thoughts & outlooks from me, something that is quite difficult to do on Twitter unless you commit to a 9-part threaded tweet (not a fan!) I will also be able to post month/season forecasts on here as well as possible features such as month reviews or week ahead forecasts. I won’t be blogging daily, nor weekly – but I’ll be sure to tweet a heads up when I do.

And me? I hate talking about myself but I’ll give it a go. I’m Nick – I think most of you know that 🙂 – I’m 23 (nearly 24) at the time of writing this – feeling old but still a spring chicken. Born & bred in Cornwall, right down in the west in Penzance, not far from Lands End – a couple of miles inland in a small, rural village which stinks of manure every summer annoyingly on the warmest of days. Grew up here, moved up to Norwich in East Anglia when I was 20 – swapping fields, tractors & pasties for fields, tractors & turkeys. Loved Norwich – great city – but missed Cornwall too much and moved back after 2 and a half year just a few months ago. Now back in Penzance, feeling as Cornish as ever and enjoying the freedom to grab a pasty whenever I wish.

I call myself Cornish but my dad is a Londoner and my mum is from “up country” (Yorkshire) so I’m not entirely a Cornish pirate 😂 Love the weather – of course – the more extreme the better. Growing up in Cornwall made that a bit of a task but I got my first memorable snow in 2010, have witnessed more windstorms than I care to remember and then got treated to nearly a foot of snow in Norwich during the 2018 BFTE. Love summer heat, love snow, love autumn gales and love thunderstorms. I’ve loved all of this from as young an age as I can recall, I used to….actually still do….drive my family nuts with weather hype, especially with snow potential in the winter, as soon as a flake falls the curtains open, then the front door and I soon revert to a super excited 12 year old who’s never seen the magic of snow before.

For many years, my weather interest was limited to “out the window” weather and watching the TV forecasts but more recently I’ve picked up this interest in forecasting, looking ahead, model watching – and that’s where Twitter started, only last Summer.

So that’s me, a bit of background on that annoying guy with the stupidly bright orange Twitter logo, the one who posts pictures every day from Cornwall like it’s a photography account, the one who occasionally – yes only occasionally – posts off-topic, tongue in cheek tweets & replies in an attempt at humour. You follow me (I assume) & are still reading so I must be doing something right!

That’s enough blah, I said I didn’t like talking about myself but I feel I contradicted myself here.

Ta for reading, or gracias, merci, vielen dank or bedankt if you had to translate all of that and feel the need for a bit of appreciation, let’s be honest – nobody did – but I wanted to end on a random note 😂

Nick