UK "Snow Streamer" events.

[Tom Quintavalle]

In light of the recent snowfall event on the other side of the "Pond", namely at the eastern end of Lake Erie, around the Buffalo area, I thought it would be interesting for members to share their own experiences of "Snow Streamer" events.

You may well have experienced this type of convective snowfall, in areas adjacent to the Cheshire Gap, The Wash, Forth-Clyde Valley, Pembrokeshire Coast (aka The Dangler), etc, etc.

For some NW members, they have been responsible for some of our most impressive  snowfall events and again for some, in some instances, give us our best shot of recording a decent snow depth.

 

Focusing in on my own area of SE England, a flow from between N and E during our coldest months of the year can result in a convective snow streamer setting up in certain areas of Essex, Surrey, Kent, Sussex, London and can indeed affect areas further afield.

 

A NNE flow can result in a train of snow showers affecting the extreme east of Kent

A NE streamer in the southeastern part of our area, normally results in a line of showers  running in from the NE coast of Kent and exiting around about the eastern part of the East Sussex  coast.

 

Coming much closer to home, namely the eastern part of the Thames Corridor (South Essex, N/NW Kent, E/S.London and on into Surrey), an ENE flow can result in the "much fabled" Thames Streamer.

 

Below I've detailed some of my own experiences of Thames Streamer events, having lived for most of my life on the border of NW.Kent/SE.London, I've seen a few!

 

25th DEC.1970.

 

 

Although not having the benefit, obviously, of being able to view radar returns from that time, this almost certainly was a Thames streamer type event, which gave 4 ins of snow, in this area, and a couple of cracks of thunder,in the early hours of Xmas morning and snow showers on Boxing Day too, giving a very festive feel to the holiday period.

Remember listening to the Shipping Forecast at half midnight, whilst watching big fat snowflakes falling against the light of the lamppost, at the bottom of our garden. 

 

2nd FEB.2009.

 

 

An unusual Thames Streamer event this with areas west of the meridian recording greater depths of snow than those further east. I know from own local experience that Bromley (live) would normally have a greater depth than Croydon (work). The reality was very different to the norm, with around 6" in Bromley but nearer 9", further SW in Croydon.

I did, of course fair much better than areas further east, notably around Southend where the event is still referred to as "The Great Polystyrene Ball Conspiracy", poor Paul Shermans' still in therapy!

Paul, bless him, plucked up the courage to put together a brilliant analysis of explaining why this streamer behaved so differently, than other such Thames events.

This event was also accompanied by four very loud cracks of thunder, in my area, and I unashamedly post up "that" video clip again, recorded at Dartford, North Kents' equivalent of Buffalo.

 

 

22nd FEB 2005

 

The chart above depicts the synoptic situation a few days into this amazing spell, indeed the weather stayed wintry well into the 2nd week of March. It also shows the perfect angle of flow for a Thames snow streamer, which indeed was occurring at the time.

Had soil temps not been so anomalously high, due to a very mild Winter up to that time, depths would probably have accumulated a bit more than 2 to 3 inches that fell, in this 6 hour event. My area went on to record snow falling on consecutive days for nearly 2 weeks, albeit mostly in flurry form, apart from the 2 streamer events we experienced, incredible for this locale. The chart below, shows the situation during the 2nd streamer event.

 

 

The situation just an hour or two before the end of the 2nd streamer, another 2 to 3 inch fall. I'd waited years to experience this type of snowfall, brought about by an ENE flow, lo and behold two occur, within four days, amazing! 

 

8th JAN.2003.

 

 

Perhaps doesnt look much at face value but 6 hours later a convergence zone developed in the Thames Estuary and a snow streamer began around the Southend area and developed further WSW, towards N.W. Kent and S.E. London. Started snowing here, on the Kent/London border, around 7 a.m. and finally petered out in the early afternoon, depositing around 4 inches. Worst hit areas reported around 8/9 inches, between Southend and Dartford, also places with a bit of elevation over N.W.Kent.

 

BBC Forecast 8th Jan 2003

 

 

There's no doubt that the type of streamer event that affects the Thames Corridor area is partly due to the topography of the Kent and Essex coast aiding convergence, funnelling the flow as  it enters the mouth of the Thames and fuelling further instability, combining with that caused by deeply cold Continental upper air flowing out from the Low Countries over the S.North Sea and on into the Thames Estuary.

 

I, for one, start to take note when the METO draw up a FAX chart with a tell-tale trough indicating convergence, stretching down the mouth of the Thames and out into the N.Sea, as was the case in Feb 2009, a forecast which they nailed perfectly.

 

Having moved to my new location in April 2013 and like a lot of NW members, I failed to see a single snowflake last Winter, I will be hoping for an ENE flow with bitter cold uppers at some point during the Winter months, with luck I'll then experience my locales own version of "Lake Effect" snowfall. I understand from locals that these snowfall events are accentuated by a very localised pnenomenon, that being P.E.S. (Pond Effect Snow). I live barely half a mile to the west of Chislehurst Ponds and apparently depths can be a couple of inches deeper, a little to the west of the Ponds, than areas just to the east! 

 

As residents on the eastern shore of Lake Erie can atest to, these streamer type snow events can be very localised indeed and result in wildly varying distribution, over very short distances.

 

I would love to hear members own "Snow Streamer" event experiences, from whichever part of the country  you live in.

 

Regards, 

Tom.

Edited November 20, 2014 by TomBR7

[I remember Atlantic 252]

3rd to 5th Feb '03, 30th Nov to 02 Dec '10

 

Xmas day '04, not a huge amount but a white Xmas

[marksiwnc]

The menai straights streamer it stretches s/sw to n/ne and can bring shower activity in any northerly and southwesterly direction

[MP-R]

Great read there! Being on the other side of the country, the streamers we get here are often affected by the Severn Estuary, more so at the front end of the season and then it's luck of the draw where streamers set up during the second half of the winter. Here are some examples that produced shower streamers off the Severn Estuary and gave quite localised differences in snow amounts.

 

 

Christmas Day 2004 brought snow shower after snow shower during the morning here but due to being right on the edge of the streamer only 2.5cm accumulated. Some places on the Mendips had much better totals apparently.

 

 

Showers lined up nicely on a NNW flow and intensified on crossing the Severn Estuary from Wales during the early morning. Showers became confined to areas further west during the afternoon. This day brought a classic Pembrokeshire dangler.

 

 

Again in the early morning, a line of showers set up between about 04:00 and 09:00 giving repeated snowfalls. A very similar day to 25/11/2005 in that showers became confined further west as the day progressed only this time a lot of the morning snow melted in sparkling sunshine during the afternoon.

 

 

This is perhaps the best one in recent years with a direct flow off the Severn Estuary so my area got blasted with 10cm, more on higher ground. Clevedon, 5 miles to the northwest received noticeably more but areas south of had less than an inch.

 

 

and this would be the second best example of recent years. Again, I was right on the edge but remember driving out of Bristol late afternoon in the sunshine and driving into dark skies and blizzard-like conditions by the time I got to Yatton. Some areas south of the Mendips were knee-deep in the stuff by the following morning.

 

I can't remember specific occurrences in years before the first chart but these are a few examples. Each situation is slightly different but the general concensus is a northerly with a westerly element can do the trick here.

[Deep Snow please]

Can someone with a bit more knowledge than me explain what sort of set up we'd need to get something like the Buffalo event in Britain?

[Hocus Pocus]

Can someone with a bit more knowledge than me explain what sort of set up we'd need to get something like the Buffalo event in Britain?

A return to the ice age.

[NorthYorksWeather]

Can someone with a bit more knowledge than me explain what sort of set up we'd need to get something like the Buffalo event in Britain?

 

 

Im unaware of the exact conditions they had over there but the North Sea would have to be warmer than it currently is and we would need to see sub -20 850hpa upper air temps crossing on a strong easterly gale, even then I'm not sure we would get 7 feet ..

[Summer Sun]

Can't remember the exact date (possibly Sunday 5th into Monday 6th) in Dec 2010 wow what a snowfall it was a good 4 to 6 inches fell overnight then the Monday morning was a winter wonderland

 

 

[Hellboy]

 

8th JAN.2003.

 

 

Perhaps doesnt look much at face value but 6 hours later a convergence zone developed in the Thames Estuary and a snow streamer began around the Southend area and developed further WSW, towards N.W. Kent and S.E. London. Started snowing here, on the Kent/London border, around 7 a.m. and finally petered out in the early afternoon, depositing around 4 inches. Worst hit areas reported around 8/9 inches, between Southend and Dartford, also places with a bit of elevation over N.W.Kent.

 

I remember this event quite well. I was only 13 at the time and remember thinking how great the timing of it was (7am ish) as it meant I got the day off of school. Alot of people got stuck for most of the day unfortunately.

I think I had 5-6 inches here and it seemed to be turn into more 'wet snow' just before midday for about an hour. It petered out here mid afternoon and at one point we had some of the 'polystyrene balls' that Paul referred to a few year later.

Definitely the Greenhithe/Dartford area bore the brunt of it with patches of snow remaining considerably longer than in Medway.

ETA: Does anyone have the post from Paul with his explanation of the 'polystyrene balls'?

Edited November 20, 2014 by Hellboy

[Yarmy]

Wash streamer late Dec 09 produced several inches of powder here (more than a foot inland at selected spots). I don't think we could ever get the low enough upper temps, high enough SSTs and large enough depression from the North to East quadrant to produce several feet (outside of a drift).

[Daniel*]

I don't think we've had a thames streamer since 09'

god we are overdue one they are a thing of beauty - the build up is is pure ecstasy! Very unpredictable And what follows, does not disappoint I'd take it over a west to east, snow event any day of the week.

In 09' we got 25cm-30cm super impressive for my location total gridlock it doesn't happen often

[J10]

Great read there! Being on the other side of the country, the streamers we get here are often affected by the Severn Estuary, more so at the front end of the season and then it's luck of the draw where streamers set up during the second half of the winter. Here are some examples that produced shower streamers off the Severn Estuary and gave quite localised differences in snow amounts.

 

 

Christmas Day 2004 brought snow shower after snow shower during the morning here but due to being right on the edge of the streamer only 2.5cm accumulated. Some places on the Mendips had much better totals apparently.

 

 

Showers lined up nicely on a NNW flow and intensified on crossing the Severn Estuary from Wales during the early morning. Showers became confined to areas further west during the afternoon. This day brought a classic Pembrokeshire dangler.

 

 

Again in the early morning, a line of showers set up between about 04:00 and 09:00 giving repeated snowfalls. A very similar day to 25/11/2005 in that showers became confined further west as the day progressed only this time a lot of the morning snow melted in sparkling sunshine during the afternoon.

 

 

This is perhaps the best one in recent years with a direct flow off the Severn Estuary so my area got blasted with 10cm, more on higher ground. Clevedon, 5 miles to the northwest received noticeably more but areas south of had less than an inch.

 

 

and this would be the second best example of recent years. Again, I was right on the edge but remember driving out of Bristol late afternoon in the sunshine and driving into dark skies and blizzard-like conditions by the time I got to Yatton. Some areas south of the Mendips were knee-deep in the stuff by the following morning.

 

I can't remember specific occurrences in years before the first chart but these are a few examples. Each situation is slightly different but the general concensus is a northerly with a westerly element can do the trick here.

 

Many of those events delivered snow here, on the evening of 25 Dec 2004, we had snow showers, but only gave around 1 inch and it turned slushy by Boxing Day morning, however this is not as good as a similar event on 25 Dec 01 which gave several inches of snow, and stuck around for a few days.

 

25 Nov 2005 gave around 4 inches of snow and this stuck around for a number of days.

 

17 Dec 2010 was a fairly rare beast, not only a snow streamer which gave about 4-5 inches of snow, the cold at that time, meant that is stuck for around 10-11 days.

 

Late December 09 doesn't ring any bells but I'll check my records

 

After such a good start to the century in terms of NNW winds giving snow streamers, things have gone very quiet on that front for a number of years.

[johnholmes]

The only major event for this low area of England is 30 Nov-1 Dec 2010 when in 12 hours we had 35cm dropped on this area. I did a fairly detailed post which you might find somewhere in Net Wx files with a map showing 20, 30 and 40+cm in Lincs, Yorks and Derbyshire, along with T-phi info, sat piccs etc.

 

found it amongst my own files, so hope it copies into here

 

Snowfall of 30 November into 1 December in this area.doc

 

I was going to upload some photos/videos of around my house but not able to will try again tomorrow

Edited November 20, 2014 by johnholmes

[cheese]

I don't think we've ever had a streamer event here.

[Weather-history]

NWly winds often bring streamers to Merseyside, Cheshire, South Lancashire and Greater Manchester, all year round, rain or snow.

Late December 2001

The big event was the night of 4th/5th January 2010

[Deep Snow please]

Im unaware of the exact conditions they had over there but the North Sea would have to be warmer than it currently is and we would need to see sub -20 850hpa upper air temps crossing on a strong easterly gale, even then I'm not sure we would get 7 feet ..

 

So basically the mother of all NE'lys and a huge dose of luck?

[Summer of 95]

The best streamer events here in recent years were:

17 Dec 2010 Cheshire Gap setup established during the early hours, and persisted with showers on and off till the evening. Was quite localised though, 8cm had accumulated in Shrewsbury by the evening but there was barely 1cm just 5 miles to the west. The following day had more general snow where the areas that missed out got in on the act

1-2 Dec 2010. A rare case of a Wash streamer reaching all the way here, giving 2 days of snow showers that accumulated to 7cm.

25 Dec 2004 a brief one but good while it lasted, Cheshire gap again. 3cm fell in less than an hour during the evening to give a white Christmas. Only lasted till the 27th.

[LomondSnowstorm]

Strangely I posted about almost exactly the same thing earlier ('North Sea effect' snow moreso since that's by far the most common round here):

A few of these from memory:

One of the better snowfalls here from the February 2005 cold spell, got 3 inches off this one in Freuchie from about 18 hours worth of snow showers from Tuesday afternoon to Wednesday morning, although melted soon after.

Quite an impressive snowfall in an otherwise awful winter for snow, although that was partly because we were in Crieff at the time.

 

 

About 3 inches from this in the ultimately disappointing February 2009 cold spell, our convective accumulations were melted by a front moving north from London introducing less cold uppers which turned the snow to rain. 

 

 

December 2009/January 2010:

The first snowfall of that exceptional spell, as with the February '09 one featured (I believe) a Forth-Clyde streamer (or was that the rare 'Tay-Clyde' streamer event?) which gave substantial snow all the way through the central belt to Glasgow. 

The Inverness hogmanay blizzard. Not much snow this far south but impressive totals for the Highlands.

Decent easterly this with snow already on the ground almost everywhere, another Forth-Clyde streamer and places either side of the Forth got pelted, moreso south Fife. 

November 2010:

The ultimate convective easterly, brought well over a foot for most of eastern Scotland, the most snow I can remember, and I think almost everywhere had some cover from it. After a trough which was characteristically similar to a polar low brought heavy snow and 1-2 inches in a very short space of time on the Friday night the main event kicked off on a frigid Saturday evening, when the wind shifted easterly and the first band headed inland. After that, wave after wave of snow came in only eventually stopping by the Friday, and even then we still had another snowfall the following Monday.

One that delivered a fair amount (4 inches widely, more like 8 I think for parts of Edinburgh) but promised even more. So slack was the flow that the first wave of snow sat out in the North Sea for about 8 hours on Saturday night before eventually making landfall, after which the more sporadic showers (which are usually better IMO) brought snow inland throughout Sunday.

Synoptically one of the best of recent times in the best month (and actually the coldest too) synoptically since December 2010, but with lower SSTs and stronger sunlight than during the early part of winter it could've been so much better. Still, -5C with snow falling on the Monday morning was impressive and so was almost managing to get an ice day in central Edinburgh in mid-March. 

 

 

Another few events, broadening out to streamers in general:

Another from the incredible December '09-January 2010 spell, a Clyde-Forth streamer which delivered a few inches across the central belt.

A very interesting event where a trough developed along the (almost unforecast) west-to east 'kink' in the flow almost perfectly aligned topographically for central Scotland, bringing over a foot to the M 8 and leading to the sacking of our transport minister for failing to consult the forum instead of relying on the MO ice/1-2cm of snow yellow warning issued the night before (upgraded to orange once the snow was already on the ground)

 

The classic Newcastle-Fort William streamer, another quirky snowfall which was short lived but very heavy and gave 1-3 inches for much of northern Britain, moreso central, southern and eastern Scotland and northeast England.

[Weather-history]

New Year's Eve 1996 brought a streamer from the Humber all the way to North Wales

[Snowmadsam]

Don't forget the classic Pembrokeshire Dangler too, this bought heavy snowfall to Western area around the 25th November 2005  

[FetchCB]

Feb 2009 Streamer analysed by Paul Sherman

 

https://forum.netweather.tv/topic/53635-thames-snow-streamer-event-12nd-feb-2009/

[Wynn D Woo]

Don't forget the classic Pembrokeshire Dangler too, this bought heavy snowfall to Western area around the 25th November 2005

Not just Pembrokeshire that got affected then either. We were living in Pontyclun at the time and got a good 5/6 inches out of that north northwesterly.

[virtualsphere]

Not just Pembrokeshire that got affected then either. We were living in Pontyclun at the time and got a good 5/6 inches out of that north northwesterly.

 

The 2005 event was the best I've experienced, affecting parts much further east than usual.  Here in Carmarthenshire we had the deepest snowfall I'd seen since at least 1996, possibly longer (although we've since had more in Feb '07, Jan '10, Dec '10 and Jan '13, so that may just illustrate how poor the 1997 - 2004 period was for snow here).

http://news.bbc.co.uk/1/hi/wales/4470188.stm

http://news.bbc.co.uk/1/hi/wales/4468222.stm

Some good analysis here: http://www.geologywales.co.uk/storms/autumn05b.htm

 

J10's earlier post also reminded me of the 2001 event which delivered some decent snowfall on Boxing Day for us:

 

 

We also had a dusting on Christmas Day 2004. For Christmas Day snowfall though 1993 was the best I can remember, although looking at the charts I'm not convinced it was a northerly streamer set-up:

[Jackfrost]

December 17th 2010 was a classic streamer in these parts. It was very localised with a band of very narrow, very intense snow stretched across Wales from NW to SE. Fortunately I was under it for the duration and it deposited 12-15 inches eventually.

 

Pictures here.

 

https://forum.netweather.tv/gallery/image/13037-picture-11467jpg/

 

December 21st 2009 was quite an unusual event in that it saw a continuous stream of showers moving into South Wales from the Bristol Channel; very localised but that deposited five inches or so in these parts. 

Edited November 21, 2014 by Jackfrost

[Tom Quintavalle]

A quick thanks to all those who have shared their "Streamer" experiences and an additional thanks to FetchCB for posting a link to Paul Shermans' superb analysis of that Feb 2009 event.

 

Another favourite "Streamer" event of mine occurred in Feb 1983 but as it took place on the East Kent coast, it entailed a "Snow Chase" trek by train/bus, across the whole length of the county, from my home in Bromley (Kent/London border).

 

FEB 7th/8th 1983

 

 

The Winter of 1982/1983 had been pretty mild and non-eventful up until the first week of February but the situation changed rapidly on the 5th/6th, as an area of low pressure dived SE from Iceland, down through the N.Sea, to settle over N.Italy, meanwhile a mid-Atlantic high threw up a ridge towards the Greenland/Iceland area and a very cold N/NE flow became established by the 7th, especially over the E/SE of the UK. Obviously, without access to weather radar I was unaware of the amount of snow that was falling, moreso to the extreme east of Kent. I became alerted to the situation whilst listening to a broadcast by Philip Eden, during a weather slot he had at the time, on LBC radio, a staion that can be heard in the London area. A 36 hour streamer had set-up in the N/NE flow and had given copious amounts of snow, all the way from the extreme NE tip of Kent down towards the Folkestone area.

I promptly phoned my place of work and hastily arranged to have the day off (9th Feb). On the Kent/London border we'd had a few lightish snow showers that had given a sporadic covering. I was concerned that I was about to embark on a "wild goose chase" but I neednt had feared the outcome. As my train sped eastwards, deeper into Kent, more definite patches of snow could be seen on the tops of the N.Downs as we approached the Medway towns of Rochester/Chatham and Gillingham. Once we had cleared Faversham, snow depths increased as this part of the N.Kent coast is fully exposed to the NE, no longer being sheltered by the Isle of Sheppey. On reaching Canterbury depths had increased further, around 3"/4". The railway line then turns SE towards Dover and it was here that the full effect of this streamer could be viewed, as we travelled on through the old Kent coal mining villages of Snowdown (well named!) and Shepherdswell, I estimate snow depths were around 9" or so. Finally my train arrived at Dover, snow lay around 6" deep around the town, even down on the seafront, a mantle of white lay a few inches deep.

 

But I wanted more, Philip Eden had mentioned some of the heaviest falls had occurred on the extreme eastern end of the N.Downs, between Dover and Folkestone, at the village of Capel-le-Ferne (500/550 ft asl). Locating Dovers' Bus Station, I managed to find the service that runs to Folkestone via Capel. As I boarded the bus and enquired about the fare to Capel, the driver gave me a look and questioned my sanity but I insisted that I wanted to be put down at Capel. As the bus climbed the West Hill out of Dover, I actually started to doubt my own sanity, as the landscape became one mass of white, with no discernible features no longer visible. 

We finally arrived at Capel and with the driver mumbling something like "I told you so and good luck", I stepped off the bus and promptly sank into snow, an inch or so, above my knees ! I decided that my safest route would be to keep to those areas of pathway that had been cleared. Although I had taken the precaution of wearing plenty of layers of clothing, the NE wind was unforgiving and literally took my breath away. I walked along to the cliff top above the Channel and encountered a few of the locals attempting to clear their driveways. That part of the Kent coast is littered with many bungalows and the drifting of the snow, was a sight to behold, up to the eaves of the properties, probably 10 feet or so in places. Speaking to some of the locals it seems that once the snow showers had initiated, they continued virtually unabated for a day and a half and there were reports of a few properties being damaged by lightning strikes, along the E.Kent coast.

 

I decided that I'd had enough, as my whole body by that time was starting to feel numb with cold, so I then proceeded to catch the next available bus back down into Dover and then caught a train and returned home to Bromley.

 

Analysis of the event showed that part of the reason for such high snowfall rates in the area, accompanied by frequent lightning/thunder, was due to unseasonably high SSTs in the southern N.Sea/Dover Straits, adjacent to the E.Kent coast.

 

It certainly was an amazing experience and one that triggered my fascination for these "Snow Streamer" events. And any of you snow junkies out there who like their snow especially deep, crisp and drifted, and live in striking distance of the area, I would certainly recommend a trip up to Capel-le-Ferne, when conditions are ripe for an East Kent streamer! 

 

Regards,

Tom.

Edited November 22, 2014 by TomBR7