Kentspur

January 6

3 hours ago, Challock Weather said:

Up on the North Downs halfway between Ashford and Faversham #sesnowcapital

Found a fair few in my Grandads side of the family tree from there and surrounds my mums from East Kent originally

January 6

11 hours ago, Kent Blizzard said:

Afternoon Met4Cast

I'm also keeping a close eye on it, I've a landscaping project starting in Lordswood. Even 2-3cm would most likely rule out it starting, That depth can also cause chaos on the roads round that way off the.main routes.

Ive been stuck in Lordawood at a friends twice in the past lol once when lower ground i.e Chatham had no snow!

January 6

18 minutes ago, Purga said:

Blimey - another easterly for the south at day 11 !

So much better than a failed dry Northerly which gets threatened by the Iberian high everytime it attempts to move south of the Midlands think im going to stick to the snow potential in the reliable period Monday for now too far away still to know about this period! Exciting times fellow Southern/Southeasterners

January 6

While many are looking in fi still. In the nearer term what's Icons take via Ventusky. Seems like a mid Kent&Medway Clipper becomes a Thames streamer followed by some light wintry showers making it further SW to parts of the south coast and IOW then onwards to the likes of Devon eventually. For my part of Kent Surrey Sussex/S Essex and London it Definitely looks an upgrade particularly during Monday night and lasts longer too!

January 5

5 minutes ago, Purga said:

There'll be more than a few Swearing AGAIN*d off southerners if this verifies.

And this confirms why us southerners/SE are more interested in anything from the East as per the more reliable timeframe if Kasims 2-8cms comes off for here I'd happily take that if this was to materialise with 0 snow later in Jan

January 5

25 minutes ago, booferking said:

Polar low moving north to south

I'd let the north hog this in fi as long as we get atleast a little dusting in the more reliable timeframe from the east this coming week hows that?

January 5

27 minutes ago, Coopsy said:

Yup could def see a few cms from this set up. Locally more for those in the firing line.

North Kent generally benefit well from this set up, from the streamer type formation as well as the advantage of having orographic lift from 0-200m plus in a few miles.

Though anyone on the north sea coast and further inland could benefit depending on wind direction and intensity and how far inland they get.

Usual spots at higher elevation could do well along North Downs of Kent from Biggin Hill along to Detling Hill, and in between like Lordswood, Walderslade, BlueBell Hill etc.

Definitely I've been stuck at my friends who used to live in Lordswood twice before once 8inches of snow while there's a slush fest 2miles away on lower ground! Same.here there won't be anything by the Thames a 2mile drive south or east and it can be like Narnia. Interesting how there's no mention on TV forecasts yet not even "possible Showers"

January 5

Mention of Hill snow on local Met update for London&the SE finally! But national weather not mentioning anything just dry. Well here's the latest tale from Ventuskys Icon precip charts-

Looks like a Kent&Medway& East Coast Clipper gradually becomes a bit of a Thames Streamer down to the south coast& IOW and a few isolated wintery showers further west as the winds turn more E of NE nothing major but would be nice to see it come off!

January 5

37 minutes ago, sheikhy said:

Massive changes over the pole aswell on ecm with stronger heights!!not sure where all that strong ridging into greenland has dissapeared off to though in the last 24 hours!!!!i know some keep saying we dont need strong heights but this is making me kinda nervous lol!!

GFS the trend finder right? Despite its recent verification stats

January 5

17 minutes ago, Mark wheeler said:

Have posted in regional but for one last time will do here too as it's been spoken about for some time . Nmm backs aprege . With uppers not to different to the 12z Ecm coming out .

Seems a light streamer from the far E/S of Essex increasing a little as it crosses the Thames through my area down to the North Downs of East Surrey and NW Kent &Weald of Sevenoaks and surrounds and down to the Sussex South Downs even a light dusting id take I had my snow fix in Sweden in November

January 5

Just now, Jason M said:

Yes, but actually the northern side of the estuary looks better placed this time (unusually). I think here I'll see a bit of light snow but even right in the sweet spot it will amount to very little. We are not going to see much snow with pressure that high.

Surprised by that! Don't think I've ever seen a ENEly wind flow forecast bring more of the white stuff north of the Thames only a Direct Ely or a ESEly like during the Feb 2018 Beast most the models I just looked at show a line from the far east coast of East Anglias through here to West Kent- Sussex with others towards the Isle of Wight etc

January 5

9 hours ago, Tom Quintavalle said:

A very good Morning, all.

Hope I find yourselves and your Families well, and that you havn't been affected by flooding after the recent heavy rainfall.

My attention now turns to the anticipated Cold Spell that has been "flagged up", in Forecast Outlooks.

It's been a while since I've been able to post about my "Pet Subject". That being "Thames Snow Streamers", which have been notably absent in recent Januarys.

Although in this January, my interest is tempered by the knowledge that I will need to have an intensive course of Radiotherapy after a diagnosis of Prostate Cancer, a Week before Christmas. I've already had a Telephone Consultation cancelled with an Oncologist due to the pressure on the Lewisham/Greenwich NHS Trust, in part due to the Junior Doctor's strike.

My course of Radiotherapy will be conducted at Queen Mary's Hospital, Sidcup.

Should the Weather become Wintry as we head further into January, road conditions out in that area could become very tricky, and cause me problems getting to and from Sidcup.

I just want to post up some examples of notable "Thames Snow Streamer" events that have affected our Region, in the last few Decades.

Firstly, a Wikipedia explanation of the dynamics of how these "Snow Streamer" events, develop

"Lake-effect snow is produced during cooler atmospheric conditions when a cold air mass moves across long expanses of warmer lake water. The lower layer of air, heated by the lake water, picks up water vapor from the lake and rises through colder air. The vapor then freezes and is deposited on the leeward (downwind) shores.

The same effect also occurs over bodies of saline water, when it is termed ocean-effect or bay-effect snow. The effect is enhanced when the moving air mass is uplifted by the orographic influence of higher elevations on the downwind shores. This uplifting can produce narrow but very intense bands of precipitation, which deposit at a rate of many inches of snow each hour, often resulting in a large amount of total snowfall."

Now, how the same process can affect our Region, and One that affects the N.W. of England.

UNITED KINGDOM

"In the United Kingdom, easterly winds bringing cold continental air across the North Sea can lead to a similar phenomenon. Locally, it is also known as "lake-effect snow" despite the snow coming in from the sea rather than a lake. Similarly during a north-westerly wind, snow showers can form coming in from the Liverpool Bay, coming down the Cheshire gap, causing snowfall in the West Midlands—this formation resulted in the white Christmas of 2004 in the area, and most recently the heavy snowfall of 8 December 2017 and 30 January 2019.

The best-known example occurred in January 1987, when record-breaking cold air (associated with an upper low) moved across the North Sea towards the UK. The result was over 2 ft of snow for coastal areas, leading to communities being cut off for over a week. The latest of these events to affect Britain's east coast occurred on November 30, 2017; February 28, 2018; and March 17, 2018; in connection with the 2018 Great Britain and Ireland cold wave.The second event of winter 2017/18 was particularly severe, with up to 27.5 inches (70 cm) falling in total over the 27th–28th."

Currently, the Sea Surface Temperature of the Coast of Southend-on-Sea is, 8.9°C.

Below, is the UKMO Forecast Chart [500hPa] for Mon. 8th January, with the accompanying Upper Air [850hPa] Forecast Chart, for Midnight. This would give a temperature differential of around 16C between the Upper Air and the Southern North Sea but with Air Pressure of between 1035mbs and 1030 mbs, should be too high to allow any convection, to develop.

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Now, a few examples of more conducive Synoptics that allowed some more notable Snowfall events, for our Region.

The most notable of these has to be the widespread and heavy Snowfalls that affected our Region, in January 1987.

With Upper Air [850hPa] close to around -20C over the Southern North Sea and a Sea Surface Temperature of around +8C.

With a Temperature differential of around 28C, it was no wonder that the Snowfall was so heavy. More like a Sea of Snow, than a Streamer!!

  /

Now, what was my first recollection of a "Thames Snow Streamer" event, and one that was to give a "White Christmas" for some parts of our Region and a huge crack of Thunder, in the early hours of Christmas Morning, 1970:

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The following "Thames Snow Streamer" was the subject of an excellent Thread in the Historic Weather Forum, by our own, DANM.

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Below, is a Youtube clip of Peter Gibbs with the Morning Forecast, depicting that "Thames Snow Streamer", moving across our Region, during the Morning of 8th January 2003:

Two final notable "Thames Snow Streamer" events that gave some appreciable Snowfalls, for our Region,

Firstly, on 1st/2nd February 2009.

The temperature differential between Upper Air [850hPa] and the Southern North Sea would have been around 25C.

This event also gave "Thunder Snow" in the East of our Region, including my location.

/

Finally, the infamous  event, in late February 2018.

Below, are the 500hPa and 850hPa [Upper Air] charts for the early Evening of 26th February.

This would have given a rough temperature differential between the Southern North Sea and the Upper Air of around the mid +20'sC:

/

I hope for the newest members of our Region the above will partly explain why these Synoptics and "Thames Snow Streamer" events in particular for some in our Region are the "Holy Grail" in the Months of Meteorological Winter, and what to look out for, if you're wanting a repetition of something sinilar.

Now, I realise I've probably gone and "jinxed" the chances of some long overdue January Snowfall for our Region but as I mentioned at the start of this post, my interest is tempered by my current health issues, anyway.

Regards,

Tom Q.

Thanks Tom sorry to hear your plagued with another health issue. I've been working at Sidcup lately maybe see you around. Latest models showing some light convection for our part of the world with atleast -10c 850s Monday/Tuesday

January 5

33 minutes ago, Jason M said:

With pressure pf 1035 - 1040 at that point, this must surely be over egging things. Maybe some snow grains around the place but I'll be very surprised if away from areas right on the coast there is much. Even in coastal regions of Kent / Essex only a light dusting I'd have though. I reckon its blown a gasket but we will soon find out!!

In this example though would you class Gravesend/Dartford as Coastal even though they're estuary towns, As normally I think of East Kent etc and Southend as "coastal" but due to.the likely E/ENE wind flow wouldn't my area be in the firing line it seems like the charts show precip heading here also

January 5

Well it gets better the GFS and later on CFS ensembles now bring back the risk of a major SSW!

January 5

7 minutes ago, Kentspur said:

Wow Just look how great UKMO is towards the end of this for the North Atlantic region! Didn't it first call this potential cold spell ahead of the flatter ECM and GFS too? Correct me if I'm wrong

Does this also suggest Christmas day its only worth checking UKMO model for any idea of the forecast for a few days away look at the very poor performance by all the other models. Assuming the balloon data that gets mentioned every Christmas period. Very intriguing!!

January 5

7 minutes ago, RainAllNight said:

Here is some objective data on this subject:

https://charts.ecmwf.int/products/plwww_w_other_ts_upperair?area=Europe&day=5&score=Anomaly correlation

Wow Just look how great UKMO is towards the end of this for the North Atlantic region! Didn't it first call this potential cold spell ahead of the flatter ECM and GFS too? Correct me if I'm wrong

January 5

Thankfully that GFS 18z op run was a outlier at the dodgy timeframe ensembles much better so Increasingly colder with still a small risk of light snow flurries in parts of the SE most runs place Medway down to Sevenoaks Weald etc in with a fair shout and maybe a few miles either side of this too Monday.

Then we see a slight warm up to just below average temps as the high re- orientated before ridging to the North&NW followed by a even colder and potentially snowier period going by the ensembles fingers crossed morning runs are a goodun too!

January 5

3 hours ago, MAF said:

and still raining here in SE18, roads are flooded but idiots still think they can drive as if its bright, sunny, dry and there are no hazards to consider. Grrr.

Had to literally stop on the A2 by Crayford/ Dartford earlier as the road was completely flooded in parts shocking!

January 4

2 minutes ago, Mark wheeler said:

Terrible run Lol . This is where we end up on a negative run.

Dry sunny and frosty nights for the South during most northerlies anyway looks like a outlier post 12th Jan

January 4

Since when was the GFS pub run the run to watch isnt it with less data/lower res than 0z and 12? Combined with verification stats post day 9/10 I'm waiting for the 0z runs to see if there's a new trend?

January 4

31 minutes ago, Kasim Awan said:

Sorry I didn't look properly with -2.5 uppers it is full snow down to 550m so in intensity could be sleet down to 150-200m.

Icon has the Kent streamer.

I'd label this one a light Medway streamer bone dry at my place 2miles further east Shorne to Sheerness the white stuff I'll have to visit my mum in Strood

January 4

24 minutes ago, MATTWOLVES 3 said:

Mike will.do a better job of these clusters but the signal for Blocking is sublime..

@Mike Poole thanks Mike didn't realise you had already done them.

Looks like S/SE especially most at risk there to me in 1st cluster on 14th?

January 4

5 minutes ago, ICE COLD said:

Nice pool of -10 850s on the ECM at T86

-11c over my place wheres the streamer posters gone? Or is it a odd flake in the wind?

January 4

4 minutes ago, Nick F said:

Well, Greece and Turkey get in on the deep cold before we do on 12z GFS

Is Nick Sussex in Cyprus directing the flow east

January 4

1 hour ago, WinterOf47 said:

Thanks! Guessed it was something like that. It is quite insane that despite the evolution in computing power, the ability to forecast with much precision beyond 5 days has only improved incrementally since the 1980s. I am pretty sure AI will fix this. The simple fact is that despite the humongous amount of variables, the weather today should be predictable from the surface and atmospheric data available 3 weeks ago. I know that with each day there is an exponential increase in the amount of calculations, but still, I think there should have been greater improvements than we have seen.

However, would make these discussions a little more boring!

The GFS is showing a potential streamer for Sunday night into Monday morning for the South east. Could give some in West Kent, South Essex, East Surrey, North Sussex and SE London their first snow of the winter, and the first taster of what will hopefully be a memorable spell. Unfortunately the resolution this far out is not great and I’m not sure how granular they get. In Canada we used to have predicted radar down to 3km and that was great at predicting LES, and a little smudge like we see below could drop 20cm in the space of 2 hours! Now only 4 nights away, so may be the GFS is picking up first signs of some potential activity. Just a subtle shift in wind could kill it off though, or enhance it. Close to the coast would be a mix, but inland on the downs especially, could be snow.

I'm in the heart of that streamer what's the latest on that the apps have gone dry any high res models in range yet?

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