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NickR
24 February 2018 07:29:48
ECM basically = huge snow totals in SW and NE. Add in extra for convection in the E.

https://weather.us/model-charts/euro/2018022400/england/snow-depth-in/20180306-0000z.html 
Nick
Durham
[email protected]
Nordic Snowman
24 February 2018 07:31:09


 


There was the famous February 198X debacle. 


Originally Posted by: Brian Gaze 


Yes.


Having now seen ECM, it is also remarkable with its consistency in keeping on the right side of marginal. A snow-fest for sure for large swathes of the S.


I also alluded to a possible 'rinse and repeat' after yesterday's ECM and I can see that again this morning. We know that GFS is generally prone in being too progressive and in this instance, I have far more credence with ECM. EPS will be interesting later, as will the METO extended outlook. I rather suspect that the outcome in both will be good for fans of both snow and cold...


Bjorli, Norway

Website 
Crepuscular Ray
24 February 2018 07:37:34
Mods....i'll put this in here. Would it be possible to keep this weeks threads simple?

Models
Media
Snow Reports
Snow Potential
Low temperatures
Current Conditions (for the snow starved)

Rather than cluttering with similar titles where posts maybe lost and unread?

It's going to get manic in here
Jerry
Edinburgh, in the frost hollow below Blackford Hill
Gooner
24 February 2018 07:38:58


 


Indeed, my location is one that used to do very well back in the day, as did much of the north Kent coastal strip.


Something worth mentioning is that the raw forecasts from the GFS have been slowly ramping up snow volumes here. I find XCWeather's presentation to be really nice, so here's the link to MBY:


http://xcweather.co.uk/forecast/leysdown


Of note is that from Sunday night snow is forecast even though it doesn't show a snow symbol - it seems anything under 0.5mm rainfall equivalent is just shown as cloud.


As we know, the models struggle to resolve shallow cumulus/cumulonimbus clouds and thus tend to underestimate convective snowfall. Yesterday was a prime example. The models showed unbroken sunshine all day, yet shallow cumulus built up during the morning and by afternoon the sky was mostly obscured.


I've been keeping the senior team at the school where I work updated these past few days. The Head was most sceptical, believing it'd just get cold and sunny (as the automated forecasts at the time were showing), but they've ordered in extra salt as a precaution. Not, as the site team say, it'll do much good with blowing powder snow!


I've got Monday off work, booked that day off ages ago, so should miss the first round of traffic chaos. I'm not much looking forward to Tuesday's commute, though!


Originally Posted by: Retron 


I have just put Banbury into the XCWeather link and on todays showing we had hammered at the end of the week, worth keeping an eye on.


EDIT yet the weather.us gives me nothing from the ECM run, something I find very hard to believe. IMBYism for sure


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Rob K
24 February 2018 07:52:45

ECM basically = huge snow totals in SW and NE. Add in extra for convection in the E.

https://weather.us/model-charts/euro/2018022400/england/snow-depth-in/20180306-0000z.html

Originally Posted by: NickR 


Spot the "Doughnut of Despair" along the Thames Valley, with snow on all sides. ;)


Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
Arbroath 1320
24 February 2018 07:59:38

The GFS 00z ENS for Edinburgh are nuts, particularly the Control run. The Op is on the mild side of the mean from 3 March:


https://www.theweatheroutlook.com/twodata/gefs.aspx?run=na&lg=850&lglocation=edinburgh


 


 


GGTTH
kmoorman
24 February 2018 07:59:52


 


Spot the "Doughnut of Despair" along the Thames Valley, with snow on all sides. ;)


Originally Posted by: Rob K 


 


Is that simply rain in that narrow area?


Home: Durrington, Worthing, West Sussex. (16 ASL)
Work: Canary Wharf, London
Follow me on Twitter @kmoorman1968
Brian Gaze
24 February 2018 08:07:30

Big health warning as usual with snow depths but ICON doesn't look too dissimilar to the UK warnings. Many people are likely to be disappointed if the projections are near to the mark. 


FWIW the ICON EUNEST (0.0625) is double the resolution of the ECM IFS (0.128) 



Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
NickR
24 February 2018 08:11:39
That is VERY different from GFS and ECM accumulation charts, Brian. Any idea why?
Nick
Durham
[email protected]
Brian Gaze
24 February 2018 08:16:13

That is VERY different from GFS and ECM accumulation charts, Brian. Any idea why?

Originally Posted by: NickR 


I've not looked in-depth today so don't know. The ICON chart is for the next 120 hours.


Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
Whether Idle
24 February 2018 08:20:57

,


Big health warning as usual with snow depths but ICON doesn't look too dissimilar to the UK warnings. Many people are likely to be disappointed if the projections are near to the mark. 


FWIW the ICON EUNEST (0.0625) is double the resolution of the ECM IFS (0.128) 


 


Originally Posted by: Brian Gaze 


Snow depth charts at a range of more than 2 days I have found to be hugely misleading in the past, nevertheless, speaking from my own perspective, with wind direction being key, only places prone in a ENE or Ely wind should expect much in the way of accumulations.


Most folk on here will know what that means for them.  IMBY it means very little if any, accumulation, most times  a NEly is required.


Dover, 5m asl. Half a mile from the south coast.
doctormog
24 February 2018 08:22:47

I suspect that the ICON model is seriously underdoing or simply not modelling any convective precipitation. Indeed it also seems to be underestimating the snow from any embedded features. I guess it could be right but I would say it is in the minority and doesn’t seem to reflect synoptics.


Whether Idle
24 February 2018 08:24:08

I suspect that the ICON model is seriously undergoing or simply not modelling any convective precipitation. Indeed it also seems to be underestimating the snow from any embedded features. I guess it could be right but I would say it is in the minority and doesn’t seem to reflect synoptics.

Originally Posted by: doctormog 


The ICON diverges as early as t72.  (see my post from earlier this morning, a page or two or three back).


 


Dover, 5m asl. Half a mile from the south coast.
Brian Gaze
24 February 2018 08:24:52


,


Snow depth charts at a range of more than 2 days I have found to be hugely misleading in the past, nevertheless, speaking from my own perspective, with wind direction being key, only places prone in a ENE or Ely wind should expect much in the way of accumulations.


Most folk on here will know what that means for them.  IMBY it means very little if any, accumulation, most times  a NEly is required.


Originally Posted by: Whether Idle 


That's why the coming week will be so interesting. Genuinely cold uppers from the east but for many people this could turn out to be a complete bake. If low pressure quickly pushes up from the south after Thursday it may be sunny and cold days ("wrap up warm"), sharp nighttime frosts then several hours of heavy snow followed by rain and spring. That's not me "trolling". I'm just offering one possible scenario. An alternative is for heavy snow showers to be widespread and then blizzards to sweep the south late in the week before the cold block reasserts itself.


Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
forestedge
24 February 2018 08:26:41


For me the GFS is blowing the Low up in situ which is something it has a bias to do, this is an old school spell and those of us old enough to remember know that the first attack never succeeds is dislodging the cold air, but may bring plenty of snow to the far SW/S. I favour the ECM solution of the Lows spinning back and the UK remaining on the cold side until at least day 9.


Originally Posted by: Shropshire 


Yes exactly, the first attempt usually failed. That is such a massive block I feel the lows will stay south with perhaps only extreme southeast being grazed by milder uppers 


Roger
Ashurst Bridge (New Forest)
9m ASL
https://www.newforestweather.co.uk 
Whether Idle
24 February 2018 08:27:23


 


That's why the coming week will be so interesting. Genuinely cold uppers from the east but for many people this could turn out to be a complete bake. If low pressure quickly pushes up from the south after Thursday it may be sunny and cold days ("wrap up warm"), sharp nighttime frosts then several hours of heavy snow followed by rain and spring. That's not me "trolling". I'm just offering one possible scenario. An alternative is for heavy snow showers to be widespread and then blizzards to sweep the south late in the week before the cold block reasserts itself.


Originally Posted by: Brian Gaze 


Agreed.  the key is to keep expectations low, as then you wont be disappointed.  For me I know the wind direction is simply too East, and I accept that, but there could be an embedded trough if I'm lucky.


Meanwhile, the ECM ens paint a cold cold picture:


https://www.weerplaza.nl/15daagseverwachting/?type=eps_pluim&element=&r=zuidwest


 


Dover, 5m asl. Half a mile from the south coast.
Bertwhistle
24 February 2018 08:28:14

Nearly half a metre of snow modelled here for Cheshire/ NE Wales.


https://www.theweatheroutlook.com/twodata/chart.aspx?chart=///www.theweatheroutlook.com/charts/gfs/00_204_uksnowdepth.png?cb=949


 


Bertie, Itchen Valley.
Retire while you can still press the 'retire now' button.
marting
24 February 2018 08:30:41


 


Another tick from me too. I mentioned yesterday that I have seen similar situations result in the attack from the S end up being over France - to the point where we are egging it on to push far enough N to at least affect the far S. I also agree that even the EPS (along with GEFS) will not have this sorted yet because the reality is that the embedded cold can prove notoriously stubborn to displace.


I feel this could be one of those situations where we will see a large swing within the ENS 24-48 hr notice regarding that Low and where it will go.


I really do have a feeling, especially with the METO forecasts, that we will strike it lucky and get the snow and just about remain on the cold side.


Originally Posted by: Nordic Snowman 


Totally agree with this analysis. Very likely that The low will slip through into France and staying cold given METO long term and ECM ensembles.


martin


Martin
Greasby, Wirral.
Bertwhistle
24 February 2018 08:31:44

GFS ensemble mean goes under the -15 850 mark.


https://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gefs/gefsens850london0.png?cb=235


 


Bertie, Itchen Valley.
Retire while you can still press the 'retire now' button.
Joe Bloggs
24 February 2018 08:33:29

Interesting discussion regarding convective precipitation. 


With a cold pool as deep as this I really don’t think it’ll be particularly dry. 



Some places may miss out but I think the amounts of snow could be noteworthy, especially in the east. At the moment it’s just impossible to say exactly where. Lots of radar watching next week. 



Manchester City Centre, 31m ASL

nsrobins
24 February 2018 08:33:51


 


That's why the coming week will be so interesting. Genuinely cold uppers from the east but for many people this could turn out to be a complete bake. If low pressure quickly pushes up from the south after Thursday it may be sunny and cold days ("wrap up warm"), sharp nighttime frosts then several hours of heavy snow followed by rain and spring. That's not me "trolling". I'm just offering one possible scenario. An alternative is for heavy snow showers to be widespread and then blizzards to sweep the south late in the week before the cold block reasserts itself.


Originally Posted by: Brian Gaze 


Spot on. We simply don’t know, but what was just radar and curtain twitching 20 years ago is now an impressive raft of models and data and tweets offering professional insight so we should know on day to day basis where the CVZs and streams will set up. Still can’t predict this though at this range, and the ppn charts are as has been said sometimes next to useless.


Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Rob K
24 February 2018 08:35:23


Big health warning as usual with snow depths but ICON doesn't look too dissimilar to the UK warnings. Many people are likely to be disappointed if the projections are near to the mark. 


FWIW the ICON EUNEST (0.0625) is double the resolution of the ECM IFS (0.128) 



Originally Posted by: Brian Gaze 


But that's before any major snow event, so surely about what would be expected? Snow on the coasts (probably more tthan modelled along a narrow coastal strip too small to be modelled) and areas exposed to streamers, plus NYM etc, but not much inland: that is standard for an easterly isn't it? I don't think anyone other than the usual suspects are expecting more than the odd shower until the end of the week.  


Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
BJBlake
24 February 2018 08:35:35

Whatever happens with the detail now, this is going to be a historic and memorable event, just watching the models advect the cold air - the high orientated NE - Sw dragging Siberian air into Western Europe and then seeing the high flatten E-W and propell that sub 510 DAM air over the ok like an ice dragon,  sucking in momentarily before spewing its icy fury at the UK, is a jaw dropping sight, reminiscent of yesteryear, when these things were a little more common, but as these events seem to come in clusters, this alludes to the possibility of us being spoiled by a repeat next year, as we inch closer to the maunder low, combined with a millennial low sun-spot period, which, even in these globally warmed times, will see some historic winters return. If there is a cold pool - it can be sent our way by the right Synoptics, and the low sun-spot period provides more chance of this, although the causal link is not so clear as far as I have reAd. 


It is a delight how the rankles and bickers have now stopped as us weather geeks unify in celebration of a shared wonder at such obviously stocking model outputs that are the stuff of our dreams - I open this forum every morning with eagerness and am never disappointed with the insights. - and frankly enjoy the manic ramping too.  Here's to the ice-dragon beast from the east!!


Brecklands, South Norfolk 28m ASL
Rob K
24 February 2018 08:39:00


 


Agreed.  the key is to keep expectations low, as then you wont be disappointed.  For me I know the wind direction is simply too East, and I accept that, but there could be an embedded trough if I'm lucky.


Meanwhile, the ECM ens paint a cold cold picture:


https://www.weerplaza.nl/15daagseverwachting/?type=eps_pluim&element=&r=zuidwest


 


Originally Posted by: Whether Idle 


You can see the uncertainty kick in by Friday. The op run was on the low side especially in terms of dewpoint but of course that's for Holland so a low heading further east could introduce milder air there while the UK keeps colder air on the northern flank. 


Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
Heavy Weather 2013
24 February 2018 08:39:35
This link shows up the potential for streamers already.

WRF NMM:
https://images.meteociel.fr/im/821/tempresult_vzf8.gif 

I am based in Stratford, East London - So pretty confident of seeing something over the next few days.

Experience tells me that the low
Pressure pushing up from Sourb will be slower and may miss altogeather.

I’ve been a long term lurker and previous member here, and frankly I am the most excited I have ever been since I found TWO back in 2001


Mark
Beckton, E London
Less than 500m from the end of London City Airport runway.
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