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Model output discussion - proper cold spell inbound?

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1 hour ago, Frosty. said:

Well, what a run, I can't contain my enthusiasm:D! cold shots galore with frosts, ice and snow showers / frontal rain / sleet and snow rapidly following each other across the uk on the Gfs 12z hardly drawing breath before the next cold shot sweeps in from the w / nw with extra zing..exciting stuff if you're in the firing line, which most of us would be!!

Potentially the most interesting / exciting period of this winter so far on a nationwide scale is almost upon us..starting with very cold air seeping in from the east through the first half of next week with severe frosts and even snow for some areas ❄❄❄❄❄❄❄❄!!:cold-emoji::)

Well although I like your enthusiasm I think from experience of splitting my time between 200m asl in the pennines and 0m asl on the Thames the models aren't going to provide much in the way of lying snow away from northern regions.

The problem that we have is that the current cold uppers expected to come in from the east aren't associated with a low and thus the air won't be unstable enough to bring much in the way of showers, cold and dry mostly.

The PM flow after won't bring air cold enough for lying snow, its very hard to see lying snow (away from transient accumulation) from North Westerlies, uppers need to be somewhere in the region of -9, as we have seen over the years so many north westerlies bring disappointments. 

Still if your in Northern England northward Tuesday could well bring a covering of snow from a decaying front which will be nice to see, the NWly after would provide some wintry showers, accumulations reserved for the tops of the hills. 

This spell again will not be nationwide, though good luck to northern areas. 

Edited by Cheese Rice

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20 minutes ago, chicken soup said:

I think were about to see the old adage..get the cold in first and the snow will follow exposed for the BS that it is....hi res arpege kills tuesdays front and thurs fri is looking like rain...dont see any other oppurtunitys in the models except maybe a slight dusting on the south east...then more than likely back to mild.

 

I can confidently say your talking bs as temps are already down on yesterday's.

As they continue downwards before long were know if snowfall is likely.

From my amateur eye and remember crazy winters of the 80s then the models are looking amazing and unusual with very cold north Atlantic as cold or even colder than to our east.

ECM is got to be a blinder tonight 

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5 minutes ago, Ice Day said:

GFS and ECM at 72.  Notice that the milder sector has completely filled in on the ECM

GFS gfsnh-1-72.png?12 ECM ECH0-72.GIF?03-0

but our areas seeing no snow Tuesday, FAX suggests same, downgrade on yesterdays runs

fax72s.gif

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to my eyes the ecm continues to downgrade. mild upers coming in with the next ststem yet again. i have to agree with others that this really initially looked good but not much at all now. i think the models will point to a fairly average feb with nothing special apart from snow on the mountains n highest ground.

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Just now, chicken soup said:

And its a very big caveat...pm air has proven to be garbage even here in the northwest..gfs is wrong about the front on tuesday...arpege is a higher res model ...and thurs is as i said looking like rain.

pm air is not garbage, maybe your exact location hasn't seen much snow but that's hardly the weather's fault, the clue is in the 'P' as in 'Polar'.......secondly how on earth can the GFS be wrong about something that hasn't happened yet, that's just a throwaway statement.....the 'arpege/GFS hi-res which is better?' argument is an irrelevance to what happens Tuesday onwards, the GFS verifies well in the short/medium time frame, again IMHO , but I'm not going to start arguing verification stats, as that's for another thread, and who exactly is rain looking like for Thursday?....You?....possibly, but not for many others, Thursday might well produce some snowfall, we won't know until then, but your post was based on the 12z GFS output, I quote "dont see any other oppurtunitys in the models except maybe a slight dusting on the south east...then more than likely back to mild.", that's your intepretation of the model run, not your prediction.....that's fine, I just simply disagree with your intepretation :)

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1 minute ago, Cheese Rice said:

Well although I like your enthusiasm I think from experience of splitting my time between 200m asl in the pennines and 0m asl on the Thames the models aren't going to provide much in the way of lying snow away from northern regions.

The problem that we have is that the current cold uppers expected to come in from the east aren't associated with a low and thus the air won't be unstable enough to bring much in the way of showers, cold and dry mostly.

The PM flow after won't bring air cold enough for lying snow, its very hard to see lying snow (away from transient accumulation) from North Westerlies, uppers need to be somewhere in the region of -9, as we have seen over the years so many north westerlies bring disappointments. 

Still if your in Northern England northward Tuesday could well bring a covering of snow from a decaying front which will be nice to see, the NWly after would provide some wintry showers, accumulations reserved for the tops of the hills. 

This spell again will not be nationwide, though good luck to northern areas. 

I thought it was an exciting run but each to their own, at least the models are looking a lot more interesting compared to the last few Meh weeks which were so dull model wise i couldn't be bothered to post anything.:)

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it is actually true that in NW England, particularly by the coast, you really do need around -10C 850s to deliver snow in *most* (not all) cases where frontal systems are involved (away from high ground and west of the M6. Now people might think I'm on a wind up but I have enough experiences to tell me the last few winter that if there's even the slight chance of an onshore breeze, then rain/sleet could be the outcome here anyway. 

It definitely favours inland areas better, I find the Midlands does well from this type of scenario, and actually sometimes the east and Southeast, if the preciptation reaches there.

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36 minutes ago, danthetan said:

GFS showing frontal snow and then snow showers affecting Pembs Tuesday into Wednesday. Pembrokeshire dangler will be in full swing with a keen North wind blowing down the Irish sea.

84-574UK.gif

66-574UK.gif

Shame, a max of 7C and min 4C is forecast during that time in Tenby = cold rain or sleet if we're lucky 

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Can we please have a rolling eyes for the choice of "thanks" because some peoples posts have my eyes rolling out of my skull and onto the floor. 

ECM is an improvement early doors, no warm sector to speak of across the UK, mid-range is something of a trend now and I think North-Westerlies are looking highly likely to follow the Easterly, remaining rather cold.

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Just now, chicken soup said:

I think were about to see the old adage..get the cold in first and the snow will follow exposed for the BS that it is....hi res arpege kills tuesdays front and thurs fri is looking like rain...dont see any other oppurtunitys in the models except maybe a slight dusting on the south east...then more than likely back to mild.

 

Well one things for sure Chicken soup without the cold there definitely won't be any snow at all. GFS 12Z looks like an upgrade to me but we shall see what weather does.

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2 minutes ago, Dafydd Tomos said:

Shame, a max of 7C and min 4C is forecast during that time in Tenby = cold rain or sleet if we're lucky 

GFS 12z is suggesting it'll be colder than that around your area 

image.jpeg

image.jpeg

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Very good trough disruption at 144 with the Siberian High beginning to back Westwards towards us, very nicely aligned too

Disruption.thumb.gif.ee09e68294751623376a72cb2763f01f.gif

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Well said low heads towards Africa at 168 and a lot of the cold Uppers are washed out. 144 is encouraging though and one to keep an eye on for the 00z.

06604EC8-9EC7-4D12-A9A9-E6E9C002B703.thumb.png.146f032a52d200b6fd65593ff0baddf7.png139785EE-41D1-482C-9A46-9EE8C0722CDF.thumb.png.3693b1a45fe63121fece7cf9fafe3de0.png

 

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Away from this week and into the medium term, there appears to be signs that instead of mild westerlies returning on saturday and then the Azores high could ridge to scandi. By no means a certainty but it could prolong the below average temperatures and help a cold pool return to Scandinavia. An example of this in this GFS ensemble member. This is probably the best case scenario shown but a few others are treading along the same path.

image.thumb.png.d575faede3040c03b1d020a50797941b.png

Although the north-west Atlantic is cold, some milder air will get mixed into the flow, unless the NAO can turn negative with Atlantic ridging. However with the active PV that would be difficult. Fingers crossed high pressure can return to Scandinavia once more.

Edited by Quicksilver1989

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Despite some being dubious about the model output. Next weekend the models continue to suggest a less cold W,ly spell. How long this lasts is up for question and hopefully it will be shortlived and be replaced by colder N/E,lys.

Still my advice is even if the model output doesn't fit the MJO Analogs or any other teleconnection you cannot dismiss the output. Obviously the models are spotting something we aren't!

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1 hour ago, Daniel* said:

Agreed it seems much of the agro comes from those outside SE all I see in polar northwesterlies no offence to @northwestsnow of which I have no issue with. Is it’s great for NW with all the excitement, while often we are subject to miserable cold wet days further south...

50% or the UKs population lives within this circle. I myself in my location have not seen a covering in 5 years yes you heard that right only dustings since. Understandably some are putting an IMBY spin on it, we are all guilty of this? Keep it related to models and there’s nothing wrong with it, perhaps it’s more suited to regionals.. the upcoming week has opportunity for all areas not just SE England.

FE165B94-E39B-4BBF-A48D-CDB2B9DDB6CF.thumb.jpeg.2f70f5b334b704ccda1c529f72e930c9.jpeg

Just to level this out, if this year doesnt deliver for some of us in the north west of England, its been bad for snow all over the uk for a number of years unless you live at 300m up north which 99.9% dont. I hope you guys do get snow i really do, for me just for proof we still can get snow at low levels in this stunning and beautiful island of ours south north and in the middle

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GFS 12z ensembles shows operational is one of the milder members for that warm sector for Thursdays band. Mean as 850s of -2/3c for the midlands. And saturdays band actually.

image.thumb.png.5e512e5b582a16ec4a76bb9b8f4c2ce7.png

Edited by Paceyboy

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The last two frames of the ECM look cold but most importantly the model doesn't know what to do. Much better than the previous run and may be a reaction to the strato warming.

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It seems to me that people see what they want to see and get upset when others have a different view.

FWIW I think this week looks underwhelming and I say that as someone living in the SE. That said, others (Frosty for one) clearly see something different. As always, time will tell.

Meanwhile looking into the longer term the GFS suite is poor tbh but I do note a stronger signal in the GEM ensembles for something mid month from the east. Yes, I know its GEM but I have to say the GEM ensemble suites have by and large wanted nothing to do with the phantom easterlies being shown this year. They were also first to pick up on recent height rises to our south after the last cold blip so maybe an early trendsetter. From memory (and I may be wrong) I think the GEM ensemble suite runs at higher resolution than the GEFS albeit clearly its a lesser model. 

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The highlights package from the Ecm 12z is quite extensive with predominantly cold or very cold weather nationwide with frosts, ice and some snow around during the next 10 days and only blink or miss it less cold / milder blips!:D:cold:

24_mslp850uk.png

48_mslp850uk.png

48_mslp850.png

72_thickuk.png

72_mslp850uk.png

96_mslp850uk.png

144_thickuk.png

192_thickuk.png

192_mslp500.png

216_thickuk.png

216_mslp850uk.png

240_mslp850uk.png

240_thickuk.png

240_mslp850.png

240_mslp500.png

Edited by Frosty.

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I think the south  east can do better than low land northwest if it can tap into cold continental air if available,here just a giant heat pond to our west .

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