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Model output discussion - Winter approaches


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Hi all . I’m back from my summer hibernation . A warm welcome to all the new members . It’s hard to believe we’re back again chasing those hard to come by good winter charts . It’s true the older

This is the ECM at 96 hrs v's the reanalysis for the 3rd of Nov 2010 and bears similarities in our part of the world now you wouldn't think that the epic winter of 2010 would come from that

Time to start wheeling out the ECM snow depth charts then 😍. Please remember it is mandatory to reply with how unreliable they are and how it accumulates all falling snow even if it doesn’t settle bla

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Blimney things have changed again 😞 Whats really impressive is the ability to sweep the cooler weather completely away 1000ths of kms away from whole of Europe. Used to be the case when cold spels didnt reach UK they dropped to at least central Europe but this one is being blown away even from me in Slovakia. The seasonal model signals for -NAO in Nov/Dec is looking just ridiculous right now as this cool spell courtesy of Scandi/Ural block will fall victim of the Greenland cyclogenesis - what was meant to be a mid.Atlantic ridge favorable route is actualy turning out the opposite way.

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12 hours ago, Zak M said:

And lastly, here's the GFS/ECM 8-10 day 500mb mean:

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They're both not the best and don't really look like they are showing something cold for us. We really need that HP cell over NW Europe to migrate either northwards or eastwards for the better chance of seeing any cold. But I'd rather hear the opinions of two far more experienced and knowledgeable people: @johnholmes and @mushymanrob, and even a few others!

 

 

😄

ZM

 

Personally, i dont use those charts although John does. I use the NOAA only.

The latest charts do build a ridge to our east more then previously, an evolution/correction id expect myself as things develop.  Whilst there is ridging to our East, theres still a moderate westerly sourced upper flow so yesterdays GFS northern blocking was never an option. Id suggest the current GFS 00z, and to a degree the current 06z both of which are closest to what id expect the 6-10 day mean anomaly chart to produce, are most likely to be nearer the final solution.

There is still room to manoever, imho the current ECM runs bring the Atlantic in too soon and something may well emerge over the next few days.

The 00z GFS suggest quite a lot of quiet, rather settled but not totally settled, conditions as we still retain a mean upper southwesterly. Temps average or slightly above and largely dry.

On the plus side (for cold prospects) the 8-14 day chart does suggest low pressure in the Bering sea / Aleutian islands which favours the development of a Scandi high?.. does it not?

 

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Edited by mushymanrob
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2 hours ago, mb018538 said:

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GFS 00z ensembles certainly don't match the Met Office extended outlook. It's trending unsettled rather than trending settled like this morning's update says below:

Saturday 21 Nov - Monday 30 Nov

Spells of rain will spread southwards across England and Wales on Saturday with brighter, showery conditions in Scotland and Northern Ireland. Sunny spells are expected in the south of the UK on Sunday with blustery showers across the north. For the remainder of November conditions will begin to become more widely settled, especially across the south and east where there will be an increased risk of slow clearing fog. Unsettled interludes bringing spells of rain and strong winds are still likely at times, especially in the north and west. Temperatures look to be around average with increasing incidence of overnight frost, as is typical for this time of year, as well as bringing an increasing chance of wintry precipitation

Monday 30 Nov - Monday 14 Dec

Heading into the middle of December, high pressure is likely to become the dominant weather pattern across the UK, bringing settled conditions to many parts. Occasional unsettled periods with outbreaks of rain and strong winds are still likely at times, these most likely to affect northwestern areas of the UK. Temperatures will probably be close to or below average with an increasing chance of wintry precipitation, notably for higher ground in the north

A bit of a stand off developing perhaps!

To be fair, I didn't say the ensembles matched the MO long-range forecast. I said the 0z op run matched it. 

And the 6z still shows potential for fog and settled conditions in England and Wales so still aligns with the MO text but, of course, in the longer term, it's heading towards wet and not-cold again. However, the 06z ensembles still do not feature many precipitation spikes for London

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The MO are still talking about below average temps into December. While they're still talking like that, I remain hopeful that cold will come. And I know they get things wrong but better to have them talking about cold than not

Edited by LRD
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Another easterly bites the dust within 24 hoursl.You need them to be modelled all  the way down to 72 hours or just accept they WONT verify until they reach that timeframe.

The uk would be in a big freeze if any of these fl scenarios ever came off in the Winter months lol.Nearly always they never verify in the end.

On to the next chase...😞

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4 minutes ago, LRD said:

To be fair, I didn't say the ensembles matched the MO long-range forecast. I said the 0z op run matched it. 

Unfortunately the 6z goes against the MO and the trend is, undoubtedly, heading towards wet and warm again. But the MO are still talking about below average temps into December. While they're still talking like that, I remain hopeful that cold will come. And I know they get things wrong but better to have them talking about cold than not

I'm not sure.... the MO only talks about wintry precipitation at the end of November (which is 300 hours away - well outside of the reliable in the charts), then "unsettled periods of wind and rain", and only for an increasing chance of wintry precipitation into mid-December - well beyond the T+384 period. As such there is nothing unsurprising in the output in my view. Is only 17th November today (still autumn), and a long way to go before we need to start seeing decent wintry output coming into a more regular view in the model output.

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22 minutes ago, SLEETY said:

Another easterly bites the dust within 24 hoursl.You need them to be modelled all  the way down to 72 hours or just accept they WONT verify until they reach that timeframe.

The uk would be in a big freeze if any of these fl scenarios ever came off in the Winter months lol.Nearly always they never verify in the end.

On to the next chase...😞

I've said before that the models just can't seem to forecast Scandi highs with any reliability. Greenland Highs they're much better at hence why my interest was triggered yesterday because it showed more a GH than a SH. Must be something to do with underestimating the amount of energy heading NE. Scandi highs usually appear at relatively short notice. Can't remember how accurately the Feb 18 E'ly was modelled

Edited by LRD
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I was about to throw in the towel myself but then I spotted the recent outputs by CFS and NASA models which put me in freezer, so all is great,for sure ECMWF is wrong here 🙂

cfs-0-222.png

geos-0-204.png

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15 minutes ago, Paul_1978 said:

I'm not sure.... the MO only talks about wintry precipitation at the end of November (which is 300 hours away - well outside of the reliable in the charts), then "unsettled periods of wind and rain", and only for an increasing chance of wintry precipitation into mid-December - well beyond the T+384 period. As such there is nothing unsurprising in the output in my view. Is only 17th November today (still autumn), and a long way to go before we need to start seeing decent wintry output coming into a more regular view in the model output.

Quite so Paul 1978. Anything in late Novemeber/December's these days is just a massive bonus. We were spoilt in Decs 2009 and 2010 but in truth for Southern England at least pre Xmas snow is a very rare delight. Which is why even when models show its 280 plus there is a real buzz on these boards. We know it most likely won't verify but there's always that hope because we know that (albeit very rarely) that it has in the past.

 

 

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4 hours ago, Steve Murr said:

Its been the coldest November on Record in FI...

I'm seriously thinking of packing my things and moving to FI - the weather seems great there. 

Does anyone know what the cost of living is there?

In all seriousness, for coldies, it all comes down to the fact that for our maritime climate, there are many, many more paths to mild or not cold, than there are to cold and snow - so it stands to reason that cold/snowy will always be the outsider. 

The 06z op looks pretty flat again compared to recent output, however I wouldn't be surprised to see some more blocked scenarios crop again in the 252-300 hour range in the next day or so as GFS has a habit of teasing in the very long range, dropping the idea and then picking up on it again. 

But, despite advances in supercomputers in the last 20 years, I'd give the same advice I did when I started looking at forecast models in 2000 - which is, until anything is in the 72-96 hr range, don't believe any of it.

 

 

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3 hours ago, feb1991blizzard said:

we might need it the other way around by January, a Wave to come and give us the snow, a propagating wave in the stratosphere!

Indeed 😂 Especially if we were to still get a cold front loaded Winter from the La Niña-esque pattern with the rest of the season being mild. A Stratospheric warming event or something could for sure help to come to our rescue during January, or perhaps February. 

The operational models do look quite disappointing this morning with lack of favourable Scandinavian ridging. I guess it doesn’t surprise me and I imagine there will be more ups and downs to come. Still a chance of some drier weather later into the weekend and into next week as ridging tries to build over the UK and towards our East. Length of the possible drier period is uncertain. In a way, depending what the UK/Eastern UK ridge does, whether it has a clear enough path to migrate North, and how events upstream behave.

The models not totally without interest regarding cold, as the 00Z ECMWF does rock out some mid Atlantic ridging at the end of its run, which may lead to a chillier North-Westerly flow later down the line. And although the 00Z GEM has blocking too far to our North-East - main core of upper heights towards Russia, it could help Lows out West to be sent on an East to South-East tragedy through the UK and into mainland Europe (unless that Azores ridging to our South-West got pulled over with it)

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But to be fair, getting too carried away with what the operationals show can lead to a risk of throwing massive toys out of prams considering their garden path nature. And the way they can quickly sweep away peoples’ high hopes. 

For the next few days, a standard Atlantic setup on the whole with areas of High Pressure moving around to the South of the UK and Low Pressure dominating to the North-West of us. A brief wintry interest for those over Northern High ground during Thursday as a transient Northerly develops. Upper heights in the mid-Atlantic temporarily splitting up Low Pressure to the North and North-West of the UK with some amplification to the flow. Some of the showers during Thursday could be wintry down to some lower levels even, especially across Scotland, as cold 850 hPa temperatures flood into Northern areas:

8ADE4D49-D57C-4680-B5C1-5115B4DB6639.thumb.png.eabbd1c4bdf61423cf92b28b88af18cd.pngC316EC6B-6DFA-4E36-B573-8377AFC2FAF9.thumb.png.5afa7059881c72f292992fc969f49337.png

Edited by DiagonalRedLine
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32 minutes ago, jules216 said:

I was about to throw in the towel myself but then I spotted the recent outputs by CFS and NASA models which put me in freezer, so all is great,for sure ECMWF is wrong here 🙂

cfs-0-222.png

geos-0-204.png

Mind you, both models have the jet stream barrelling through to the north of Europe which doesn't bode well for sustained cold - it just ends up cutting off the taps to the cold air, unless you live in Svalbard. 

Edited by PerfectStorm
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I’m sure the Scottish ski resorts would be more than happy with the pattern on the last GFS run , but we all know this will be gone on the next run!! image.thumb.png.6bc4c5f6af595e25d16b8b7abbccf47a.png

 

Edited by Ali1977
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2 minutes ago, Ali1977 said:

I’m sure the Scottish ski resorts would be more than happy with the pattern on the last GFS run , but we all know this will be gone on the next run!! image.thumb.png.6bc4c5f6af595e25d16b8b7abbccf47a.png
 

Shame they probably it won’t be able to open any time soon due to COVID 😫

Re the met office outlook...GFS is showing exactly what they mention - increasing chance of snow on high ground in the north and unsettled especially in the North West so those dismissing current output based on the met office forecast might want to read it again...

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24 minutes ago, Tim Bland said:

Shame they probably it won’t be able to open any time soon due to COVID 😫

Re the met office outlook...GFS is showing exactly what they mention - increasing chance of snow on high ground in the north and unsettled especially in the North West so those dismissing current output based on the met office forecast might want to read it again...

DA56DAE1-33F6-4B7C-831D-4A80DE2D9F2A.png

CEA17DFD-E3F0-4F9F-940B-99A92C57C86B.png

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The problem with PM shots in recent years is uppers of -8 invariably are not enough even at 200m asl in the west  Pennine foothills due to the warming seas...

Snow line locally from North Westerlies tends to be 250m asl and above with uppers of -8, broadly speaking.

Easterlies please !!

Edited by northwestsnow
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6 hours ago, Steve Murr said:

Its been the coldest November on Record in FI...

Lol,and you need one of these to catch it😆

download.thumb.jpg.48fec40b14b1f12adc926381ae5e2125.jpg

in all seriousness let's get the pattern reset and maybe a cold NW/N shot could be the form horse in a couple of weeks>, with a La nina inprint we could be looking at Atlantic heights up into Greenland,something to keep an eye on on the NWP's

 

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17 minutes ago, northwestsnow said:

The problem with PM shots in recent years is uppers of -8 invariably are not enough even at 200m asl in the west  Pennine foothills due to the warming seas...

Snow line locally from North Westerlies tends to be 250m asl and above with uppers of -8, broadly speaking.

Easterlies please !!

Rain/sleet/wet snow at -8 uppers? 😮 I'm not sure if I fully agree with that particular threshold of -8 ... I think the vast majority of the time uppers of -8 should be cold enough to give something more in the way of snow rather than rain, I'd put my threshold more to -5 give or take... (but baring in mind a NW'ly incursion imo tends to deliver average uppers of around -5 rather than -8 anyway, in my opinion? unless I'm mistaken).. 

But either way I agree with yourself/others in that I reckon what the MO is trying to hint at is just typical wintry stuff on higher hills from NW'ly incursions (in an otherwise westerly driven pattern)- they aren't suggesting anything out of the ordinary in my opinion and it can be fairly normal/typical for this time of year

20 minutes ago, Allseasons-si said:

in all seriousness let's get the pattern reset and maybe a cold NW/N shot could be the form horse in a couple of weeks>, with a La nina inprint we could be looking at Atlantic heights up into Greenland,something to keep an eye on on the NWP's

 

Agree completely - we can always get excited and clutch at a few straws when we see eye watering heights drawn up to our N/NE to try and establish something significant, but I for one am looking at the more likely situation - hopefully we can gauge a few NW/N shots in the next 2-3 weeks or what have you - as I said I don't think this is too abnormal for this time of year and always a chance one of those incursions may have a bit of potency about them.

Something like this, I guess

image.thumb.png.52425df550adc372dba40be6d6cd6ac5.png

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It’s going to be a long winter if people grow so despondent over one GFS run surely some should know much better by now? I think @johnholmes once gave good advice to just look at 12Z outputs, and see how that evolves over a few days. To get a sense of whether is something off or on table and see trends/patterns, evidently if yesterday they shifted cold and day before mild they evidently don’t have much of a clue typically with normal mild regimes once they go mild they don’t go back but possibly things could be a bit different. I have observed this year the models have been particularly erratic, it is possibly down to corona and less flights getting high altitude data. A cold easterly has never been near to us, possibly some benign continental flow. What I would say late November isn’t looking as mild as it has been for most of month. 

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3 hours ago, Mr Frost said:

Quite a shock to the system when Thursday arrives - not for long of course. 

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Think those temps might be a bit on the low side...BBC at lunch today showed 10c for my location which is only normal for the time of year, shows you just how bad things have got!

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On 13/11/2020 at 11:04, booferking said:

And to think a few cold heads had nearly giving up on Winter earlier this week before it even begun.👀

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It's best to ignore charts like that that far out - they hardly ever come true. If Europe and Scandanavia stay mild then so do we - just like happened last winter.

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Impressive how this November evolves..

According to the models, we are having a very short break from south-western winds this week, but the trend will probably continue afterwards..

I believe we will record the warmest November ever here in Norway. Currently 2018 holds the record

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