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DiagonalRedLine

Model Output Discussion - Happy New Year!

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Well we seem to get more snow in springtime now anyway,so i’m sure SM will be back for that.But this pattern will break,and when it does some experts think extreme cold will follow,because of so much cold bottled up in the Arctic,Greenland recorded its coldest ever temp of minus 66c ! 2 days ago

 

So you can understand why some think extreme cold,will flood South later on this winter,but really awful chartsf for cold,for the time being...

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Checked the ECM individual ensembles tonight.

 

By the time we get to around 20th January, the 51 runs are split roughly 60% with a mostly Atlantic influence for the UK and 40% with a mostly continental influence due to heights to the east.

 

Even within these 40%, not many get a decent enough draw from the east to threaten snowfall, and actually many of the coldest runs come from a WNW flow. 

 

The danger for coldies is the, as often happens at this time of year, any block over the continent is too far south to allow injections of cold from the east to our location, yet at the same time it is too far north and too robust to allow polar maritime incursions. The "sceuro high". It's a real carrot danger - you can see an easy route to deep cold if it would budge slightly, or if an Atlantic low could throw off an undercut, but if it doesn't budge it keeps the UK in the mild slot. 

 

The alternative to this is if the centre of the sceuro high encroaches into the UK (usually over the SE), introducing dry surface cold conditions. In fact this may be the most likely route to cold from this set-up in eastern areas - good for frosts, not for snow. I wouldn't be at all surprised if this is outcome for the final third of January. 

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Posted (edited)

Interesting that the clusters which reflect upper pattern rather than surface pressure are more keen on a scandi high than the eps members looked individually re slp patterns  (though with Azores support so little sign of Atlantic undercut possible ) 

Edited by bluearmy

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1 minute ago, ICE COLD said:

More cold for the USA 🤨😩😩

B5FE4B4F-CC25-4D61-A788-B9BE1B2AAEBE.png

Colder in Mexico than here based on that chart..

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5 hours ago, Ali1977 said:

The GFS makes more of it, with colder 850s. Doesn’t make a diff to any snow in the U.K. though!! 

C96B9C2C-15A7-4B03-84FE-E951AE02C865.gif

618D651E-C96F-4BB9-8A40-3ED16BC67A59.png

He was referring to the depth of the low. Which is a lot shallower. 

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I'm a little more optimistic with the outlook, tonight's Euro puts the high much closer to the UK keeping England largely settled and amplifying the flow into Russia a little.

With regards to US, the IOD signature (dragging down glaam and producing the -PNA cold west pattern) does look like it has given way but with a westerly wind burst if any near Indonesia which maintains a similar pattern over the US and may flatten our own down the line.

That said, look for a wave to move east through the tropical Pacific in a week or two and deliver a potentially more favourable change to the pattern during the final third of the month.

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Can we, can't we? Still the potential there for a Scandi high to build by the end of the month, ens will be interesting.

gfsnh-0-384.png

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Posted (edited)
On 04/01/2020 at 23:32, Tim Bland said:

But you said this in December, following a claim by you that the forecasts of a mild winter were going to be wrong? ....

C4FBC816-7A89-4069-AD5A-2012F5C990AC.jpeg

No I said forecast of a mild December were wrong (front loaded), not winter....as I was hopeful for Dec with a penetrating pM airflow and front loaded winter , and early model guidance in late Nov looked good, but it reverted ‘to my concern’ re pM being a let down and it was mild not cold (god help us now!) 🤣.  I haven’t called a cold winter......unfortunately Jan looks very  much for a raging PV, HP generally to SW, S and ESE looks anchored.....not to be moved for some time.

 

 

BFTP

Edited by BLAST FROM THE PAST

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Posted (edited)

Regarding that low for Thursday most models now have it as a complex system with more than one centre of circulation some uncertainty over how much development there will be still but what does look quite likely is a spell of quite prolonged heavy rain for England and Wales during Wednesday night into Thursday here's some animated charts showing this below.. 

Ecmwf..👇

hQp7ay2lrG.thumb.gif.5b5f7220b338eb84abbbe038d52c1885.gif

Icon.. 👇

moDNFnAaG0.thumb.gif.6a3e09f3fbc89d33653f041d7d554e53.gif

GFS overview.. 

Disorganised centres.. 👇

1748945345_EUROPE_PRMSL_78(8).thumb.jpg.2b75dd320982891aa3224f261a574fbf.jpg

IMG_20200105_230128.thumb.jpg.ebc87d73f7fb64bd0a292ccb209787e6.jpg

Gem overview.. 👇

1612359227_EUROPE_PRMSL_RAIN_84(6).thumb.jpg.5558037f572f5c1cacebe6536677b727.jpg

408575652_EUROPE_PRMSL_RAIN_90(3).thumb.jpg.aef5b5af2cf7d2620519dd3c4dc27a59.jpg

Latest data shows between 15-30mm locally more but a few days away ofcourse so details may change. 

Later tonight into tomorrow is looking very windy for northern areas with a spell of rain moving through all through the day although not particularly heavy for central southern and Eastern areas and not lasting too long an hour or two. 

Icon.. 👇

18_15_ukwindvector_gust.thumb.png.f915d80eb3beed4804638f42569be4dd.png

Tuesday is when stormy weather is likely for Scotland in particular with gusts atm shown as high as 60-70mph particularly for central and northern Scotland especially on hills but very windy for northern Ireland and northern England with gusts of around 50-60mph.. there could be gusts of around 65-75mph for the pennines. Shetland gusts of around 80mph are likely at times. These stormy conditions ease for mainland Scotland later tuesday but likely to continue into Wednesday for Shetland with very strong wind gusts 60-70mph for a time before easing on Wednesday afternoon. 

Icon.. 👇

18_42_ukwindvector_gust.thumb.png.1c649126ea76390228acbd826075ef4e.png

18_48_ukwindvector_gust.thumb.png.92f21d5c5c17ea10222a11f14d51ca5c.png

18_51_ukwindvector_gust.thumb.png.14906e94f113b62bb3dc6e76e893bf67.png

Edited by jordan smith

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Clusters tonight at D15

ec-ens_nat_z500scenarios_2020010512_360.

Not far from a cold high to the east on cluster 1 but need heights to drop more over Europe. SE England could get sucked into continental surface cold evenso. Cluster 2 is verging on BBQ weather ;)

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Terrible op runs this morning - GEM holds a torch with some tentative height rises at day 10, but GFS and ECM are flat as a pancake.

If we compare Oslo vs London 00z pressure ensembles:

image.thumb.png.062a4f1d184ce650054c815b49a9df83.pngimage.thumb.png.8b48af6c1763210fa29080f2b1aab49d.png

The mean is actually higher in London. Perhaps suggests something flatter with a Euro rather than Scandi high.....though models are having issues pinning this down. Either way it still looks dire. Going to be 50% through winter in another weeks time, and not a sausage so far. Desperate.
 

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Not even a 10 day wonder chart from ECM, Unless of course you love it mild .off to buy the Express, but will be back tonight for 7pm , perhaps a miracle will come cheers .

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image.thumb.png.77f0771e4b5043ea2d23e8855e0de543.png

ECM OP an unsettled outlier - though the mean is only at 1017mb by day 10....doesn't look great. Too much energy across the Atlantic probably going to win out....yet again.

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Posted (edited)

image.thumb.png.08e433e94adf85c4e28eb6743443dba7.png

EC MEAN day 10 showing a large Euro high refusing to budge.

That would be mid Jan and it has been present by and large, since the beginning of December.

the sad thing is if we land close to that mean we can almost certainly write off another 2 weeks ..

As previously posted, we are looking at Feb to save 'winter'.

I wonder if the very strong WQBO has ruined this Dec/Jan?( one of the fiercest recorded upto Nov apparently).

Edited by northwestsnow

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30 minutes ago, northwestsnow said:

image.thumb.png.08e433e94adf85c4e28eb6743443dba7.png

EC MEAN day 10 showing a large Euro high refusing to budge.

That would be mid Jan and it has been present by and large, since the beginning of December.

the sad thing is if we land close to that mean we can almost certainly write off another 2 weeks ..

As previously posted, we are looking at Feb to save 'winter'.

I wonder if the very strong WQBO has ruined this Dec/Jan?( one of the fiercest recorded upto Nov apparently).

Will the eQBO which has just started have any effect on the weather for the 2nd half of Jan and Feb ?

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1 minute ago, prolongedSnowLover said:

Will the eQBO which has just started have any effect on the weather for the 2nd half of Jan and Feb ?

I would of thought it would be Spring before the eQBO is felt, next winter will be a eQBO though 

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11 hours ago, carinthian said:

I have a collection of old Weather Mags which were published by the Royal Met Society. Some of the journals were about forecasting the 1947 Feb snow fest. At the time there were no model charts just raw daily data to go on. Basically reading between the lines , the forecasters at time never had an inkling what was about to happen after a few weeks of fairly mild pattern flow and were stunned by the speed of change from docile winter to one that ended in the most extreme possibly ever. I suppose these day, the models would forecast this abrupt change or would they ? I suppose we will never know as a Feb of 47 has never been repeated as yet !

C

 

 

If 1947 had access to the same data has this winter, I think a lot of people would have had optimism that such a mild first 2/3 of January could evolve into a cold spell at least. It mustn't be forgotten that there had been cold spells and easterlies in the winter at that point so it was reasonable to assume that another one could come along and even act as a tipping point to change the dynamic.

I see no such form in this winter however. The constant theme has been to flatten out the pattern without offering any real hope that it could change.

1946/47 was about trying to start a fire and getting one going a few times before it petered out  only to finally get a big sustainable one going.

2019/20 is trying to get optimistic at the sight of a spark over damp starting material.

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Good morning all!:hi:

Well, with charts like these, is it really surprising that the Post New Year LRF Denial Season is now in full swing?:gathering:

h500slp.png    h850t850eu.png

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Posted (edited)
18 minutes ago, prolongedSnowLover said:

Will the eQBO which has just started have any effect on the weather for the 2nd half of Jan and Feb ?

Not sure ...

I read the WQBO was incredibley strong in the run up to Dec and i think it has now gone negative.How long it will take to effect the trop i have no idea.

There are a few members who are far more knowledgable in things QBO so they might be able to offer more insight as to whether it has been responsible for the dire winter.

Edited by northwestsnow

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25 minutes ago, northwestsnow said:

I read the WQBO was incredibley strong in the run up to Dec and i think it has now gone negative.

The QBO is in the easterly descending phase, and all looks fairly normal:

qbo_plot.png?v=20200106

Source: 

ACD-EXT.GSFC.NASA.GOV

Scientific and technical content intended for our scientific colleagues

 

 

The usual single figure quoted for the QBO index is the zonal mean at 30hPa. That number peaked quite high in May/June, but not excessively or unusually so. As others have alluded to, I suspect the Pacific profile and the +IOD are the more likely culprits for the lack of any meaningful amplification so far this winter.

 

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23 minutes ago, jules216 said:

I haven't seen any meaningful theory that explains the quasi permanent feature of Euro high, although it has been successfully forecast for past summer and this winter, can we say it is because of colder stratosphere or IOD? Would be happy to see the research documentation to link this together, rather then just reading some suggesting posts. About time more focus is being put that way. In past lets say pre 2014, even the mild winters in UK didn't necessary mean mild winters in Europe as whole as there was more throughing activity present, though since 2013/14 we are all in it together, almost like in summer when UK taps in to continental heat more often since 2013, it is a tax we are paying for Euro high, at least in summer you can say it does reward UK but in winter it is pay back time. Our only saving comfort here in central Europe is the inversion cold that will ensure numerous ice days even without exciting synoptics, but poor poor ski resorts which will see temperatures like in April. 

Yep, we have been put on alert for next week to save as much snow as possible. To warm above the inversion to operate snow cannon feed. Poor outlook for snow lovers across much of Eouroland.

C

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