Model output discussion - 20th Feb onwards

[The Beast From The East]

2 minutes ago, Hull snow said:

I think the ssw could help a lot of people who crave cold and snow as its not to late for it to still get very cold and snowy let's hope the changes are imminent in the models 

I'm not sure if the models are starting to show it yet or not. Apparently it could start to take effect mid to late March according to this .

http://m.huffpost.com/uk/entry/9341878

 

[winterof79]

25 minutes ago, Siberian Xpress said:

Any updates on GFS or UKMO ? It's so quiet on here .  ❄❄❄

Cold and showery UKMO fairly wintry for the East

[weirpig]

Just one run and  nearly 48 hours out   but...  Hirlam showing snow showers hitting wales and england ang ireland  during Wednesday

Edited February 29, 2016 by weirpig

[chris55]

Lots to keep us interested this coming week after tomorrows front pushes through.

And with charts like this, although not perfect, there certainly are some opportunities for some snow under the right conditions within the broad-scale pattern

 

 

[The Beast From The East]

16 minutes ago, winterof79 said:

Cold and showery UKMO fairly wintry for the East

Thank you , liking the sound of that.  ❄❄❄

[fergieweather]

48 minutes ago, Paul_1978 said:

So an SSW is imminent apparently. Are the models now picking up on this fact, or not yet?

Not really, i.e. not the operational ones. The longer range suites are/have been assimilating it, but with outcome for UK still uncertain. The SSW is expected to be potentially major (in UKMO assessment at least) but not the final seasonal warming. The net possible result is exhibited in e.g. EC's colder look throughout March and also how GloSea5 has a noticeably blocked, colder start to April, too. Tonight's EC Monthly will offer a more informed steer, given where we now stand on the SSW modelling (versus where we were on that last Thurs). Either way, outcome is not expected to be severe/exceptional cold as seen in the March 2013 set-up and longevity of colder, blocked weather still remains uncertain further through March: likely becoming more periodic in nature, with periods of mobility allowing an erratic trend upwards in temperatures back towards average, but the month still being below average overall (and perhaps ditto early April).

Edited February 29, 2016 by fergieweather

[Paul]

Those commenting on the lack of comments this afternoon, maybe head over to the model viewers and share some of your own views. You don't have to be an expert to give a view on what you think's happening, everyone starts somewhere so don't be afraid to have a look at the charts, give an opinion or two, ask questions and so on - no-one here bites  

The page below is a good place to start as you have the GFS there + links to various other of the major models:

http://www.netweather.tv/index.cgi?action=nwdc;sess=

The thread is a bit quieter at the moment as it's been a long winter which many people have exerted a lot of energy chasing cold/snow, and unfortunately for them perhaps, just as it's turning quite interesting they've run out of steam - as is often the case at this time of year - it's a marathon not a sprint this winter malarkey!

[SMU]

With Ian highlighting the stratospheric profiles heading to warmer waters I wonder what odds he would give on a spring colder than Winter

certainly Dec V March could be 5c different....

s

[Man With Beard]

15 minutes ago, chris55 said:

Lots to keep us interested this coming week after tomorrows front pushes through.

And with charts like this, although not perfect, there certainly are some opportunities for some snow under the right conditions within the broad-scale pattern

 

 

This would usually be a source of great interest, but there's just not enough bite in the cold in our side of the hemisphere. Scotland, Pennines, Lakes, Peaks and Welsh mountains probably will go white. 

The most interesting chart I saw today was actually the GFS 00Z chart at T384, which showed the main vortex moving to Scandi/Siberia. Now by no means am I forecasting a D16 chart, but it showed what might be possible if such an alignment could propel the cold from Siberia towards us - uppers are still in the -20C to -30C category. That would have the bite needed even in late March. But it's such a long shot it's not really worth thinking about.

[The PIT]

50 minutes ago, Siberian Xpress said:

I'm not sure if the models are starting to show it yet or not. Apparently it could start to take effect mid to late March according to this .

http://m.huffpost.com/uk/entry/9341878

 

I stopped reading when I saw -14C in the first paragraph.

Anyway back to this week my main concern is the mixing out of the cold uppers if this happens then you're going to need to see some very high ground to have a chance of the white stuff on Wednesday as it is I would expect places like Fox house in the peak district to have a covering and maybe a brief one where I live. If they get mixed out zippo chance here and wet snow or sleety stuff at Fox House. Tomorrow evening will give us a good indication. 

[Banbury]

Potential this week

Friday might see MBY get a covering

[chris55]

27 minutes ago, Man With Beard said:

This would usually be a source of great interest, but there's just not enough bite in the cold in our side of the hemisphere. Scotland, Pennines, Lakes, Peaks and Welsh mountains probably will go white. 

The most interesting chart I saw today was actually the GFS 00Z chart at T384, which showed the main vortex moving to Scandi/Siberia. Now by no means am I forecasting a D16 chart, but it showed what might be possible if such an alignment could propel the cold from Siberia towards us - uppers are still in the -20C to -30C category. That would have the bite needed even in late March. But it's such a long shot it's not really worth thinking about.

Yes i do agree uppers are not that cold, as i said "not perfect" however with the right conditions within the bigger picture, ie, light winds and heavy frontal ppn or heavy convective showers snowfall is certainly possible at lower levels in England and Wales.

Of course the best scenario would be for there to be a deep cold pool to draw upon, but alas, after the mildest winter on record we have to pick our fights lol.

I haven't seen one snowflake this year.....NOT ONE!!! That's the first time in my 12 or so years of model watching that I have not seen even a flake fall from the sky all winter. 

But hey Sera Sera, whatever will be will be eh. Hers hoping March can deliver a flake!

[Captain Shortwave]

ECM day 4

   

Low pressure sliding through the channel with a front across the southern half of England and Wales. 850s looking decent enough to turn the rain to snow away from the South coast (probably a line through Winchester northwards) on this run.

The UKMO has a similar position and orientation to the low on Friday with strong easterly winds across the south. The GFS takes the low a hundred or so miles further north and is quicker at moving the low through, so more mixing out and lower chance of snow with the precipitation looking more of a wintry mix with only areas such as the Welsh mountains getting something.

Before then conditions look good for the north west during Wednesday morning with a window of cold 850s along with some deep instability which will drive showers south east through the UK, the further south and east you go these will fall as more of a mix of rain/hail/sleet/snow with rain becoming more dominant as the day progresses as the 850s tend to mix out.

In terms of cold patterns it isn't too bad (though less marginality would be a plus), but overall the cyclonic and mainly north to north west flow will give sun and some pretty beefy showers as opposed to the drier and cloudier conditions you would get from an east/north easterly. The weekend looks showery, especially in the north and east with the showers again falling as a mix of pretty much every precipitation type going.

Edited February 29, 2016 by Captain Shortwave

[nick sussex]

I think the ECM has two possible snow interests, the first Friday and then the next between T144 and T168hrs as a shortwave heads south from Iceland.

Whether this produces snow again its been like pulling teeth this winter so at this stage a chance but we've been here before!

[moffatross]

19 minutes ago, The PIT said:

I stopped reading when I saw -14C in the first paragraph.

Yes, sensationalist poop, but the really sinful act in that item is the inference that the UK Met Office have been quoted as saying a 'White Easter' is on the way. And of course it has provoked all the usual comments and criticisms of the Met Office too.

[Banbury]

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/02/29/basis12/ukuk/prty/16030200_2912.gif

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/02/29/basis12/ukuk/prty/16030206_2912.gif

 

Shows the cold air rushing back across the UK, turning ppn rather wintry

[Cloud 10]

6 minutes ago, nick sussex said:

I think the ECM has two possible snow interests, the first Friday and then the next between T144 and T168hrs as a shortwave heads south from Iceland.

Whether this produces snow again its been like pulling teeth this winter so at this stage a chance but we've been here before!

 

Its times like this it would be nice to have charts at 12hr increments on the ECM to see exactly whats sliding where!

[KyleHenry]

ECMWF has Saturday as the coldest day of this episode.

[Summer Sun]

Latter stages of tonight's ECM shows the high slowly moving in though remaining chilly and a continued risk of frosts

Plenty of weather to get through before this we have some opportunities for snow during the week and plenty of chilly days and cold nights ahead

Edited February 29, 2016 by Summer Sun

[chris pawsey]

50 minutes ago, Banbury said:

Potential this week

Friday might see MBY get a covering

As much as I would like to see these charts verify I fear that these snowy charts will get watered down due to the amount of variables involved when forecasting snow... like all the ppn charts have as of late. It will no doubt go down to the wire and we'll all be lamp post watching, some areas might do well, others will be disappointed like the many times this winter. I do however have hope that we see a flake or 2 this week. 

[feb1991blizzard]

1 hour ago, fergieweather said:

Not really, i.e. not the operational ones. The longer range suites are/have been assimilating it, but with outcome for UK still uncertain. The SSW is expected to be potentially major (in UKMO assessment at least) but not the final seasonal warming. The net possible result is exhibited in e.g. EC's colder look throughout March and also how GloSea5 has a noticeably blocked, colder start to April, too. Tonight's EC Monthly will offer a more informed steer, given where we now stand on the SSW modelling (versus where we were on that last Thurs). Either way, outcome is not expected to be severe/exceptional cold as seen in the March 2013 set-up and longevity of colder, blocked weather still remains uncertain further through March: likely becoming more periodic in nature, with periods of mobility allowing an erratic trend upwards in temperatures back towards average, but the month still being below average overall (and perhaps ditto early April).

 

1 hour ago, Steve Murr said:

With Ian highlighting the stratospheric profiles heading to warmer waters I wonder what odds he would give on a spring colder than Winter

certainly Dec V March could be 5c different....

s

 

I'm very surprised that its not likely to be the final SSW, I know its early but in the mid - top it looks completely destroyed to me. but as per Steve's post, if there is another reformation of and destruction of the vortex, it could be a below average spring.

[Speedway Slider]

19 hours ago, Bring Back1962-63 said:

I suggested (in my post yesterday on page 36 and my previous post on page 25, last Tuesday), based on Dr Judah Cohen’s  Arctic Oscillation forecast, I was expecting much greater amplification in the North Atlantic with strong HLB to our north-west, north and eventually north-east with low heights dropping into Europe.  I am delighted to see Nick F reporting that the 12z EPS is now predicting similar synoptics. The problem brought up by many posters, including Nick, is will there be any decent cold to tap into? Can we import sufficient cold to establish a cold pool in central Europe? Will the 850 uppers be low enough? Well, after scratching my head and doing a bit of lateral thinking, I spent some time this evening trying to find anything positive – and I have some good news but you’ll need to read on before I get there!

I think it is widely known that the part of the Arctic directly to our north from north of Iceland and Norway through the Barents Sea, Kara Sea and towards the North Pole, has seen some extremely warm weather. Surface temperatures have sometimes been above freezing between December and February. Here is a link to temperatures recorded in Svalbard.

http://www.yr.no/place/Norway/Svalbard/Longyearbyen/statistics.html

The readings are taken at their official observatory, based at Svalbard Airport which is just 28m above sea level and a couple of miles from the capital, Longyearbyen. There is a graph for the last year to January 2016 and a separate chart for February 2016. You will see just how warm it has been. The 30 day average has been -5.1c which is 11.1c above their February mean of -16.2c. In fact the lowest temperature all month was -13.6c on February 9th (ie: continuously above the mean) and they managed + 1.7c on February 18th. The forecast for the next few days is not much better with maximum temperatures between -1c this Wednesday and gradually falling to -6c by early next Tuesday (March 8th). At that point I thought this is continuing to be exceptionally warm and I almost gave up.

With a little more fiddling around I came across a 2 week forecast and….bingo!!! For the first time this winter, temperatures are forecast to fall below average!  This can be seen in this link.

http://www.timeanddate.com/weather/norway/longyearbyen/ext

The average for the whole of March is around -15c and only marginally higher than in February, in fact average temperatures hardly rise until mid-April. You’ll see that maximums start off around -6c on Tuesday March 8th and steadily fall away to -17c by March 13th with the minimum around -24c/-25c***. In fact it looks like Svalbard will have a decent cold spell by “their” standards. ***Please note that the figures on this chart are updated hourly (I have just adjusted them at 0655 on Monday, 29th February). 

The timing would seem to be almost perfect, coinciding with our airstream veering into the north-north-east and probably sourcing air from precisely that area! . Although there are other factors to weigh in, surely having much colder surface air over our part of the Arctic will help with importing some much needed colder air. Usual caveats apply. I have no idea of the reliability of the weather forecast which is provided by “CustomWeather” but I believe it comes from the Norwegian Met Office? Perhaps Nick can comment on this. Several charts show around -20c to -28c uppers in that area towards the end of next week. If those verify and we tap into the surface cold surely things will be a lot more promising for us. This is the GEM control 850s chart for March 14th which also shows a broadly similar surface pattern.

http://www.meteociel.fr/modeles/cmc_cartes.php?code=0&ech=360&mode=1&carte=1

Right, I'll leave it up to you guys and girls to comment on this. I have a really busy week ahead but I may post a couple of brief updates on this topic later in the week if I can find the time.

IMPORTANT AMENDMENT: The 2 week forecast that I refer to above does not seem to be reliable - it's automatically updating every hour and the overnight predicted temperatures for the March 10th-14th period have been raised considerably this morning. There are also other stations in the area with differing and much less cold forecast temperatures. Please accept my apologies for misleading anyone. See next page for who corrected me and other links.

"CustomWeather" is a San Francisco based company providing worldwide forecasts. They appear to have quite a good verification record. They are NOT linked to the Norwegian Met Office. If I provide further updates on the Svalbard region temperature forecasts, I will try to obtain them from the Norwegian weather service.

I also see that the GEM chart that I posted above has been substantially downgraded on the next run. I have been guilty of being overly reliant on several sets of figures and charts and using them to support my point. I shall be much more guarded in future. Sorry folks. 

Where can I look to find information on the Polar Vortex?

Thanks

Karl 

Edited February 29, 2016 by Speedway Slider

[MR EXTREMES]

I really do think we need better deeper cold its like watching paint dry and still no favourable northern blocking mlb toppling eventually over the uk.

but I really am interested to see what effect the strat warming has.

I read its record breaking so have we seen what effect this will have this time before ?

[Paul]

32 minutes ago, Speedway Slider said:

Where can I look to find information on the Polar Vortex?

Thanks

Karl 

This should help

http://www.netweather.tv/index.cgi?action=news;storyid=6291;sess=

[Nouska]

1 hour ago, Cloud 10 said:

 

Its times like this it would be nice to have charts at 12hr increments on the ECM to see exactly whats sliding where!

The ECM 156 and 162 hour precipitation charts from Icelandic weather service.