Model output discussion - 20th Feb onwards

[mountain shadow]

15 minutes ago, Nick L said:

ECM continues the cold and dry theme. A few light sleet/snow showers here and there but nothing significant. The annoying thing is though this easterly may just bring in overcast skies for the majority after the sunny week ahead.

Yes, a poor run for any end of Winter snow prospects, with a period of drier weather until the Atlantic pushes in next week again. The problem as always is the permanent PV segment to the NW which seems to be able to over ride any supportive teleconnections such as the MJO.

 

 

[Liam J]

13 minutes ago, Nick L said:

ECM continues the cold and dry theme. A few light sleet/snow showers here and there but nothing significant. The annoying thing is though this easterly may just bring in overcast skies for the majority after the sunny week ahead.

Indeed and Ian has just more or less said the same above, frustrating! On the plus side IMBY that sort of cloudy easterly set up I tend to be sheltered by the high ground here (not all the time) so more chance of keeping the sunshine by day and cold frosty nights. 

Shame the 850's weren't nearly 10 degrees colder like 3 years ago!  

[The Enforcer]

2 hours ago, Weather-history said:

Is UKMO bringing that low closer with each run?

See above - I think it is difficult to draw conclusions about snowfall or lack thereof when the position and orientation of the low pressure system has not been agreed. The next 0z output could continue the eastward trend of the midday Friday chart, for example, which would then lead to a different pressure pattern and consequential temperature and precipitation distribution thereafter.

[blizzard81]

Just now, mountain shadow said:

Yes, a poor run for any end of Winter snow prospects, with a period of drier weather until the Atlantic pushes in next week again. The problem as always is the permanent PV segment to the NW which seems to be able to over ride any supportive teleconnections such as the MJO.

 

 

Yes, that segment of pv you mention has been unbelievably persistent throughout the whole winter. Quite remarkable really but not in a good way.

[Paul White.]

Hello everyone I was a little curious about how March 2013 got going so I have just had a read through the MoD thread leading up to that period. 

have a read it's very interesting and quite insightful 

 

paul

[fergieweather]

16 minutes ago, marksiwnc said:

Let's hope the west/south West will see some snow at least.  Although probably the chances of this remains 0 probably 

It was 15% based on 00z runs. The breadth of outcomes re frontal inroads E'wards (and resultant snow risk) was very marked in MOGREPS. This uncertainty remains now: eg check EC12z (almost dry even in SW by early Sat) versus 12z JMA. It has all the hallmarks of remaining unresolved until short lead time.

[winterof79]

11 minutes ago, Paul White. said:

Hello everyone I was a little curious about how March 2013 got going so I have just had a read through the MoD thread leading up to that period. 

have a read it's very interesting and quite insightful 

 

paul

Having read that I think my head still hurts from banging it against a brick wall. Somethings haven't changed on here LOL.

[Jason M]

1 hour ago, Daniel* said:

Definitely not, are you having a laugh - I'm not quite sure how you could say that over the last odd few winters the best we have mustered is a potent PM lasting a matter of days, ultimately only substance has been up north the cold spell would hold more significance if it was mid winter alas we're approaching March so you have to face reality in your expectations, there is a threat of signicant snow for southwest fri/sat I assume this is muted amongst it all, but the risk is there interesting model watching to come. Regarding temperatures anything from an easterly orientation with -7C uppers will not be marginal inland, furthermore SST are on warm side the Thames Estuary in particular, thus this reduces the need for exceptional upper air temps, under showers temperatures would take a tumble yes during daylight accumulations will be limited but by nightfall snow will settle readily. 

Nope, not having a laugh at all. nothing wrong with you setting out a contrary view, but why be so aggressive in doing so? Not really sure what the last few winters have to do with anything anyway? 

I stand by my assessment of a bog standard winter cold snap. -7 uppers in Dec through to early Feb from the east equals possible ice days, in late feb / early March the 2m temps could easily be 4-5c under sunlight. If we get showers (and it's a big 'if' frankly) they could fall as snow, but it's nothing severe tbh. Anyway, believe me or don't as it doesn't really matter tbh. Plenty of different interpretations of the charts available on this thread this evening so no doubt lurkers will make their own minds up.

To be clear, I am not ruling out a covering of snow over the next week or so (as my earlier post made clear), but I'm not seeing anything to get excited about yet.

edit see link below for 2m temps for 1pm 

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=144&mode=9

 

Edited February 22, 2016 by Jason M

[Liam J]

Would like to see deeper cold at this time of year. We seem to be saying this quite often but it's a shame it didn't happen earlier in the winter! Even with the -6/-7c 850's the temps can climb sharply as we get towards midday at this stage in the winter thanks to the stronger sun.  

NetWx-MR model, 850's & predicted temps for Saturday which look a bit on the high side though but similar to the Met Office map for the same time.

 

 

 

[fergieweather]

9 minutes ago, fergieweather said:

It was 15% based on 00z runs. The breadth of outcomes re frontal inroads E'wards (and resultant snow risk) was very marked in MOGREPS. This uncertainty remains now: eg check EC12z (almost dry even in SW by early Sat) versus 12z JMA. It has all the hallmarks of remaining unresolved until short lead time.

Just saw latest UKMO 12z Model assessment & MOGREPS update. Essentially as cited above: MOGREPS paints a 10% risk of >5cm snow by end of Fri effectively covering Bristol down to New Forest, across to Dartmoor and up to Exmoor. So, similar risk area to 12z GFS. So, in public forecasts for now, we will just continue to express a low threat of something significant Fri-Sat, for SW/W Country in particular.

[January Snowstorm]

1 hour ago, fergieweather said:

Hmm. Not yet convinced. All the forcing has run away SE, perhaps a few PV strips/filaments aside, circulating in the flow N of the departing low centre. Last UKMO profiles I saw for E coast (but not 12z data) looked like StCu of limited depth, under a lot of higher cloud... all unlikely to yield ppn. 12z EC has no snow at all anywhere south of Pennines all the way from T+24 to T+240, but much can and doubtless will change even by Sat. 

Hi Ian

Have you backed away from your thoughts a few days ago of a very cold start to Spring? I remember you saying that many weeks of blocking and below avg temps was favoured.

If yes, does this mean that the ukmo monthly and mogreps are as fickle as the charts we see such as gfs ecm etc.

I suppose the point I am getting at is are any computer models reliable beyond 7 days. Imo they have all performed poorly throughout Winter

[Lampostwatcher]

Is there any computor model that can predict the weather accurately for T12 hours ?

[feb1991blizzard]

7 minutes ago, January Snowstorm said:

Hi Ian

Have you backed away from your thoughts a few days ago of a very cold start to Spring? I remember you saying that many weeks of blocking and below avg temps was favoured.

If yes, does this mean that the ukmo monthly and mogreps are as fickle as the charts we see such as gfs ecm etc.

I suppose the point I am getting at is are any computer models reliable beyond 7 days. Imo they have all performed poorly throughout Winter

He never said a very cold start to spring, he said a below average start to spring, he posted earlier today re- this.

[karlos1983]

3 minutes ago, Lampostwatcher said:

Is there any computor model that can predict the weather accurately for T12 hours ?

Euro4 not a bad shout at that range 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=euro4&MODELLTYP=1&BASE=-&VAR=prec&HH=3&ARCHIV=0&PANEL=0&ZOOM=0&PERIOD=

Good for predicted DP's 850's etc 

or ofcourse netweathers very own 

Edited February 22, 2016 by karlos1983

[Duane S.]

Hopefully that's the willy waving over until at least the 18z rolls out. Chill folks, we've got potential on our doorsteps, yep snow flurries look more likely than anything too significant at the mo but it doesn't take a genius to see it wouldn't take too big an upgrade to turn things back in our favour ppn wise. Noone can argue it's going to be a bit nippy though!

And here's something I have been waiting for all winter, GEFS mean running below 0 from start to finish for my tropical neck of the woods...

Tells its own story that.

Some may hate the phase "get the cold in first" but it has plenty of merit. I think it is often used in 2 different but equally relevant ways...

Firstly that embedded / entrenched cold (as opposed to freshly arrived cooler air) always helps when it comes to marginal situations.

Secondly, simply, get the cold in first and THEN let's see what falls from the sky.

 

[karlos1983]

4 minutes ago, s4lancia said:

Hopefully that's the willy waving over until at least the 18z rolls out. Chill folks, we've got potential on our doorsteps, yep snow flurries look more likely than anything too significant at the mo but it doesn't take a genius to see it wouldn't take too big an upgrade to turn things back in our favour ppn wise. Noone can argue it's going to be a bit nippy though!

And here's something I have been waiting for all winter, GEFS mean running below 0 from start to finish for my tropical neck of the woods...

Tells its own story that.

Some may hate the phase "get the cold in first" but it has plenty of merit. I think it is often used in 2 different but equally relevant ways...

Firstly that embedded / entrenched cold (as opposed to freshly arrived cooler air) always helps when it comes to marginal situations.

Secondly, simply, get the cold in first and THEN let's see what falls from the sky.

 

Nice to see the Control go cold, I was just looking at the ensembles and about to come and post about it, so seems fluid if I do it in reply to your post.

op goes warm(er) but then rejoins the control and goes cold(er) again.

 

 

[bobbydog]

25 minutes ago, Lampostwatcher said:

Is there any computor model that can predict the weather accurately for T12 hours ?

"as they say in america"

"computor".....

[Faronstream]

To be honest i find todays 12z charts from ECMWF ( or as you call it ECM) very mediocre for being end of February, no real cold or unusual mild weather, and it looks really dry ( North and west europé)

The lack of snow In parts of Germany, the Baltic countries and Poland makes the cold winds also mild up on the way down Europé, and this time of the year we must have more requirements to get snow laying on the ground longer time ( sun is stronger and South Europé is slowly warming up), it's not December anymore ;/

[IPredictASnowStorm]

Still showing this on gfs 

[feb1991blizzard]

Just now, IPredictASnowStorm said:

Still showing this on gfs 

With those charts, assume anything below 1mm per hour as nothing, in doing that, you get a more accurate picture which unfortunately on this occasion means negligible PPN except for Scotland, you really need to be seeing 4mm per hour at least to be looking at anything significant.

[johnholmes]

Looking beyond this weekend and the 6-15 day upper air outlook is nicely shown below on the two NOAA charts, backed up by ECMWF-GFS. My own comments re daily checking I do is below the link.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

Noaa

6-10 and its pretty similar in major aspects with the trough perhaps a shade more marked as is the ridge w of it with uk in n of w flow with height bit above 546dm under ridge effect-origin n of Vancouver?

8-14 keeps the pattern going, so n of w flow looks odds on out to at least 6/7 march, and probably beyond

 

I notice Met are using the term 'cold' so 4 or 5C below the average for your own area. To me this means values of 8-9C for afternoon temperatures so probably in the range 3 or 4 to maybe 5+ or so?

 

Edited February 22, 2016 by johnholmes

[chris pawsey]

6 minutes ago, IPredictASnowStorm said:

Still showing this on gfs 

Still on for mothers day then... trends, trends! Please, please, please!! Give me an excuse??? 

[Daniel*]

2 hours ago, Nick L said:

ECM continues the cold and dry theme. A few light sleet/snow showers here and there but nothing significant. The annoying thing is though this easterly may just bring in overcast skies for the majority after the sunny week ahead.

@Jason M sorry for the harsh tone it's what a couple of bad winters do to you....

I must say I'm unconvinced, I suppose on the day itself we'll know....

GFS/UKMO being the ideal model for convective business. I would be stunned even on ECM between 120-144 southern/eastern parts do not see something, more than a flurry.

18z rolling out hopefully it plays nice  

[karlos1983]

-8 uppers pushing into the south west and Wales by +66

the cold is in place 

[feb1991blizzard]

This could be an upgrade - If the troughing to the NE and NW engage each other further North, that could mean any convective Easterly lasts longer - Just a punt though not sure about this.