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Model output discussion 25th Jan - The final third of winter beckons..


Paul

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Posted
  • Location: County end Oldham 202 m Above sea level
  • Location: County end Oldham 202 m Above sea level

    Just a quickie about the distribution of snow on the 00z runs, carol kirkwood just mentioned snow for pennine areas on friday which probably ties in with gfs at 84 hrs.

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    Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

    Lots of obituaries being written this morning before the very cold Easterly even arrives:nonono:

    Great post as always from Bring Back 1962-63:)

    Models show a cold and wintry spell later this week..enjoy it!

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    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    Bit more shower activity from UKMO at D6 now assuming the air was cold enough we'd have a good chance of seeing some fairly widespread snow

    ukm2.2017021300_144_lant.troplant_prp_fcst.gentracker.thumb.png.e42ffa964a1dc857785cbf6ed7c510e9.png

    D7 still has some showers around but more so in the north

    ukm2.2017021400_168_lant.troplant_prp_fcst.gentracker.thumb.png.1f9f0437962196679f4fe84d6c9ce4f6.png

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    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    The ECM Op is on the colder side of the mean from Friday till around Monday next week it continues to go for something slightly less cold

    43645654.thumb.png.b0c95a90df2ec7fd1b0029fc4cbc4526.png

    So a colder period remains later this week then continued hints from ECM of the 850's becoming less cold during next week going from around a peak low of -6 to a peak high of +2 based on the mean

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    Posted
  • Location: County end Oldham 202 m Above sea level
  • Location: County end Oldham 202 m Above sea level

    Somewhat suprisingly the ukmo model also shows the bulk of the precip across the north! Cant really see the SE though on the chart..

    day3

    ukm2.2017021012.084.lant.troplant.prp.fc

     

    day5

    ukm2.2017021200.120.lant.troplant.prp.fc

    Wont let me post day 4 for some reason.

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    Posted
  • Location: Kilmersdon Radstock Somerset
  • Weather Preferences: None Really but a snow lover deep down
  • Location: Kilmersdon Radstock Somerset
    59 minutes ago, blizzard81 said:

    The ecm has been struggling on and off all winter,  not to mention the ecm monthly lol.  The ecm was the only model that didn't really go for this easterly in the first place. Think back to late last week with those dodgy runs .  It has been poor in the 6 day plus range all winter. Was better before the upgrade. 

    The ECM is and has not been poor. It constantly verifies greater than GFS and UKMO. Remember a few days ago when it churned out that awful run when it showed High pressure drifting South and cutting off the cold period while all the other models maintained us in the freezer for next week. A couple of days later all models have caught up on the theme albeit in a modified form. ECM has modified its own version of that event but you cannot discount it because it hasn't been showing what you want it too. Wait till after the event then criticize. We've not even got to the cold spell yet so all models could be proved wrong but not until we reach the end of next week. You have to use longer range charts over say Day 5-6 for trends only not for specifics and that day in my mind when ECM pulled out that rogue run was the beginning of a new trend, one which has now spread across all output. From my POV the current trend is for milder conditions early next week but with the possibility of a return to colder conditions later. My reasoning being that is the trend I accomplish by a blend of all models, ensembles etc over this mornings and the last few runs. Heres the latest 10 Day Verification Stats for the 00zs.

    http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

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    Posted
  • Location: Cyprus and North east Swindon. 104 ASL
  • Location: Cyprus and North east Swindon. 104 ASL
    10 minutes ago, Summer Sun said:

    The ECM Op is on the colder side of the mean from Friday till around Monday next week it continues to go for something slightly less cold

    43645654.thumb.png.b0c95a90df2ec7fd1b0029fc4cbc4526.png

    So a colder period remains later this week then continued hints from ECM of the 850's becoming less cold during next week going from around a peak low of -6 to a peak high of +2 based on the mean

    At one point a day or so ago this was looking like a prolonged cold spell - that has somewhat died off from this mornings charts which is a little disappointing; but can't grumble as this weekend looks good.  Hopefully most of us see something white over the next few days.

    Beyond next week we need to see what happens to our North I think.  Hopefully the 06Z starts to show something better for prolonging this weekends cold spell though!

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    Posted
  • Location: oldham
  • Location: oldham
    22 minutes ago, Gibby said:

    The ECM is and has not been poor. It constantly verifies greater than GFS and UKMO. Remember a few days ago when it churned out that awful run when it showed High pressure drifting South and cutting off the cold period while all the other models maintained us in the freezer for next week. A couple of days later all models have caught up on the theme albeit in a modified form. ECM has modified its own version of that event but you cannot discount it because it hasn't been showing what you want it too. Wait till after the event then criticize. We've not even got to the cold spell yet so all models could be proved wrong but not until we reach the end of next week. You have to use longer range charts over say Day 5-6 for trends only not for specifics and that day in my mind when ECM pulled out that rogue run was the beginning of a new trend, one which has now spread across all output. From my POV the current trend is for milder conditions early next week but with the possibility of a return to colder conditions later. My reasoning being that is the trend I accomplish by a blend of all models, ensembles etc over this mornings and the last few runs. Heres the latest 10 Day Verification Stats for the 00zs.

    http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

    So those stats are for the area above the UK? Or Western Europe?

    Just to add, I see these verification stats a lot, but what it fails to support is that any one model is better for the UK, it's no good saying model "x" is better than model "y" based on a few percentage points different if both models get the area above the UK wrong, of if by some quirk the model with a the lower percentage outcome gets area above the UK right whislt the other model with a better overall verification gets it wrong.

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    Posted
  • Location: Brighton, East Sussex
  • Location: Brighton, East Sussex

    Pretty much unanimous support for a 'warm up' in the medium term amongst the ECM and GFS ensembles, what happens after that is up in the air.

    i would add that just because there's a certain amount of agreement doesn't mean they are right, just a few days ago the 2/3 day period with -8 or below uppers was a -3 mean for my location

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    this is in the in depth more leisurely thread

    sorry I keep getting another link but simply go to the other thread

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    Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire
    28 minutes ago, Ali1977 said:

    At one point a day or so ago this was looking like a prolonged cold spell - that has somewhat died off from this mornings charts which is a little disappointing; but can't grumble as this weekend looks good.  Hopefully most of us see something white over the next few days.

    Beyond next week we need to see what happens to our North I think.  Hopefully the 06Z starts to show something better for prolonging this weekends cold spell though!

    I did warn a few days ago when the ECM Op was a massive outlier compared to its ensembles that we should be wary of ruling it out. I am however referriing to the SE,ly early next week rather than the ECM +192 to +240 charts. Still think a return of cold from the N is more likely than what the ECM is showing.

    Just add it looks as though I am wrong about the snow shower distribution for Fri/Sat. Does appear the S extent of shower activity could be around Wash/Lincs/Norfolk. The poor old SE which normally does well appears to currently miss out.

     

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks
    24 minutes ago, frosty ground said:

    So those stats are for the area above the UK? Or Western Europe?

    Just to add, I see these verification stats a lot, but what it fails to support is that any one model is better for the UK, it's no good saying model "x" is better than model "y" based on a few percentage points different if both models get the area above the UK wrong, of if by some quirk the model with a the lower percentage outcome gets area above the UK right whislt the other model with a better overall verification gets it wrong.

    Sadly the statistics are not available for the UK only, all we have are the northern hemisphere. For large scale patterns, the main ridges and troughs, then the statistics are real and far better than someone suggesting from memory this or that happened. They will rarely be far enough out to give a wrong impression of how the UK sat in those main upper air patterns.

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    Posted
  • Location: Chisinau, Moldova.
  • Location: Chisinau, Moldova.

    Ah, so annoying to work with means sometimes. Any comments from those who can see all the 51 members? To me, going by the mean, it seems like the ECM Op does have considerably support from its suite. Not saying it's accurate, just that looking at the means and the Op, they might not be singing the same tune, but the melody is similar.

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    Posted
  • Location: East Ham, London
  • Location: East Ham, London

    Morning all :)

    More excellent output in the short term this morning.

    The T+144 output from the suite of 00Z OP runs has a lot of consistency for the British Isles in terms of a SE'ly flow but the orientation and strength (and indeed on GEM the very existence) of the Iberian LP is very different. These charts scream cold and dry to me with a harsh wind chill through the weekend and into early next week:

    UW144-21.GIF?07-06

    gfs-0-144.png

    ECM1-144.GIF?07-12

    gem-0-144.png?00

    Moving on and as we can't see what UKMO would offer at T+240, let's start with GEM:

    gem-0-240.png?00

    Anticyclonic and if anything the HP seems to be building back into Scandinavia - no sign of the Atlantic or any milder weather - with luck, sunny cold days and cold very frosty nights.

    ECM at T+240 and I know a lot of people will be going on about downgrades and all the rest of it:

    ECH1-240.GIF?07-12

    The Northern Hemisphere overview tells a rather different story. The HP has sunk but that has allowed the PV to drain out of Greenland/Canada and across to Siberia and signs of heights building behind that. The progression from there offers plenty of "potential" for a Greenland height rise so not one to be too upset about.

    GFS at the same time:

    gfs-0-240.png

    Superb chart for those liking cold and possibly even more with that trough over us - not so much full on retrogression but a broad block from Greenland to Europe with the Greenland core the more prominent. The 850s aren't fantastic though as always they don't tell the whole story. The far edge of FI has the PV more or less due north of the British Isles and the trough trying to drop over Scandinavia so plenty of cold available there.

    Just skimming the GEFS at T+240 - as you'd expect a lot of solutions are on the table but hardly a SW'ly zephyr to be seen. The majority cluster keeps us in an E'ly flow of some sport with plenty of HLB but a lot to be resolved as you'd expect.

    The path into the weekend looks set and the early part of next week looks to continue in the cold and blocked theme. I realise many on here want snow and some of today's charts will be a disappointment - HP too close, 850s all wrong etc.- and I understand that though the longevity and pattern of this cold spell is still evolving and with the three main models at T+240 offering such divergent evolutions there's a long way to go yet. 

     

     

     

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    Posted
  • Location: oldham
  • Location: oldham
    6 minutes ago, johnholmes said:

    Sadly the statistics are not available for the UK only, all we have are the northern hemisphere. For large scale patterns, the main ridges and troughs, then the statistics are real and far better than someone suggesting from memory this or that happened. They will rarely be far enough out to give a wrong impression of how the UK sat in those main upper air patterns.

    I am not sure i agree, unless you can see the verified locations then your simply guessing, Of course when the Pro's say the ECM is the better performing model i tend to side with them.

    What that graph is asking us to do is is the equivalent of rolling a dice and assuming the number you got based on a percentage without knowing the actual outcome. 
     

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    Posted
  • Location: Cyprus and North east Swindon. 104 ASL
  • Location: Cyprus and North east Swindon. 104 ASL

    Early doors but by T60 the colder air (-4c 850 line)  is slightly further SW, and although GFS precip charts aren't great it does show a little bit more flurry activity.

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    Posted
  • Location: Hernia Bay
  • Weather Preferences: Heavy Snow
  • Location: Hernia Bay
    26 minutes ago, TEITS said:

    I did warn a few days ago when the ECM Op was a massive outlier compared to its ensembles that we should be wary of ruling it out. I am however referriing to the SE,ly early next week rather than the ECM +192 to +240 charts. Still think a return of cold from the N is more likely than what the ECM is showing.

    Just add it looks as though I am wrong about the snow shower distribution for Fri/Sat. Does appear the S extent of shower activity could be around Wash/Lincs/Norfolk. The poor old SE which normally does well appears to currently miss out.

     

    Please God no. I've been waiting all winter for something decent and our best chance is from an easterly I like in Kent that would be beyond cruel however I think k it's early days to call where exactly snow will fall. That would just be dreadful come on GFS 

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    Please note: I have copied this post across to the "in depth thread" should anyone wish to discuss any points that I have raised and share their views in a less frantic environment

    TIME FOR A GOOD "OLD-FASHIONED" LOOK AT THE FAX CHARTS

    TODAY’S  0Z OUTPUT:

                   T+6:  0600 TUE FEB 7TH                                   T+24: 0000 WED FEB 8TH                               T+36: 1200 WED  FEB 8TH                             T+48: 0000 THUR FEB 9TH                  

        20170207.0648.PPVA89.png             20170207.0409.PPVE89.png             20170207.0501.PPVG89.png              20170207.0515.PPVI89.png     

                T+60: 1200 THUR FEB 9TH                                T+72: 0000 FRI FEB 10TH                                 T+84: 1200 FRI FEB 10TH                           CURRENT LIVE CHART FOR COMPARISON

        20170207.0553.PPVJ89.png             20170207.0603.PPVK89.png             20170207.0626.PPVL89.png                      pression2_eur2.png

    YESTERDAY’S 12 OUTPUT  (THESE LAST 2 CHARTS ARE UPDATE AROUND 1400 EACH DAY)    

               T+96: 1200 FRI  FEB 10TH                                  T+120: 1200 SAT FEB 11TH                            UKMO 0Z T+120 SUN FEB 12TH                             UKMO 0Z T+144 MON FEB 13TH                   

        20170206.2228.PPVM89.png            20170206.2300.PPVO89.png                 UW144-21.GIF                    UW120-21.GIF               

    COMMENTS:

    I am surprised that no one has posted all these charts as they show us so much short term detail. Obviously they are all available here on the NetWeather site and can be checked at any time but we need a little analysis.

    Firstly, note that the fax charts are today's 0z output (which go up to 1200 Friday),  except the last two which are yesterday’s 12z output (which repeats the 1200 output for Friday as a good comparison and goes out to 1200 Saturday).  I also include the UKMO 0z T+120 and T+144 for comparison.

    The T+6, T+24, T+36 and T+48 charts show the fronts stalling over the east of the UK and then returning westwards as the cold air from the east undercuts the remaining Atlantic air. We still do not know how much of the rain will turn to snow during this two day phase. Probably nothing really significant as it all fizzles out. All the time we see the Scandinavian HP building and edging westwards. It is only shown to attain a central pressure of 1050 mb by T+72 on Friday. As I said in my post on page 132, it is already stronger than this and likely to exceed 1050 mb during today (watch this on the live chart) and set to intensify further (my guess is perhaps 1055 mb by later tomorrow). This extra strength may well be important down the line in terms of the HP holding its position as well as forcing more of the cold pool towards us around its southern flank. The minor area of LP (forming on the occluded front) to or over the south-west of the UK is moving away east-south-eastwards and is likely to help the undercutting,  bringing in the easterly slightly more quickly. The Italian LP looks very static now and that should help to prop up the HP and provide a more direct easterly flow as time goes on.

    By T+72 onwards, we see a succession of troughs and minor fronts moving west-south-westwards in the flow towards and across the UK. These features plus the upper cold pool(s) mostly associated with them need to be watched carefully. There is plenty of potential for some more widespread snow. The latter period out to the weekend shows a continuation of this pattern with several more disturbances. The UKMO 0z shows the HP expanding both south-eastwards and westwards (perhaps linking with the Azores high to form a loop to the north of us). The LP approaching from the south-west (if that pattern develops like that - plenty of uncertainty) will be hitting some very cold surface air over all of north-west Europe and the UK. This could well produce a good and widespread snowfall. Thereafter, I do not see a big sinking of the HP but rather a strong ridging to the north-west and towards Greenland to set up phase two of this cold spell. My strong hunch is that the HP will be far more resilient sitting over the ever deepening surface cold and remaining close to its current position for over a week or longer. The eventual change to the northerly may actually be quite a smooth transition will little or no slightly less cold period in between. I think that some of the models and the ECM in particular are once again hugely under estimating the strength of the cold block which will be right over us , almost all of Europe , Scandinavia, Russia and way into eastern and central Asia. Very exciting times ahead.

     

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    Posted
  • Location: County end Oldham 202 m Above sea level
  • Location: County end Oldham 202 m Above sea level
    1 minute ago, Weathizard said:

    Frustratingly stuck in no mans land, it will still feel cold but nothing out of the ordinary really. 

    IMG_7546.PNG

    IMG_7547.PNG

    Yup, by sunday gfs6z has temps of 4, 5 and 6 degrees! Hoping thats a milder run on the suite!

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    Posted
  • Location: Cyprus and North east Swindon. 104 ASL
  • Location: Cyprus and North east Swindon. 104 ASL
    5 minutes ago, northwestsnow said:

    Yup, by sunday gfs6z has temps of 4, 5 and 6 degrees! Hoping thats a milder run on the suite!

    Yes this is not what many were hoping for - snow chances look minimal, apart from a few flurries for most and then it's followed after a few days by a less cold SSE flow.  If this is all it can muster then it's not a classic cold spell thats for sure.  It also looks very unlikely we will get a Northerly neither at T174, hard to see much change for the better as once this high sinks a little it won't be quick to budge.  I have a feeling we may have a chance late Feb but these have to be really good set ups for prolonged lying snow.

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