Jump to content
Cold?
Local
Radar
Snow?

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


Paul

Recommended Posts

Posted
  • Location: Pershore
  • Location: Pershore

    Time for a fresh thread, as the final third of winter closes in. 

    Please keep posts model related in this discussion - and head over to the model banter thread for emotional reactions to the models/weather, ramps, moans and general chat..

    All charts/date can be found here on Netweather:

    NetWx-SR (Hi-res short range)
    http://www.netweather.tv/index.cgi?action=netwx-sr;sess=
     
    NetWx-MR (Medium range)
    http://www.netweather.tv/index.cgi?action=netwx-mr;sess=
     
    GFS
    http://www.netweather.tv/index.cgi?action=nwdc;sess=

    GFS Para
    http://www.netweather.tv/index.cgi?action=gfspara;sess=

    GFS vs GFS Para
    http://www.netweather.tv/index.cgi?action=gfscomp;sess=
     
    Ensembles
    http://www.netweather.tv/index.cgi?action=ensviewer;sess=
     
    ECMWF
    http://www.netweather.tv/index.cgi?action=ecm;sess=
     
    ECMWF EPS
    http://www.netweather.tv/index.cgi?action=ecmens;sess=
     
    Met Office Global
    http://www.netweather.tv/index.cgi?action=meto;sess=
     
    Met Office Fax
    http://www.netweather.tv/index.cgi?action=charts;type=fax;sess=
     
    GEM
    http://www.netweather.tv/index.cgi?action=gem;sess=
     
    Model Comparison
    http://www.netweather.tv/index.cgi?action=modelcomp;sess=

    Link to post
    Share on other sites
    Spotted a post you think may be an issue? Please help the team by reporting it.
    • Replies 3.8k
    • Created
    • Last Reply
    Posted
  • Location: New Ash green 150M / 500 FT
  • Location: New Ash green 150M / 500 FT

    Evening Guys -

    Well its been an utter rubbish day on the model front- 

    last nights call was based on the european models- more especially the ECM displaying the exact scenario & evolution it did in 2013 & the UKMO had joined the party on the 00z ( tues ) but did move away yesterday 12z-

    The GFS was to flat to start with & the ECM even at 120 was to amplified- the median point yet again coming out with another stella performance was the UKMO -

    I cannot praise this mode high enough this year- every single cold spell that hasnt varified- which has been most if not nearly all- The UKMO has never really been on board & perhaps I should have waited till 00z today to post-

    However when the data is almost identical from the yesteryear right down to the zonal mean dropping again- almost identical to 2013 then it seemed a no brainer.

    so yep the call was wrong... 

    it may interest a few that this year Im going to work on a new teleconnection, ive not named it yet however it will be based on 2 specific weather patterns that deliver cold for the UK & within that the leads up focussing on MJO data & Strat data -

    for example, since 1979 there have have probably been around 15 -20 greenland highs - it will be interesting to see my results of what the zonal mean was when these developed, especially in non SSW years - have we had any GHs in non SSW years...

    Anyway - enjoy your eves -- im as frustrated as anyone ...

    S

    Link to post
    Share on other sites
    Posted
  • Location: Scarborough, North Yorkshire
  • Location: Scarborough, North Yorkshire

    Have to agree. With the odd wobble the UKMO has to be respected and has been very consistent this winter. Has been a strange winter to call with all the varying signals.

    Link to post
    Share on other sites
    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    UKMO extended looking windier and for some wetter as we move into the final month of winter

    ukm2.2017020112.168.lant.troplant.prp.fcst.gentracker.png

    ECM and GFS don't agree with UKMO though they keep the low further away

    ecm2.2017020112.168.lant.troplant.prp.fcst.gentracker.pnggfs2.2017020112.168.lant.troplant.prp.fcst.gentracker.png

     

    Link to post
    Share on other sites
    Posted
  • Location: Drayton, Portsmouth
  • Location: Drayton, Portsmouth
    9 minutes ago, on the coast said:

    Have to agree. With the odd wobble the UKMO has to be respected and has been very consistent this winter. Has been a strange winter to call with all the varying signals.

    I would add the GEM. Bearing in mind it goes out to T240. No easterly nonsense at all, but got on board for the mini-arctic break of a couple of weeks ago. 

    A good little test for it coming up, though - it's been fairly bullish about dropping the jet south a touch - northern areas could get on the right side of the polar front if its recent runs are correct:

    gem-0-240.png?12

    Link to post
    Share on other sites
    Posted
  • Location: New Ash green 150M / 500 FT
  • Location: New Ash green 150M / 500 FT

    ^ its still retaining the wedge of heights to the north .....

    Link to post
    Share on other sites
    Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

    There is no need to eat humble pie whatever the possible outcomes. You offered an opinion which is as valid as any on a voluntary internet forum:)

    There is also no need for me to repeat (yet again) the specific GSDM mechanics mantra of the winter with regard to the combination of weak La Nina and strong w/QBO forcing. 

    Suffice to say though that persistent Branstrator ridges have flourished during considerable sections of this winter thus far - within the weak ENSO engine of this regime. Subjective maybe to weather taste and preference, but imo they have at least provided a very welcome break from the dreadful Atlantic storms of most recent years.

    Despite the absence of warm unstable stratospheric high latitude blocks due to the w/QBO driven stratospheric profile, there has still been the potential capacity to produce greater amplification of these anomalous mid latitude ridges in the guise of poleward Atlantic and Scandinavian features than has been the case so far. This capacity continues through the rest of winter of course, but the emphasis on finding the right combination code to take things onto that higher level gets more and more pressing the longer it stays elusive. Self evidently.

    However, sited as the UK is, at a betwixt and between crossroads of warm ocean pump to the west and a large continental landmass to the east,  there has continued to be lack of coherent co-operation between the global tropics and extra-tropics to engineer greater tropospheric amplification wind-flows and orientate these mid latitude ridges to generate upper cold advection to our specific crossroads. The crucial inflection points of what amplification there has been, always too far south and east of us to provide the desired in-house combination of upper cold and instability. Notwithstanding of course the latest protracted period of surface cold to southern and eastern UK which has flattered monthly temperature returns for these parts - its always been a case as far as I am concerned of the limits available, as restricted within this regime, due to the inability of the blocking to attain sufficient latitude stemming from the insufficient initial Atlantic amplification that created it shortly before mid January.

    As soon as it was clear that the starting amplification inflection point was less than even occurred in the modest cold spell of early Feb 2012, and which enabled even that extra 100 to 200 mile adjustment westward and northwards of the cold air advection to create a frontal snowfall event before heights took over at a better latitude than seen this last 10 days or so, then it was a matter of time before the high sunk without ever seeing upper cold rather than elevate northwards and provide them. Hence my own lack of excitement and enthusiasm at recent NWP suggested solutions - very much including the ECM attempted lounge lizard man-flirt of last night

    There has not been the tight knit interlinked tropospheric/stratospheric fury of last winters w/QBO, but both the upstream Pacific pattern and the westerly gyre of the polar field have still conspired to keep the Atlantic sector far too flat - with the key amplification areas within the Pacific ( sensible and logical conclusion given weak Nina forcing and atmospheric angular momentum inhibited from reproducing its promising late autumn ENSO disconnect flourishes) and also to our east as a result of too energetic a northern arm/polar jet whenever any little downstream amplification has arrived (such as approaching mid Jan).

    In respect of the much touted SSW, the La Nina/wQBO combo are naturally inhibitive of clean cut transfer of stratospheric anomalies to the troposphere. They also generally make a displacement vortex more likely than a split. It is indeed the case we see a displacement, and as Nick F suggests in his post earlier today this is unfavourably positioned in the foreseeable period for cold air advection blocking (and irrespective of other factors which do not favour it at the moment)

    Jan 2009 under a w/QBO (and actually stronger Nina forcing than we currently see) was one notable exception and still managed to feature a massively spilt vortex, but even here, the full potential tropospheric impacts were not meted out in one whammy and featured a trickling laddering of down-welling negative (easterly) anomalies that was drawn out into the Spring. Beyond the initial wintry start to February, the surface impacts beyond this were quickly diffused into a protractedly chilly Spring, that reflected this erratic propagative laddering effect, rather than any intense sustained winter cold and snow impacts. Such as were initially expected leading into that event in late Jan 2009.

     Rather instead, the sequence featured switches between down-welling warm negative anomalies decelerating the polar westerlies at intervals (but not necessarily in our sector of the NH) and pockets of stronger positive zonal anomalies (sibling vortices) broken away from the main destabilisation which unerringly frustrated a sustained cold synoptic pattern for the UK by phasing energy back into the polar, or northern branch of the jet.   Taking into account we are looking at initial displacement activity and then a continued drip feed of stratospheric attack this late in the winter, I think that expectations need to be adjusted accordingly this time - and to a level that almost certainly promises less than the cold spell of late Jan/early Feb 2009

    A weakly Nina profile will generally favour a Canadian/Greenland arm of vortex as part of the downstream pattern arrangement stemming from the characteristic height anomalies in the Pacific that are classically signatory to it. This always provides a potential spoiler risk even under a split vortex regime (such as it did in 2009), let alone a displaced vortex where the dominant chunk of vorticity is placed where they are, and will inevitably frustrate amplification precisely where it is needed for cold air advection to the UK.   We also continue to require tropical forcing to be much more of a downstream amplification contributor to the efforts on going in tandem with mountain torque induced troposphere>stratosphere destabilising efforts within the extra tropics.  Tropical and extra tropical co-operation sadly went AWOL after late autumn.

    It does still look possible that downstream amplification inducing tropical forcing in the troposphere, and also continued and more effective stratospheric ammunition to diffuse the polar vortex might arrive to orientate things more favourably during February.

    Will it be too little too late?  Too soon to say of course, but there is limited cloth to play with this winter and its a case of hoping to make at least the smallest silk cloth out of it.

    This is Tamara's post from the previous thread; we can't have her words of wisdom being missed out on :wink:

    Here's my take, or some of it;

    A lot hangs on the fact that the oceanic Nina signal is making an exit now which leaves the atmosphere more open to follow suit if tropical foricng can provide the springboard... ECM ensembles continue to look good for this to happen.... eventually. GEFS has other ideas that could in theory produce a quicker but shorter-lived move toward blocking to our N/NW but it would have to overcome the displaced vortex problem when actually a slower arrival of the right MJO forcing could be better timed as the vortex may be weaker and displaced further from the North Pole. Depending on whether we see further pulses of warming activity or not.

    The very short term actually looks like one of those small-scale details that can create a variation away from what large-scale forcing might suggest simply by circumstance; a small low may or may not get caught up in the strong jet running south of the UK and travel along that line during Sunday, causing the trough to the west to take on more of a negative tilt, with more of a ridge able to build ahead of it, and so on. Very fine margins with the placement of the small low while it's out west on Saturday make or break this. They're at a finer resolution than teleconnections/drivers can appreciably influence - at least in my opinion. Which makes what ECM showed yesterday an pretty much impossible to anticipate version of events that could still conceivably materialise for all anyone knows.

    Even if it doesn't come off, regional feedbacks may still provide a strong resistance to our east so I'd not be surprised to see the mainland turning cold again before long, but of course we might just get stuck under stalling Atlantic systems with rainfall amounts making up for lost time in the south.

    Link to post
    Share on other sites
    Posted
  • Location: NR LOURDES SW FRANCE
  • Location: NR LOURDES SW FRANCE

    Regarding Tamaras and Singularitys posts . The MJO NCEP update discusses that destructive interference with the MJO should lessen in week 2  and we might see this replaced with constructive interference enhancing the MJO signal. This of course is just a forecast so best not get ones hopes up as I think we're all reaching into our model interest reserves to see out the winter. 

    Link to post
    Share on other sites
    Posted
  • Location: Lincolnshire - 15m asl
  • Weather Preferences: Frost and snow. A quiet autumn day is also good.
  • Location: Lincolnshire - 15m asl
    5 minutes ago, Singularity said:

    This is Tamara's post from the previous thread; we can't have her words of wisdom being missed out on :wink:

    Here's my take, or some of it;

    A lot hangs on the fact that the oceanic Nina signal is making an exit now which leaves the atmosphere more open to follow suit if tropical foricng can provide the springboard... ECM ensembles continue to look good for this to happen.... eventually. GEFS has other ideas that could in theory produce a quicker but shorter-lived move toward blocking to our N/NW but it would have to overcome the displaced vortex problem when actually a slower arrival of the right MJO forcing could be better timed as the vortex may be weaker and displaced further from the North Pole. Depending on whether we see further pulses of warming activity or not.

    The very short term actually looks like one of those small-scale details that can create a variation away from what large-scale forcing might suggest simply by circumstance; a small low may or may not get caught up in the strong jet running south of the UK and travel along that line during Sunday, causing the trough to the west to take on more of a negative tilt, with more of a ridge able to build ahead of it, and so on. Very fine margins with the placement of the small low while it's out west on Saturday make or break this. They're at a finer resolution than teleconnections/drivers can appreciably influence - at least in my opinion. Which makes what ECM showed yesterday an pretty much impossible to anticipate version of events that could still conceivably materialise for all anyone knows.

    Even if it doesn't come off, regional feedbacks may still provide a strong resistance to our east so I'd not be surprised to see the mainland turning cold again before long, but of course we might just get stuck under stalling Atlantic systems with rainfall amounts making up for lost time in the south.

    I think much of this is accurate and well thought out. We have had a UK high nearly all season so far with surface cold in the south and dry weather everywhere.... and micro changes in this setup could possibly bring a temporary channel runner or a battleground event of some kind. February is not a given by any means...

    But I would have to add that my reading of the signals and anticipated rate of change points to any impact of stratospheric warming and movement away from a Nina setup as hitting us in March/April rather than February. I have to say - and its a sickener - that we could well end up with a cold spring and all the "right" looking charts arriving 10 weeks too late.

    I continue to hope that my glum reading of the signals proves wrong - but actually I'd modify Tamara's post a bit and suggest that well before we failed to get the high lat block in mid January we had emerging signs of falling GLAAM and a vortex that powered up much faster than anyone expected pre Christmas... and this led to sudden changes in model long term output and a definite lowering of expectations from those who see global teleconnections as significant. The combination of the two has created a disappointing January and I dont think February will be much different. As various BBC weather staff on social media have been stating - perhaps events in the Strat can bring about something exciting in the latter stages of February. Fingers crossed. Certainly cant rule it out because there is still much about the impacts of strat warmings that are not fully understood and predictable. But it is feeling like a long shot at the moment in the context of the background Nina pattern and raging wQBO referred to by Tamara.

    Link to post
    Share on other sites
    Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

    Oh dear its all gone very quiet in here this evening, the lows of Monday, the highs of yesterday, and back to the lows of today - all typical of the MOD thread it seems. 

    What are they showing - a theme of unsettled conditions setting in as we move through the weekend and more significantly next week,  the jet will be taking a more flatter westerly trajectory, but also signs that it will be more southerly placed than recent weeks and may still come unstuck...

    There is a suggestion the alantic frontal system due to move in on Monday could be quite negatively tilted, struggling against the block.. I say reliable timeframe is Monday at best, indeed some form of channel runner is being forecasted, and a bit of a messy slack airstream to its north.

    (I felt I needed to post something to keep this thread alive and wake people up..)

    Link to post
    Share on other sites
    Posted
  • Location: South Essex
  • Location: South Essex

    I suspect its more stunned silence than anything else. GFS rolling out now is something of a horror movie. Its a Bartlett set up tbh. Of course may not happen like, but pretty grim tbh.

     

     

    Link to post
    Share on other sites
    Posted
  • Location: st albans
  • Location: st albans

    Latest day 5 FAX is interesting as it has a disruptive look about it and certainly builds the ridge ahead more than today's runs have

    It is not taken from the ukmo run

    as far as mondays front bringing anything wintry is concerned, thicknesses look much too high, even on that more interesting FAX 

     

    Link to post
    Share on other sites
    Posted
  • Location: Santry, Dublin, Ireland. 50 metres ASL.
  • Location: Santry, Dublin, Ireland. 50 metres ASL.

    As long as the jet stream is acting in this buckled manner, anything is possible.

    http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=192&mode=5

    I'm not hopeful at all, but I'm still keeping a watchful eye.

    Link to post
    Share on other sites
    Posted
  • Location: frogmore south devon
  • Location: frogmore south devon

    I think after all that came out of the GFS, ECM, GEM. and every other model and then the UKMO is right on every turn of the dice it we have it in our power to follow the one model thats why it is quite on here to night 

    Link to post
    Share on other sites
    Posted
  • Location: North East Hampshire
  • Location: North East Hampshire
    22 minutes ago, Jason M said:

    I suspect its more stunned silence than anything else. GFS rolling out now is something of a horror movie. Its a Bartlett set up tbh. Of course may not happen like, but pretty grim tbh.

     

     

    It's a poor run, but let's not kid ourselves  - it's nothing like a Bartlett set up.

    Link to post
    Share on other sites
    Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire
    21 minutes ago, bluearmy said:

    Latest day 5 FAX is interesting as it has a disruptive look about it and certainly builds the ridge ahead more than today's runs have

    It is not taken from the ukmo run

    as far as mondays front bringing anything wintry is concerned, thicknesses look much too high, even on that more interesting FAX 

     

    You'e certainly right BA and in my experience it's unusual for the fax to be modified as much as it has been.

    Must admit as I found the change in the output yesterday morning baffling I equally find the change in todays output equally baffling.

    I wouldn't be surprised if we see more drama yet.

    Link to post
    Share on other sites
    Posted
  • Location: South Essex
  • Location: South Essex
    14 minutes ago, Johnp said:

    It's a poor run, but let's not kid ourselves  - it's nothing like a Bartlett set up.

    Nope not kidding, its a Bartlett set up. Persistent band of high pressure to our SE. Its not exactly the same as the 1988 version of course and as said above it might not happen like that, but IMHO the 18z is a Bartlett set up (much like most of Dec tbh).

    Your perfectly entitled to a different view but in terms of the weather we experience its splitting hairs.

    Edit: Control going the same way, albeit still just enough variation in the GEFS to just leave a little doubt this evening.

     

    Link to post
    Share on other sites
    Posted
  • Location: Santry, Dublin, Ireland. 50 metres ASL.
  • Location: Santry, Dublin, Ireland. 50 metres ASL.
    7 minutes ago, Jason M said:

    Nope not kidding, its a Bartlett set up. Persistent band of high pressure to our SE. Its not exactly the same as the 1988 version of course and as said above it might not happen like that, but IMHO the 18z is a Bartlett set up (much like most of Dec tbh).

    Your perfectly entitled to a different view but in terms of the weather we experience its splitting hairs.

    Well, technically, he's correct, it is not a Bartlett. It doesn't matter if it produces the same weather for us, it's still not a Bartlett.

    Link to post
    Share on other sites
    Posted
  • Location: South Essex
  • Location: South Essex

    Hi Rochey,

    The term Bartlett was an internet forum invention and doesn't actually exist in meteorological text books. See below description lifted from the web...

    However, in recent years (this written in autumn, 2005), these situations have been notable by their absence. What 'high' blocks there have been stay teasingly just too far east and more often than not, a broad band of high pressure extends from the Azores area, east-north-eastwards towards the Biscay / English Channel region - perhaps now & then displaced towards the Alps, as storm upon storm sweeps in from the North Atlantic, hurried along by an often powerful upper jet (see "What are jetstreams?"). Rain, gales and above average temperatures prevail, with any 'wintry' weather confined to brief incursions of Polar Maritime west or WNW'lies, or perhaps a temporary Arctic Maritime blast from the north - which is shunted away as the next surge of mild air hurries in from the west. The apparently semi-permanent belt of high pressure in the 'wrong' place has been christened ... "The Bartlett High", in honour of Paul Bartlett, a luminary of this ng, who used to put his experience of forecasting to the test by publishing a reasoned winter forecast for all to see. As Les Crossan has noted (also a stalwart of this ng), this has come to be regarded as a 'slug' - nothing moves it, not even extracting a pair of dividers and skewering the said beast as it sits dominating any particular synoptic chart!

    In essence I'm just using the term to describe a particular set up a bit like the 'Murr sausage' (I still shudder at that one :rofl:). If you had said no such thing exists you would have been technically correct, however you and Johnp seem to be suggesting that a Bartlett is something else which is puzzling?

    Anyway, things must be bad when this is being debated, so lets all just agree to disagree :D. Hopefully things will change and I can describe it as a 'displaced Bartlett' (always wanted to use that!).

     

    Link to post
    Share on other sites
    Posted
  • Location: Rotherhithe, 5.8M ASL
  • Location: Rotherhithe, 5.8M ASL
    8 minutes ago, Rocheydub said:

    Well, technically, he's correct, it is not a Bartlett. It doesn't matter if it produces the same weather for us, it's still not a Bartlett.

    GFS 18z is very cyclonic a continual theme we see very cold air spilling out across the pond reinvigorating the Atlantic & the jet stream. For the British Isles pressure hits the ceiling at 1015mb through the entirety of the GFS 18z, not even near anticyclonic, jet stream largely head on or to the S of us, I suppose with some more adjustments there is a risk of northern areas being on the "right side". Quite frankly the assertion of a Bartlett is misleading. Hp to SE is fairly transient definitely not entrenched. Scottish mountains should see the return of some snow at least by opening week of February, where it's been very snow barren. 

    I think some on here enjoy fabricating something different to the reality!! The models seem indecisive to me but when are they not...who knows what today will bring. :wink: 

     

    Link to post
    Share on other sites
    16 hours ago, bluearmy said:

    Latest day 5 FAX is interesting as it has a disruptive look about it and certainly builds the ridge ahead more than today's runs have

    It is not taken from the ukmo run

    as far as mondays front bringing anything wintry is concerned, thicknesses look much too high, even on that more interesting FAX 

     

    THE COLD BLOCK CONTINUES TO HOLD ON BUT FOR HOW MUCH LONGER?                            ***Please see my 0830 Thur. Jan. 26th update at the end of this message***

    BA - I was preparing this post and just noted your comments and I had also noticed the subtle changes on the MetO 18z fax charts compared to their UKMO 12z model output. The next 5 days may be very interesting. 

    Firstly, the strength of the Euro cold block. The cold has steadily deepened during the last 48 hours and it has become much more extensive again. The live charts update every few minutes. I have frozen the third chart at 2350. The last two charts show the max temps for Monday and Tuesday. There's a progressively wider area of France with below zero max temps.

    Please note that all the times shown on the Meteoceil charts are 1 hour ahead of GMT  

            NW Europe temps "live"                                        All Europe temp live                             All Europe temps at 2350                         NW Europe Max Temps Tue 24th                   NW Europe Max Temps Wed 25th

    temp.png        temp_eur2.png      temp_eur2-23.png          tx.png         tx12.png

    The HP has only moved very slightly eastwards - from Germany into eastern Euriope during thre last 24 hours, far less than forecast 24 hours ago and less than the earlier model output suggested (see my posts on page 312 and 313 on the old winter model thread). The the separate cell over south-east Finland last night has merged with the main HP. overall the HP block looks remarkably steady. The central pressure is still slowly rising. I also provide a link to the archive charts to view the changes over the last 24 hours. Just click on "animation on 24" above the chart and it take 10 seconds to load up. All four charts have 1 millibar pressure gradients.

            Live Europe Pressure Chart                                Europe Pressure 0050 Thursday                                        Live France and UK Chart                                              France and UK Pressure at 2348     

      pression2_eur2.png                    pression2_eur2-00.png                         pression2.png                               pression2-23.png

      

    The link to the Animated Chart:       http://www.meteociel.fr/observations-meteo/pression.php?region=eur2

    Met Office 18z Fax Charts vs UKMO Model 12z:

               MetO Current 1800 Wed 25th                 MetO  T+24   1800 Thur 26th                    MetO     T+36 0000 Fri 27th                   MetO     T+48 1200 Fri 27th                      MetO  T+60 0000 Sat 28th                        

      20170125.1900.PPVA89.png  20170125.2156.PPVE89.png 20170125.1658.PPVG89.png  20170125.1658.PPVI89.png    20170125.1804.PPVJ89.png

                 MetO  T+72 1200 Sat 28th                     MetO  T+84 0000 Sun 29th                        MetO  T+96 1200 Sun 29th                      MetO  T+120 0000 Mon 30th          

    20170125.1804.PPVK89.png     20170125.0556.PPVL89.png    20170125.2221.PPVM89.png    20170125.2226.PPVO89.png                                                                                  

                                                         

                                    UKMO T+72 1300 Sat 28th                                    UKMO T+96 1300 Sun 29th                                         UKMO T+120 1300 Mon 30th  

                        UW72-21.GIF                     UW96-21.GIF?25-18                         UW120-21.GIF?25-18        

     

    The fax charts only go up to T+120 and the UKMO model only starts at T+72. So, I have only included the three UKMO charts in the overlapping period. The Fax charts are only updated a few hours after the 12z UKMO but they are less progressive and the fronts look like they will stall or disrupt against the HP to east. Even after the initial break through, it looks like the Euro HP will be fighting back. Even though we are looking at D1 to D5, it looks like this will be a forecasters nightmare - no wonder the models are struggling with the very short term yet to be resolved! This will be a fascinating period to watch and I expect some very sudden changes in the next few runs.

    Finally, the live satellite imagery. This shows the increasing south-south-easterly drawing in the very cold air from France (as at 0030 on Thursday).

             NW Europe Satellite "live"                                NW Europe Satellite Thur 26th 0030                                       NW Europe "live" surface winds                      NW Europe surface winds Thur 26th 1248             

    anim_ir.gif                   satir-00-30.gif                                vent.png                   vent-12.png                   

     Link to Archive Satellite Imagery:             http://www.meteociel.fr/observations-meteo/satellite.php?region=eur2    (click on "archive", set date and time and click"OK")

    EDIT (1230 Thur. Jan 26th):  I have just added the surface wind charts above. This demonstrates that, even with the south-south-easterly to southerly airstream, the surface winds are south-easterlies over the Channel and southern England and are east-south-easterlies of most of north-west France. For any signs of the milder air encroaching, watch out for a slight veering to due south or south-south-west along with temperature rises over western France, particularly the Brest Peninsular, as well as Cornwall. At the time of writing, the Atlantic fronts are still being held at bay - as can be seen with the line of frontal cloud in the live satellite imagery making hardly any eastward progress between 0030 and 1230.  Some milder air is encroaching into western France. Further north and east, this should not be confused with the natural daytime max temps. There is also an upper level cold pool moving up from France which should be over the south-east by Friday morning. This may produce a light snowfall just ahead of the milder air moving in later in the day. I'll do a separate post on this shortly but  for those interested please keep referring back here to the live charts. Plenty to keep an eye on today and tomorrow!

            Live Precipitation Radar

    lastradar.gif

    UPDATE (0830 Thur. Jan. 26th):

    The HP has slipped a little further east overnight but has continued to intensify. The cold over France is again more widespread and slightly deeper this morning (more mid blues).

          All Europe Min Temps Wed 25th             All Europe Temps Thur 26th 0750                NW Europe Min Temps Wed 25th               NW Europe Temps Thur 26th 0748

    tn_eur2.png    temp_eur2-07.png      tn.png       temp-07.png 

    The UKMO 0z run is more similar to its 12z run yesterday and the 18z fax charts remain a little different - rather puzzling? As others have mentioned, the strengthening Jet Stream is "likely" to push the block further east during the next 5 days but it may still be a messy transition. If the milder air pushes through during Friday, it would only take a minor change (like a very minor backing of the flow) to bring back the cold from France, albeit temporarily. This is probably merely delaying the inevitable but fascinating to watch unfold. 

     

     

     

    Link to post
    Share on other sites
    Posted
  • Location: Broxbourne, Herts
  • Weather Preferences: Snow snow and snow
  • Location: Broxbourne, Herts

    I spoke at work to a girl in Minnesota yesterday who had opted to work from home on account of hearing that heavy snow was due to arrive  at 3pm that afternoon.Speaking to her again today,it transpired that the snow didn't arrive until after midnight and wasn't of the intensity predicted. She said what had been predicted for her area had ended way way south.

    It struck me that if the models that are no doubt prompting incorrect short-term forecasts are not getting a grip with what is happening in such a short term over ther, the knock on effect on the four and five day modelling for our neck on the woods has got no chance.

    It did leave me wondering whether the poor forecast was prompted by what turned out to be a promising cold ECM run,while the butterfly wings of reality was what led to the more disappointing follow-ups.

    Either way it does seem that there the generally such variability about for whatever reason that little local fluctuations upstream are  having more significant effects on subsequent mode runs than is usually the case.

    The Atlantic ought to have broken through now going on what we were seeing last week.  As many have stated, potentially it won't for another week and ho knows another week after that. Then again it might!! I do take some comfort from the fact that,for all the strides in technology and our understanding of how weather patterns develop, there is much that remains as yet beyond the realms of scientific understanding.

    I'm expecting a cracking UKMO 0z run when I wake up in the morning  :)   

    Link to post
    Share on other sites
    Posted
  • Location: Santry, Dublin, Ireland. 50 metres ASL.
  • Location: Santry, Dublin, Ireland. 50 metres ASL.
    4 hours ago, Jason M said:

    The term Bartlett was an internet forum invention and doesn't actually exist in meteorological text books. See below description lifted from the web...

    Very well aware of its origins ad it's meaning. Thanks.

    3 hours ago, Timmytour said:



    I'm expecting a cracking UKMO 0z run when I wake up in the morning  :)   

    I'm afraid you'll be sadly disappointed!

    http://www.meteociel.fr/modeles/ukmo2.php

    Link to post
    Share on other sites

    Archived

    This topic is now archived and is closed to further replies.

    Guest
    This topic is now closed to further replies.
    ×
    ×
    • Create New...