Jump to content
Problems logging in? ×
Snow?
Local
Radar
Cold?

Met4Cast

Members
  • Posts

    5,430
  • Joined

  • Last visited

  • Days Won

    15

Posts posted by Met4Cast

  1.  alan.duckers

    The Shannon Radar should be re-added to the composite data by late April, whilst it's now operational additional data for calibration is still required, there are also an additional 5 radars being put up.

    So, hopefully by the end of April the dark spot across southern Ireland will be gone & we'll have a fully functional radar system again.

    • Like 1
  2. On 02/03/2024 at 12:46, Met4Cast said:

    The direction of +AAM anomalies is equally important and we're seeing +AAM anomalies moving poleward as the previous cycle completes, this is suggestive of a stronger jet and is further evidence of a quicker flattening of the pattern.

    Unsurprisingly the blocked model outputs from a week or so ago didn’t really materialise, here was a run for today vs how things actually looked today; 

    IMG_5739.thumb.png.e423b641ffceda3bd922f56e506ac0dc.pngIMG_5740.thumb.png.603143646170eb96c3fe8b285e23b6fd.png

    The teleconnections are sometimes rubbished on this forum if it doesn’t snow in X location but once again they’ve proved a very useful tool in viewing NWP outputs with added context, as they have done for the majority of this winter. 

    It seems instead we’re in for a fairly prolonged period of above average temperatures with the March CET likely coming out above average if the current direction of travel continues. 

    Perhaps signs of something a little colder thanks to Atlantic ridging late March/early April as the MJO continues to progress eastwards through the Maritimes & into the Pacific with AAM tendency fairly positive at the moment as a result.

    • Like 2
  3. 5 minutes ago, Sherry said:

    I think people need to forget about SSW events clearly not one of them did anything in the past winter! And everyone said the background signals were good! 

    Background forcing has been against the idea of colder weather since the mid January cold spell, a marker divergence appeared around the 22nd January when I (and others) noted the likelihood of a cold February was diminishing. 

    Indeed, background forcing remains unfavourable for strongly blocked/colder patterns with the Iberian high continuing to play a larger role in the broadscale patterns (despite major SSW)

    April however does show some tendency towards higher latitude blocking as the MJO continues to progress into phase 7-8 but by this point does anybody really want colder blasts of air? Probably not. 

    • Like 4
  4.  RJBingham

    Yup.

    I've struggled to see the enthusiasm for anything properly cold to be honest, besides some deterministic runs/outlier ENS members modelling has been pretty consistent with predicting temperatures remaining around average for the foreseeable with very little sign/support of anything significantly colder. 

    Later in the month will likely see some renewed high latitude blocking as the MJO cycles into more favourable phases in the context of rising AAM but by and large, it's game over for cold chasers. 

    • Like 9
  5. On 26/02/2024 at 10:48, Met4Cast said:

    With the recent sharp fall and rise in AAM tendency it does seem plausible that we'll see the jet stream encountering some road blocks in the form of high pressure, probably to the NE of the UK (though as mentioned previously, the high probably too far NE to influence the UK much) before the pattern flattens out again by the end of week 1 into week 2 of March.

     

    Going back to this post from the 26th February we are now seeing this broader evolution play out within modelling. 

    High pressure forming across Scandinavia but increasing support that it’ll be too far NE to really drive energy SEwards & advect cold west across Europe. 

    The pattern flattening out is now well advertised. 

    IMG_5536.thumb.png.92939fb0ab6b5195a35048ef35dc093f.png

    I think it’s probably fairly safe to rule out any cold weather through the first half of March & probably beyond now. 

    • Like 5
  6.  Mike Poole

    The EC46 has been spectacularly poor this year. I wonder if the now daily updates just highlight this more, was a little harder to keep track when the model only updated twice a week. I don't think i'll be putting much weight into it in the future, it's inability to drop a signal that it's latched onto when it's clear the trend has changed isn't great. 

    I think 1-2 weeks it can be helpful to provide support for current trends within other models but as an isolated long-range forecasting tool it's poor.

    • Like 1
  7. 2 minutes ago, Addicks Fan 1981 said:

     Met4Cast we need @Tamaraon here to tap into the diagnostics before people have this reactive panic on these scenarios because signals obviously lead the models not the other way round.   

    Total AAM tendency has been strongly negative of late thanks to the MJO decaying into COD, this re-emergence into the Indian Ocean and quick progression eastwards through the Maritimes though has begun to reverse this with AAM tendency now slightly positive.

    gltend_sig.90day.thumb.gif.6e852f04672b61070990c47e4f860d5b.gif

    I do wonder just how much overall +ve AAM will rebound to though, a fast MJO progression as is currently predicted would suggest less westerly momentum being injected into the atmosphere, I'd be surprised if we reached values seen through late January/most of February again, especially with El Nino beginning to fade.

    The recent abrupt decline in AAM tendency combined with the SSW is likely generating the blocking to the NE of the UK across Scandinavia and we are seeing a regressive signal towards Greenland within NWP modelling, the only real issue is the lack of cold across Europe to advect into the UK, I do also think, as stated previously, the high might end up being too far NE to really drive Atlantic energy to the south of the UK and the means are now showing this with winds broadly S/SErly across the UK rather than true easterly, this essentially stalls the low across the UK bringing yet more rain.. wont that be nice. 

    The direction of +AAM anomalies is equally important and we're seeing +AAM anomalies moving poleward as the previous cycle completes, this is suggestive of a stronger jet and is further evidence of a quicker flattening of the pattern.

    ME.thumb.png.dc855f021bd94b58d67056ed99033f28.png

    I do think we've probably missed the boat here in terms of anything colder, at least through the first half of the month. Continued MJO progression into phase 7/8 later this month could potentially allow for another attempt late March/early April but honestly but that point we'd need a very direct northerly to produce, an easterly at that time of year is very unlikely to cut it. 

    For those wanting one last bite of cold/snow, the outlook is poor. For those wanting some early spring warmth the outlook is equally poor. 

  8. Despite the blocked charts there's very little cold on offer to tap into, ensembles across all models are generally sticking to climatology (average) with temperatures gradually rising a little throughout the forecast period.

    ens_image_php.thumb.png.4e715a939e7fe14f4b0ed7f8e2e14d7d.png

    Blocking to the NE may well retrogress towards Greenland but MJO moving through typically zonal phases and rising AAM suggests a flatter pattern, rather than a blocked one. My expectations are still for the pattern to flatten out rather quickly, at least across the Atlantic sector with a west based -NAO seemingly the direction of travel following retrogression with nothing notable in terms of cold or snow potential, despite the SSW tropospheric drivers are not favourable to produce proper cold weather across the UK. 

    Impressive looking synoptic patterns but sadly, no cold.

    • Like 4
  9. GFS det was a rather obvious outlier unfortunately. 

    There continues to be a complete lack of support for colder/notably colder weather into the UK with the majority of ensembles favouring milder weather (at least at the 850hPa level)

    IMG_5488.thumb.png.5d003c71644c730911da99ed887c3d35.png

    This comes as no surprise really given the MJOreturning to the Indian Ocean and progressing eastwards through phases not typically supportive of blocking. 

    • Like 8
  10. Yesterday’s CPC MJO update suggests a return to the Indian Ocean before progression through the Maritimes as the cycle resets so further away from the typical “blocking” phases than originally anticipated, having said that the SSW early March could have some impacts on the MJO & thus forecasts are more uncertain than usual. 

    IMG_5446.thumb.jpeg.b1a8657cc5b84aa05394bafb992cf176.jpeg

    Assuming this is the direction of travel though, the next surge in momentum is fairly predictable with an uptick in frictional torque followed by a return to positive mountain torque values adding westerly momentum to the atmosphere thanks to the MJO progressing eastwards.

    With that in mind, it continues to seem less likely that’ll we’ll see colder patterns establishing for the UK with high pressure early March likely to be too far NE of the UK with a rather active Atlantic jet hitting that road block, it could potentially be quite wet, especially in the north & west depending on exactly where any blocking highs set up before the patter, I suspect, quickly flattens out coinciding with this next momentum push. 

    I see the Met Office extended is more inline with this & indeed with my thoughts posted yesterday morning a page back.

    Any blocking is a result of the recent abrupt drop in AAM tendency as westerly winds are scrubbed, i.e increasing easterly trade wind strength. 

    El Niño is on very thin ice now. 

  11. 7 minutes ago, knocker said:

    What I was suggesting is that posting comments on teleconnections, Stratosphere/Troposphere interactions and synoptic meteorology all in the model discussion thread, is in my humble opinion operation overload and asking a lot from many punters, including myself.. And there really is no need for the separate threads in that case.

    I think the separate threads serve well for more prolonged conversations but I don’t see an issue with highlighting various teleconnections or the strat in this thread given the role & importance they play in the weather & the modelling that this thread is for. 

  12. 19 minutes ago, knocker said:

    Why should this thread become even more filled with teleconnections and Stratosphere talk?

    Because they go hand in hand with the models, they provide context to modelling which can help to understand why modelling is doing what it’s doing, I don’t see how a bit of knowledge on that is a bad thing? 

    The rest of your post is a little bizarre if i’m honest, nobody has suggested synoptic modelling can’t be discussed?

    • Like 3
  13. My focus is primarily on the stratosphere at the moment & potential impacts from a major SSW during early March. Still not much urgency to downwell the -ve anomalies quickly, modelling now goes out to the 10th March.

    gfs_nh-u60_20240224.thumb.png.18888d119db6c3f55fb82fd1f62fdd1a.pnggfs_nh-namindex_20240224.thumb.png.ab9c18094596604a73b465096cf13440.png

    Strongly -NAM state despite this though but with little blocking to speak of in the troposphere. We've seen quite an abrupt change in MJO forecasts in recent days too, initially looking like a return to phase 5 has now switched to returning to phase 3/4 in the Indian Ocean following the previous decayed signal. Phase 3/4 composites for March are very unsettled for the UK, phase 3 perhaps a little chillier.

    GEFS.thumb.png.179054ee8b7b77c2d6120753345e1a9e.png

    In essence though - For those still chasing cold/snowier outcomes, I think it might almost be time to give up the ghost. 

    • Like 2
  14. 6 hours ago, MattH said:

    Just a quick one, but some caution here...If you're after amplification to the pattern and a more buckled jet stream then you don't want +ve AAM anomalies propagating to higher latitudes, you want -ve E'ly AAM anomalies. This is where some of the GSDM plots can be misleading, on the MT plot you're statement is "correct" but in the grand scheme of things, if you look at the AAM transport plots, along with the Total AAM plot, relative AAM plot then it is the other way around. +AAM through the mid-latitudes would help to reinforce a westerly flow.

    Thanks for the correction, appreciate that! 

    • Thanks 1
×
×
  • Create New...