Jump to content
Cold?
Local
Radar
Snow?

The hunt for cold - Model discussion (late November)


Recommended Posts

Spotted a post you think may be an issue? Please help the team by reporting it.
  • Replies 8.5k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Meant to post this last night  but some forecasters saying mild Christmas. At this range ,about any thing could turn up ,strange year weather wise so far ,snow in the forecast tomorrow , STORMY with i

I'm sorry for being off topic but I'm sure mods will forgive me for this one. Very sorry to hear you're missing your wife, this time of year can be especially hard and you can't just switch off that s

I love having the FV3 now.  There used to be that dead time between the end of the GFS and the start of the ECM where I had to talk to the wife.  Not any more ?

Posted Images

Posted
  • Location: Essex, Southend-On-Sea
  • Weather Preferences: Warm, bright summers and Cold, snowy winters
  • Location: Essex, Southend-On-Sea

    Perhaps it's best to avoid starting this conversation again @Easton Luna Boys...

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

    i'm inclined to make a call here that until we see the effects of either the Alaskan ridge (slowing down the upstream pattern) or an SSW quick trop response, that the atlantic will never relent for long enough to allow nw Europe to receive deep cold uppers (for long enough to bring proper wintry surface conditions) - in the meantime, the nwp will throw out lots of pretty patterns and keep us enthralled with 'potential'

    • Like 5
    • Thanks 1
    Link to post
    Share on other sites
    Posted
  • Location: County end Oldham 202 m Above sea level
  • Location: County end Oldham 202 m Above sea level
    4 minutes ago, bluearmy said:

    i'm inclined to make a call here that until we see the effects of either the Alaskan ridge (slowing down the upstream pattern) or an SSW quick trop response, that the atlantic will never relent for long enough to allow nw Europe to receive deep cold uppers (for long enough to bring proper wintry surface conditions) - in the meantime, the nwp will throw out lots of pretty patterns and keep us enthralled with 'potential'

    Interesting Blue..

    Would it be fair to say strat warmings are already underway though?

    • Thanks 1
    Link to post
    Share on other sites
    Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth
    2 minutes ago, bluearmy said:

    If only we could get a proper wintry looking chart like this to verify ......

    7729E841-84FC-4742-863E-DF53A65ADF8B.thumb.jpeg.e13e1d817022f97371a86c563b6c69b2.jpeg

    In January not tomorrow ??

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Lincolnshire
  • Location: Lincolnshire
    3 minutes ago, SLEETY said:

    Amazing how people get so wound up because someone’s opinion is different to their own.Poster was correct too,after 6 days is basically guess work,but an educated guess for people that have put a lot of research trying to understand how the weather works.

    I'm glad we agree ?

    Not to go further off topic, but anything beyond 144 IS Fantasy Island. % accuracy is historically very poor and very erratic, and that's putting it mildly. Ensemble data enables a general overview of cluster options but are there only for guidance as they cannot be considered high resolution. Tight clustering (has to be consistent on subsequent runs - as per the great run in to Nov/Dec 2010) is a good indicator of forecast confidence, but if we are really honest with ourselves here, consistent tight clustering is not a common occurrence, with the all too predictable unraveling of the spaghetti pasta runs leading to uncertainty - bringing cries of "more runs needed" from the congregation. 

    I am a firm believer that the national weather organisations should invest less in the crystal ball gazing of LRFs and more in the short term models. 

    <144 is the future baby. 

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: st albans
  • Location: st albans
    1 minute ago, northwestsnow said:

    Interesting Blue..

    Would it be fair to say strat warmings are already underway though?

    QTR via a split rather than displacement NWS

    ec op looks flatter upstream than ukmo/gfs - more akin to gem …… could still be a decent fi if the upstream cavalry can be held back to avoid phasing …….

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: st albans
  • Location: st albans
    1 minute ago, That ECM said:

    In January not tomorrow ??

    its mid December ……. we were here a couple years ago with good sypnotics but poor continental uppers  ……………….. pretty sure the atlantic was quieter then too

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Wantage, Oxon
  • Weather Preferences: Hot, cold!
  • Location: Wantage, Oxon
    16 minutes ago, booferking said:

    Getting pretty hot up there..

    Yes, that is one of the biggest warnings we've seen on the charts yet.  The FV3 run ends up here, T384:

    image.thumb.jpg.0db0fc9eabec2990e04871506465e5c2.jpg

    One very displaced vortex...but, I really want to see what happens next, the consensus seems to be that this massively weakened vortex will have pressure out on it to split, want to see that start to be shown in the modelling soon.

    Link to post
    Share on other sites
    Posted
  • Location: Wantage, Oxon
  • Weather Preferences: Hot, cold!
  • Location: Wantage, Oxon
    9 minutes ago, bluearmy said:

    If only we could get a proper wintry looking chart like this to verify ......

    7729E841-84FC-4742-863E-DF53A65ADF8B.thumb.jpeg.e13e1d817022f97371a86c563b6c69b2.jpeg

    Not falling for that one a second time!  

    image.thumb.jpg.988a9df4dcfb133ea0de76a8859f2bcd.jpg

    its today!

    • Like 6
    Link to post
    Share on other sites

    A MAJOR SUDDEN STRATOSPHERIC WARMING (SSW) LATER THIS MONTH?  TESTING AN IMPORTANT RECENT THEORY

    I just posted this on a teleconnections thread on a US weather forum and thought that you might like to read it over here.

    For the second time this year we are seeing a significantly weakened and disrupted stratospheric polar vortex (SPV) with many specialists forecasting a very early substantial warming event and a probable major SSW.  We know from past experience that we have seen some  "near misses" with the wind reversals in the stratosphere struggling to propagate through to the lower tropospheric layers right down to the surface.  With my fairly limited stratospheric knowledge (still learning), it's beyond my pay grade to comment on the main reasons for this.  From the papers that I've read and accounts of earlier SSWs, I can see that although forecasting these events has seen huge improvements in recent years, we still have a lot to learn about the latter stages - the type of SSW, the timing and extent of propagation (or lack of it) to the surface and where, how much and how widespread will the high latitude cold be displaced towards the middle latitudes. There have been some fascinating recent studies into what causes the final triggering of a major full on SSW and I will focus on this very important aspect of the whole process in this post.

    Malcolm @Blessed Weather and I each produced very long posts on this topic as part of our "2018 SSW Debate" back in April. They both appear on page 3 of that thread and as I will be be referring to both of them in this post, here are the direct links: 

    Malcolm - A Review of events leading to the 2018 Sudden Stratospheric Warming (SSW)

    https://www.33andrain.com/topic/868-teleconnections-a-more-technical-discussion/?do=findComment&amp;comment=86401   

    David - 2018 SUDDEN STRATOSPHERIC WARMING DEBATE - EVOLVING THEORIES ON SSW CAUSES AND MORE ON MOUNTAIN TORQUE

    https://www.33andrain.com/topic/868-teleconnections-a-more-technical-discussion/?do=findComment&amp;comment=86675

    To summarise very briefly, Malcolm, in his superb post, examined the state of the stratosphere right through the 2017/18 winter season and focused on the main teleconnections and the key role that they played in assisting the development of and impacting on the 2018 SSW.  This included the ENSO state (La Nina at the time but a temporary easing in January), the east based (Quasi Biennial Oscillation) eQBO,  the low Arctic ice extent, the "uncoupled" state of the strat and trop, the "Aleutian high" causing the main SPV to shift to the Siberian side, the blocking high over north Asia (assisting further vertical wave activity flux) the MJO moving through its Indian Ocean and Maritime Continent phases of 3, 4 and 5 at increasing amplitude and then on to phases 6 and 7 at even higher (record high) amplitude (favouring high latitude blocking), the Global Wind Oscillation (GWO) moving through phases 3, 4 and 5 with rising relative Global Atmospheric Angular Momentum(GLAAM) from a low point, with rising Frictional Torque (FT) and rising Mountain Torque (MT) with the usual 10 to 14 day time lag, with East Asian Mountain Torque (EAMT) being particularly strong. All this showing how the main components of the Global Synoptic Dynamic Model (GSDM) were all playing out exactly as would have been expected with almost perfect timing. The southerly east Asian jet stream branch was blowing strongly across across the Himalayas and the Tibetan Plateau and there was a huge spike in EAMT around February 2nd/3rd.  The 100hPa zonal winds were at a record high (since 1979) on February 10th and this triggered a dramatic collapse during the next 2 days in the zonal winds at 10hPa (60N) which went negative (reversed to easterly) on February 12th and the 2018 SSW was underway. 

    I have over simplified the events and I strongly recommend that anyone interested in this (learners as well as specialists) to take time out to read Malcolm's post which is so clearly laid out with numerous annotated charts. Malcolm and I had already been studying the impacts of MT spikes on SSWs prior to the 2018 event.  It was very timely that Malcolm found a brand new paper entitled: Orography and the Boreal Winter Stratosphere: the Importance of the Mongolian mountains  (click on the title for a link to the abstract in the Research Portal where there is a direct link to the paper).  I was preparing my very long post (which took over a week to research) and this paper was so relevant to our research and it was written "before" the 2018 SSW event.  The last part of my huge post covers a detailed review of that paper and I shall return to it below.

    The first part of my post (which in hindsight should have been split into at least 2 posts!) looked into the history of SSWs, the development of understanding them, the causes and the evolving theories.  I referred to a couple of excellent papers by Amy Butler including this 2017 paper:   A sudden stratospheric warming compendium  (portal link).  I reviewed those papers and I also referenced and reviewed this 2012 paper by Thomas Ehrmann:    Identification and Classification of Sudden Stratospheric Warming Events (portal link).  This includes this table:

    700727879_sswtable.PNG.497c7403348c38037

    1820980991_sswtable2.PNG.4dd0530141d0cbb

    Very briefly, this shows us that early major SSW events were quite common in the 1970s to 1990s but much rarer this century. The last one with a central date in December was 2001 (day 361 = Dec 27th) and only 2004 (central date Jan 3rd) started in late December since then. The lack of major "early" SSWs this century looks to be far more than just a statistical quirk. It may be due to the warming Arctic and reduced ice extent or to more indirect factors or natural variations.  Anyway, if we do see a major SSW within the next 10 days or so, it'll be the earliest since at least 2000 and probably the 4th or 5th earliest since 1978 when the continuous satellite records began. 

    Most of my post covers MT. I examine all types of mountain waves with numerous charts - look at wave breaking, critical layers and much more. I refer to and review some important papers covering MT and these include the highly acclaimed papers by Dr Klaus Weickmann (who developed the GDSM and GWO phase charts with Ed Berry while they worked at NOAA from around 1999 to 2015).  Klaus was amongst the first to identify that EAMT had much more influence on SSWs than the other torques.  I went into a lot of detail explaining the different torques and 85% of all global MT is produced by EAMT and NAMT (North American Mountain Torque). The original thinking was that meridional mountain ranges like the Rockies and Andies (SAMT) had far more impact on generating vertically propagating rossby (or planetary) waves by being perpendicular to the jet stream. This earlier research could not explain why EAMT had such a strong impact as most of that mountain massif was more east/west or west north west/east south east, such as the Himalayas. It was known that these mountains have powerful influences on the south Asian jet stream with strong impacts on the Asian and Indian monsoon seasons.  In winter time, it was also recognised that EAMT impacted on the down stream flow right across the Pacific and on into western North America.  More recently, the Tibetan Plateau was identified as a major source of EAMT and then in the last year or so, the very latest research identified that the most powerful uplifts were generated by the Mongolian Mountains and particularly the Altai range.  In fact, the whole central and east Asian mountain massif is by far the largest elevated area in the world. 

    I reviewed several papers on this in my post and especially the one referred to above. What actually happens is that the powerful west to east (sometimes south west to north east) jet is obstructed by the vast Himalaya range.  The jet is forced over it.  Then the lower past of the jet descends rapidly across the Tibetan Plateau while the upper part continues on its merry way. The plateau is the largest in the world and is generally 3,500 m to 5,000 m high sloping slightly downwards north from the foot hills of the Himalayas which are on the southern boundary.  The lower part of the jet is effectively channelled or funneled northwards and north eastwards and continues until it hits the Mongolian ranges to the north. It is then forced upwards again with some huge uplifts generated - thought to be the strongest anywhere in the world.  This uplift catches up with the upper part of the jet stream and generates powerful vertically propagating rossby (or planetary) waves.  Under the right conditions these waves pass through the troposphere, often right through the stratosphere and even into the lower mesosphere.  They then reach the "critical level" (see my main post for a fuller explanation) and the waves start breaking and gradually start falling back down, breaking at lower and lower levels.  A prolonged and powerful EAMT event will continue this process for several days.  I quote this from my post which I extracted from the paper: 

     "- Flattening orography results in substantial differences in stratospheric flow from October - May, with the greatest differences     in November - December.

     Contrary to expectations based on mountain heights the Mongolian mountains have the largest impact on stratospheric flow.

    - The effect of the Mongolian (Tibetan) mountains is to decrease the flow significantly.

    - The Rockies produce no significant zonal wind changes.

     - The Mongolian and Tibetan mountains both produce anomalous convergence near the region of largest zonal wind.

    - Changes in horizontal divergence dominate the response to Mongolia while both vertical and horizontal divergence changes are important for the Tibetan response.

    - In contrast to the Asian orography, the Rocky mountains slightly increase EP flux divergence in the stratospheric jet region.

     - The presence of the Mongolian or Tibetan mountains produces a strong increase in wave activity propagating upwards from the surface into the upper troposphere.

    - Orography induced EP flux anomalies have generally different propagation pathways from the troposphere to the upper stratosphere than climatology.

    - Mountains also induce changes in wave propagation paths.

    - Orography induced changes in EP flux divergence cannot be attributed solely to the orography acting as an additional source of Rossby waves.

    - The Mongolian mountains  allow more wave activity to propagate vertically into the stratosphere.

    - The Tibetan mountains have a similar spatial structure to the changes due to the Mongolian mountains but are of smaller magnitude.

    - Compared to Mongolia or Tibet, the Rockies have a much smaller impact on the stratospheric zonal wind.

    -  These results indicate that changes in refractive index are of central importance for the impact of orography on the wintertime stratospheric circulation.

    -  The Mongolian mountains have a greater impact on the upper tropospheric wintertime circulation than the Tibetan plateau.

    - Without the Mongolian mountains, the frequency of SSWs drops from 0.6 SSWs per year to 0.08.

    - Removing the Tibetan mountains also reduces the frequency of SSWs, albeit weakly compared to the Mongolian mountains.

    - Removing the Rockies has no statistically significant impact.

    - The presence of mountains causes no significant change in the date of the seasonal vortex breakdown at the end of polar winter.

    -  The delay in the switch from westerlies to easterlies when the orography is not present is not statistically significant with 40 years of data.

    - Reductions in both displacement and split SSWs occur when the Mongolian or Tibetan mountains are removed."

    I highlighted the key point in bold. The experiment simulated the impacts of the main mountain ranges and looked at what would occur by removing each range in turn. Without the Mongolian Mountains, the frequency of SSWs drops from the average of 0.6 events per year to to just 0.08 per year - a huge difference.  Furthermore, the enormous uplifting is almost always associated with the major SSW events - the stronger the EAMT the stronger the impact on the SPV. This is no "one off" piece of research.  The experiments have been tested and verified by some other specialist in this field. A whole host of papers are now in the pipeline, not least linking this research to the 2018 SSW. When Malcolm and I examined the precursors to the 2018 SSW, we were amazed how everything fitted into place. Although it is too early to draw absolute conclusions from this, it's a fascinating piece of research and it almost blows away some of the early theory out of the window.  many scientists will need time to comment on this and react to it.

    Now, we can put this theory to the test again with the probable upcoming SSW event due later this month.  Although, there are some slightly different parameters and teleconnection fundamentals this time around, if anything we have an even better fit that the February SSW event.  In stead of a La Nina we have a developing weak El Nino - often considered to be the best ENSO phase to favour SSWs.  We have shifted during the summer from an eQBO to a wQBO. The former is much more supportive of SSWs but the transition has only recently been completed and was not considered to be particularly relevant (as shown in several tele and strat thread posts during the last few weeks/months) and only yesterday (just above this post) Steve @Superstorm93 referred to a tweet from Sam Lillo stating that "the latest MQI phase space plot shows the QBO in westerly shear mode, which when compared to a climatology of stratosphere vortex weakening events, is consistent with increased favorability in December."  A whole raft of recent forecasts are showing a thoroughly disturbed SPV.  The preconditions are building. 

    Now let's sprinkle a little MJO, AAM, torque and jet stream activity into the mix of ingredients. 

      13g.thumb.PNG.ac6fcf35a1cf3f1d19ab80ec63cb1893.PNG

    The MJO is currently at moderate amplitude in phase 3 (the I/O) and all the models predict it to rise through phase 4 into phase 5 (the Maritime Continent).  I show GFS and ECM which predict moderate amp but weakening slightly during week 2. Several other models (not shown) show the MJO continuing at decent amp.

       13h.thumb.PNG.a7080e2f62aa2ff988d8123212ad84af.PNG

    I posted the AAM and FT charts just 2 days ago.  They showed a big spike in GLAAM tendency and a rise in FT from it's low point last week (albeit not a particularly strongly +ve phase).  

      13f.thumb.PNG.79e01e88287398b22946b054850f7c9e.PNG

    The GWO has seen Total GLAAM remain +ve (the relative GLAAM tendency anomaly went -ve and then spiked to strongly +ve). It's emerging in phase 5 which is strongly suggestive of rising MT (reminder in chart below). 

      30g.thumb.PNG.173ec55b189aab2ce8c0e8ff459b69b2.PNG

    Then we have this amazing and extremely timely MT chart:

     13e.thumb.PNG.ba6fa1d1291b7e4ab717e2c62c1dab00.PNG

    GLMT (black line) dipped to its lowest level of the year 2 weeks ago and spiked to its highest level a couple of days ago. EAMT (red line) has spiked more than the other regional torques. Now, looking at the upper part of the chart (the dates from the bottom still apply) we can see where this is occurring. Around Dec 2nd EAMT was -ve as shown by those blue blobs at 30N to 40N. Then we have the spike to Dec 11th (still rising slightly at the end of the run) and we have deep red blobs from 28N to 48N and at its strongest around 40N.  The main Himalayan peaks are around 28N and the majority of the Tibetan Plateau is around 29N to 37N.   Mongolia is mostly between 42N to 52N and the Altai range is around 43N in the south east and 48N in the north west (there are other ranges too).  I provide other maps and much more detail in my main post.  The strongest EAMT is centred right over the Altai range!  

    13jj.thumb.png.f26ee443486ab574543786386d001bef.png

     13i.thumb.PNG.5208ee33bd262e250650714b8be49d79.PNG

    I compare the current EAMT event to last February (see Malcolm's April post for full details). EAMT peaked around Feb 2nd/3rd 2018 - 9 to 10 days prior to the SSW.  it saw another (even larger) peak around Mar 7th with a secondary warming (or further SSW impacts) around 10 days later. 

    Going back to the current (2 day time lag) MT chart, a similar time lag for triggering the upcoming SSW would be around Dec 20th to 22nd with "possible" surface impacts a few days later (perhaps around or just after Xmas).  This ties in with the strat predictions.  What can possibly go wrong? ? Remember this is all still based on theory and is yet to be fully proven. If we do get an SSW, just how/when will it propagate down to the surface and where will it impact?  Given that we are seeing such a strong EAMT event right over the Mongolian Mountains (stronger even that the ones in February and March during the last SSW event) I shall be following this very closely and half expect us to see a major full on SSW! 

    Some readers will be more familiar with the jet stream charts. I recently found a good site showing the jet over the east Asian region. It's part of the excellent "StormSurf" site. Here's the link:  http://www.stormsurfing.com/cgi/display_alt.cgi?a=nindi_250  I've set it to the jet from now until T+180.  It's animated but I cannot copy a gif link - so I show the T+0 and T+120 charts below (and you'll need to go to the site for the animation): 

      13a.thumb.PNG.674e956b11fff0bdaa9a5abae35727cb.PNG

    A very powerful west/east jet streak has been passing over the Himalayas and Tibetan Plateau region during the last few days.

     13b.thumb.PNG.125286d012f5db64b048d66eb90424d4.PNG

    This is predicted to continue through to at least day 5 - making it a prolonged and very strong event and consistent with the really strong EAMT event. 

     13c.thumb.PNG.c32d632c7f80531f81f293dbe17bb9de.PNG

    Another feature often associated with SSW precursors is the high pressure (HP) blocking over central and northern Asia - there is anomalous fairly high pressure there but we can see a strong belt of HP stretching from west to east centred around 50N to 60N.  No coincidence, given the well defined and powerful jet to the south.  

     13d.thumb.PNG.09782a018af115ae2c566645388c7f2a.PNG

    By day 5 the belt of HP continues but has built strongly to the west and north west with a new cell developing over western Russia - perhaps another good sign as a precursor to renewed Russian blocking and well primed for high latitude blocking (HLB) following the expected SSW impacts in 12-15 days time.

    Overall, a lot to follow, a lot of interest and perhaps the perfect set up for a great Xmas present for cold and snow hunters in Europe, the UK and eastern CONUS.  Things are looking really interesting for the run into the New Year and through at least the first half of January. David ?   

    Edited by Guest
    check links are working and correct typos
    Link to post
    Share on other sites
    Posted
  • Location: Longton, Stoke-on-Trent.
  • Location: Longton, Stoke-on-Trent.
    5 minutes ago, Mike Poole said:

    Yes, that is one of the biggest warnings we've seen on the charts yet.  The FV3 run ends up here, T384:

    image.thumb.jpg.0db0fc9eabec2990e04871506465e5c2.jpg

    One very displaced vortex...but, I really want to see what happens next, the consensus seems to be that this massively weakened vortex will have pressure out on it to split, want to see that start to be shown in the modelling soon.

    GFS has another warming very shortly after this one, and the GFSP showed the same the other day. That could be a killer blow to the PV. Assume it’s not come up on this run though.

    • Like 2
    Link to post
    Share on other sites
    Posted
  • Location: G.Manchester
  • Location: G.Manchester
    27 minutes ago, MattStoke said:

    Find it laughable that people think dismissing scientific techniques of weather prediction and just making predictions based on a hunch is credible. Never mind that all the predictions linked to background signals have been right so far this winter. Makes you wonder why those people are even bothering to be on a thread like this.

    But that’s just my opinion!

    Lately I've seen the word 'god' thrown around lately. Lets be realistic....

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: st albans
  • Location: st albans
    5 minutes ago, Mike Poole said:

    Not falling for that one a second time!  

    image.thumb.jpg.988a9df4dcfb133ea0de76a8859f2bcd.jpg

    its today!

    interesting that we will have see two of these within a couple weeks of each other and precious little wintry conditions as a consequence 

    • Like 2
    Link to post
    Share on other sites
    Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth
    32 minutes ago, Bring Back1962-63 said:

    Overall, a lot to follow, a lot of interest and perhaps the perfect set up for a great Xmas present for cold and snow hunters in Europe, the UK and eastern CONUS.  Things are looking really interesting for the run into the New Year and through at least the first half of January. David ?   

    Thanks but I’ve got a “hunch” it might be mild????

     

    brilliant post??

    Edited by Mapantz
    • Like 4
    Link to post
    Share on other sites
    Posted
  • Location: Longton, Stoke-on-Trent.
  • Location: Longton, Stoke-on-Trent.
    2 minutes ago, Optimus Prime said:

    Lately I've seen the word 'god' thrown around lately. Lets be realistic....

    What?

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: st albans
  • Location: st albans
    3 minutes ago, MattStoke said:

    GFS has another warming very shortly after this one, and the GFSP showed the same the other day. That could be a killer blow to the PV. Assume it’s not come up on this run though.

    i think further warmings such as this will keep the vortex displaced longer but it would return and strengthen as soon as they eased off - we need the wave two hit courtesy of further trop amplification to bring the fella down ……... 

    • Like 2
    Link to post
    Share on other sites
    31 minutes ago, Bring Back1962-63 said:

    Overall, a lot to follow, a lot of interest and perhaps the perfect set up for a great Xmas present for cold and snow hunters in Europe, the UK and eastern CONUS.  Things are looking really interesting for the run into the New Year and through at least the first half of January. David ?   

    Well wibble me what an amazing post. this is the exact stuff we need in here to help us learn and go forward.. now i need a lay down and a bottle of Buckfast....

    Edited by Guest
    Link to post
    Share on other sites
    Posted
  • Location: sheffield
  • Weather Preferences: cold ,snow
  • Location: sheffield
    1 minute ago, s4lancia said:

    ECM not even toying with trough disruption around D7.

    No it looks a bit hit and miss.lots of ridging but know real shape or forcing .

    Link to post
    Share on other sites
    34 minutes ago, MattStoke said:

    Find it laughable that people think dismissing scientific techniques of weather prediction and just making predictions based on a hunch is credible. Never mind that all the predictions linked to background signals have been right so far this winter. Makes you wonder why those people are even bothering to be on a thread like this.

    But that’s just my opinion!

    I agree by in large. However the background signals have been wrong so many times in the 5 years I've followed netweather forum so I can see how some people are dubious about them. 

    • Like 1
    Link to post
    Share on other sites
    Message added by Paul

    If you're hunting for cold potential in the model output, this thread is for you. But if you'd like to look more widely at the models, please head over to the general model discussion thread.

    This is a model related thread, so a general, frequent theme of the model output is a given, but it will not be strictly enforced:

    • Some topic drift, humorous responses etc are fine
    • Posts likely to lead the thread off on an entirely off topic tangent are not ok. For example (but not solely limited to): Posts entirely or mainly about Met Office, BBC or media forecasts with little or no model context, and posts solely asking for a weather forecast in a specific location.
    • Posts which start with something like 'I know this is off topic but ...' are not ok.
    • Posts which break the forum guidelines are not ok (eg trolling, troll-hunting, weather guilt tripping, overly defensive/aggressive, abusive, disrespectful to others)
    Guest
    This topic is now closed to further replies.
    ×
    ×
    • Create New...