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Paul

Site development
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Everything posted by Paul

  1. This is a new thread option we're trialling, which hopefully will become a regular. Please use it to discuss the model output at short range (between 0 and 72 hours). For longer term discussion, please head over to the main model thread: Want to have a bit of banter or a ramp and moan only loosely related to the models? The banter thread is for you: https://www.netweather.tv/forum/topic/86721-model-moans-ramps-and-banter/ Want to talk about the weather in your part of the country? The regional threads are the place for you: https://www.netweather.tv/forum/forum/142-regional-discussions/ Want to view the model outputs? You can get all the major ones here on Netweather: GFS GEFS Ensembles ECMWF ECMWF EPS NetWx-SR NetWx-MR Met-Office Fax GEM GFS Hourly Snow forecast and precip type Model Comparison Global Jet Stream Stratosphere Happy New Year!
  2. Sorry all, we may never get to the bottom of where the previous thread went unfortunately, but here's a fresh thread to get going with..
  3. Please use this thread if you have any problems with the site or the forum, we will then do our best to help out..
  4. A new thread, for posting and discussing tweets about the forecast models currently. Please only post tweets in this thread, not the main model or banter threads. The reason for this change is that a tweets are, by their nature brief, which in turn can leave them open to multiple interpretations, which in the fast-moving model thread can mean a lot of reaction to misinterpretations which pulls the whole thing off on a tangent.
  5. Paul

    Stormchase 2018 - Chase Day 6 - Colorado

    Its not at the moment, they're having some connectivity issues, will hopefully be back up soon. Here's what they were looking at earlier
  6. Paul

    Stormchase 2018 - Chase Day 6 - Colorado

    The team are streaming now, nice cumulus clouds popping up https://www.netweather.tv/weather-forecasts/travel/storm-chase-live
  7. The storm chase is now underway and the team will be streaming the action every step of the way on the page below: http://www.netweather.tv/index.cgi?action=chaselive;sess= Please bear in mind that they are reliant on a mobile signal to stream so it will drop out on occasion. When the stream isn't live the player won't appear on the page, as soon as they start streaming it will load automatically. Happy virtual chasing!
  8. Paul

    Storm Chase Live Video Streaming

    You don't. As I posted in the other thread earlier, it's in the usual streaming page. It's just being cross posted to Facebook as well.
  9. Paul

    Stormchase 2018 - Chase Day 2 - WY.NE/CO

    It was also in the normal place on the site: https://www.netweather.tv/weather-forecasts/travel/storm-chase-live
  10. As promised, here's a quick rundown of some of the new features on the forum since the update earlier this week. Fluid View Firstly, there's a new layout option. Known as a fluid view it changes the forum homepage. Instead of viewing everything via sections and forums, it simply lists the topics with the latest posts. You can also tailor it to change the ordering, and list posts only from certain parts of the forum. It's a great way to discover topics and posts which you may have otherwise missed, and personally I find it a better way to use the forums than the old school view. You can select fluid or traditional view from near the top of the forum homepage: The fluid view itself looks like this Reactions The like/reputation system has had an update, with the option to react to posts in different ways - currently there's like, thank you, laugh, confused and sad as options. But we can add to these. Gallery improvements The gallery has been made much nicer to upload images and albums to. On top of this, embedding your gallery photos and albums into posts has become much simpler. So for instance, to embed this image into the post, all I have done is copy the url of the page with the image on it: You can do the same with albums as well. As before, you also can embed posts and topics from the forum in the same way. And it works in the same way from other sites and social networks - such as facebook, twitter, youtube, instagram etc, just copy and pasete the url of the page into your post. Promoted topics and content There is now also the option for us to promote particular topics, posts and gallery albums on the forum index, and potentially across other parts of the site. We'll be able to use this to show topics which may be of interest, great, informative posts, amazing photos, hidden gems which many may have missed & so on. Clubs This functionality hasn't been switched on yet, as it's brand new and we need to work out the best way to use it. But there is now a club option, so people can create groups and clubs based around certain topics and interested. For instance we could have a UK storm chasers club that those who are interested in chasing storms can join, share favourite chase locations (and add them to a map), arrange chases, share experiences and so on. This is one possibility, and as we understand the system more, I'm sure we'll develop other ideas. There are numerous other improvements and updates behind the scenes, along with new options for us to expand the functionality in the future, so I'll try to keep this thread updated.
  11. Here we go then, already plenty of interest in the strat this year, and with a La Nina likely, perhaps a less hardcore strat than last year can be expected? @chionomaniac will be along soon to fill in his thoughts on where things may be headed this year, but in the meantime, I've copied his excellent strat guide from 2015 below. For more info you can also read his full tutorial here: https://www.netweather.tv/charts-and-data/stratosphere/tutorial Ed's opener from 2015/16 As ever, the first post will become both a reference thread and basic learning thread for those wanting to understand how the stratosphere may affect the winter tropospheric pattern, so forgive me for some repeat from previous years, but it is important that those new to the stratosphere have a place that they can be directed to in order to achieve a basic grasp of the subject. The stratosphere is the layer of the atmosphere situated between 10km and 50km above the earth. It is situated directly above the troposphere, the first layer of the atmosphere and the layer that is directly responsible for the weather that we receive at the surface. The boundary between the stratosphere and the troposphere is known as the tropopause. The air pressure ranges from around 100hPa at the lower levels of the stratosphere to below 1hPa at the upper levels. The middle stratosphere is often considered to be around the 10-30hPa level. Every winter the stratosphere cools down dramatically as less solar UV radiation is absorbed by the ozone content in the stratosphere. The increasing difference in the temperature between the North Pole and the latitudes further south creates a strong vortex – the wintertime stratospheric polar vortex. The colder the polar stratosphere in relation to that at mid latitudes, the stronger this vortex becomes. The stratospheric vortex has a strong relationship with the tropospheric vortex below. A strong stratospheric vortex will lead to a strong tropospheric vortex. This relationship is interdependent; conditions in the stratosphere will influence the troposphere whilst tropospheric atmospheric and wave conditions will influence the stratospheric state. At the surface the strength and position of the tropospheric vortex influences the type of weather that we are likely to experience. A strong polar vortex is more likely to herald a positive AO with the resultant jet stream track bringing warmer and wet southwesterly winds. A weaker polar vortex can contribute to a negative AO with the resultant mild wet weather tracking further south and a more blocked pattern the result. A negative AO will lead to a greater chance of colder air spreading to latitudes further south such as the UK. AO chart The stratosphere is a far more stable environment then the troposphere below it. However, the state of the stratosphere can be influenced by numerous factors – the current solar state, the Quasi Biennial Oscillation (QBO), the ozone content and distribution and transport mechanism, the snow cover and extent indices and the ENSO state to name the most significant. These factors can influence whether large tropospheric waves that can be deflected into the stratosphere can disrupt the stratospheric polar vortex to such an extent that it feeds back into the troposphere. Ozone Content in the stratosphere Ozone is important because it absorbs UV radiation in a process that warms the stratosphere. The Ozone is formed in the tropical stratosphere and transported to the polar stratosphere by a system known as the Brewer-Dobson-Circulation (the BDC). The strength of this circulation varies from year to year and can in turn be dictated by other influences. The ozone content in the polar stratosphere has been shown to be destroyed by CFC's permeating to the stratosphere from the troposphere. The overall ozone content in the polar stratosphere will help determine the underlying polar stratospheric temperature, with higher contents of ozone leading to a warmer polar stratosphere. The ozone levels can be monitored here: http://www.cpc.ncep.noaa.gov/products/stratosphere/sbuv2to/index.shtml One of the main influences on the stratospheric state is the QBO. This is a tropical stratospheric wind that descends in an easterly then westerly direction over a period of around 28 months. This can have a direct influence on the strength of the polar vortex in itself. The easterly (negative) phase is thought to contribute to a weakening of the stratospheric polar vortex, whilst a westerly (positive) phase is thought to increase the strength of the stratospheric vortex. However, in reality the exact timing and positioning of the QBO is not precise and the timing of the descending wave can be critical throughout the winter. Diagram of the descending phases of the QBO: (with thanks from http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo/index.html ) The QBO has been shown to influence the strength of the BDC, depending upon what phase it is in. The tropical upward momentum of ozone is stronger in the eQBO , whereas in the wQBO ozone transport is stronger into the lower mid latitudes, so less ozone will enter the upper tropical stratosphere to be transported to the polar stratosphere as can be seen in the following diagram. http://www.atmos-chem-phys.net/13/4563/2013/acp-13-4563-2013.pdf However, the direction of the QBO when combined with the level of solar flux has also been shown to influence the BDC. When the QBO is in a west phase during solar maximum there are more warming events in the stratosphere, as there is also during an easterly phase QBO during solar minimum, so the strength of the BDC is also affected by this – also known as the Holton Tan effect . http://strat-www.met.fu-berlin.de/labitzke/moreqbo/MZ-Labitzke-et-al-2006.pdf http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50424/abstract http://onlinelibrary.wiley.com/doi/10.1002/2013JD021352/abstract The QBO is measured at 30 hPa and has entered a westerly phase for this winter. As mentioned warming events are more likely during solar maximum when in this westerly phase – with the solar flux below 110 units. Currently, we have just experienced a weak solar maximum and the solar flux heading into winter is still around this mark. This doesn’t rule out warming events, but they will not be as likely – perhaps if the solar flux surges then the chance will increase. Latest solar flux F10.7cm: http://www.swpc.noaa.gov/products/solar-cycle-progression Sudden Stratospheric Warmings: One warming event that can occur in the stratospheric winter is a Sudden Stratospheric Warming (SSW) or also known as a Major Midwinter Warming (MMW). This, as the name suggests is a rather dramatic event. Normally the polar night jet at the boundary of the polar vortex demarcates the boundary between warmer mid latitude and colder polar stratospheric air (and ozone levels) and this is very difficult to penetrate. SSWs can be caused by large-scale planetary tropospheric (Rossby) waves being deflected up into the stratosphere and towards the North Pole, often after a strong mountain torque event. These waves can introduce warmer temperatures into the polar stratosphere which can seriously disrupt the stratospheric vortex, leading to a slowing or even reversal of the vortex. Any SSW will be triggered by the preceding tropospheric pattern - in fact the preceding troposheric pattern is important in disturbing the stratospheric vortex even without creating a SSW. Consider a tropospheric pattern where the flow is very zonal - rather like the positive AO phase in the diagram above. There has to be a mechanism to achieve a more negative AO or meridional pattern from this scenario and there is but it is not straightforward. It just doesn't occur without some type of driving mechanism. Yes, we need to look at the stratosphere - but if the stratosphere is already cold and a strong polar vortex established, then we need to look back into the troposphere. In some years the stratosphere will be more receptive to tropospheric interactions than others but we will still need a kickstart from the troposphere to feedback into the stratosphere. This kickstart will often come from the tropics in the form of pulses and patterns of convection. These can help determine the position and amplitude of the long wave undulations Rossby waves - that are formed at the barrier between the tropospheric polar and Ferrel cells. The exact positioning of the Rossby waves will be influenced by (amongst other things) the pulses of tropical convection, such as the phase of the Madden Jullian Oscillation and the background ENSO state and that is why we monitor that so closely. These waves will interact with land masses and mountain ranges which can absorb or deflect the Rossby waves disrupting the wave pattern further - and this interaction and feedback between the tropical and polar systems is the basis of how the Global Wind Oscillation influences the global patterns. If the deflection of the Rossby Wave then a wave breaking event occurs – similar to a wave breaking on a beach – except this time the break is of atmospheric air masses. Rossby wave breaks that are directed poleward can have a greater influence on the stratosphere. The Rossby wave breaks in the troposphere can be demonstrated by this diagram below – RWB diagram: https://www.jstage.jst.go.jp/article/jmsj/86/5/86_5_613/_pdf This occurs a number of times during a typical winter and is more pronounced in the Northern Hemisphere due to the greater land mass area. Most wave deflections into the stratosphere do change the stratospheric vortex flow pattern - this will be greater if the stratosphere is more receptive to these wave breaks (and if they are substantial enough, then a SSW can occur). The change in the stratospheric flow pattern can then start to feedback into the troposphere - changing the zonal flow pattern into something with more undulations and perhaps ultimately to a very meridional flow pattern especially if a SSW occurs - but not always. If the wave breaking occurs in one place then we see a wave 1 type displacement of the stratospheric vortex, and if the wave breaking occurs in two places at once then we will see a wave 2 type disturbance of the vortex which could ultimately squeeze the vortex on half and split it – and if these are strong enough then we would see a displacement SSW and split SSW respectively. The SSW is defined by a reversal of mean zonal mean winds from westerly to easterly at 60ºN and 10hPa. This definition is under review as there have been suggestions that other warmings of the stratosphere that cause severe disruption to the vortex could and should be included. http://birner.atmos.colostate.edu/papers/Butleretal_BAMS2014_submit.pdf A demonstration of the late January 2009 SSW that was witnessed in the first strat thread has been brilliantly formulated by Andrej (recretos) and can be seen below: The effects of a SSW can be transmitted into the troposphere as the downward propagation of the SSW occurs and this can have a number of consequences. There is a higher incidence of northern blocking after SSW’s but we are all aware that not every SSW leads to northern blocking. Any northern blocking can lead to cold air from the tropospheric Arctic flooding south and colder conditions to latitudes further south can ensue. There is often thought to be a time lag between a SSW and northern blocking from any downward propagation of negative mean zonal winds from the stratosphere. This has been quoted as up to 6 weeks though it can be a lot quicker if the polar vortex is ripped in two following a split SSW. A recent paper has shown how the modelling of SSW and strong vortex conditions have been modelled over a 4 week period. This has shown that there is an increase in accuracy following weak or strong vortex events – though the one area that the ECM overestimates blocking events following an SSW at week 4 is over Northwestern Eurasia. http://iopscience.iop.org/article/10.1088/1748-9326/10/10/104007 One noticeable aspect of the recent previous winters is how the stratosphere has been susceptible to wave breaking from the troposphere through the lower reaches of the polar stratosphere - not over the top as seen in the SSWs. This has led to periods of sustained tropospheric high latitude blocking and repeated lower disruption of the stratospheric polar vortex. This has coincided with a warmer stratosphere where the mean zonal winds have been reduced and has led to some of the most potent winter spells witnessed in recent years. We have also seen in recent years following Cohen's work the importance of the rate of Eurasian snow gain and coverage during October at latitudes below 60ºN. If this is above average then there is enhanced feedback from the troposphere into the stratosphere through the Rossby wave breaking pattern described above and diagrammatically below. Six stage Cohen Process: The effect of warming of the Arctic ocean leading to colder continents with anomalous wave activity penetrating the stratosphere has also been postulated http://www.tos.org/oceanography/archive/26-4_cohen.pdf As ever, I will supply links to various stratospheric websites were forecasts and data can be retrieved and hope for another fascinating year of monitoring the stratosphere. GFS: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/ ECM/Berlin Site: http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html Netweather: https://www.netweather.tv/charts-and-data/stratosphere Instant weather maps: http://www.instantweathermaps.com/GFS-php/strat.php NASA Merra site: http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html Previous stratosphere monitoring threads: 2016/17 https://www.netweather.tv/forum/topic/86485-stratosphere-temperature-watch-201617/ 2015/16 https://www.netweather.tv/forum/topic/84231-stratosphere-temperature-watch-20152016/ 2014/2015 https://forum.netweather.tv/topic/81567-stratosphere-temperature-watch-20142015/ 2013/2014 https://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/ 2012/2013 https://forum.netweather.tv/topic/74587-stratosphere-temperature-watch-20122013/ 2011/2012 https://forum.netweather.tv/topic/71340-stratosphere-temperature-watch-20112012/ 2010/2012 https://forum.netweather.tv/topic/64621-stratosphere-temperature-watch/?hl=%20stratosphere%20%20temperature%20%20watch 2009/2010 https://forum.netweather.tv/topic/57364-stratosphere-temperature-watch/ 2008/2009 https://forum.netweather.tv/topic/50299-stratosphere-temperature-watch/
  12. Paul

    Introductions!

    If you're a new member and you would like to drop in and say hello, here's the thread to do it! Feel free to introduce yourself and ask any questions you may have, you'll find we're all a friendly bunch (apart from Oon, watch him!).
  13. A fresh model thread as we enter a new phase of weather post-beast. As always please keep it to the models in here. Want to view the model outputs? You can get all the major ones here on Netweather: GFS GEFS Ensembles ECMWF ECMWF EPS NetWx-SR NetWx-MR Met-Office Fax GEM GFS Hourly Snow forecast and precip type Model Comparison Global Jet Stream Stratosphere
  14. With a potential cold end to winter and start to spring on the horizon, here's a thread to discuss the ins and outs of that, how the latest forecasts are looking and so on. There's obviously a lot of chat in the model thread about this currently, and you can also find info about the SSW over in the strat thread. Nick has also blogged about the SSW here: Sudden Stratospheric Warming This Weekend, But What Is It & How Will It Affect Our Weather? And about the model mayhem currently being caused by it here: Sudden Stratospheric Warming Brings Weather Model Mayhem It's fair to say that confidence in the exact weather we're going to see from mid-next week onward is currently very low, but the Met Office are confident enough in the likelihood of cold weather that they've recently put out a press release: https://www.metoffice.gov.uk/news/releases/2018/a-sudden-stratospheric-warming-and-potential-impacts-on-uk Winter could be set to go out with a bang it seems, but it's not nailed on, yet.....
  15. Hi, sorry that we seem to have had problems a few times in recent days, we have a bug in the system somewhere which is causing small maintenance tasks which run to crash the system. It's obviously frustrating, but we'll hopefully get to the bottom of it imminently, and in the meantime are trying to ensure nothing runs which may cause it to happen again. Paul
  16. We will be closing the forum for a short while this morning to do some maintenance and get to the bottom of our bug, should hopefully be no more than 10-20 minutes when we do.
  17. Paul

    New Radar apps RAIN SNOW

    Can't say I've ever seen the tiles not loading as you've got there. It looks like the next zoom level isn't loading for you. Which device do you have? Also, what kind of connection are you on, mobile/wifi, fast/slow? In terms of the mall zooming too far, that one is a known bug and will be fixed in a future release, as is the auto zoom not coming on when you restart the app
  18. Paul

    New Device LOgin

    I've always found the locations on these things to be a bit useless tbh, as they're generally just ip based. But regardless, I will get it switched off, but I can't until the task/settings bug we have at the moment is cleared, unfortunately (the one which caused some downtime during the week). We're going to be taking a closer look at the causes of it next week.
  19. A busy spell coming up, as the beast from the east arrives. As the focus of the model thread is often a bit further ahead, for those wanting to talk more exclusively about the shorter term outputs, we do have a short-range thread up and running. (You're still welcome to discuss the shorter term in here too though). This thread is all about discussing the models - but we have loads of other options for other topics: As always, please keep it to the models in here, and head over to the banter thread for any moans, ramps and general chat. For threads related to the cold spell, met office forecasts, the winter overall and much more on top, please take a look at the general weather forum: https://www.netweather.tv/forum/forum/1-winter-and-general-weather-discussion/ And finally, if you're wanting to chat about your local weather, the risk of snow in your particular location etc, then the regional threads are for you: https://www.netweather.tv/forum/forum/142-regional-discussions/ Want to view the model outputs? You can get all the major ones here on Netweather: GFS GEFS Ensembles ECMWF ECMWF EPS NetWx-SR NetWx-MR Met-Office Fax GEM GFS Hourly Snow forecast and precip type Model Comparison Global Jet Stream Stratosphere
  20. Paul

    Problem uploading pictures

    It may be the speed of connection uploading, I'd recommend resizing it to 1600px wide as a max, then the file will be much smaller + it's an ideal size for most screens.
  21. Try resizing them to no more than 1600px wide.
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