KeegansPerm

Regarding these long range scripts I've had a browse through the Met Office website to see if any of the jobs or careers on there mentioned writing scripts. I found this role called an Operational Meteorological Technician (link below). This role appears fairly new, I don't think I've seen it when looking for jobs at the MO in the past, and mentions one of the responsibilities is writing media scripts. It also only lists 4 weeks of basic meteorology training, and 4-8 weeks on the job training. To become a MO forecaster I've seen total training durations of >12 months mentioned on previous adverts in the past! Do you think it could be the case that new "technicians" are now writing these scripts with perhaps as little as 8-12 weeks of training behind them when they start?-it may explain some of the strange things that appear to pop up in them from time to time? Could be feasible in my mind. I wonder if the MO realise how many people read and place value in these, from some of the recent scripts it appears that not a huge amount of time with day after day repeats of the same script, and evidently very little checking is being done. It seems a real shame. I'm sure their forecasters have some great knowledge and reasoning behind things, I note the recent excellent MO 10 day trend on YouTube, but little of that seems to be getting through in these scripts for some reason. The role of an Operational Meteorologist Technician WWW.METOFFICE.GOV.UK We have recently introduced a new role at the Met Office - the Operational Meteorologist Technician (OMT).

I wonder if they could be referring to this recent paper from Daniela Domeien and others published August 2020?-I've added the link below. It suggests that if Greenland blocking is present at the time of the SSW, as probably the case in the recent event. This often leads to a warming trend across much of Central Europe 2-4 weeks after the event, and from the 500hPa height anomalies you could assume this pattern would not be overly cold for the UK (image attached). From this study the European blocking SSW looks to be the most favourable for UK cold, and that was not the case with the recent event (image attached). It is a very small sample size used in the study though, but we've only got a small sample of these events to look at in the satellite era. I guess one of the reasons why there are so many unknowns and uncertainties in the world of weather forecasting. The role of North Atlantic–European weather regimes in the surface impact of sudden stratospheric warming events WCD.COPERNICUS.ORG <p><strong>Abstract.</strong> Sudden stratospheric warming (SSW) events can significantly impact tropospheric weather for a period of several weeks, in particular in the North Atlantic–European (NAE) region...

Hello Monotone, This paper from 2008 produced by Klaus Wieckmann and Edward Berry is definitely the place to start. https://psl.noaa.gov/map/clim/wb08_revised_final.pdf . Edward Berry also did a talk at the College DuPage in March 2018. I'd also recommend this, although it's not the easiest and most fluent English to understand. There is also an incredibly useful paper showing the detailed mathematics and derivations behind them to compute various functions of AAM from the Met Office back in 1982. This helped my understanding on the topic immensely and is available to download for free from the following page: ROYALSOCIETYPUBLISHING.ORG Good luck with your investigations.

The latest EC EPS clusters (or should I say cluster) for early January do suggest increasing ridging edging in from the west. This can be seen in the 500hPa geopotential heights and anomalies. The corresponding surface charts likewise show a build of surface pressure from the west too. The text from the current MO outlook (valid until Thursday 7th January): Into early January there are signs that higher pressure may start to build from the southwest bringing more settled weather. Should this occur, overnight frosts will become more widespread with the risk of morning fog patches. Temperatures are likely to remain below average through this period with wintry hazards. This seems a fairly reasonable story to me. Even looking at the GFS Ensemble Mean from the 24th 00 UTC run at T+240, pressure across the UK is building upwards of 1010hPa. I don't quite see why people are interpreting the tentative use of the phrase "signs that higher pressure may start to build from the southwest" as anything more than the MO just trying to convey that this change has a reasonable probability of occuring. They still maintain cold conditions and a risk of wintry hazards. Of course there is spread in solutions with a whole host on offer (including some snowier ones). But having this tentative sign mentioned in the forecast looks a fair, reasoned and well balanced to me. The plume image attached is the EC EPS plume for 500hPa geopotential height for Manchester, UK. Not the EC HRES has lower gph than the ensemble mean in early January.

I'm also a fan of freezing fog, especially when it is long duration and allows a good rime to build up on objects (I've attached a picture I took in Lincolnshire in January 2013!). The fog you are most likely talking about is radiation fog, which forms due to radiation processes overnight. How does radiation fog form? Radiation fog (whether freezing or not) forms when the air at the surface cools to its dew point. Dew point is the temperature that air must be cooled to become saturated with respect to water vapour. Once you reach this temperature water vapour can begin to condense out as cloud /fog droplets, which would be as fog is the temperature above zero, or freezing fog with supercooled water droplets if the temperature is below zero. However the point where the air becomes saturated and fog forms is difficult to assess, as processes that lead to decreasing air temperatures overnight, often lead to a decreasing dewpoints too. So overnight when skies are clear the ground radiates heat to space and cools, this cools the air immediately above resulting in a shallow cold stable layer of air forming close to the surface. However in this routine scenario the ground is cooler than the air, meaning that the ground normally cools below the dewpoint of the overlying air first and this means that as the air comes into contact with the ground is deposited as either dew (or frost when the ground is below zero), and these processes will remove water vapour hence the dewpoint of the overlaying air. You often get into this evolution, where as the air is cooled towards it dewpoint (the point at which fog can form) by the colder underlying ground at the same underlying ground is reducing the dewpoint of the air by capturing the water vapour in the air and locking it up as either dew or frost deposits. See attached graph. Hence you need to achieve conditions where the air is able to cool to its dewpoint, faster than the ground is able to capture the moisture.....often very finely balanced! What factors help fog form? Some additional factor can aid the formation of fog if the conditions described above are met, these include abundant aerosol/pollutants which encourage water vapour to condense out into fog, being near wet ground especially with standing water (and being downwind from a lake or sea) which remains warmer than the surrounding ground and continues to provide additional moisture, light winds to continue to mix moisture down close to the cool surface (to replace that lost as dew or frost), and then the advection of more moisture rich air to your location overnight, and being in a hollow where the coldest air from all around drains into (via density currents). In the UK low lyying river valleys, vales and marshlands often have the most favourable for radiation fog to form for these reasons. What about once fog forms? When fog initially forms it is generally very shallow, meaning although you cannot see very far horizontally (indeed shallow fog often gives the poorest horizontal visibilities), you can often see the stars and moon. This means that the ground is able to radiate to space still and continue cooling. However through turbulent mixing and other processes the depth of the fog will often increase into a mature fog (with the sky no longer visible through it). This completely changes the radiation process with the ground (due to warmer temperatures at depth) now warming the surface radiating into the fog layer and slightly warming this, with the top of the fog layer now being the surface that radiates to space and and cools....this leads to the fog been warmer at the base, and cooler at the top and leads to gradual convective overturning further increasing the fog depth. A mature fog is significantly less likely to clear or be slower to clear during the following day. See diagram. How does fog clear? Put simply the temperatures of the air has to exceed the dewpoint, leading to the fog droplets to evaporate and become water vapour once more. However in this case the processes which work against fog formation overnight, work against fog clearance during the morning. The ground heated by the faint rays of the sun warms first, and then the air overlaying this is warmed by the ground. This means that as air temperature rises, so does dew point as moisture is released from melting frost and evaporating dew. This means that fog often clears from the bottom up, lifting into low cloud as the warmer lower layers become unsaturated first before finally clearing . See attached graph (above). Other things can clear fog very effectively, including increasing wind speed which turbulently mixes warmer and drier air down to the surface, and the advection of drier air into a region. What other types of fog exist? Fog can form anywhere that air is cooled to it's dewpoint, so warm air over cold sea or snow covered ground is an effective way of generating fog (advection fog common in the spring and early summer), and a similar scenario can occur in the mixing area of frontal zones (frontal fog). But if you live inland radiation fog will dominate for you. Hope that helps give you a good baseline understanding of the processes around radiation fog. If you want anymore info feel free to get in touch.

It really depends what your interested in and the day (it varies), and it's like an arm's tace with all the modelling centres releasing at least a couple of new upgrades each year. You can check a whole host of verification statistics for many centres on ECMWFs charts verification section (link and sample image below). If you were to choose a single deterministic model though ECMWF would be the statistical choice....but just don't use it for snow depths without understanding it's overly snowy characteristics in marginal rain/snow events for example. Not all centres solutions are fully independent either. I believe ICON (and potentially ARPEGE) use the ECMWF analysis for their models initial conditions, and the Korean and Australian models are older generations of the UKMO. ECMWF has a longer assimulation window (time to gather later observations than other modelling centres) as it does not appear until 3 hours after the other global models (a great advantage) as it is not needed to generate boundary conditions for limited area higher resolution models like the UKV and AROME that national met services have to run. In general though the greatest success is found in looking at all (including ensembles), verifying against reality (work out sensitive regions), and weighting the output accordingly for biasses. We call this a multi-model or "poor man's ensemble", hard work but yields the best results. http://apps.ecmwf.int//webapps/opencharts/favicon.ico ECMWF | Charts APPS.ECMWF.INT Overall looking for synoptics the one deterministic that would bring

This is a very simplified answer, and probably not the thread to do this in (feel free to move or removed moderators). Pressure is literally the weight of the earth's atmosphere above a point, hence the higher you get, less atmosphere above you and pressure decreases. Geopotential height is the measure in dm (10*metres) of a pressure surface (for example 300hPa geopotential height is around 10KM on average) above the geoid (this accounts for the variation in gravity between equator and poles and makes the maths much simpler). If you think of the earth's atmosphere like a balloon, if you cool a section of it the air molecules will lose energy, move more slowly, and be able to get closer together (increasing density), and the balloon would we seen to deflate, if you heated the air inside the balloon the opposite would be true and it would inflate. In the earth's atmosphere this means that in areas where the atmospheres mean temperature is cooler, the air is denser and where warmer less dense etc. This means that in a cool area you if you were firing a rocket upwards you may pass through the 300hPa at say 10 KM, whereas in a warm airmass at 10KM the pressure would be higher say 350hPa in this example. This difference is typically at a maximum at the top of the troposphere (the part of the atmosphere where the weather occurs) and hence the jet stream is typically strongest around this height in the mid-latitudes where this temperature/or height of pressure surface gradient is strongest. In winter at high latitudes the net radiation balance sees energy lost to space....hence net cooling. This is more marked over land than ocean (which has a much higher heat capacity)., and once land snow covered sunlight reflected further cooling etc... As such at the same degree of latitude over land the mean temperature of the airmass (if it persisted here) would reduce and geopotential height of the pressure surfaces would reduce. This would cause a minima in geopotential height to form (a trough) relative to the surrounding oceans, and the jet stream to dip southward to the southern boundary of this cooler airmass to where the geopotential height gradient is greatest, and then move north to find the gradient nearer Greenland / Iceland / the sea ice edge in the North Atlantic. There are other factors such as lee troughs (to the lee of the Rockies) which often favour troughing over North America too. But hope this sort of helps explain the general broad pattern. But note the jetsream on the boundary between cold and warm airmasses, so further south across Asia (large cold continent), and generally shifts north in the Pacific and Atlantic oceans (ECMWF 200hPa height and winds image for today attached).

There is a known difficulties with NWP in the Austral Summer / Boreal Winter regarding the MJO propagating from the Indian Ocean across the Maritime Continent into the the West Pacific. Which is based around zonal and meridional moisture gradients, some events are blocked and do not cross the Maritime Continent, while others are able to cross in the Western Pacific. Generally strong MJO event are able to achieve better premoistening across the Maritime Continent (promoting an E'ward movement of convection), and have a greater chance progressing into the Western Pacific. I've popped a few model graphics below to show the MJO across the Indian Ocean on the 16th Nov where you can see the amounts of moistening ahead of the convection max which we can roughly infer from the zone of enhanced 850hPa westerly winds, and as this enters the Maritime Continent on the 22nd in GFS there is significant areas showing negative precipitable water anomalies and not showing a great environment of pre-moistening (on both GFS and GEFS) and hence unlikely propagation of a marked MJO into the Western Pacific. As a result in this case from the GFS and GEFS data I can see, I would suggest the MJO will likely get blocked and not make it to West Pacific, much as shown by EC and GFS Wheeler and Hendon plots.

Not impossible, generally dew points are too high in GFS. So in reality I'd expect the LCL (convective cloud base) to be a fair bit higher than shown by GFS. A higher LCL reduces tornado risk.

Elevated convection in the morning across the SW and Wales where the in the areas where mid level cloud abundant, here CAPE around 750Jkg, so lightning and heavy precipitation the main hazards. Although some mid-level cloud extends further east towards southeast England drier higher level air should prevent much elevated convection here. Pic 1: 10/0600 UTC Mid Level Clouds from EC Pic 2: SkewT to from GFS valid over mid Wales at 10/0600 UTC This elevated convection then extends north as the upper trough which assists in de-stabilising the zone pushes northwards, it is then the question whether the cap that exists to the E of this zone can be broken and release, always a close call in these events but a combination of surface heating and convergence (including from outflows left by the elevated convection earlier in the day) could combine to release some isolated but extremely violent thunderstorms (>2500Jkg of CAPE, with very large hail, strong winds, frequent lightning and incredible precipitation rates possible). Difficult to judge area at the highest risk from these....but I'd guess a zone from Wilshire towards Greater Manchester....and these could take well into the day early evening to fire (if they do at all). Pic 3: SkewT to from GFS valid over West Midlands at 10/1800 UTC

Agreed it's very complex statistics. The main point I was trying to draw out of it is the broadscale synoptics (especially mid-upper troposphere) are the key measures via which NWP centres compare each other against. Generally NWP is not optimised for any one thing (surface temperatures, snowfall accumulations, tropical cyclones, snow depths, wind speeds) and we must look at the individual fields with that in mind. It's all a compromise, with the main aims of development being to perform well against others NWP models in the bench mark statistical skill scores (which correlates with give broadscale forecasting). Although I suspect the GFS may sacrifice this slightly to better resolved some of the non-linear features such as cold pools with severe convection, which is used for initialisation and boundary conditions for higher resolution models run across the USA....these often mess up the broadscale!

It's amazing how much we expect often expect of NWP whatever the weather element of interest. Remember that these models are generally scored via official metrics with their performance we geopotential height, temperature and winds speeds at mid/upper levels, not by how well they forecast a maximum temperature over London....examples can be seen in the paper attached. Think of all the elements that models that cover a global domain have to forecast, from tropical cyclone tracks and intensities, precipitation accumulations from deep tropical convection to snowfall which is orographically enhanced by flow over high mountains. Temperatures from the hottest desert regions over sand surfaces by day, to the arctic with snow cover / permafrost in the dead of the winter night, to wind speeds and gusts over seas and mountains. These models also have to provide initial and ongoing boundary conditions for the limited area higher resolution models that nest inside them. As these are unified forecast systems (one model forecasting all variables) each forecast element is a trade off against something else. For example if you were to try and fix the low temperature bias during warm days in the mid-latitudes....increasing temperatures could ruin CAPE and convective precipitation forecasts...with this then potentially ruining synoptic patterns. GFS is often derided for its wildly varying synoptics which are often out of line with others across the UK. However from using it and the higher resolutions models that feed off it across the USA at short lead times I am confident that is performs better than others with several features of severe convection such as generating strong cold pools (and the hazards associated with these). I believe that this may be one of the models failings in synoptic forecasting as severe convection in the wrong location leads to large head aches for NWP (as we will no doubt see this week in the UK). Even the UKV is a trade-off between all these different weather elements temps, cloud cover, wind, gusts, precipitation accumulations and many others...fixing one can worsen others. It's all a big trade off. We're lucky they are often as good as they are! Progress in Forecast Skill at Three Leading Global Operational NWP Centers during 2015–17 as Seen in Summary Assessment Metrics (SAMs) | Weather and Forecasting | American Meteorological Society JOURNALS.AMETSOC.ORG

Just to let you know that is not correct, the pixelated nature if the RADAR returns is due to range of the object from the RADAR head. It appears that the netweather RADAR only utilises the UK / Ireland Weather RADAR network including Jersey in the Channel Islands. So RADAR returns in NE France are being scanned at range from the RADAR at Thurnham in SE England and hence look more pixelated in output. In addition at this range even the lowest radar beam (I believe it's 0.5 degrees for Thurnham) is scanning storms over France at fairly high elevations (see the graph for WSR-88D), so will not pick up on showers produced by shallow surface based convection across NE France (tops below 8,000-10,000 FT), but will pick up deeper convection from surface based cells across NE France.

You've yet to reach the temperature needed for cumulus formation. A weather balloon from Nottingham Watnall at 11:00 UTC, suggested a temperature of of around 20 C needed to initiate surface convection (in the air that sampled). Lack of cumulus on the satellite images suggests that is still the case E of the Pennines, surface observations suggest the temperature more like 18-19 C in the Leeds region, where it is low 20s C further W (across NW England) where convection is deeper, and probably more moisture at mid levels.

Hi there, I've used both Weather Stations - Accessories and Parts - Greenfrog Scientific WWW.GREENFROGSCIENTIFIC.CO.UK and HamRadioStore for spares. The Fine Offset Station come under many brands (mine looks exactly like the image you shared and is branded as a Watson), but all the parts that you recognis from your station alreadye (despite the brand differences) work well with mine.

Sorry I stuck this on the wrong page before. Moderating guys your welcome to delete. I know you can't take GFS at face value, but this pattern fits well with the other output I've seen over the last day or two. If we could get the infromation from ECMWF and UKMO to derive LI and CAPE, I'd expect similar values on Sunday and Monday. Tuesday perhaps slightly more in doubt. Sunday: LI and CAPE higher than that today which managed to produce several thunderstorms across East Anglia. Although may take some forcing, you would fancy sea breeze convergence lines along the North Sea to trigger a few beauties. Monday: This could be something special. MSC's perhaps even home grown and not inported from France! Could be some strong downbursts from storms in this set up ... gusts on the surface of 60-70 KT if not a little more. Tuesday: Slightly in doubt but if this were to be true everything that Monday has plus a little bit more. Chance of some locally serious weather

Hi there, A little late, but the 582 dam he is referering to is the height that you would have to ascend to above the earths surface to reach a pressure of 500 MB, not sure why it was origionally done this way instead of plotting the pressures at some x KM height. These areas often correlate well (especially if cut off) with the position of surface highs and lows (which are in MB at mean sea level). The highest ever surface pressure recorded was 1085.6 mb; Tosontsengel, Khövsgöl Province, Mongolia, December 19, 2001. KP

This German university is a fantastic place to start for all things stratospheric, QBO and sunspot related. Some excellent papers with here will give you plenty of the information you need and its all been peer reviewed! http://www.geo.fu-berlin.de/en/met/ag/strat/publikationen/ge2000.html If you can’t get the papers from this website google the authors name and you can often find them through there personal websites as below: http://strat-www.met.fu-berlin.de/labitzke/ Enjoy.