Jet stream weather charts for Es research - chart drawer

Discussion in 'Radio Propagation Questions' started by Jim Bacon g3yla, May 1, 2015.

  1. Friday 19th May 2017

    The main feature on the 300mb upper air charts for today is undoubtedly the major upper trough over the British Isles. Ahead of this, we find an upper ridge over Central Europe and, ahead of that, a northerly jet stream from western Russia to Greece. This particular jet stream seems to be delivering some turbulence as it crosses the mountainous regions of the Balkans with a cluster of paths over this area. Not reachable from the UK, but nice to see a correlation with the jet stream/mountains and Es.

    Another 6m set of paths picks out an area just west of Sardinia, which is the location of the base of the sharp upper trough, which is affecting the UK. This western Mediterranean basin has all the necessary ingredients of jet stream and sharply rising/falling contours and, in addition, the axis of the trough is pushing forwards quite markedly between the time steps; so all good reasons to expect turbulence.

    Regarding the trough over UK and its bordering jet stream flows, there are good reasons to suspect that paths to the NE into Scandinavia should be worth exploring, since they would cross the southeasterly jet stream ahead of the trough; and it may even be worth considering the odd period beaming towards TF, capturing any triggers caused by the jet stream crossing the Scottish Highlands. The northwesterly part of the jet stream which crosses Biscay and Spain is also a very good candidate in today's selection, since it embodies rising contours within the blue lines and interaction with the mountains of northern Spain and later today, the Pyrenees.

    73 de Jim
  2. Saturday 20th May 2017

    I'm on an early shift today, so limited time to add commentary this morning...

    There's a good supply of jet stream material today and much of it will be accessible from the UK, useful if it were to produce some gravity wave turbulence for making Es. I'll start with the strong southeasterly jet stream over the Low Countries and the North Sea, which will be a good source of turbulence and there have already been some Es up to 6m over the North Sea just north of Holland. This zone of strong winds will slowly edge eastwards, but remain within reach today, and therefore I would suggest beaming at LA/SM/OH/Baltic as good choices.

    The other region is on the western side of the sharp upper trough over eastern Britain, and this is a northwesterly jet which is blowing across Ireland into Biscay and the Pyrenees. There are regions of rapidly rising contour heights here and this, together with the effect of the Pyrenees, means that paths to the south into EA/IS0 could be possibilities from the UK later. Remember that because of the rotation of the earth, the favourable upper tidal winds in the E region migrate westwards and this puts paths to Spain at the tail end of the morning and late afternoon Es 'windows'.

    The pattern is too complex to mention all the smaller jet stream elements, but I'm sure other paths across the various jets will all be capable of throwing up a few random paths, although not necessarily from Britain. By the way, don't ignore the option of looking across the Highlands towards TF and OY.

    73 de Jim
  3. Sunday 21st May 2017

    Another complex looking jet stream chart this morning and, although none of the European players are especially strong, they are very numerous, so this should provide opportunities for most directions from the UK.

    The Balkans look well served with two small upper lows with small jet stream segments around them. These should provide several localised regions of gravity wave wave generation and already there are paths plotted on the clusters centred on western Bulgaria. These are out of reach for a first hop, but these regions could form part of a multi-hop path from the UK.

    The next most likely options are probably going to be to do with the sharp upper trough over the North Sea with the small jet stream segments either side of the trough axis. This appears to be a region of rapidly changing height values with the red and blue lines enclosing areas where the values are changing and so might also be good locations for generating gravity waves. Its a good idea to add paths to Scandinavia to todays list of directions.

    Other features of interest are to do with the jet stream across Spain and western France, which could open up paths to the south, especially where this albeit weak flow impinges upon the Pyrenees and Alps.

    Such is the complexity of jet streams today that any option is worth checking and the above highlights the strongest features. I note that the Atlantic is starting to fill with a nice looking jet stream wave train, so may provide some stepping stones across to the States later today.

    73 de Jim

  4. Monday 22nd May 2017

    The central part of Europe is looking a bit quieter today, but there are some smaller features which may contribute to the Es locations if we look hard enough.

    Over in the east, the small cut-off upper low over the Black Sea is surrounded by minor jet stream segments and the paths already flagged for 6m are crossing the jet stream to the west of the centre over the Balkans. Staying over in the east, there is quite a solid looking southwesterly jet stream over the eastern Mediterranean basin and this could produce paths from 4X to SV for example.

    Weak ridges and very small paths of stronger flow in central Europe could play a role, since they are at a good location for paths from the UK. I did notice some very fine detailed cirrus cloud yesterday as it crossed the UK, and this is now over mid continent. I mention it because it is typical of summer ridge patterns and is a signal of turbulent motions at that height, even though no jet stream is present.

    The third item to mention is the very strong Atlantic jet stream pushing into Britain. Several directions become available from this as it generates gravity waves needed to produce Es. The most obvious being the core of the jet stream over the Highlands and therefore paths, say, from southern Uk to OY/TF look possible outcomes. The southern end of this flow over Biscay and western France also could feature, especially since there are strong rising contours (within the blue lines) initially. Paths to the south into EA etc. look the more likely outcome.

    Finally, two other lesser areas to mention. The small cut-off low over southern Norway has the look of something that could generate gravity waves, so possible paths to LA/SM, while looking to the west, the Atlantic has an extended jet stream link down towards the Caribbean.

    73 de Jim

  5. Tuesday 23rd May 2017

    A busy time at the moment for Es, but as is typical of this mode, it is rare for all parts of the UK to be able to access it at the same time.

    The main area at present is over the southern Baltic along the coast of Poland. There are numerous paths between central Europe and Scandinavia. These appear to be aligned with the advancing front of the northwesterly jet stream blowing down across Scotland into northern Germany. On the forward edge of this flow there appears to be a region of shear and marked by an arc of cloud on the satellite pictures. This type of cloud edge was over eastern England yesterday evening and looked very promising then. The conclusion is that this area is moving away fairly steadily eastwards, so will remain out of reach from the UK.

    The southern side of this jet stream has produced some interest over the English Channel and western France and are is also migrating east, so paths from central and northern UK may find a beam direction to the south-southeast worthwhile.

    The Atlantic is beginning to form a nice contorted looking wave train and should be worth exploring for paths to the States, particularly during the second half of today.

    73 de Jim

  6. Wednesday 24th May 2017

    There are some quite useful potential weather triggers for Es today and their positioning should be favourable for paths from the UK, so a good day to set aside some quality shack time for the 10m and 6m bands.

    The main item of interest is the strong northwesterly jet stream blowing southeastwards from Iceland down across the North Sea into Europe, crossing the Alps before finishing over southern Italy. Anywhere along this track, there could be some gravity waves generated, which might go on to determine the location of any Es. The current early morning 6m paths seem to be over the southern end of the jet stream across the eastern Mediterranean basin on the forward edge of this strong jet stream flow. Its the same properties that crossed the UK on Monday creating the turbulent cirrus clouds. The net result of all this is that you should try any paths from northeast to SM/OH round through east to SP/Baltic and thence to southeast for HA/UX/LZ/YO etc.

    The small 300hPa circulation over the Baltic states is remarkably persistent and may again be a region of turbulence and produce some Es, although its probably just out of reach from UK.

    Casting the net wider you will see strong jet streams over northwest Russia and central Russia. Obviously too far to consider for first hop paths, but may form the basis of multi-hop routes to the far east.

    The Atlantic looks to be set up nicely for several 'stepping stone' jet stream segments to the States, so worth taking the beams round that way to test the water now and again.

    73 de Jim

  7. Thursday 25th May 2017

    The fine summer weather continues and typically is doing a good job producing some Es this morning, up to 6m at present.

    The main feature is still the northerly jet stream blowing south from Norway across eastern Europe into southern Italy. This is an active region for generating gravity waves, turbulence which can extend upwards to the E region and contribute to making Es form. There are several paths across this jet stream flow along its whole length, which means try any direction form NE round to SE to cash in on this weather trigger. This is a particularly active feature on 10m, but even on 6m is giving a good account of itself. This movement of the axis of this strong upper air flow is very slow, even though the winds within it are fast, so it should remain available for the rest of today.

    The second and currently active region is an upper ridge pattern, which extends from eastern Spain north into the southern UK. These are less common features for making Es, but appears to be delivering several paths across the Pyrenees into southern Spain and EA8 and CN, so well worth a look.

    Elsewhere the Atlantic is showing a nice jet stream wave train with troughs and ridges separated by jet stream segments, which like yesterday, could provide stepping stones to the States.

    73 de Jim


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