Jet stream weather charts for Es research - chart drawer

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

  1. Monday 7th August 2017

    Its still there and, although the jet stream over the UK has lost its 100kt+ strength in our part of Europe, there is a very active looking upper trough about to stir things up over Biscay and Spain.

    The paths so far this morning have been over the Alps, Italy and Adriatic coast. This is probably due to the tail end of the previous jet stream easing away to the east, but leaving just enough flow over the mountains, together with a small upper trough. This part of the upper air weather pattern is moving away to the east, so unlikely to remain in active state this afternoon.

    Looking at where the current weaker jet stream over the UK intersects with the radial distance rings, it would suggest paths towards the Baltic and OH might be worth checking.

    The main show in town is undoubtedly the approaching upper trough moving into Biscay. There are rapidly falling (red lines) and rising (blue lines) counter heights associated with this so a big plus for paths into EA/CT today, especially later.

    The Atlantic is doing fairly well with a strong waving jet stream flow developing and putting the stronger segments at suitable distances for multi-hop points across the pond to the States.

    73 de Jim

  2. Tuesday 8th August 2017

    A very sharp and potentially very active upper trough over the country today with jet stream strength either side of it. Getting towards the latter stages of the Es season, so openings may be fleeting, but the weather patterns are certainly doing all they can to help.

    It has pretty much encircled the UK with jet stream winds filling the radial rings for the ideal location for a first hop from central UK. The primary direction seems to be to the southeast, where there are falling contours within the red lines, plus other areas around the upper trough with similar rapid changes of contour heights.

    The Atlantic is well set now with several jet stream segments to support paths to the USA.

    73 de Jim

  3. Wednesday 9th August 2017

    The unsettled weather is still providing plenty of jet stream options around the British Isles. There is an isolated path over the eastern Black Sea, which seems to be associated with the entrance to the jet stream heading into southern Russia.

    The closer jet stream around the upper trough over Britain is capable of providing options around the compass, since there are strong winds in between the range rings in nearly all directions from the UK. Look for areas where the jet stream interacts with mountains to get the best chance of gravity wave activity, e.g. the one path as I write is over the eastern Alps.

    The Atlantic has a few smaller regions jet stream activity, which can provide stepping points to the other side of the pond. At the moment the main path with the right geometry is from southern Portugal to the northeastern States.

    I am sure that the next few days will continue to provide some good jet stream triggers as the sharp upper trough migrates slowly east into the continent, so good reasons to keep watching for openings.

    73 de Jim

  4. Thursday 10th August 2017

    The jet stream situation is still looking good with numerous jet stream segments available to generate gravity waves to make Es.

    The initial thoughts appear to favour paths to the northeast as a new westerly jet stream segment arrives over the Norwegian mountains. There is also another jet stream segment, as a southerly wind, across Denmark; so two reasons to look in that direction.

    Otherwise its a case of all sectors are up for grabs from nW round through N and NE to SE and S. This means that looking towards the Balkans, Italy and Spain are all viable today. The only sector without jet stream activity at the right distance is to the southwest and west.

    73 de Jim

  5. Friday 11th August 2017

    The bands are producing some early activity and the abundance of jet streams is doubtless helping out, along with the impending peak of the Perseids meteor shower and a low K index.

    Again, today is just so well-stocked that its impossible to define all the options, other than to say concentrate on paths where the stronger winds intersect with mountains ranges or appear within the two feint radial rings. For today this means looking to the southeast and the Balkans round to south for Spain and Portugal. The other direction is to the northwest round to the northeast, which will include paths to the States/TF/OX/OY and to Scandinavia/JW/JX.

    Although out of reach from the UK, the southern end of the trough over the Mediterranean is likely to be a region of string gravity wave generation, so paths across the Med E-W are quite likely and may form part of a multi hop path towards the eastern Med or Egypt.

    73 de Jim
  6. Saturday 12th August 2017

    Its getting off to a good start today with two main centres of Es activity. One is located over southern Sweden around the entrance region of the southwesterly jet stream over Scandinavia, also accompanied by a region of rapidly falling contour heights within the red lines. The second primary zone of activity is located over the western Balkans. This is also a region of strong southwesterly jet stream winds and falling contour heights within the red lines on the Adriatic coast. The continuation of this jet stream across Ukraine is also producing some gravity waves, which may be behind the paths from 4X4 to Scandinavia.

    In general, so far today, the UK has not had much connection to these openings, which were outside of the two preferred concentric rings for mid-point Es from the UK. The jet stream bisects the UK and makes it possible for Es to develop too close to home, but it also extends to the radial rings either side and the directions to the southeast and northeast are reasonably placed, as is the path across the Atlantic to the west. The jet stream in that direction is however fairly weak so working across the pond may be a long shot, although there is good lateral extent covering the whole of the Atlantic.

    So to recap, option A is paths to Scandinavia and option B is for paths to Italy and the Balkans, possibly multi-hop.

    73 de Jim

  7. Sunday 13th August 2017

    The jet stream is neatly placed right across the UK and again it is the regions where this flow crosses the radial rings that offer the best chances. This probably means that southeast round to northeast (improves to northeast later today) should be the preferred directions, although there are options to the west and northwest looking upstream into the westerly jet stream and these could allow paths to the States.

    There are still some strong upper winds around the small cut-off low over the Adriatic and this has probably contributed to the earlier paths from the Middle east into central Europe, using the southwesterly jet stream over Greece and Turkey as part of a multi-hop sequence.

    The main area of activity is seems to be over southern Germany where the entrance to the southwesterly part of the jet stream into Scandinavia abuts the exit of the westerly jet stream from the UK.

    73 de Jim

  8. Monday 14th August 2017

    Today's upper air forecast charts have continued to show a plentiful supply of jet streams across Europe and beyond.

    The main Polar Front jet stream is looking quite distorted now with several identifiable troughs propagating through the flow. Think of someone hold a skipping rope in Newfoundland with the other end tied to Norway and giving it a flick, the wave pattern would then ripple along the rope; and thats just what is happening to the pattern of the 300mb winds shown in these charts.

    It looks as though later today a new trough will swing into the British Isles and may well produce some strong gravity waves over the country, so perhaps some very short skip on the HF bands between the SE and EI, for example. Otherwise the core directions where the jet stream crosses the radial ring suggests that paths to the NE into Scandinavia, and to the S into Spain and Portugal later today, are probably the best placed.

    Other paths may also be available across the Mediterranean, where a weaker branch of the jet stream flow is present. Also, its well worth a look west over the Atlantic as various new short wavelength features ripple out from the northeastern States. These, of course would be multi-hop paths, but that also applies to the European sector since there could be a favourable placing of the two jet stream branches towards the southeast into 4X4 and the Middle East.

    73 de Jim
  9. Tuesday 15th August 2017

    Plenty of weather options on today's upper air forecast charts. The dominant Atlantic jet stream remains the main focus and its right over the top of us again, so some prospects for good inter-G short skip on the HF bands.

    The radial rings seem to be fully-filled around the compass, but based on the paths being reported this morning it would appear that those to the south into Spain, as the trough over Biscay sharpens, are a good call.

    In the nearby sector towards the southeast; this will benefit from rapidly changing contour heights within the red and blue lines, together with severe thunderstorms, so check out paths to Italy and the Balkans later.

    The Atlantic is in good shape with a broad jet stream across to the States and worth listening for fleeting multi-hop signals from the USA and Caribbean.

    73 de Jim

  10. Wednesday 16th August 2017

    Strong jet streams are the key to proceedings once again, and with a very strong core approaching from the Atlantic with speeds above 100kt, shaded yellow, the prospects are good for the next few days.

    The primary directions today are to the east and northeast into Scandinavia, and to the south into Spain and France. This southern path will become a strong contender tomorrow when the jet stream has propagated farther inland into western Europe.

    The Scandinavia direction is driven by the minor upper trough with rapidly changing contours (red and blue lines) which is moving northeast, quickly, and already just going out of range, so less excited about that for the afternoon.

    The Atlantic emphasis is shifting a bit farther south, so benefitting the Caribbean and South America perhaps.

    73 de Jim

  11. Thursday 17th August 2017

    The current Polar Front Jet Stream just keeps on giving... it has brought a useful upper air pattern to our part of Europe once again and should provide plenty of options.

    A small part of the pattern with a northerly flow across the Balkans and Adriatic is allowing paths from Greece to DL/F. A separate area, currently on 10m is to be found over N Germany, Poland and S Sweden, which is due to the approaching jet stream over the North Sea and Denmark.

    So what of the rest of today?, well a very strong jet stream is now approaching Britain and should, with a core above 100kt and regions of rapidly falling and rising contours, be a good generator of gravity waves to help produce the Es. This makes almost a full azimuth range of directions available today, but particularly to the south to Spain and Portugal.

    The Atlantic is also fairly well set with a further strong core >100kt leaving the States and heading east, so worth looking towards both N & S America during the day.

    73 de Jim

  12. Friday 18th August 2017

  13. Saturday 19th August 2017

  14. Sunday 20th August 2017

    I'm back! Sorry for the unexpected absence, totally unavoidable I'm afraid.

    A bit late to say much about this set of charts so late in the day, but its the northwesterly jet stream segment which is doing the work with a few paths on 6m across France and the Adriatic.

    It looks like a good supply of jet stream segments lined up for the next day or so and still worth seeking out Es. Hopefully back online at a sensible time tomorrow.

    73 de Jim
  15. Monday 21st August 2017

    The jet stream is still a fairly dominant feature on the charts today, although it feels as though there is a general weakening of the flow. So if anything happens, it a case of make the best of it.

    Once more the directions on offer for paths from the UK are numerous, so its a good option to be aware of whats happening on the clusters and beacons to see which direction is active. The first thoughts are that the primary direction will be to the southeast, into Ukraine and the Balkans, down the line of the northwesterly jet stream into eastern Europe.

    Another possibility is that the strong upper ridge over Spain could be beneficial for paths to the south, especially if there is some good wind shear turbulence on the southern border of the jet stream over Biscay.

    The Atlantic is doing fairly well with several spaced regions of stronger flow across to the States to check out later today; no idea how the eclipse may play out with those, but it may be an idea to find some activity or beacons over the there to monitor.

    73 de Jim
  16. Tuesday 22nd August 2017

    Another good day of jet stream activity. There are two areas of primary interest this morning, one over the Baltic and Poland, which seems to be colocated with the northwesterly jet stream over Poland and its companion southwesterly jet just to the east of the upper trough over the Baltic. This region is not moving much in the 6-hourly charts, so similar prospects remain through today.

    The other area of activity is located over the Low Countries where the northwesterly jet stream segment just begins to pick up strength ahead of an upper ridge moving in across France. The sharp change of wind direction on the ridge axis, plus the acceleration in the entrance of the downstream segment of the northwesterly jet stream ahead of it, all contribute to an increased chance of gravity waves. The overall picture suggests paths around the compass from Scandinavia round to the Balkans and Spain with varying chances of success, most likely to the east or southeast.

    Other parts of these jet streams outside our radial rings will doubtless be behind other paths within Europe. For example, over Slovakia and southern Italy, where there have been some isolated 6m paths.

    Lastly the Atlantic is still blessed with some activity around a cut-off upper low just west of Britain, which is at the right distance for a first step across the pond. I'm not sure how good the subsequent steps are, since the jet stream looks to weaken westwards. The positioning of the jet stream probably favours paths to the Caribbean at the moment.

    73 de Jim


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