Jet stream weather charts for Es research - chart drawer

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

  1. Please see the attached explanatory notes for the Jet Stream forecast charts, which will appear regularly during this 2015 season and will be added to this folder. Use the discussion thread for comments, this is for charts only, many thanks.

    73 de Jim
    g3yla

    Attached Files:

  2. First of a series of daily charts during the 2015 Es season. 73 de Jim g3yla

    Attached Files:

  3. I am busy on shift today, so a bit late with this, but just time to add a brief note to accompany the jet stream charts for today.

    The primary areas of interest are those shaded green 40-80kt winds or, even better, yellow/amber 100-120kt wind speed isotachs (isotach=line of equal windspeed). The jet stream over Scandinavia is also useful because it also has the purple lines showing a maximum region for changes of contour height (the height of the 300mb pressure level). Note also that a new jet stream propagates across southern Britain later and that too has a small area of purple contour height change. These two aspects (strength of jet stream and rapidly rising pressure heights) tend to favour the generation of gravity waves, which may affect the E region to produce Es.

    So lots of jet stream potential today; paths across Scandinavia and N France/English Channel look most promising, but there are many other regions (green shading) which could be useful. This is typical of early season where the weather patterns still have lots of jet stream energy; don't expect such favourable hunting grounds in high summer!

    73 de Jim
    g3yla
  4. Good morning,

    Another day with plenty of jet stream activity across Europe. There still appears to be a missing link somewhere after yesterday's lacklustre performance, given the jet stream strength; possibly the light winds in the stratosphere?

    Anyway, for today, the main contributors seem to be favouring paths to the east. In eastern Scandinavia the green shaded jet stream and rising contour heights shown within the purple line look promising, but elements are weakening during the day and edging farther eastwards, probably already too far away for paths into UK.

    All is not lost because another strong jet stream is migrating across the UK and out over the North Sea to Scandinavia and it also has rising contour heights; this could become useful later today.

    The third item is the strongest jet stream currently in the European domain (yellow and amber in the core, so >100kt) advancing into Iberia and this could become very helpful in generating mountain gravity waves and well worth a look later today for paths to the south.

    Lastly time to introduce severe thunderstorms; long known as a possible source of gravity waves and suspects in the Es location. These appear on the charts as orange 'blobs' as seen over western France in the 12z and 18z panels. Note they do appear in similar locations to jet streams so often hard to separate the causes. Its because severe thunderstorms need large wind shear, which of course is often found near jet streams. Great article by Chris Barnes GW4BZD in RadCom Plus on Es, RSGB members should read it.

    Good Es, 73 de Jim
    g3yla

    06Z04MAY2015_300mb_4panel.jpg
  5. A strong southwesterly jet stream (blowing from the southwest) over France is in a good position on all time steps during today, plus we still have activity over Scandinavia and down into eastern Europe with a jet stream and rapidly rising contour heights (purple lines), although this region is getting a bit out of range for the UK now.

    Overall the general swamping of the European domain with jet stream activity (remember first green shading is 40kt, then 20kt intervals to yellow at 100kt) means that the troposphere has plenty of opportunity to generate atmospheric gravity waves (AGW) which could propagate up to the E region to produce wind shear there.

    We'll only realise how good these charts are when we reach high summer and there is barely a single jet stream over the whole domain! So it still feels as though there is another ingredient missing after another quiet day yesterday. The stratospheric winds have been light and variable, which is probably not good.

    Good Es, 73 de Jim
    g3yla
  6. Of course, the above would make more sense if I actually uploaded the chart!

    06Z05MAY2015_300mb_4panel.jpg
  7. The very unsettled weather pattern is producing numerous areas of jet stream activity (green/yellow shading) across Europe and a look at any atlas will show that these cross many of the larger mountain ranges, so there is scope for disturbed airflow over the Pyrenees, Alps, Dolomites, Central Massif of France and mountains of Norway...really spoilt for choice!
    The regions of rising contour heights shown within the purple lines also flag up paths to the south into EA, CT etc.
    There are some indications of thunderstorm activity over southeastern Europe, shown by the orange blobs on the 12z and 18z frames.
    Lastly there is a very sharp upper ridge pattern from the Baltic states southwards into the Balkans, and this is a type of feature which has co-located with Es in the past when none of the other 'triggers' have been available.
    I hope one of these manages to encourage some Es, certainly no shortage of opportunity today.
    Good Es, 73 de Jim
    g3yla 06Z06MAY2015_300mb_4panel.jpg
  8. Good morning all,

    A little activity yesterday on 6m over southwestern France which seemed to locate with a jet stream over the Pyrenees and evidence of mountain wave cloud (cloud which appeared locked to the mountain, despite the wind blowing through it).

    Today's charts are again full of opportunity with some early 6m activity near the entrance to the jet stream over the Baltic Sea. (entrances and exits of jet streams are known areas of turbulence) This part of the pattern is moving slowly east.

    The jet stream on the other side of the upper trough from the UK down to southeast Europe is also of interest, especially over the Alps where there has been one 6m path already this morning. This region also has the purple line enclosed area where the contour heights are rising rapidly, another good sign for turbulence which might generate atmospheric gravity waves (AGW) which can propagate upwards to disturb the winds in the E region. This area is weakening and also edging slowly east.

    The southwesterly jet stream over Iberia is another good choice, since it produced yesterday, and still has isotachs (lines of equal windspeed) over 100kt marked by the yellow shading, this is especially useful since it crosses the Pyrenees. Look for fixed lines of cloud along the axis of the Pyrenees on satellite picture animations.; in fact, any fixed line of cloud on animating satellite pictures is worth a look since it usually indicates mountain wave activity.

    There is still a sharp upper ridge pattern over western Russia down to the Ukraine and an area of severe thunderstorms (orange blobs on 12z and decaying on 18z panels) over the Balkans this afternoon to add to the options for today.

    Good Es, 73 de Jim
    g3yla

    06Z07MAY2015_300mb_4panel.jpg
  9. Good morning,

    Some Es activity yesterday and one area of interest is still there this morning. The sharp upper trough pattern over Scandinavia, with a southerly jet stream over Finland and westerly jet stream over Norway, together with strongly rising contour heights, will be a good first direction to check out today.

    The extension of the Norwegian jet stream into southeast Europe may also be worth checking, especially since it involves a narrow region of rising contour heights enclosed by the purple line, although it may be rather too far east to be useful from the UK.

    The third region of interest lies over Biscay and Iberia with a broad jet stream (remember jet streams shaded green/yellow) running in across Spain into the Mediterranean. This could well see a strong west to southwesterly jet stream blowing across the Pyrenees, and should be a good source of mountain waves.

    Good Es, 73 de Jim
    g3yla

    06Z08MAY2015_300mb_4panel.jpg
  10. Morning all,

    We still have a good selection of jet streams on this morning's upper air charts. The previous favourite area over Scandinavia is too far away from us, but was useful yesterday within Europe.

    The largest area is, for much of today, almost too close, since it lies right over the UK. A strong jet stream shown by the green shading, starting at 40kt, then 20kt increments to yellow at 100kt etc., shows that this moves in across the UK during the day. This is also accompanied by rapidly rising 300mb contour heights enclosed by purple lines; think of these as a bit like contours on an OS map at 30,000ft. The rising contour heights together with the fact that the strong wind flow aloft is crossing many of the UK's mountain ranges, which could set up mountain waves, means that the UK could be the mid point of some Es activity. The main question is who can benefit? Its hard to find suitable candidates, perhaps OY to PA/DL or possibly later, EI to PA/DL etc.

    The extension of the Uk jet stream into France and over the mountains of southern Europe does suggest that paths from say, EA/CT to DL/OE/I may be worth checking within Europe.

    It is however interesting that the stronger events this season, so far, seem to have been over the northern half of Europe. No strong views on that, except that this year the stratospheric wind regime has changed over to its summer easterly from the north moving south, but flows are still quite weak. Indeed, over the traditionally useful Es areas within Europe, to the south of UK, the stratospheric winds have been almost light and variable. In a very subjective sense, I have noticed that Es activity in recent years has tended to favour times with stronger stratospheric winds, say 20kt, and this current position is not such a 'good look'.

    A difficult one folks, but could be better over the next few days as the UK jet stream moves into Europe, although I still prefer the more northern paths.

    Good Es, 73 de Jim
    g3yla

    06Z09MAY2015_300mb_4panel.jpg
  11. Chris Deacon G4IFX

    Chris Deacon G4IFX New Member

    Thanks Jim, this is really useful 73
  12. Morning everyone,

    I'm on shift today, so this may have to be a little briefer than usual.

    The 300mb forecast charts show another region of strong jet stream (shaded green/yellow) activity over the UK and the North Sea, moving slowly east and extending southwards into the Mediterranean. There are regions of rapidly rising contour heights enclosed by the purple lines within this area and the jet stream is well located with respect to some of the mountain ranges within Europe to produce mountain wave activity.

    This all points to a very promising day if the other factors like K index remain well behaved, staying 3 or less. In fact, I would have to say its a good day to check the whole directional spread of beacons on 10m and 6m bands from Scandinavia round through southeastern Europe and into the Mediterranean and Spain. Since the stratospheric winds are beginning to become more easterly, even over the Mediterranean, then paths E-W across Sardinia and Italy could also be productive.

    Lastly, there may be some large thunderstorms near southern Italy and Greece as shown by the orange blobs on the forecast chart, which are also known weather triggers for Es. Too far away from us, but may be useful for the Mediterranean stations.

    Shift swap anyone?

    Good Es, 73 de Jim
    g3yla
    06Z10MAY2015_300mb_4panel.jpg
    Nick 2E0LUN/KC2VWR likes this.
  13. Morning all,

    The K index was at 4 for quite some time yesterday and this seemed to put a dampener on things, Sporadic E-wise. There was some activity within Europe over the Alps on 6m late in the day, probably due to the northerly (blowing from the north) jet stream generating mountain waves and producing wind shear in the E region.

    The northerly jet stream is farther east today, extending from Finland down to southern Italy and the Balkans. It still has a core above 100kt (yellow) and, at least initially, has strongly rising contour heights enclosed by the purple lines. The yellow 'blobs' represent severe thunderstorm activity, so another reason to feel that the eastern Mediterranean area is a good choice for today, but the high K index may be a spoiler again. This whole area is probably too far away from the UK to help us, but a good area for our European colleagues.

    The next item, moving west and closer to the UK, is a sharp upper ridge pattern in the 300mb contour heights (black lines on the charts) and extends from Scandinavia southwestwards through Germany to eastern Spain on the 12z panel. These are often areas of clear air turbulence in the aviation forecasting world, so could also be of interest in generating atmospheric gravity waves (AGW). If the ridge pattern is moving, it tends to perform 'better' and this makes the northern end quite interesting. Look for changes between successive panels to gauge movement.

    Lastly, we move close to home and yet another strong Atlantic jet stream is moving into the UK. This is stronger than we've seen for some time (measured at over 130kt at midnight) and will probably become a real player over the next few days as it progresses into northwest Europe.

    This set of charts would be about as good as it gets in the peak of the season, but there are several caveats at present, not least of which is the high K index, still 4 as I write this. This may not be a total disaster in view of the jet stream strengths and their locations relative to mountain ranges. Additionally, there is still a weakness in the stratospheric easterly winds. An interesting day again...

    Good Es, 73 de Jim
    g3yla
    06Z11MAY2015_300mb_4panel.jpg
  14. Good morning,

    Yesterday was a good day generally with many active Es areas across Europe. A couple of interesting points; one there were some good areas of activity when the K index was up at 4, so don't take the general notion that it has to be less than 3 too literally, although it did decline to 2 later in the day. The other item of interest was that there was a very apparent shift in activity from east to west, both during the morning and evening sessions. This is quite probably due to the east to west migration of the semi-diurnal tides which affect the wind conditions in the E region.

    Now, onto today's contributions. The upper air charts are awash with opportunity today and there should be no difficulty finding suitable weather triggers in the troposphere (where the weather is) since the waving green/yellow shaded jet stream covers much of the European domain.

    The eastern Mediterranean has a sharp upper trough with a southwesterly jet ahead of it (eastern side) and a northwesterly jet behind it (western side). There are also signals for severe thunderstorms again (orange blobs), so this area is worth considering for paths within Europe since its too far away for the UK, I suspect.

    The northerly jet stream from Belarus across the Balkans to Italy is a good place to look since it crosses some large mountain ranges, especially in the south. This is followed by a very sharp upper ridge from Finland southwestwards to eastern Spain. It is hard to separate the ridge from the jet stream edges either side of it, but it does cover a large range of directions from the UK from the east to Scandinavia round to the south for Spain.

    Closer to home, there is a strong jet stream over pretty much all of northwestern Europe from Spain to Scandinavia with some stronger segments of the core well over 100kt. Note that the region coming into the UK also has strongly rising contour heights within the purple lines. Although this jet stream is over the UK, paths along it or across it should be useful so expecting the GM and EI/GIs to be well placed. Just to put it 'out there', so to speak, the alternating jet stream and ridge pattern across the Atlantic is potentially useful for multi-hop trans-Atlantic paths this evening once the semi diurnal tide has migrated to that side of the chart.

    Good Es, 73 de Jim
    g3yla

    06Z12MAY2015_300mb_4panel.jpg
  15. Morning all,

    With all the jet streams around yesterday, there were some very nice Es openings across Europe and the migration of the semi-diurnal tidal 'window', when the winds in the E region are favourable, was very obvious as paths moved around from the east, through southeast to end up pointing towards Biscay/Spain. It is worth noting that by the time the Biscay/Spain path is well underway, the next favourable tidal phase is probably opening up over the Baltic.

    Today, the first thing to say is that the K index is very high; at K=6 a short while ago. Traditionally this is not a 'good look' for Es since a disturbed geomagnetic field tends to preclude Es because the wind shear mechanism is too haphazard. Not quite sure about this, since it appears that any changes to lower values can quickly lead to Es patches developing, and in any case the K index is really the Kp index and applies to the whole planet, whereas the 'local' K may be lower anyway; something to investigate. There is always auroral Es to consider where the ionisation comes from the particle input around the auroral zone and not the more traditional meteor debris.

    Onto the weather, where we are once again spoilt for choice. The southeastern corner of the 300mb jet stream charts show the two jet streams (green/yellow) shading and thunderstorms (orange blobs) over the eastern Mediterranean. These are all good candidates for generating atmospheric gravity waves which reach the E region and produce wind shear, but they haven't for the last few days, so what's wrong here? My feeling is that the stratospheric winds are still too slack above this region and the gravity waves do not propagate upwards through the stratosphere, but are quenched by the slack flow, which was still there earlier today at midnight.

    The sharp upper ridge in the 300mb flow pattern is there again from Russia down through the Balkans, towards the central Mediterranean. These are worth considering, but hard to separate from the nearby jet streams on such a busy chart and in any case are probably too far away for single hope paths from UK.

    Next item westwards is again the broad area of jet stream activity over virtually the whole of western Europe and Scandinavia. The stronger jet streams, at more than 100kt, are over Denmark, northern Germany and the Baltic states and Finland. Paths from east round to northeast are worthwhile directions to check out today. Since the jet stream area also covers Germany, Low Countries, France and northern Spain, including some large mountain ranges, the other paths are worth checking as the tidal window swings around to the south.

    Last pointer for today is the that we have some signal for the development of large thunderstorms over eastern France and the northern side of the Alps shown by the dark orange/magenta blobs on the 12z and 18z panels. Big, slow-moving thunderstorms like these are good generators of gravity waves which can propagate upwards to the E region to give the required wind shear.

    Good Es, 73 de Jim
    g3yla

    06Z13MAY2015_300mb_4panel.jpg
    G8VPE likes this.
  16. Good morning,

    Another fine Es day coming up...yesterday the high K index meant that Es were very limited, mainly to 10m. Today the geomagnetic field is lower at K=3 and there are still plenty of weather triggers on the 300mb upper air jet stream chart; I've just worked LZ so already up and running! As usual, I will work across the chart from east to west and describe the main trigger areas to watch.

    Remember that since these jet stream patterns are largely part of a slowly progressive west to east movement of the weather features, then the Es will tend to be farther east in the second period, late afternoon, compared to the morning period. However, within the early or late periods themselves, the movement of the favourable semi-diurnal tidal winds in the E region is in the opposite direction from east to west, hence the tendency for the opening to appear to move around (when seen from the UK) from the Baltic via the Balkans to Italy and then Spain as each available weather trigger is 'illuminated' by the tidal wind regime.

    The strong jet stream (green/yellow) and thunderstorm activity (orange blobs) over the far southeastern corner of the charts is too far away and still seems associated with weak stratospheric flow aloft and so far has not produced anything useful even for multi hop paths.

    The northwesterly jet stream over Denmark, together with rising contour heights enclosed by the purple lines suggests its worth looking to east or northeast into Scandinavia and the Baltic region. To the south of this the broad westerly jet stream pattern crossing central Europe and the Alps, Dolomites etc is also a very strong contender (probably the reason for my LZ this morning) and there are also some thunderstorms in this region around the middle of the day.

    Feeling quite positive about the new northwesterly jet stream with a 100kt core driving southeast into Biscay and northern Spain. This also has rising contour heights and some very useful mountain ranges to go over, so plenty of reason to expect to see some atmospheric gravity waves generated here later today, which could propagate upwards to modulate the winds in the E region and produce the wind shear necessary for Es.

    Good Es, 73 de Jim
    g3yla

    06Z14MAY2015_300mb_4panel.jpg
  17. Morning,

    A busy day yesterday with multiple lengthy 6m openings into Europe and today's upper air 300mb charts (about 30,000ft) show supply of jet streams right across the board.

    The K index is low (2) and 6m is already open. The principle players are the two main jet stream regions. From yesterday, the northwesterly jet stream over the Norwegian mountains and across Denmark into Poland is still favourably placed and extends south into the Balkans, where there are many mountain ranges to help generate wave motion as the strong flow is disturbed by the high ground. So options exist for paths from Scandinavia to the Ukraine. Note that there are also purple lines enclosing areas of rapidly rising contours, another good sign.

    There is also a strong connecting jet (80kt) with a weak upper ridge pattern over central Europe including the Alps (where there are also thunderstorms at first from recent observations). This will bring path options from the UK through to the Balkans.

    A very strong jet stream across Biscay into Spain and then arching back over the central Mediterranean onto N Italy should also provide good opportunities to eastern Spain and the central Mediterranean/Italy region. Note this are also has strong rising contours enclosed by the purple lines.

    Lastly, there is another new Atlantic jet stream powering east from the NE States and will place some good potential for generating atmospheric gravity waves over N Scotland, so it may well be worth a look at the OY and TF beacons later today.

    Good Es, 73 de Jim
    g3yla 06Z15MAY2015_300mb_4panel.jpg
    G3MPN and Flt Lt David like this.
  18. G3MPN

    G3MPN New Member

    Thanks Jim,

    Quite illuminating.!!

    David

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