Propagation News – 5 May 2019

| May 3, 2019

Well, it is now May and that means the sporadic E season has started. There have already been some sporadic E openings on 10m, but the best is yet to come. Meanwhile, a lack of sunspots and continuing coronal hole activity means F2-layer DX is a little harder to come by.

Last week’s International Marconi Day saw some reports of poor conditions, but with a few propagation nuggets to keep the spirits up. GB0CMS at Caister Lifeboat in Norfolk worked 36 countries, including eight US states and a contact with Indonesia on 20m, so there is propagation about if you look for it.

NOAA predicts the solar flux index will remain around 68-72 next week and we can expect unsettled geomagnetic conditions this weekend with a maximum K-index of four. Once that has passed, the rest of the week should be more settled. This is due to a large elongated coronal hole on the solar surface, the same one that was responsible for poor geomagnetic conditions on Thursday, 2 May. By next weekend we may see the return of sunspot groups 2738 and 2739 as they rotate into view again. The STEREO Ahead spacecraft shows they have been active, emitting solar flares and coronal mass ejections, so we might be in for a bumpy ride.

Otherwise, the HF bands are starting to stay open longer in the evening as we move towards summer, but a change in the ionospheric chemistry may mean we may have to wait until the autumn to see the return of optimum DX conditions.

VHF and up

The weather charts for next week appear to be fully tilted towards the unsettled side, with low pressure either over the country, or close-by. At first this weekend there is a weak ridge of high pressure near western parts of Britain, but it will soon decline and does not look good for tropo.

The sporadic E season has started for traditional modes now with paths opening into Spain on 24th and Eastern Europe on the 26th on CW and SSB.

To keep up to date, use to see the daily weather jet stream charts with a sporadic E blog detailing possible areas of interest. The main advice is to follow the jet streams and check the clusters. There is a reasonable link between meteor debris and potential sporadic E, so the Eta Aquarids peaking tomorrow should keep the enthusiasm going.

Look out for rain scatter on the GHz bands due to the heavy showers that are likely to be a feature of the coming week. The bigger storms with hail and thunder are the most promising, and you’ll be able to track them down using one of the many online weather displays.

The Moon reaches maximum declination this coming Thursday, and path losses are falling as it moves in to perigee a week on Monday, so it’s a good week for EME.

Category: GB2RS Propagation News