Propagation News – 18 October 2020

We had a little flurry of solar activity last week, but it didn’t amount to much. Region 2775 decayed to a spotless plage and didn’t contribute at all after Tuesday, the 13th. A new region began forming while on the far side of the Sun and has turned into view off the east limb. The new region has been assigned active region 2776 and, while a few spots are currently visible, so far only minor B-class solar flares have been detected.

Geomagnetic conditions were quiet, with the Kp index fluctuating between zero and one. This was due to a lack of coronal hole activity, which meant the solar wind was subdued, generally keeping below 300km/s. As a result, HF conditions have been quite good, with lots of DX being reported by CDXC members. Patrice, FK8HA in New Caledonia has been reported on 15m SSB, as has Mike, 5H3EE in Tanzania on 15m CW.

October can also be a good month for 40m contacts into Australia and New Zealand. A number of contacts have been logged and predtest.uk shows that 0600-0700hrs is probably best for a long-path contact; 1300-1600hrs might favour a short-path one.

Next week NOAA predicts the solar flux index will remain around 70, but the Kp index may rise, probably due to a returning coronal hole. It predicts a Kp index of four on the 20th and unsettled geomagnetic conditions which may peak around the 25th to 26th with a Kp index of six. So the conclusion is, make the most of the HF this weekend, as the predicted conditions are likely to be poor for the rest of next week. Otherwise, look for auroral contacts on 10m next weekend.
VHF and up:

This is a tricky week to predict, but hopefully with some chance of tropo. The VHF highlight though is the peak of the Orionids meteor shower on the morning of the 21st. With a ZHR of 20 it’s one of the larger ones of the year. The shower is already under way and runs from about 2 October to 7 November. It’s caused by the stream of debris left behind by Comet Halley.

On the tropo front, we ended last week with high pressure occupying much of the country, and offering a chance of paths primarily between the UK and France, plus across the North Sea to southern Scandinavia and Baltic. Early next week a low tracks south-east from Iceland towards Denmark, and introduces colder showery weather and a good prospect for rain scatter, with heavy showers over the adjoining coastal waters. After mid-week, a new high builds in from the west and leaves us in high-pressure tropo weather to finish the week.

The Moon’s declination is negative all week, reaching a minimum on Wednesday, so Moon visibility windows are short. The maximum Moon elevation in south-east England is just 12 degrees and, as we passed perigee last Friday night, path losses will increase. The 144MHz sky noise is high until the end of this week, above 2600 kelvin on Wednesday, so all in all it is a poor week for EME.

Finally, keep an eye out for auroral propagation due to the predicted disturbed Sun. (rsgb.org)