Propagation News – 8 December 2019

| December 6, 2019

We had very settled geomagnetic conditions last week with the Kp index not rising above two and often sitting at zero. The solar flux index sat at 70/71, reflecting zero sunspots and a blank Sun.

As we approach midwinter it is a good time to concentrate on the lower bands, with both 80 and 160 metres showing good DX potential throughout the night. For short wave listeners, medium wave also comes alive with the possibility of DX stations from the USA coming in during the early hours. As a start, try listening for station WBBR in New York on 1130khz. This is usually one of the loudest transatlantic stations to be heard.

And don’t forget to look out for DX on 40 metres, especially around sunset and sunrise.

Next week should see more of the same with NOAA predicting a solar flux index of 70, zero sunspots, but a settled geomagnetic Kp index of two all week. The critical frequency graphs at suggest that 20m will be the main daytime DX band next week, with occasional openings on 17 metres.

VHF and up

Next Saturday sees the peak of the biggest meteor shower of the year, the Geminids. The shower is already under way and is expected to reach peak activity at around 1900UTC on 14 December. With a peak zenithal hourly rate of 120, it promises to produce some excellent meteor scatter QSOs.

Last week saw some good tropo paths, but the high pressure declined mid-week. The forecast charts show no indication of a return of a high, so tropo cannot be promised, other than a brief return of a ridge across southern areas at the end of the coming week.

The rest of the country will be predominantly driven by low pressure crossing northern areas from west to east and at times leaving us with a cold northwesterly down the North Sea. At this time of the year this means that strong convection bringing showers is likely as the cold air flows south across the relatively warm sea. These may be good for rain scatter, so plenty of opportunities for GHz bands operators.

Last week saw a few reports of sporadic E, chiefly on digital modes, but also a few paths on the more traditional CW or SSB. This is a good reminder that there is no month with a zero chance of sporadic E. In this case, conditions were probably enhanced by strong meteor activity. Meteors provide the ionisation as they burn up entering the upper atmosphere and this can combine with stronger jet streams in the winter months.

The Moon reaches maximum declination on Friday and path losses will fall all week. Combined with a generally low 144MHz sky temperature, it’s a good week for EME.

Category: GB2RS Propagation News