Propagation News – 14 December 2014

NOAA and the US Air Force had predicted that last week’s solar flux index would be in the range 160 to 180, which turned out to be slightly over-optimistic. Geomagnetic conditions were also predicted to be unsettled towards the end of last week due to a recurrent coronal hole, but reality was a little better. This just goes to show how hard it can be to accurately predict solar conditions and events.

This week the sun looks like it will continue in a similar vein, with the solar flux index predicted to remain in the 170s. We run the risk of continuing C and M-class solar flares, which could cause HF blackout problems at times.

With the winter solstice just around the corner on 21 December, now is the time to concentrate on the lower bands, 160m, 80m and 40m. The long hours of darkness offer plenty of opportunity for DX, with much reduced D layer absorption during the day on paths in the Northern Hemisphere as well.

If you really fancy a challenge, listen out for US medium wave broadcast stations during the night and around UK sunrise. WBBR on 1130kHz in New York City is one of the louder ones, but you may need a decent antenna and quiet geomagnetic conditions to snag it.

The lead up to Christmas looks like a continuation of the unsettled pattern with the main Atlantic jet stream in the upper atmosphere still driving areas of low pressure across northwest Europe. This means more wet and windy weather with very little chance of significant temperature inversions developing. It’s likely to be a quiet time again on VHF/UHF during the coming week. The nearest area of high pressure is located over the Azores, with the hint of a weak ridge into Biscay and Spain. This is unlikely to be very productive for radio paths from the UK.

As a long shot, this is the time of the year when the relatively rare winter Sporadic-E events can occur, so check the jet stream positions and the 10m and 6m beacons and you could put some out of season Sporadic-E contacts in the log.

The Geminids meteor shower is past its peak now, but the Quadrantids are less than a month away, so it’s back to early morning random meteors for MS enthusiasts.

And that’s all this week from the propagation team.

Category: GB2RS Propagation News