Propagation News – 24 February 2019
The Sun played ball this week and matched our predictions. The Kp index soared to four on Thursday, the 21st, thanks to ongoing coronal hole activity, but it was otherwise settled. There had been good conditions earlier in the week. The ARRL International DX Contest gave people contacts into nearly all the US states over the weekend of the 16th and 17th. Meanwhile, Chris, G0DWV worked a host of West Coast US stations, including some in Oregon and Washington, via 40m long path late afternoon on Wednesday the 20th, although his beam helped a lot. This may have also been due to a pre-auroral enhancement, as the Kp index surged upwards later that evening.
Next week we can expect more of the same, with NOAA predicting the solar flux index at 68 to 70 again. Geomagnetic conditions will be settled to start with, but expect the Kp index to rise again from around the 27th due to recurrent coronal hole activity. We may expect the Kp index to hit four or five between 27 February and 2 March, so expect subdued maximum usable frequencies after the potential for enhanced conditions before the geomagnetic storm bites.
As we head into March we can start to kiss goodbye to the long nights that have brought good 160m conditions. It’s time to say hello to better HF conditions, with excellent north-south paths, especially around noon and early afternoon. Eighty metres may also start to continue to be open to the UK after dark, with the critical frequency just managing to cover the whole band at times this week.
VHF and up
The large area of high pressure nearby to the east and south of Britain will continue to provide good tropo conditions during the first part of the coming week. This long run of tropo weather, pretty much since the start of the month, is typical of slow-moving winter highs, but eventually the Atlantic lows and their frontal systems will always break through. This time it seems the changeover starts from mid-week, as the pressure falls, and the quality of the lift conditions fade. It’s still too early to talk of sporadic E propagation, so that leaves the cupboard bare for other weather-related modes this week, but keep watch in case the odd aurora chances by.
Es’hailSat continues to surprise and activity is high, with reports of people copying narrowband signals with just an LNB pointed at the satellite and no dish! A 45cm Sky dish seems to give acceptable results receiving the narrowband transponder.
Moon declination is negative and falling this week so the Moon will be at low elevation for a short period each day and losses are increasing as we go towards apogee a week tomorrow.
Category: GB2RS Propagation News
